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Sample records for vdms predict vegetation

  1. Global vegetation change predicted by the modified Budyko model

    Energy Technology Data Exchange (ETDEWEB)

    Monserud, R.A.; Tchebakova, N.M.; Leemans, R. (US Department of Agriculture, Moscow, ID (United States). Intermountain Research Station, Forest Service)

    1993-09-01

    A modified Budyko global vegetation model is used to predict changes in global vegetation patterns resulting from climate change (CO[sub 2] doubling). Vegetation patterns are predicted using a model based on a dryness index and potential evaporation determined by solving radiation balance equations. Climate change scenarios are derived from predictions from four General Circulation Models (GCM's) of the atmosphere (GFDL, GISS, OSU, and UKMO). All four GCM scenarios show similar trends in vegetation shifts and in areas that remain stable, although the UKMO scenario predicts greater warming than the others. Climate change maps produced by all four GCM scenarios show good agreement with the current climate vegetation map for the globe as a whole, although over half of the vegetation classes show only poor to fair agreement. The most stable areas are Desert and Ice/Polar Desert. Because most of the predicted warming is concentrated in the Boreal and Temperate zones, vegetation there is predicted to undergo the greatest change. Most vegetation classes in the Subtropics and Tropics are predicted to expand. Any shift in the Tropics favouring either Forest over Savanna, or vice versa, will be determined by the magnitude of the increased precipitation accompanying global warming. Although the model predicts equilibrium conditions to which many plant species cannot adjust (through migration or microevolution) in the 50-100 y needed for CO[sub 2] doubling, it is not clear if projected global warming will result in drastic or benign vegetation change. 72 refs., 3 figs., 3 tabs.

  2. Recall of vegetable eating affects future predicted enjoyment and choice of vegetables in British University undergraduate students.

    Science.gov (United States)

    Robinson, Eric; Blissett, Jackie; Higgs, Suzanne

    2011-10-01

    Predictions about enjoyment of future experiences are influenced by recalling similar past experiences. However, little is known about the relationship between hedonic memories of past eating episodes and future eating behavior. We investigated recall of previous experiences of eating vegetables and the effect of recall on future predicted liking for and consumption of vegetables. British University undergraduate students were asked to retrieve memories of previous occasions when they ate vegetables and were asked to rate how enjoyable those experiences were (Study 1, n=54). The effect of different types of memory recall (including vegetable eating recall) and visualization of someone else eating vegetables (to control for priming effects) on predicted likelihood of choosing vegetables and predicted enjoyment of eating vegetables was examined (Study 2, n=95). Finally, the effect of recalling vegetable eating memories on actual food choice from a buffet was assessed (Study 3, n=63). It is reported that people recall positive memories of past vegetable consumption (Precall of a personal nonfood memory, a nonvegetable food memory, or visualization of someone else enjoying eating vegetables (increase of approximately 70% in vegetable portion size compared to controls). The results suggest that recall of previous eating experiences could be a potential strategy for altering food choices. Copyright © 2011 American Dietetic Association. Published by Elsevier Inc. All rights reserved.

  3. The Prediction of Drought-Related Tree Mortality in Vegetation Models

    Science.gov (United States)

    Schwinning, S.; Jensen, J.; Lomas, M. R.; Schwartz, B.; Woodward, F. I.

    2013-12-01

    Drought-related tree die-off events at regional scales have been reported from all wooded continents and it has been suggested that their frequency may be increasing. The prediction of these drought-related die-off events from regional to global scales has been recognized as a critical need for the conservation of forest resources and improving the prediction of climate-vegetation interactions. However, there is no conceptual consensus on how to best approach the quantitative prediction of tree mortality. Current models use a variety of mechanisms to represent demographic events. Mortality is modeled to represent a number of different processes, including death by fire, wind throw, extreme temperatures, and self-thinning, and each vegetation model differs in the emphasis they place on specific mechanisms. Dynamic global vegetation models generally operate on the assumption of incremental vegetation shift due to changes in the carbon economy of plant functional types and proportional effects on recruitment, growth, competition and mortality, but this may not capture sudden and sweeping tree death caused by extreme weather conditions. We tested several different approaches to predicting tree mortality within the framework of the Sheffield Dynamic Global Vegetation Model. We applied the model to the state of Texas, USA, which in 2011 experienced extreme drought conditions, causing the death of an estimated 300 million trees statewide. We then compared predicted to actual mortality to determine which algorithms most accurately predicted geographical variation in tree mortality. We discuss implications regarding the ongoing debate on the causes of tree death.

  4. Predicting gender differences in liking for vegetables and preference for a variety of vegetables among 11-year-old children.

    Science.gov (United States)

    Lehto, Elviira; Ray, Carola; Haukkala, Ari; Yngve, Agneta; Thorsdottir, Inga; Roos, Eva

    2015-12-01

    We studied the factors that predict liking for vegetables and preference for a variety of vegetables among schoolchildren. Additionally, we examined if there were gender differences in the predictors that explain the hypothesized higher scores in liking vegetables and preferences among girls. The data from the PRO GREENS project included 424 Finnish children (response rate 77%) aged 11 to 12. The children completed validated measures about social and environmental factors related to their liking for vegetables and preferences both at baseline 2009 and follow-up 2010. The associations were examined with regression and mediation analyses. The strongest predictors of both girls' and boys' liking and preferences were higher levels of eating vegetables together with the family, previous vegetable intake and a lower level of perceived barriers. Liking was additionally predicted by a lower level of parental demand that their child should eat vegetables. Girls reported higher levels of liking and preferences in the follow-up. This gender difference was mainly explained by girls' lower level of perceived barriers related to vegetable intake and girls' higher previous vegetable intake. Interventions that aim to increase the low vegetable intake among boys by increasing their liking for vegetables and preference for a variety of vegetables could benefit from targeting perceived barriers, namely boys' perception and values concerning the consumption of vegetables. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Employing lidar to detail vegetation canopy architecture for prediction of aeolian transport

    Science.gov (United States)

    Sankey, Joel B.; Law, Darin J.; Breshears, David D.; Munson, Seth M.; Webb, Robert H.

    2013-01-01

    The diverse and fundamental effects that aeolian processes have on the biosphere and geosphere are commonly generated by horizontal sediment transport at the land surface. However, predicting horizontal sediment transport depends on vegetation architecture, which is difficult to quantify in a rapid but accurate manner. We demonstrate an approach to measure vegetation canopy architecture at high resolution using lidar along a gradient of dryland sites ranging from 2% to 73% woody plant canopy cover. Lidar-derived canopy height, distance (gaps) between vegetation elements (e.g., trunks, limbs, leaves), and the distribution of gaps scaled by vegetation height were correlated with canopy cover and highlight potentially improved horizontal dust flux estimation than with cover alone. Employing lidar to estimate detailed vegetation canopy architecture offers promise for improved predictions of horizontal sediment transport across heterogeneous plant assemblages.

  6. Predicting landscape vegetation dynamics using state-and-transition simulation models

    Science.gov (United States)

    Colin J. Daniel; Leonardo. Frid

    2012-01-01

    This paper outlines how state-and-transition simulation models (STSMs) can be used to project changes in vegetation over time across a landscape. STSMs are stochastic, empirical simulation models that use an adapted Markov chain approach to predict how vegetation will transition between states over time, typically in response to interactions between succession,...

  7. Predicting the effect of fire on large-scale vegetation patterns in North America.

    Science.gov (United States)

    Donald McKenzie; David L. Peterson; Ernesto. Alvarado

    1996-01-01

    Changes in fire regimes are expected across North America in response to anticipated global climatic changes. Potential changes in large-scale vegetation patterns are predicted as a result of altered fire frequencies. A new vegetation classification was developed by condensing Kuchler potential natural vegetation types into aggregated types that are relatively...

  8. Impact of vegetation variability on potential predictability and skill of EC-Earth simulations

    Energy Technology Data Exchange (ETDEWEB)

    Weiss, Martina; Hurk, Bart van den; Haarsma, Reindert; Hazeleger, Wilco [Royal Netherlands Meteorological Institute (KNMI), De Bilt (Netherlands)

    2012-12-15

    Climate models often use a simplified and static representation of vegetation characteristics to determine fluxes of energy, momentum and water vapour between surface and lower atmosphere. In order to analyse the impact of short term variability in vegetation phenology, we use remotely-sensed leaf area index and albedo products to examine the role of vegetation in the coupled land-atmosphere system. Perfect model experiments are carried out to determine the impact of realistic temporal variability of vegetation on potential predictability of evaporation and temperature, as well as model skill of EC-Earth simulations. The length of the simulation period is hereby limited by the availability of satellite products to 2000-2010. While a realistic representation of vegetation positively influences the simulation of evaporation and its potential predictability, a positive impact on 2 m temperature is of smaller magnitude, regionally confined and more pronounced in climatically extreme years. (orig.)

  9. Spatiotemporal variability and predictability of Normalized Difference Vegetation Index (NDVI) in Alberta, Canada.

    Science.gov (United States)

    Jiang, Rengui; Xie, Jiancang; He, Hailong; Kuo, Chun-Chao; Zhu, Jiwei; Yang, Mingxiang

    2016-09-01

    As one of the most popular vegetation indices to monitor terrestrial vegetation productivity, Normalized Difference Vegetation Index (NDVI) has been widely used to study the plant growth and vegetation productivity around the world, especially the dynamic response of vegetation to climate change in terms of precipitation and temperature. Alberta is the most important agricultural and forestry province and with the best climatic observation systems in Canada. However, few studies pertaining to climate change and vegetation productivity are found. The objectives of this paper therefore were to better understand impacts of climate change on vegetation productivity in Alberta using the NDVI and provide reference for policy makers and stakeholders. We investigated the following: (1) the variations of Alberta's smoothed NDVI (sNDVI, eliminated noise compared to NDVI) and two climatic variables (precipitation and temperature) using non-parametric Mann-Kendall monotonic test and Thiel-Sen's slope; (2) the relationships between sNDVI and climatic variables, and the potential predictability of sNDVI using climatic variables as predictors based on two predicted models; and (3) the use of a linear regression model and an artificial neural network calibrated by the genetic algorithm (ANN-GA) to estimate Alberta's sNDVI using precipitation and temperature as predictors. The results showed that (1) the monthly sNDVI has increased during the past 30 years and a lengthened growing season was detected; (2) vegetation productivity in northern Alberta was mainly temperature driven and the vegetation in southern Alberta was predominantly precipitation driven for the period of 1982-2011; and (3) better performances of the sNDVI-climate relationships were obtained by nonlinear model (ANN-GA) than using linear (regression) model. Similar results detected in both monthly and summer sNDVI prediction using climatic variables as predictors revealed the applicability of two models for

  10. Contribution of Dynamic Vegetation Phenology to Decadal Climate Predictability

    NARCIS (Netherlands)

    Weiss, M.; Miller, P.A.; Hurk, van den B.J.J.M.; Noije, van T.; Stefanescu, S.; Haarsma, R.; Ulft, van L.H.; Hazeleger, W.; Sager, Le P.; Smith, B.; Schurgers, G.

    2014-01-01

    In this study, the impact of coupling and initializing the leaf area index from the dynamic vegetation model Lund-Potsdam-Jena General Ecosystem Simulator (LPJ-GUESS) is analyzed on skill of decadal predictions in the fully coupled atmosphere-land-ocean-sea ice model, the European Consortium Earth

  11. The role of self-identity in predicting fruit and vegetable intake.

    Science.gov (United States)

    Carfora, V; Caso, D; Conner, M

    2016-11-01

    This research investigated whether the Theory of Planned Behavior (TPB) with the addition of self-identity could predict fruit and vegetable intake when controlling for past behavior. Previous research had demonstrated the efficacy of TPB to predict intention and behavior in relation to food choice and the additional power of self-identity, but had failed assess the effects of self-identity while controlling for past behavior. At baseline (N = 210) TPB components and past behavior in relation to fruit and vegetable consumption plus self-identity as a healthy eater were measured by questionnaire in a sample of university students. At time 1, 4 weeks later, self-reported fruit and vegetable consumption was measured. Structural Equation Modelling (SEM) indicated attitude, PBC and self-identity to be significant predictors of intention (subjective norm and past behavior were not significant). Intention, self-identity and past behavior were direct predictors of behavior. The current findings support the independent effect of self-identity as a healthy eater on both intentions and future behaviour when controlling for TPB variables and also past behavior. The discussion considers the importance of self-identity in changing intentions and behavior for behaviors such as fruit and vegetable consumption. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Prediction of fruit and vegetable intake from biomarkers using individual participant data of diet-controlled intervention studies

    DEFF Research Database (Denmark)

    Souverein, Olga W; de Vries, Jeanne H M; Freese, Riitta

    2015-01-01

    concentrations. Furthermore, a prediction model of fruit and vegetable intake based on these biomarkers and subject characteristics (i.e. age, sex, BMI and smoking status) was established. Data from twelve diet-controlled intervention studies were obtained to develop a prediction model for fruit and vegetable...

  13. Disturbance metrics predict a wetland Vegetation Index of Biotic Integrity

    Science.gov (United States)

    Stapanian, Martin A.; Mack, John; Adams, Jean V.; Gara, Brian; Micacchion, Mick

    2013-01-01

    Indices of biological integrity of wetlands based on vascular plants (VIBIs) have been developed in many areas in the USA. Knowledge of the best predictors of VIBIs would enable management agencies to make better decisions regarding mitigation site selection and performance monitoring criteria. We use a novel statistical technique to develop predictive models for an established index of wetland vegetation integrity (Ohio VIBI), using as independent variables 20 indices and metrics of habitat quality, wetland disturbance, and buffer area land use from 149 wetlands in Ohio, USA. For emergent and forest wetlands, predictive models explained 61% and 54% of the variability, respectively, in Ohio VIBI scores. In both cases the most important predictor of Ohio VIBI score was a metric that assessed habitat alteration and development in the wetland. Of secondary importance as a predictor was a metric that assessed microtopography, interspersion, and quality of vegetation communities in the wetland. Metrics and indices assessing disturbance and land use of the buffer area were generally poor predictors of Ohio VIBI scores. Our results suggest that vegetation integrity of emergent and forest wetlands could be most directly enhanced by minimizing substrate and habitat disturbance within the wetland. Such efforts could include reducing or eliminating any practices that disturb the soil profile, such as nutrient enrichment from adjacent farm land, mowing, grazing, or cutting or removing woody plants.

  14. Remotely sensed vegetation indices for seasonal crop yields predictions in the Czech Republic

    Science.gov (United States)

    Hlavinka, Petr; Semerádová, Daniela; Balek, Jan; Bohovic, Roman; Žalud, Zdeněk; Trnka, Miroslav

    2015-04-01

    Remotely sensed vegetation indices by satellites are valuable tool for vegetation conditions assessment also in the case of field crops. This study is based on the use of NDVI (Normalized Difference Vegetation Index) and EVI (Enhanced Vegetation Index) derived from MODIS (Moderate Resolution Imaging Spectroradiometer) aboard Terra satellite. Data available from the year 2000 were analyzed and tested for seasonal yields predictions within selected districts of the Czech Republic (Central Europe). Namely the yields of spring barley, winter wheat and oilseed winter rape during the period from 2000 to 2014 were assessed. Observed yields from 14 districts (NUTS 4) were collected and thus 210 seasons were included. Selected districts differ considerably in their soil fertility and terrain configuration and represent transect across various agroclimatic conditions (from warm and dry to relative cool and wet regions). Two approaches were tested: 1) using of composite remotely sensed data (available in 16 day time step) provided by the USGS (https://lpdaac.usgs.gov/); 2) using daily remotely sensed data in combination with originally developed smoothing method. The yields were successfully predicted based on established regression models (remotely sensed data used as independent parameter). Besides others the impact of severe drought episodes within vegetation were identified and yield reductions at district level predicted (even before harvest). As a result the periods with the best relationship between remotely sensed data and yields were identified. The impact of drought conditions as well as normal or above normal yields of field crops could be predicted by proposed method within study region up to 30 days prior to the harvest. It could be concluded that remotely sensed vegetation conditions assessment should be important part of early warning systems focused on drought. Such information should be widely available for various users (decision makers, farmers, etc.) in

  15. Satellite-based hybrid drought monitoring tool for prediction of vegetation condition in Eastern Africa: A case study for Ethiopia

    Science.gov (United States)

    Tadesse, Tsegaye; Demisse, Getachew Berhan; Zaitchik, Ben; Dinku, Tufa

    2014-03-01

    An experimental drought monitoring tool has been developed that predicts the vegetation condition (Vegetation Outlook) using a regression-tree technique at a monthly time step during the growing season in Eastern Africa. This prediction tool (VegOut-Ethiopia) is demonstrated for Ethiopia as a case study. VegOut-Ethiopia predicts the standardized values of the Normalized Difference Vegetation Index (NDVI) at multiple time steps (weeks to months into the future) based on analysis of "historical patterns" of satellite, climate, and oceanic data over historical records. The model underlying VegOut-Ethiopia capitalizes on historical climate-vegetation interactions and ocean-climate teleconnections (such as El Niño and the Southern Oscillation (ENSO)) expressed over the 24 year data record and also considers several environmental characteristics (e.g., land cover and elevation) that influence vegetation's response to weather conditions to produce 8 km maps that depict future general vegetation conditions. VegOut-Ethiopia could provide vegetation monitoring capabilities at local, national, and regional levels that can complement more traditional remote sensing-based approaches that monitor "current" vegetation conditions. The preliminary results of this case study showed that the models were able to predict the vegetation stress (both spatial extent and severity) in drought years 1-3 months ahead during the growing season in Ethiopia. The correlation coefficients between the predicted and satellite-observed vegetation condition range from 0.50 to 0.90. Based on the lessons learned from past research activities and emerging experimental forecast models, future studies are recommended that could help Eastern Africa in advancing knowledge of climate, remote sensing, hydrology, and water resources.

  16. Multi-scale enhancement of climate prediction over land by improving the model sensitivity to vegetation variability

    Science.gov (United States)

    Alessandri, A.; Catalano, F.; De Felice, M.; Hurk, B. V. D.; Doblas-Reyes, F. J.; Boussetta, S.; Balsamo, G.; Miller, P. A.

    2017-12-01

    Here we demonstrate, for the first time, that the implementation of a realistic representation of vegetation in Earth System Models (ESMs) can significantly improve climate simulation and prediction across multiple time-scales. The effective sub-grid vegetation fractional coverage vary seasonally and at interannual time-scales in response to leaf-canopy growth, phenology and senescence. Therefore it affects biophysical parameters such as the surface resistance to evapotranspiration, albedo, roughness lenght, and soil field capacity. To adequately represent this effect in the EC-Earth ESM, we included an exponential dependence of the vegetation cover on the Leaf Area Index.By comparing two sets of simulations performed with and without the new variable fractional-coverage parameterization, spanning from centennial (20th Century) simulations and retrospective predictions to the decadal (5-years), seasonal (2-4 months) and weather (4 days) time-scales, we show for the first time a significant multi-scale enhancement of vegetation impacts in climate simulation and prediction over land. Particularly large effects at multiple time scales are shown over boreal winter middle-to-high latitudes over Canada, West US, Eastern Europe, Russia and eastern Siberia due to the implemented time-varying shadowing effect by tree-vegetation on snow surfaces. Over Northern Hemisphere boreal forest regions the improved representation of vegetation-cover consistently correct the winter warm biases, improves the climate change sensitivity, the decadal potential predictability as well as the skill of forecasts at seasonal and weather time-scales. Significant improvements of the prediction of 2m temperature and rainfall are also shown over transitional land surface hot spots. Both the potential predictability at decadal time-scale and seasonal-forecasts skill are enhanced over Sahel, North American Great Plains, Nordeste Brazil and South East Asia, mainly related to improved performance in

  17. Which Food Security Determinants Predict Adequate Vegetable Consumption among Rural Western Australian Children?

    Science.gov (United States)

    Godrich, Stephanie L; Lo, Johnny; Davies, Christina R; Darby, Jill; Devine, Amanda

    2017-01-03

    Improving the suboptimal vegetable consumption among the majority of Australian children is imperative in reducing chronic disease risk. The objective of this research was to determine whether there was a relationship between food security determinants (FSD) (i.e., food availability, access, and utilisation dimensions) and adequate vegetable consumption among children living in regional and remote Western Australia (WA). Caregiver-child dyads ( n = 256) living in non-metropolitan/rural WA completed cross-sectional surveys that included questions on FSD, demographics and usual vegetable intake. A total of 187 dyads were included in analyses, which included descriptive and logistic regression analyses via IBM SPSS (version 23). A total of 13.4% of children in this sample had adequate vegetable intake. FSD that met inclusion criteria ( p ≤ 0.20) for multivariable regression analyses included price; promotion; quality; location of food outlets; variety of vegetable types; financial resources; and transport to outlets. After adjustment for potential demographic confounders, the FSD that predicted adequate vegetable consumption were, variety of vegetable types consumed ( p = 0.007), promotion ( p = 0.017), location of food outlets ( p = 0.027), and price ( p = 0.043). Food retail outlets should ensure that adequate varieties of vegetable types (i.e., fresh, frozen, tinned) are available, vegetable messages should be promoted through food retail outlets and in community settings, towns should include a range of vegetable purchasing options, increase their reliance on a local food supply and increase transport options to enable affordable vegetable purchasing.

  18. Which Food Security Determinants Predict Adequate Vegetable Consumption among Rural Western Australian Children?

    Directory of Open Access Journals (Sweden)

    Stephanie L. Godrich

    2017-01-01

    Full Text Available Improving the suboptimal vegetable consumption among the majority of Australian children is imperative in reducing chronic disease risk. The objective of this research was to determine whether there was a relationship between food security determinants (FSD (i.e., food availability, access, and utilisation dimensions and adequate vegetable consumption among children living in regional and remote Western Australia (WA. Caregiver-child dyads (n = 256 living in non-metropolitan/rural WA completed cross-sectional surveys that included questions on FSD, demographics and usual vegetable intake. A total of 187 dyads were included in analyses, which included descriptive and logistic regression analyses via IBM SPSS (version 23. A total of 13.4% of children in this sample had adequate vegetable intake. FSD that met inclusion criteria (p ≤ 0.20 for multivariable regression analyses included price; promotion; quality; location of food outlets; variety of vegetable types; financial resources; and transport to outlets. After adjustment for potential demographic confounders, the FSD that predicted adequate vegetable consumption were, variety of vegetable types consumed (p = 0.007, promotion (p = 0.017, location of food outlets (p = 0.027, and price (p = 0.043. Food retail outlets should ensure that adequate varieties of vegetable types (i.e., fresh, frozen, tinned are available, vegetable messages should be promoted through food retail outlets and in community settings, towns should include a range of vegetable purchasing options, increase their reliance on a local food supply and increase transport options to enable affordable vegetable purchasing.

  19. Vegetation cover, tidal amplitude and land area predict short-term marsh vulnerability in Coastal Louisiana

    Science.gov (United States)

    Schoolmaster, Donald; Stagg, Camille L.; Sharp, Leigh Anne; McGinnis, Tommy S.; Wood, Bernard; Piazza, Sarai

    2018-01-01

    The loss of coastal marshes is a topic of great concern, because these habitats provide tangible ecosystem services and are at risk from sea-level rise and human activities. In recent years, significant effort has gone into understanding and modeling the relationships between the biological and physical factors that contribute to marsh stability. Simulation-based process models suggest that marsh stability is the product of a complex feedback between sediment supply, flooding regime and vegetation response, resulting in elevation gains sufficient to match the combination of relative sea-level rise and losses from erosion. However, there have been few direct, empirical tests of these models, because long-term datasets that have captured sufficient numbers of marsh loss events in the context of a rigorous monitoring program are rare. We use a multi-year data set collected by the Coastwide Reference Monitoring System (CRMS) that includes transitions of monitored vegetation plots to open water to build and test a predictive model of near-term marsh vulnerability. We found that despite the conclusions of previous process models, elevation change had no ability to predict the transition of vegetated marsh to open water. However, we found that the processes that drive elevation change were significant predictors of transitions. Specifically, vegetation cover in prior year, land area in the surrounding 1 km2 (an estimate of marsh fragmentation), and the interaction of tidal amplitude and position in tidal frame were all significant factors predicting marsh loss. This suggests that 1) elevation change is likely better a predictor of marsh loss at time scales longer than we consider in this study and 2) the significant predictive factors affect marsh vulnerability through pathways other than elevation change, such as resistance to erosion. In addition, we found that, while sensitivity of marsh vulnerability to the predictive factors varied spatially across coastal Louisiana

  20. Evaluation and attribution of vegetation contribution to seasonal climate predictability

    Science.gov (United States)

    Catalano, Franco; Alessandri, Andrea; De Felice, Matteo

    2015-04-01

    The land surface model of EC-Earth has been modified to include dependence of vegetation densities on the Leaf Area Index (LAI), based on the Lambert-Beer formulation. Effective vegetation fractional coverage can now vary at seasonal and interannual time-scales and therefore affect biophysical parameters such as the surface roughness, albedo and soil field capacity. The modified model is used to perform a real predictability seasonal hindcast experiment. LAI is prescribed using a recent observational dataset based on the third generation GIMMS and MODIS satellite data. Hindcast setup is: 7 months forecast length, 2 start dates (1st May and 1st November), 10 members, 28 years (1982-2009). The effect of the realistic LAI prescribed from observation is evaluated with respect to a control experiment where LAI does not vary. Hindcast results demonstrate that a realistic representation of vegetation significantly improves the forecasts of temperature and precipitation. The sensitivity is particularly large for temperature during boreal winter over central North America and Central Asia. This may be attributed in particular to the effect of the high vegetation component on the snow cover. Summer forecasts are improved in particular for precipitation over Europe, Sahel, North America, West Russia and Nordeste. Correlation improvements depends on the links between targets (temperature and precipitation) and drivers (surface heat fluxes, albedo, soil moisture, evapotranspiration, moisture divergence) which varies from region to region.

  1. Evaluating Forest Vegetation Simulator predictions for southern Appalachian upland hardwoods with a modified mortality model

    Science.gov (United States)

    Philip J. Radtke; Nathan D. Herring; David L. Loftis; Chad E. Keyser

    2012-01-01

    Prediction accuracy for projected basal area and trees per acre was assessed for the growth and yield model of the Forest Vegetation Simulator Southern Variant (FVS-Sn). Data for comparison with FVS-Sn predictions were compiled from a collection of n

  2. Multi-scale enhancement of climate prediction over land by increasing the model sensitivity to vegetation variability in EC-Earth

    Science.gov (United States)

    Alessandri, Andrea; Catalano, Franco; De Felice, Matteo; Van Den Hurk, Bart; Doblas Reyes, Francisco; Boussetta, Souhail; Balsamo, Gianpaolo; Miller, Paul A.

    2017-08-01

    The EC-Earth earth system model has been recently developed to include the dynamics of vegetation. In its original formulation, vegetation variability is simply operated by the Leaf Area Index (LAI), which affects climate basically by changing the vegetation physiological resistance to evapotranspiration. This coupling has been found to have only a weak effect on the surface climate modeled by EC-Earth. In reality, the effective sub-grid vegetation fractional coverage will vary seasonally and at interannual time-scales in response to leaf-canopy growth, phenology and senescence. Therefore it affects biophysical parameters such as the albedo, surface roughness and soil field capacity. To adequately represent this effect in EC-Earth, we included an exponential dependence of the vegetation cover on the LAI. By comparing two sets of simulations performed with and without the new variable fractional-coverage parameterization, spanning from centennial (twentieth century) simulations and retrospective predictions to the decadal (5-years), seasonal and weather time-scales, we show for the first time a significant multi-scale enhancement of vegetation impacts in climate simulation and prediction over land. Particularly large effects at multiple time scales are shown over boreal winter middle-to-high latitudes over Canada, West US, Eastern Europe, Russia and eastern Siberia due to the implemented time-varying shadowing effect by tree-vegetation on snow surfaces. Over Northern Hemisphere boreal forest regions the improved representation of vegetation cover tends to correct the winter warm biases, improves the climate change sensitivity, the decadal potential predictability as well as the skill of forecasts at seasonal and weather time-scales. Significant improvements of the prediction of 2 m temperature and rainfall are also shown over transitional land surface hot spots. Both the potential predictability at decadal time-scale and seasonal-forecasts skill are enhanced over

  3. Predicting Opportunities for Greening and Patterns of Vegetation on Private Urban Lands

    Science.gov (United States)

    Troy, Austin R.; Grove, J. Morgan; O'Neil-Dunne, Jarlath P. M.; Pickett, Steward T. A.; Cadenasso, Mary L.

    2007-09-01

    This paper examines predictors of vegetative cover on private lands in Baltimore, Maryland. Using high-resolution spatial data, we generated two measures: “possible stewardship,” which is the proportion of private land that does not have built structures on it and hence has the possibility of supporting vegetation, and “realized stewardship,” which is the proportion of possible stewardship land upon which vegetation is growing. These measures were calculated at the parcel level and averaged by US Census block group. Realized stewardship was further defined by proportion of tree canopy and grass. Expenditures on yard supplies and services, available by block group, were used to help understand where vegetation condition appears to be the result of current activity, past legacies, or abandonment. PRIZM™ market segmentation data were tested as categorical predictors of possible and realized stewardship and yard expenditures. PRIZM™ segmentations are hierarchically clustered into 5, 15, and 62 categories, which correspond to population density, social stratification (income and education), and lifestyle clusters, respectively. We found that PRIZM 15 best predicted variation in possible stewardship and PRIZM 62 best predicted variation in realized stewardship. These results were further analyzed by regressing each dependent variable against a set of continuous variables reflective of each of the three PRIZM groupings. Housing age, vacancy, and population density were found to be critical determinants of both stewardship metrics. A number of lifestyle factors, such as average family size, marriage rates, and percentage of single-family detached homes, were strongly related to realized stewardship. The percentage of African Americans by block group was positively related to realized stewardship but negatively related to yard expenditures.

  4. Prediction of fruit and vegetable intake: The importance of contextualizing motivation.

    Science.gov (United States)

    Evans, Rachel; Kawabata, Masato; Thomas, Shirley

    2015-09-01

    Motivation is identified as a key antecedent of self-regulated behaviour, such as eating fruit and vegetables. However, inaccurate measurement of this construct may lead to poor prediction of behaviour and inflate the impact of post-motivational factors, such as planning, in models of health behaviour. This study explored the properties of a newly identified measure of motivation, termed behavioural resolve (Rhodes & Horne, 2013, Psychol. Sport Exerc., 14, 455-460), in relation to intention, planning, and fruit and vegetable intake (FVI). Prospective self-report survey. University students living in the United Kingdom completed two online surveys. The first assessed demographic and predictor variables (intention, behavioural resolve, action planning, and coping planning). The second, completed approximately 2 weeks later, measured average daily FVI and perceived experience of obstacles to FVI. At Time 1, there were 195 respondents, with 139 providing follow-up data. All predictor variables were significantly correlated with FVI. Two independent multiple hierarchical regression analyses revealed that both intention and behavioural resolve were significant predictors of FVI, but behavioural resolve explained greater FVI variance (40.1%) than intention (36.4%). Furthermore, action planning showed incremental predictive utility over intention, but not behavioural resolve, in predicting FVI. The results indicated that motivation is an important determinant of FVI for students, with behavioural resolve demonstrating advantages over intention as a measure of this domain and a predictor of FVI behaviour. © 2014 The British Psychological Society.

  5. Interaction effects in the theory of planned behaviour: Predicting fruit and vegetable consumption in three prospective cohorts.

    Science.gov (United States)

    Kothe, Emily J; Mullan, Barbara A

    2015-09-01

    The theory of planned behaviour (TPB) has been criticized for not including interactions between major constructs thought to underlie behaviour. This study investigated the application of the TPB to the prediction of fruit and vegetable consumption across three prospective cohorts. The primary aim of the study was to investigate whether interactions between major constructs in the theory would increase the ability of the model to predict intention to consume fruit and vegetables (i.e., attitude × perceived behavioural control [PBC], subjective norm × PBC, subjective norm × attitude) and self-reported fruit and vegetable intake (i.e., PBC × intention). Secondary data analysis from three cohorts: One predictive study (cohort 1) and two intervention studies (cohorts 2 and 3). Participants completed a TPB measure at baseline and a measure of fruit and vegetable intake at 1 week (cohort 1; n = 90) or 1 month (cohorts 2 and 3; n = 296). Attitude moderated the impact of PBC on intention. PBC moderated the impact of intention on behaviour at 1 week but not 1 month. The variance accounted for by the interactions was small. However, the presence of interactions between constructs within the TPB demonstrates a need to consider interactions between variables within the TPB in both theoretical and applied research using the model. © 2014 The British Psychological Society.

  6. Predicting Changes in Arctic Tundra Vegetation: Towards an Understanding of Plant Trait Uncertainty

    Science.gov (United States)

    Euskirchen, E. S.; Serbin, S.; Carman, T.; Iversen, C. M.; Salmon, V.; Helene, G.; McGuire, A. D.

    2017-12-01

    Arctic tundra plant communities are currently undergoing unprecedented changes in both composition and distribution under a warming climate. Predicting how these dynamics may play out in the future is important since these vegetation shifts impact both biogeochemical and biogeophysical processes. More precise estimates of these future vegetation shifts is a key challenge due to both a scarcity of data with which to parameterize vegetation models, particularly in the Arctic, as well as a limited understanding of the importance of each of the model parameters and how they may vary over space and time. Here, we incorporate newly available field data from arctic Alaska into a dynamic vegetation model specifically developed to take into account a particularly wide array of plant species as well as the permafrost soils of the arctic tundra (the Terrestrial Ecosystem Model with Dynamic Vegetation and Dynamic Organic Soil, Terrestrial Ecosystem Model; DVM-DOS-TEM). We integrate the model within the Predicative Ecosystem Analyzer (PEcAn), an open-source integrated ecological bioinformatics toolbox that facilitates the flows of information into and out of process models and model-data integration. We use PEcAn to evaluate the plant functional traits that contribute most to model variability based on a sensitivity analysis. We perform this analysis for the dominant types of tundra in arctic Alaska, including heath, shrub, tussock and wet sedge tundra. The results from this analysis will help inform future data collection in arctic tundra and reduce model uncertainty, thereby improving our ability to simulate Arctic vegetation structure and function in response to global change.

  7. [Advance in researches on vegetation cover and management factor in the soil erosion prediction model].

    Science.gov (United States)

    Zhang, Yan; Yuan, Jianping; Liu, Baoyuan

    2002-08-01

    Vegetation cover and land management are the main limiting factors of soil erosion, and quantitative evaluation on the effect of different vegetation on soil erosion is essential to land use and soil conservation planning. The vegetation cover and management factor (C) in the universal soil loss equation (USLE) is an index to evaluate this effect, which has been studied deeply and used widely. However, the C factor study is insufficient in China. In order to strengthen the research of C factor, this paper reviewed the developing progress of C factor, and compared the methods of estimating C value in different USLE versions. The relative studies in China were also summarized from the aspects of vegetation canopy coverage, soil surface cover, and root density. Three problems in C factor study were pointed out. The authors suggested that cropland C factor research should be furthered, and its methodology should be unified in China to represent reliable C values for soil loss prediction and conservation planning.

  8. Influence of forest roads standards and networks on water yield as predicted by the distributed hydrology-soil-vegetation model

    Science.gov (United States)

    Salli F. Dymond; W. Michael Aust; Steven P. Prisley; Mark H. Eisenbies; James M. Vose

    2013-01-01

    Throughout the country, foresters are continually looking at the effects of logging and forest roads on stream discharge and overall stream health. In the Pacific Northwest, a distributed hydrology-soil-vegetation model (DHSVM) has been used to predict the effects of logging on peak discharge in mountainous regions. DHSVM uses elevation, meteorological, vegetation, and...

  9. The use of Chernobyl fallout to test model predictions of the transfer of radioiodine from air to vegetation to milk

    International Nuclear Information System (INIS)

    Hoffman, F.O.; Amaral, E.

    1989-01-01

    Comparison of observed values with model predictions indicate a tendency for the models to overpredict the air-vegetation-milk transfer of Chernobyl I-131 by one to two orders of magnitude. Detailed analysis of the data indicated that, in general, most overpredictions were accounted for by the portion of the air-pasture-cow-milk pathway dealing with the transfer from air to pasture vegetation rather than the transfer from vegetation to milk. A partial analysis using available data to infer site-specific conditions and parameter values indicates that differences between model predictions and observations can be explained by: 1) overestimation of the fraction of the total amount of I-131 in air that was present as molecular vapour, 2) overestimation of wet and dry deposition of elemental and organic iodine and particulate aerosols, 3) overestimation of initial vegetation interception of material deposited during sever thunderstorms, 4) underestimation of the rates of weathering and growth dilution of material deposited on vegetation during periods of spring growth, 5) underestimation of the amount of uncontaminated feed consumed by dairy cows, and 6) overestimation of the diet-to-milk transfer coefficient for I-131. (orig./HP)

  10. Predicting children's fussiness with vegetables:the role of feeding practices

    OpenAIRE

    Holley, Clare E.; Haycraft, Emma; Farrow, Claire

    2017-01-01

    Vegetables are commonly rejected by children, making it is important to consider factors that are associated with children's fussiness with vegetables. The current study aimed to investigate whether fussiness with vegetables is associated with a number of factors including caregiver and child vegetable consumption; caregivers' general feeding practices; and caregivers' vegetable-specific feeding practices. Caregivers (N = 297) of preschool children completed questionnaire measures of their ch...

  11. Wind erosion in semiarid landscapes: Predictive models and remote sensing methods for the influence of vegetation

    Science.gov (United States)

    Musick, H. Brad

    1993-01-01

    The objectives of this research are: to develop and test predictive relations for the quantitative influence of vegetation canopy structure on wind erosion of semiarid rangeland soils, and to develop remote sensing methods for measuring the canopy structural parameters that determine sheltering against wind erosion. The influence of canopy structure on wind erosion will be investigated by means of wind-tunnel and field experiments using structural variables identified by the wind-tunnel and field experiments using model roughness elements to simulate plant canopies. The canopy structural variables identified by the wind-tunnel and field experiments as important in determining vegetative sheltering against wind erosion will then be measured at a number of naturally vegetated field sites and compared with estimates of these variables derived from analysis of remotely sensed data.

  12. Predicting bed shear stress and its role in sediment dynamics and restoration potential of the Everglades and other vegetated flow systems

    Science.gov (United States)

    Larsen, Laurel G.; Harvey, Judson; Crimaldi, John P.

    2009-01-01

    Entrainment of sediment by flowing water affects topography, habitat suitability, and nutrient cycling in vegetated floodplains and wetlands, impacting ecosystem evolution and the success of restoration projects. Nonetheless, restoration managers lack simple decision-support tools for predicting shear stresses and sediment redistribution potential in different vegetation communities. Using a field-validated numerical model, we developed state-space diagrams that provide these predictions over a range of water-surface slopes, depths, and associated velocities in Everglades ridge and slough vegetation communities. Diminished bed shear stresses and a consequent decrease in bed sediment redistribution are hypothesized causes of a recent reduction in the topographic and vegetation heterogeneity of this ecosystem. Results confirmed the inability of present-day flows to entrain bed sediment. Further, our diagrams showed bed shear stresses to be highly sensitive to emergent vegetation density and water-surface slope but less sensitive to water depth and periphyton or floating vegetation abundance. These findings suggested that instituting a pulsing flow regime could be the most effective means to restore sediment redistribution to the Everglades. However, pulsing flows will not be sufficient to erode sediment from sloughs with abundant spikerush, unless spikerush density first decreases by natural or managed processes. Our methods provide a novel tool for identifying restoration parameters and performance measures in many types of vegetated aquatic environments where sediment erosion and deposition are involved.

  13. When Winners Become Losers: Predicted Nonlinear Responses of Arctic Birds to Increasing Woody Vegetation.

    Directory of Open Access Journals (Sweden)

    Sarah J Thompson

    Full Text Available Climate change is facilitating rapid changes in the composition and distribution of vegetation at northern latitudes, raising questions about the responses of wildlife that rely on arctic ecosystems. One widely observed change occurring in arctic tundra ecosystems is an increasing dominance of deciduous shrub vegetation. Our goals were to examine the tolerance of arctic-nesting bird species to existing gradients of vegetation along the boreal forest-tundra ecotone, to predict the abundance of species across different heights and densities of shrubs, and to identify species that will be most or least responsive to ongoing expansion of shrubs in tundra ecosystems. We conducted 1,208 point counts on 12 study blocks from 2012-2014 in northwestern Alaska, using repeated surveys to account for imperfect detection of birds. We considered the importance of shrub height, density of low and tall shrubs (i.e. shrubs >0.5 m tall, percent of ground cover attributed to shrubs (including dwarf shrubs <0.5 m tall, and percent of herbaceous plant cover in predicting bird abundance. Among 17 species considered, only gray-cheeked thrush (Catharus minimus abundance was associated with the highest values of all shrub metrics in its top predictive model. All other species either declined in abundance in response to one or more shrub metrics or reached a threshold where further increases in shrubs did not contribute to greater abundance. In many instances the relationship between avian abundance and shrubs was nonlinear, with predicted abundance peaking at moderate values of the covariate, then declining at high values. In particular, a large number of species were responsive to increasing values of average shrub height with six species having highest abundance at near-zero values of shrub height and abundance of four other species decreasing once heights reached moderate values (≤ 33 cm. Our findings suggest that increases in shrub cover and density will negatively

  14. Developing Models to Predict the Number of Fire Hotspots from an Accumulated Fuel Dryness Index by Vegetation Type and Region in Mexico

    Directory of Open Access Journals (Sweden)

    D. J. Vega-Nieva

    2018-04-01

    Full Text Available Understanding the linkage between accumulated fuel dryness and temporal fire occurrence risk is key for improving decision-making in forest fire management, especially under growing conditions of vegetation stress associated with climate change. This study addresses the development of models to predict the number of 10-day observed Moderate-Resolution Imaging Spectroradiometer (MODIS active fire hotspots—expressed as a Fire Hotspot Density index (FHD—from an Accumulated Fuel Dryness Index (AcFDI, for 17 main vegetation types and regions in Mexico, for the period 2011–2015. The AcFDI was calculated by applying vegetation-specific thresholds for fire occurrence to a satellite-based fuel dryness index (FDI, which was developed after the structure of the Fire Potential Index (FPI. Linear and non-linear models were tested for the prediction of FHD from FDI and AcFDI. Non-linear quantile regression models gave the best results for predicting FHD using AcFDI, together with auto-regression from previously observed hotspot density values. The predictions of 10-day observed FHD values were reasonably good with R2 values of 0.5 to 0.7 suggesting the potential to be used as an operational tool for predicting the expected number of fire hotspots by vegetation type and region in Mexico. The presented modeling strategy could be replicated for any fire danger index in any region, based on information from MODIS or other remote sensors.

  15. Vegetative biomass predicts inflorescence production along a CO2 concentration gradient in mesic grassland

    Science.gov (United States)

    Fay, P. A.; Collins, H.; Polley, W.

    2016-12-01

    Atmospheric CO2 concentration will likely exceed 500 µL L-1 by 2050, often increasing plant community productivity in part by increasing abundance of species favored by increased CA . Whether increased abundance translates to increased inflorescence production is poorly understood, and is important because it indicates the potential effects of CO2 enrichment on genetic variability and the potential for evolutionary change in future generations. We examined whether the responses of inflorescence production to CO2 enrichment in four C4 grasses and a C3 forb were predicted their vegetative biomass, and by soil moisture, soil nitrogen, or light availability. Inflorescence production was studied in a long-term CO2 concentration gradient spanning pre-industrial to anticipated mid-21st century values (250 - 500 µL L-1) maintained on clay, silty clay and sandy loam soils common in the U.S. Southern Plains. We expected that CO2 enrichment would increase inflorescence production, and more so with higher water, nitrogen, or light availability. However, structural equation modeling revealed that vegetative biomass was the single consistent direct predictor of flowering for all species (p grass) and Solidago canadensis (C3 forb), direct CO2 effects on flowering were only weakly mediated by indirect effects of soil water content and soil NO3-N availability. For the decreasing species (Bouteloua curtipendula, C4 grass), the negative CO2-flowering relationship was cancelled (p = 0.39) by indirect effects of increased SWC and NO3-N on clay and silty clay soils. For the species with no CO2 response, inflorescence production was predicted only by direct water content (p grass) or vegetative biomass (p = 0.0009, Tridens albescens, C4 grass) effects. Light availability was unrelated to inflorescence production. Changes in inflorescence production are thus closely tied to direct and indirect effects of CO2 enrichment on vegetative biomass, and may either increase, decrease, or leave

  16. Rapid characterisation of vegetation structure to predict refugia and climate change impacts across a global biodiversity hotspot.

    Directory of Open Access Journals (Sweden)

    Antonius G T Schut

    Full Text Available Identification of refugia is an increasingly important adaptation strategy in conservation planning under rapid anthropogenic climate change. Granite outcrops (GOs provide extraordinary diversity, including a wide range of taxa, vegetation types and habitats in the Southwest Australian Floristic Region (SWAFR. However, poor characterization of GOs limits the capacity of conservation planning for refugia under climate change. A novel means for the rapid identification of potential refugia is presented, based on the assessment of local-scale environment and vegetation structure in a wider region. This approach was tested on GOs across the SWAFR. Airborne discrete return Light Detection And Ranging (LiDAR data and Red Green and Blue (RGB imagery were acquired. Vertical vegetation profiles were used to derive 54 structural classes. Structural vegetation types were described in three areas for supervised classification of a further 13 GOs across the region. Habitat descriptions based on 494 vegetation plots on and around these GOs were used to quantify relationships between environmental variables, ground cover and canopy height. The vegetation surrounding GOs is strongly related to structural vegetation types (Kappa = 0.8 and to its spatial context. Water gaining sites around GOs are characterized by taller and denser vegetation in all areas. The strong relationship between rainfall, soil-depth, and vegetation structure (R(2 of 0.8-0.9 allowed comparisons of vegetation structure between current and future climate. Significant shifts in vegetation structural types were predicted and mapped for future climates. Water gaining areas below granite outcrops were identified as important putative refugia. A reduction in rainfall may be offset by the occurrence of deeper soil elsewhere on the outcrop. However, climate change interactions with fire and water table declines may render our conclusions conservative. The LiDAR-based mapping approach presented

  17. Validation of the marine vegetation model in Forsmark. SFR-Site Forsmark

    International Nuclear Information System (INIS)

    Aquilonius, Karin; Qvarfordt, Susanne; Borgiel, Micke

    2011-04-01

    A regression model implemented in GIS of the marine vegetation in Forsmark were developed by SKB /Aquilonius 2010/ based on field investigations and video surveys /Fredriksson 2005/ and from correlations of field data and physical properties /Carlen et al. 2007/. The marine vegetation model describes distribution and biomasses of the marine vegetation and is used as input data in the dose modeling within the safety assessments performed by the SKB. In this study the predictive performance of the vegetation model in the less examined parts of the marine area in Forsmark is evaluated. In general, the vegetation model works very well in predicting absence of biomass, except for Red algae. In total and for Fucus sp., the model also predicts the observed biomass fairly well. However, for phanerogams, Chara sp., filamentous algae and red algae the vegetation model works less well in predicting biomass

  18. Validation of the marine vegetation model in Forsmark. SFR-Site Forsmark

    Energy Technology Data Exchange (ETDEWEB)

    Aquilonius, Karin (Studsvik Nuclear AB (Sweden)); Qvarfordt, Susanne; Borgiel, Micke (Sveriges Vattenekologer AB (Sweden))

    2011-04-15

    A regression model implemented in GIS of the marine vegetation in Forsmark were developed by SKB /Aquilonius 2010/ based on field investigations and video surveys /Fredriksson 2005/ and from correlations of field data and physical properties /Carlen et al. 2007/. The marine vegetation model describes distribution and biomasses of the marine vegetation and is used as input data in the dose modeling within the safety assessments performed by the SKB. In this study the predictive performance of the vegetation model in the less examined parts of the marine area in Forsmark is evaluated. In general, the vegetation model works very well in predicting absence of biomass, except for Red algae. In total and for Fucus sp., the model also predicts the observed biomass fairly well. However, for phanerogams, Chara sp., filamentous algae and red algae the vegetation model works less well in predicting biomass

  19. Theory, methods and tools for determining environmental flows for riparian vegetation: Riparian vegetation-flow response guilds

    Science.gov (United States)

    Merritt, D.M.; Scott, M.L.; Leroy, Poff N.; Auble, G.T.; Lytle, D.A.

    2010-01-01

    Riparian vegetation composition, structure and abundance are governed to a large degree by river flow regime and flow-mediated fluvial processes. Streamflow regime exerts selective pressures on riparian vegetation, resulting in adaptations (trait syndromes) to specific flow attributes. Widespread modification of flow regimes by humans has resulted in extensive alteration of riparian vegetation communities. Some of the negative effects of altered flow regimes on vegetation may be reversed by restoring components of the natural flow regime. 2. Models have been developed that quantitatively relate components of the flow regime to attributes of riparian vegetation at the individual, population and community levels. Predictive models range from simple statistical relationships, to more complex stochastic matrix population models and dynamic simulation models. Of the dozens of predictive models reviewed here, most treat one or a few species, have many simplifying assumptions such as stable channel form, and do not specify the time-scale of response. In many cases, these models are very effective in developing alternative streamflow management plans for specific river reaches or segments but are not directly transferable to other rivers or other regions. 3. A primary goal in riparian ecology is to develop general frameworks for prediction of vegetation response to changing environmental conditions. The development of riparian vegetation-flow response guilds offers a framework for transferring information from rivers where flow standards have been developed to maintain desirable vegetation attributes, to rivers with little or no existing information. 4. We propose to organise riparian plants into non-phylogenetic groupings of species with shared traits that are related to components of hydrologic regime: life history, reproductive strategy, morphology, adaptations to fluvial disturbance and adaptations to water availability. Plants from any river or region may be grouped

  20. Perception of non-communicable diseases predicts consumption of fruits and vegetables

    Directory of Open Access Journals (Sweden)

    Charles Surjadi

    2012-12-01

    Full Text Available Background Nutrition has come to the fore as one of the major modifiable determinants of chronic disease. Establishing healthy eating habits during adolescence is important given that fruit and vegetable consumption has long-term health-protective benefits. The objective of this study was to investigate the determinant factors of fruit and vegetable consumption habits among Padang inhabitants Methods We conducted a questionnaire-based rapid assessment of 150 respondents who came from different settings: The questionnaire consisted of items on personal characteristics such as age, working status, gender, and personal knowledge of the subjects about the cause of non-communicable diseases (NCDs and their activities to prevent NCDs. Bivariate analysis was applied to look for variables significantly related to healthy eating (vegetable and fruit consumption. We applied multiple logistic regression to look for the best model to explain factors related to regular fruit and vegetable consumption. Results The age range of the subjects was 14 to 76 years, 60% of subjects were women, and 40% were men. The study indicated that 64.7% of the respondents perceived that eating habits relate to NCD, while 67.3% consumed fruits and vegetables regularly. Multivariate logistic regression analysis indicated that gender (O.R.=2.74; 95% C.I. 1.54-5.27 and perception of NCD as being related to healthy eating (O.R.=5.62;95% C.I. 2.93-10.76 were significantly related to regular fruit and vegetable consumption. Conclusion This study demonstrated that perception of NCD was the most determinant factor of regular fruit and vegetable consumption. Activities to improve practice of regular fruit and vegetable consumption are part of control of NCD risk factors.

  1. Predicting Potential Fire Severity Using Vegetation, Topography and Surface Moisture Availability in a Eurasian Boreal Forest Landscape

    Directory of Open Access Journals (Sweden)

    Lei Fang

    2018-03-01

    Full Text Available Severity of wildfires is a critical component of the fire regime and plays an important role in determining forest ecosystem response to fire disturbance. Predicting spatial distribution of potential fire severity can be valuable in guiding fire and fuel management planning. Spatial controls on fire severity patterns have attracted growing interest, but few studies have attempted to predict potential fire severity in fire-prone Eurasian boreal forests. Furthermore, the influences of fire weather variation on spatial heterogeneity of fire severity remain poorly understood at fine scales. We assessed the relative importance and influence of pre-fire vegetation, topography, and surface moisture availability (SMA on fire severity in 21 lightning-ignited fires occurring in two different fire years (3 fires in 2000, 18 fires in 2010 of the Great Xing’an Mountains with an ensemble modeling approach of boosted regression tree (BRT. SMA was derived from 8-day moderate resolution imaging spectroradiometer (MODIS evapotranspiration products. We predicted the potential distribution of fire severity in two fire years and evaluated the prediction accuracies. BRT modeling revealed that vegetation, topography, and SMA explained more than 70% of variations in fire severity (mean 83.0% for 2000, mean 73.8% for 2010. Our analysis showed that evergreen coniferous forests were more likely to experience higher severity fires than the dominant deciduous larch forests of this region, and deciduous broadleaf forests and shrublands usually burned at a significantly lower fire severity. High-severity fires tended to occur in gentle and well-drained slopes at high altitudes, especially those with north-facing aspects. SMA exhibited notable and consistent negative association with severity. Predicted fire severity from our model exhibited strong agreement with the observed fire severity (mean r2 = 0.795 for 2000, 0.618 for 2010. Our results verified that spatial variation

  2. Formation of banded vegetation patterns resulted from interactions between sediment deposition and vegetation growth.

    Science.gov (United States)

    Huang, Tousheng; Zhang, Huayong; Dai, Liming; Cong, Xuebing; Ma, Shengnan

    2018-03-01

    This research investigates the formation of banded vegetation patterns on hillslopes affected by interactions between sediment deposition and vegetation growth. The following two perspectives in the formation of these patterns are taken into consideration: (a) increased sediment deposition from plant interception, and (b) reduced plant biomass caused by sediment accumulation. A spatial model is proposed to describe how the interactions between sediment deposition and vegetation growth promote self-organization of banded vegetation patterns. Based on theoretical and numerical analyses of the proposed spatial model, vegetation bands can result from a Turing instability mechanism. The banded vegetation patterns obtained in this research resemble patterns reported in the literature. Moreover, measured by sediment dynamics, the variation of hillslope landform can be described. The model predicts how treads on hillslopes evolve with the banded patterns. Thus, we provide a quantitative interpretation for coevolution of vegetation patterns and landforms under effects of sediment redistribution. Copyright © 2018. Published by Elsevier Masson SAS.

  3. Intake of Raw Fruits and Vegetables Is Associated With Better Mental Health Than Intake of Processed Fruits and Vegetables

    Science.gov (United States)

    Brookie, Kate L.; Best, Georgia I.; Conner, Tamlin S.

    2018-01-01

    Background: Higher intakes of fruits and vegetables, rich in micronutrients, have been associated with better mental health. However, cooking or processing may reduce the availability of these important micronutrients. This study investigated the differential associations between intake of raw fruits and vegetables, compared to processed (cooked or canned) fruits and vegetables, and mental health in young adults. Methods: In a cross-sectional survey design, 422 young adults ages 18–25 (66.1% female) living in New Zealand and the United States completed an online survey that assessed typical consumption of raw vs. cooked/canned/processed fruits and vegetables, negative and positive mental health (depressive symptoms, anxiety, negative mood, positive mood, life satisfaction, and flourishing), and covariates (including socio-economic status, body mass index, sleep, physical activity, smoking, and alcohol use). Results: Controlling for covariates, raw fruit and vegetable intake (FVI) predicted reduced depressive symptoms and higher positive mood, life satisfaction, and flourishing; processed FVI only predicted higher positive mood. The top 10 raw foods related to better mental health were carrots, bananas, apples, dark leafy greens like spinach, grapefruit, lettuce, citrus fruits, fresh berries, cucumber, and kiwifruit. Conclusions: Raw FVI, but not processed FVI, significantly predicted higher mental health outcomes when controlling for the covariates. Applications include recommending the consumption of raw fruits and vegetables to maximize mental health benefits. PMID:29692750

  4. Intake of Raw Fruits and Vegetables Is Associated With Better Mental Health Than Intake of Processed Fruits and Vegetables

    Directory of Open Access Journals (Sweden)

    Kate L. Brookie

    2018-04-01

    Full Text Available Background: Higher intakes of fruits and vegetables, rich in micronutrients, have been associated with better mental health. However, cooking or processing may reduce the availability of these important micronutrients. This study investigated the differential associations between intake of raw fruits and vegetables, compared to processed (cooked or canned fruits and vegetables, and mental health in young adults.Methods: In a cross-sectional survey design, 422 young adults ages 18–25 (66.1% female living in New Zealand and the United States completed an online survey that assessed typical consumption of raw vs. cooked/canned/processed fruits and vegetables, negative and positive mental health (depressive symptoms, anxiety, negative mood, positive mood, life satisfaction, and flourishing, and covariates (including socio-economic status, body mass index, sleep, physical activity, smoking, and alcohol use.Results: Controlling for covariates, raw fruit and vegetable intake (FVI predicted reduced depressive symptoms and higher positive mood, life satisfaction, and flourishing; processed FVI only predicted higher positive mood. The top 10 raw foods related to better mental health were carrots, bananas, apples, dark leafy greens like spinach, grapefruit, lettuce, citrus fruits, fresh berries, cucumber, and kiwifruit.Conclusions: Raw FVI, but not processed FVI, significantly predicted higher mental health outcomes when controlling for the covariates. Applications include recommending the consumption of raw fruits and vegetables to maximize mental health benefits.

  5. Perception of non-communicable diseases predicts consumption of fruits and vegetables

    Directory of Open Access Journals (Sweden)

    Charles Surjadi

    2015-12-01

    This study demonstrated that perception of NCD was the most determinant factor of regular fruit and vegetable consumption. Activities to improve practice of regular fruit and vegetable consumption are part of control of NCD risk factors.

  6. Model-based prediction of nephropathia epidemica outbreaks based on climatological and vegetation data and bank vole population dynamics.

    Science.gov (United States)

    Haredasht, S Amirpour; Taylor, C J; Maes, P; Verstraeten, W W; Clement, J; Barrios, M; Lagrou, K; Van Ranst, M; Coppin, P; Berckmans, D; Aerts, J-M

    2013-11-01

    could be predicted 3 months ahead with a 34% mean relative prediction error (MRPE). This took into account solely the population dynamics of the carrier species (bank voles). The time series analysis also revealed that climate change, as represented by the vegetation index, changes in forest phenology derived from satellite images and directly measured air temperature, may affect the mechanics of NE transmission. NE outbreaks in Belgium were predicted 3 months ahead with a 40% MRPE, based only on the climatological and vegetation data, in this case, without any knowledge of the bank vole's population dynamics. In this research, we demonstrated that NE outbreaks can be predicted using climate and vegetation data or the bank vole's population dynamics, by using dynamic data-based models with time-varying parameters. Such a predictive modelling approach might be used as a step towards the development of new tools for the prevention of future NE outbreaks. © 2012 Blackwell Verlag GmbH.

  7. Hydraulic Aspects of Vegetation Maintanence in Streams

    DEFF Research Database (Denmark)

    Larsen, Torben; Vestergaard, Kristian

    1991-01-01

    This paper describes the importance of the underwater vegetation on Danish streams and some of the consequences of vegetation maintenance. the influence of the weed on the hydraulic conditions is studied through experiments in a smaller stream and the effect of cutting channels through the weed...... is measured. A method for predicting the Manning's n as a function of the discharge conditions is suggested, and also a working hypothesis for predictions of the effect of channel cutting is presented....

  8. Determinants of vegetation distribution at continental scale. The contribution of natural and anthropogenic factors

    DEFF Research Database (Denmark)

    Greve, Michelle; Svenning, J.-C.; Lykke, Anne Mette

    2011-01-01

    It has long been debated what determines distribution of vegetation types, though this has rarely been tested at continental scale. We thus aimed to determine which vegetation types are most accurately predicted by natural environmental factors, and which of these factors best predict current veg...... was also assessed, and found to be of some importance for most vegetation types. We conclude that, in addition to including environmental variables in predicting vegetation distribution, it is essential that human impact be considered, also in future climate change scenarios....... vegetation distribution across Africa. Vegetation types were extracted from the Global Land Cover Map for the year 2000, and the distribution of vegetation types modelled in terms of climate, soil and topography. Annual precipitation was the best predictor of the distribution of all vegetation types...

  9. Field determination and QSPR prediction of equilibrium-status soil/vegetation partition coefficient of PCDD/Fs.

    Science.gov (United States)

    Li, Li; Wang, Qiang; Qiu, Xinghua; Dong, Yian; Jia, Shenglan; Hu, Jianxin

    2014-07-15

    Characterizing pseudo equilibrium-status soil/vegetation partition coefficient KSV, the quotient of respective concentrations in soil and vegetation of a certain substance at remote background areas, is essential in ecological risk assessment, however few previous attempts have been made for field determination and developing validated and reproducible structure-based estimates. In this study, KSV was calculated based on measurements of seventeen 2,3,7,8-substituted PCDD/F congeners in soil and moss (Dicranum angustum), and rouzi grass (Thylacospermum caespitosum) of two background sites, Ny-Ålesund of the Arctic and Zhangmu-Nyalam region of the Tibet Plateau, respectively. By both fugacity modeling and stepwise regression of field data, the air-water partition coefficient (KAW) and aqueous solubility (SW) were identified as the influential physicochemical properties. Furthermore, validated quantitative structure-property relationship (QSPR) model was developed to extrapolate the KSV prediction to all 210 PCDD/F congeners. Molecular polarizability, molecular size and molecular energy demonstrated leading effects on KSV. Copyright © 2014 Elsevier B.V. All rights reserved.

  10. Predictive modelling of vegetable firmness after thermal pre-treatments and steaming

    NARCIS (Netherlands)

    Dekker, M.; Dekkers, E.; Jasper, A.; Baár, C.; Verkerk, R.

    2014-01-01

    Texture is an important product property that strongly affects the quality evaluation of processed vegetables by consumers. The rate of texture decrease is dependent on the processing temperature and the type of vegetable. A large data set on instrumental texture measurements of carrot and broccoli

  11. Current and future fire regimes and their influence on natural vegetation in Ethiopia

    DEFF Research Database (Denmark)

    van Breugel, Paulo; Friis, Ib; Demissew, Sebsebe

    2016-01-01

    vegetation types. The effect of climate change varies considerably between climate change models and scenarios, but as general trend expansions of moist Afromontane forest and Combretum–Terminalia woodlands were predicted. Fire-prone areas were also predicted to increase, and including this factor...... in vegetation distribution models resulted in stronger expansion of Combretum–Terminalia woodlands and a more limited increase of moist Afromontane forests. These results underline the importance of fire as a regulating factor of vegetation distribution patterns, and how fire needs to be factored into predict......Fire is a major factor shaping the distribution of vegetation types. In this study, we used a recent high resolution map of potential natural vegetation (PNV) types and MODIS fire products to model and investigate the importance of fire as driver of vegetation distribution patterns in Ethiopia. We...

  12. Measurement Of Technical Efficiency In Irrigated Vegetable ...

    African Journals Online (AJOL)

    This study measured technical efficiency and identified its determinants in irrigated vegetable production in Nasarawa State of Nigeria using a stochastic frontier model. A complete enumeration of 193 NADP-registered vegetable farmers was done. The predicted farm technical efficiency ranges from 25.94 to 96.24 per cent ...

  13. Impact of vegetation feedback at subseasonal & seasonal timescales on precipitation over North America

    Science.gov (United States)

    Kim, Y.; Wang, G.

    2006-05-01

    Soil moisture-vegetation-precipitation feedbacks tend to enhance soil moisture memory in some areas of the globe, which contributes to the subseasonal and seasonal climate prediction skill. In this study, the impact of vegetation on precipitation over North America is investigated using a coupled land-atmosphere model CAM3- CLM3. The coupled model has been modified to include a predictive vegetation phenology scheme and validated against the MODIS data. Vegetation phenology is modeled by updating the leaf area index (LAI) daily in response to cumulative and concurrent hydrometeorological conditions. First, driven with the climatological SST, a large group of 5-member ensembles of simulations from the late spring and summer to the end of year are generated with the different initial conditions of soil moisture. The impact of initial soil moisture anomalies on subsequent precipitation is examined with the predictive vegetation phenology scheme disabled/enabled ("SM"/"SM_Veg" ensembles). The simulated climate differences between "SM" and "SM_Veg" ensembles represent the role of vegetation in soil moisture-vegetation- precipitation feedback. Experiments in this study focus on how the response of precipitation to initial soil moisture anomalies depends on their characteristics, including the timing, magnitude, spatial coverage and vertical depth, and further how it is modified by the interactive vegetation. Our results, for example, suggest that the impact of late spring soil moisture anomalies is not evident in subsequent precipitation until early summer when local convective precipitation dominates. With the summer wet soil moisture anomalies, vegetation tends to enhance the positive feedback between soil moisture and precipitation, while vegetation tends to suppress such positive feedback with the late spring anomalies. Second, the impact of vegetation feedback is investigated by driving the model with the inter-annually varying monthly SST (1983-1994). With the

  14. Ages and transit times as important diagnostics of model performance for predicting carbon dynamics in terrestrial vegetation models

    Science.gov (United States)

    Ceballos-Núñez, Verónika; Richardson, Andrew D.; Sierra, Carlos A.

    2018-03-01

    The global carbon cycle is strongly controlled by the source/sink strength of vegetation as well as the capacity of terrestrial ecosystems to retain this carbon. These dynamics, as well as processes such as the mixing of old and newly fixed carbon, have been studied using ecosystem models, but different assumptions regarding the carbon allocation strategies and other model structures may result in highly divergent model predictions. We assessed the influence of three different carbon allocation schemes on the C cycling in vegetation. First, we described each model with a set of ordinary differential equations. Second, we used published measurements of ecosystem C compartments from the Harvard Forest Environmental Measurement Site to find suitable parameters for the different model structures. And third, we calculated C stocks, release fluxes, radiocarbon values (based on the bomb spike), ages, and transit times. We obtained model simulations in accordance with the available data, but the time series of C in foliage and wood need to be complemented with other ecosystem compartments in order to reduce the high parameter collinearity that we observed, and reduce model equifinality. Although the simulated C stocks in ecosystem compartments were similar, the different model structures resulted in very different predictions of age and transit time distributions. In particular, the inclusion of two storage compartments resulted in the prediction of a system mean age that was 12-20 years older than in the models with one or no storage compartments. The age of carbon in the wood compartment of this model was also distributed towards older ages, whereas fast cycling compartments had an age distribution that did not exceed 5 years. As expected, models with C distributed towards older ages also had longer transit times. These results suggest that ages and transit times, which can be indirectly measured using isotope tracers, serve as important diagnostics of model structure

  15. Factors affecting vegetable preference in adolescents: stages of change and social cognitive theory.

    Science.gov (United States)

    Woo, Taejung; Lee, Kyung-Hea

    2017-08-01

    Despite the importance of consuming sufficient amounts of vegetables, daily vegetable intake among adolescents in Korea is lower than the current dietary recommendation. The objective of this study was to examine determinants affecting vegetable preference in order to suggest a stage-tailored education strategy that can promote vegetable consumption in adolescents. Adolescents (n = 400, aged 16-17 years) from two high schools participated in a cross-sectional study. Survey variables were vegetable preference, the social cognitive theory (SCT) and stages of change (SOC) constructs. Based on vegetable preference, subjects were classified into two groups: a low-preference group (LPG) and a high-preference group (HPG). SOC was subdivided into pre-action and action/maintenance stages. To compare SCT components and SOC related to vegetable preference, chi-squared and t-tests, along with stepwise multiple-regression analysis, were applied. In the LPG, a similar number of subjects were classified into each stage. Significant differences in self-efficacy, affective attitudes, and vegetable accessibility at home and school were detected among the stages. Subjects in the HPG were mainly at the maintenance stage (81%), and there were significant differences among the stages regarding self-efficacy, affective attitudes, and parenting practice. In the predictions of vegetable preference, self-efficacy and parenting practice had a significant effect in the "pre-action" stage. In the action/maintenance stage, outcome expectation, affective attitudes, and vegetable accessibility at school had significant predictive value. In predicting the vegetable preference for all subjects, 42.8% of the predictive variance was accounted for by affective attitudes, self-efficacy, and vegetable accessibility at school. The study revealed that different determinants affect adolescent vegetable preference in each stage. Self-efficacy and affective attitudes are important determinants affecting

  16. Submersed Aquatic Vegetation Modeling Output Online

    National Research Council Canada - National Science Library

    Yin, Yao; Rogala, Jim; Sullivan, John; Rohweder, Jason

    2005-01-01

    .... Predictions for distribution of submerged aquatic vegetation beds can potentially increase hunter observance of voluntary avoidance zones where foraging birds are left alone to feed undisturbed...

  17. vegetation biomass prediction in the cattle corridor of uganda

    African Journals Online (AJOL)

    Prof. Adipala Ekwamu

    3Ministry of Water and Environment, Climate Change Unit, P. O. Box 2811, Kampala, Uganda ... (r=0.99). Precipitation has influenced vegetative biomass in the cattle corridor as there is a positive .... since they are cloud free (Campbell, 2006).

  18. Developing models to predict the number of fire hotspots from an accumulated fuel dryness index by vegetation type and region in Mexico

    Science.gov (United States)

    D. Vega-Nieva; J. Briseño-Reyes; M. Nava-Miranda; E. Calleros-Flores; P. López-Serrano; J. Corral-Rivas; E. Montiel-Antuna; M. Cruz-López; M. Cuahutle; R. Ressl; E. Alvarado-Celestino; A. González-Cabán; E. Jiménez; J. Álvarez-González; A. Ruiz-González; R. Burgan; H. Preisler

    2018-01-01

    Understanding the linkage between accumulated fuel dryness and temporal fire occurrence risk is key for improving decision-making in forest fire management, especially under growing conditions of vegetation stress associated with climate change. This study addresses the development of models to predict the number of 10-day observed Moderate-Resolution Imaging...

  19. Critical thickness ratio for buckled and wrinkled fruits and vegetables

    Science.gov (United States)

    Dai, Hui-Hui; Liu, Yang

    2014-11-01

    This work aims at establishing the geometrical constraint for buckled and wrinkled shapes by modeling a fruit/vegetable with exocarp and sarcocarp as a hyperelastic layer-substrate structure subjected to uniaxial compression. A careful analysis on the derived bifurcation condition leads to the finding of a critical thickness ratio which separates the buckling and wrinkling modes, and remarkably, which is independent of the material stiffnesses. More specifically, it is found that if the thickness ratio is smaller than this critical value a fruit/vegetable should be in a buckled shape (under a sufficient stress); if a fruit/vegetable is in a wrinkled shape the thickness ratio is always larger than this critical value. To verify the theoretical prediction, we consider four types of buckled fruits/vegetables and four types of wrinkled fruits/vegetables with three samples in each type. The geometrical parameters for the 24 samples are measured and it is found that indeed all the data fall into the theoretically predicted buckling or wrinkling domains.

  20. Impedance deduction for vegetated roof surfaces : multiple geometry strategy

    NARCIS (Netherlands)

    Liu, C.; Hornikx, M.

    2016-01-01

    The transfer function method is an efficient procedure to deduce the ground surface impedance from short-range propagation measurements using one point source. It is able to provide a reasonable prediction of the surface impedance of a vegetated roof as well, and the characteristics of the vegetated

  1. A comparative framework for broad-scale plot-based vegetation classification

    NARCIS (Netherlands)

    Caceres, de M.; Chytry, M.; Agrillo, E.; Attore, F.; Schaminee, J.H.J.

    2015-01-01

    Aims:
    Classification of vegetation is an essential tool to describe, understand, predict and manage biodiversity. Given the multiplicity of approaches to classify vegetation, it is important to develop international consensus around a set of general guidelines and purpose-specific standard

  2. Can knowledge alone predict vegetable and fruit consumption among adolescents? A transtheoretical model perspective.

    Science.gov (United States)

    El Hamid Hussein, Rania Abd

    2011-01-01

    Nutrition clearly plays a role during adolescent development. Nutritional habits are not in line with the recommendations among adolescents. Food habits that are seen more frequently among teens than in other age groups include irregular consumption of meals, and eating away from home (especially fast-food venues). In addition, many young people do not eat enough fruits and vegetables (FVs). We aimed at exploring the knowledge, attitude, and behavior toward FV consumption among adolescent Saudi girls, using a transtheoretical model (TTM). A cross-sectional study was conducted. The target group included adolescent girls aged 18-21 years, students at the Faculty of Applied Medical Sciences, at King Abdulaziz University, Kingdom of Saudi Arabia. Of a total sample of 205 participants, 73 were in the Clinical Nutrition Department. FV consumption was assessed among the whole sample, using a Food Frequency questionnaire, and then the TTM determinants were assessed. The study detected significant differences between the two groups with regard to vegetable consumption. The most frequently reported stage of change in the nutrition department was action maintenance with regard to FV consumption; self-efficacy and pros were the most significant positive predictors for FV consumption, whereas the department type (determining knowledge) had a negligible effect. Finally, we detected that TTM determinants of FV intake and their stages of change clustered. Knowledge alone cannot predict FV intake in adolescent girls. TTM stages of change and determinants seem to be somewhat related in FV consumption. Therefore, an integrated dietary change approach for both FV consumption is recommended among adolescents.

  3. Vegetation pattern formation in a fog-dependent ecosystem.

    Science.gov (United States)

    Borthagaray, Ana I; Fuentes, Miguel A; Marquet, Pablo A

    2010-07-07

    Vegetation pattern formation is a striking characteristic of several water-limited ecosystems around the world. Typically, they have been described on runoff-based ecosystems emphasizing local interactions between water, biomass interception, growth and dispersal. Here, we show that this situation is by no means general, as banded patterns in vegetation can emerge in areas without rainfall and in plants without functional root (the Bromeliad Tillandsia landbeckii) and where fog is the principal source of moisture. We show that a simple model based on the advection of fog-water by wind and its interception by the vegetation can reproduce banded patterns which agree with empirical patterns observed in the Coastal Atacama Desert. Our model predicts how the parameters may affect the conditions to form the banded pattern, showing a transition from a uniform vegetated state, at high water input or terrain slope to a desert state throughout intermediate banded states. Moreover, the model predicts that the pattern wavelength is a decreasing non-linear function of fog-water input and slope, and an increasing function of plant loss and fog-water flow speed. Finally, we show that the vegetation density is increased by the formation of the regular pattern compared to the density expected by the spatially homogeneous model emphasizing the importance of self-organization in arid ecosystems. (c) 2010 Elsevier Ltd. All rights reserved.

  4. Impacts of Vegetation Growth on Reach-scale Flood Hydraulics in a Sand-bed River and the Implications for Vegetation-morphology Coevolution

    Science.gov (United States)

    Box, S.; Wilcox, A. C.

    2017-12-01

    Vegetation alters flood hydraulics and geomorphic response, yet quantifying and predicting such responses across spatial and temporal scales remains challenging. Plant- and patch-scale studies consistently show that vegetation increases local hydraulic variability, yet reach-scale hydrodynamic models often assume vegetation has a spatially homogeneous effect on hydraulics. Using Nays2DH in iRIC (International River Interface Cooperative), we model the effect of spatially heterogeneous vegetation on a series of floods with varying antecedent vegetation conditions in a sand-bed river in western Arizona, taking advantage of over a decade of data on a system that experienced substantial geomorphic, hydrologic, and ecosystem changes. We show that pioneer woody seedlings (Tamarix, Populus, Salix) and cattail (Typha) increase local hydraulic variability, including velocity and bed shear stress, along individual cross sections, predominantly by decreasing velocity in zones of vegetation establishment and growth and increasing velocity in unvegetated areas, with analogous effects on shear stress. This was especially prominent in a study reach where vegetation growth contributed to thalweg incision relative to a vegetated bar. Evaluation of these results in the context of observed geomorphic response to floods elucidates mechanisms by which vegetation and channel morphology coevolve at a reach scale. By quantifying the influence of spatially heterogeneous vegetation on reach-scale hydraulics, we demonstrate that plant- and patch-scale research on vegetation hydraulics is applicable to ecogeomorphology at the reach scale.

  5. Path Loss Analysis of WSN Wave Propagation in Vegetation

    International Nuclear Information System (INIS)

    Sabri, Naseer; Aljunid, S A; Ahmad, R B; Malek, M F; Salim, M S; Kamaruddin, R

    2013-01-01

    Deployment of a successful wireless sensor network requires precise prediction models that provide a reliable communication links of wireless nodes. Prediction models fused with foliage models provide sensible parameters of wireless nodes separation distance, antenna height, and power transmission which affect the reliability and communication coverage of a network. This paper review the line of sight and the two ray propagation models combined with the most known foliage models that cover the propagation of wireless communications in vegetative environments, using IEEE 802.15.4 standard. Simulation of models is presented and the impacts of the communication parameters, environment and vegetation have been reported.

  6. A simple model for yield prediction of rice based on vegetation index derived from satellite and AMeDAS data during ripening period

    International Nuclear Information System (INIS)

    Wakiyama, Y.; Inoue, K.; Nakazono, K.

    2003-01-01

    The present study was conducted to show a simple model for rice yield predicting by using a vegetation index (NDVI) derived from satellite and meteorological data. In a field experiment, the relationship between the vegetation index and radiation absorbed by the rice canopy was investigated from transplanting to maturity. Their correlation held. This result revealed that the vegetation index could be used as a measure of absorptance of solar radiation by rice canopy. NDVI multiplied by solar radiation (SR) every day was accumulated (Σ(SR·NDVI)) from the field experiment. Σ(SR·NDVI) was plotted against above ground dry matter. It was obvious that they had a strong relationship. Rice yield largely depends on solar radiation and air temperature during the ripening period. Air temperature affects dry matter production. Relationships between Y SR -1 (Y: rice yield, SR: solar radiation) and mean air temperature were investigated from meteorological data and statistical data on rice yield. There was an optimum air temperature, 21.3°C, for ripening. When it was near 21.3°C in the ripening period, the rice yield was higher. We proposed a simple model for yield prediction of rice based on these results. The model is composed with SR·NDVI and the optimum air temperature. Vegetation index was derived from 3 years, LANDSAT TM data in Toyama, Ishikawa, Fukui and Nagano prefectures at heading. The meteorological data was used from AMeDAS data. The model was described as follows: Y = 0.728 SR·NDVI−2.04(T−21.3) 2 + 282 (r 2 = 0.65, n = 43) where Y is rice yield (kg 10a -1 ), SR is solar radiation (MJ m -2 ) during the ripening period (from 10 days before heading to 30 days after heading), T is mean air temperature (°C) during the ripening period. RMSE was 33.7kg 10a -1 . The model revealed good precision. (author)

  7. Beryllium-7 deposition to terrestrial vegetation in Tennessee

    International Nuclear Information System (INIS)

    Mahoney, L.A.

    1984-04-01

    Measurements of natural beryllium-7 ( 7 Be) were made in field vegetation and rainwater at the Department of Energy's Oak Ridge Reservation throughout the months of July 1982 to June 1983. Laboratory experiments were also conducted on the adsorption and desorption of 7 Be, cesium-137 ( 137 Cs), lead-210 ( 210 Pb), and iodine-131 ( 131 I) to the foliage of fescue, 3 varieties of beans, and loblolly pine. The field loss of artificially applied 7 Be to field fescue was also measured. The weathering half-life (T/sub W/) was found to be 36.5 days during November-January 1982-1983; no difference was found in the loss of 7 Be during the months March-May 1983, T/sub W/ = 38.5 days. The loss of sulfur-35 ( 35 S) was studied concurrently with the spring loss of 7 Be; the T/sub W/ for 35 S was much smaller, equal to 18.4 days. The interception fraction, r, was determined experimentally in the field using the flux of 7 Be in rainwater incident upon clover; the mean value was 0.172. Total deposition velocities were estimated using monthly 7 Be rainwater concentrations and quarterly air concentrations; the yearly average was 1.66 cm/sec. An equation for predicting vegetation concentrations was derived for 7 Be from the US Nuclear Regulatory Commission's Guide 1.109. Generic and site-specific values for deposition rate, interception fraction, effective half-life, exposure time, and biomass density were summarized separately and the derived equation was employed to make predictions of monthly 7 Be vegetation concentrations. These predictions were compared to actual field observations. With the exception of the month of May, both generic and site-specific predictions were found to underestimate the actual 7 Be vegetation concentrations. 44 refs., 9 figs., 15 tabs

  8. Unique Microbial Diversity and Metabolic Pathway Features of Fermented Vegetables From Hainan, China

    OpenAIRE

    Qiannan Peng; Shuaiming Jiang; Jieling Chen; Chenchen Ma; Dongxue Huo; Yuyu Shao; Jiachao Zhang; Jiachao Zhang

    2018-01-01

    Fermented vegetables are typically traditional foods made of fresh vegetables and their juices, which are fermented by beneficial microorganisms. Herein, we applied high-throughput sequencing and culture-dependent technology to describe the diversities of microbiota and identify core microbiota in fermented vegetables from different areas of Hainan Province, and abundant metabolic pathways in the fermented vegetables were simultaneously predicted. At the genus level, Lactobacillus bacteria we...

  9. Evaluation of airborne lidar data to predict vegetation Presence/Absence

    Science.gov (United States)

    Palaseanu-Lovejoy, M.; Nayegandhi, A.; Brock, J.; Woodman, R.; Wright, C.W.

    2009-01-01

    This study evaluates the capabilities of the Experimental Advanced Airborne Research Lidar (EAARL) in delineating vegetation assemblages in Jean Lafitte National Park, Louisiana. Five-meter-resolution grids of bare earth, canopy height, canopy-reflection ratio, and height of median energy were derived from EAARL data acquired in September 2006. Ground-truth data were collected along transects to assess species composition, canopy cover, and ground cover. To decide which model is more accurate, comparisons of general linear models and generalized additive models were conducted using conventional evaluation methods (i.e., sensitivity, specificity, Kappa statistics, and area under the curve) and two new indexes, net reclassification improvement and integrated discrimination improvement. Generalized additive models were superior to general linear models in modeling presence/absence in training vegetation categories, but no statistically significant differences between the two models were achieved in determining the classification accuracy at validation locations using conventional evaluation methods, although statistically significant improvements in net reclassifications were observed. ?? 2009 Coastal Education and Research Foundation.

  10. Interception and retention of technetium by vegetation and soil

    International Nuclear Information System (INIS)

    Hoffman, F.O.; Garten, C.T. Jr.; Huckabee, J.W.; Lucas, D.M.

    1982-01-01

    Field experiments were performed to quantify the initial interception and retention of technetium (Tc) by herbaceous vegetation as a consequence of direct deposition and uptake from soil. A simulated rain containing a solution of 95 /sup m/TcO 4 - was applied to plots of bare soil and plots with standing vegetation. Vegetation emerging in the baresoil plots obtained Tc predominantly from root uptake. Vegetation standing during the initial application obtained Tc from both direct foliar interception and root uptake. For the plots with standing vegetation, the estimated initial interception fraction (r) ranged from 0.079 to 0.17. The mass interception factor (r/Y/sub v/) ranged from 0.65 to 1.1 m 2 /kg. The retention of Tc by vegetation receiving direct foliar contamination varied with environmental half-times (T/sub w/) ranging from 15.9 to 18.7 days. Adjusting for the effects of growth dilution increased the values of T/sub w/ (range 21.6-28.7 days). For vegetation emerging from the plots of initial bare soil, retention was equivalent to a T/sub w/ of 43 days. These data indicated that uptake of Tc from soil diminished with time and that Tc was removed from plant tissue. In soil, a downward movement was evident, because Tc in the top 2 cm decreased with time and concentrations at lower soil depths (6-8 and 14-15 cm) and increased with time. The application of these data to predict steady-state concentrations of Tc in vegetation resulting from continuous deposition does not differ substantially from predictions based on the use of generic-default parameter values recommend in Regulatory Guide 1.109 of the U. S. Nuclear Regulatory Commission

  11. Statistical Models for Inferring Vegetation Composition from Fossil Pollen

    Science.gov (United States)

    Paciorek, C.; McLachlan, J. S.; Shang, Z.

    2011-12-01

    Fossil pollen provide information about vegetation composition that can be used to help understand how vegetation has changed over the past. However, these data have not traditionally been analyzed in a way that allows for statistical inference about spatio-temporal patterns and trends. We build a Bayesian hierarchical model called STEPPS (Spatio-Temporal Empirical Prediction from Pollen in Sediments) that predicts forest composition in southern New England, USA, over the last two millenia based on fossil pollen. The critical relationships between abundances of tree taxa in the pollen record and abundances in actual vegetation are estimated using modern (Forest Inventory Analysis) data and (witness tree) data from colonial records. This gives us two time points at which both pollen and direct vegetation data are available. Based on these relationships, and incorporating our uncertainty about them, we predict forest composition using fossil pollen. We estimate the spatial distribution and relative abundances of tree species and draw inference about how these patterns have changed over time. Finally, we describe ongoing work to extend the modeling to the upper Midwest of the U.S., including an approach to infer tree density and thereby estimate the prairie-forest boundary in Minnesota and Wisconsin. This work is part of the PalEON project, which brings together a team of ecosystem modelers, paleoecologists, and statisticians with the goal of reconstructing vegetation responses to climate during the last two millenia in the northeastern and midwestern United States. The estimates from the statistical modeling will be used to assess and calibrate ecosystem models that are used to project ecological changes in response to global change.

  12. Vegetation anomalies caused by antecedent precipitation in most of the world

    Science.gov (United States)

    Papagiannopoulou, C.; Miralles, D. G.; Dorigo, W. A.; Verhoest, N. E. C.; Depoorter, M.; Waegeman, W.

    2017-07-01

    Quantifying environmental controls on vegetation is critical to predict the net effect of climate change on global ecosystems and the subsequent feedback on climate. Following a non-linear Granger causality framework based on a random forest predictive model, we exploit the current wealth of multi-decadal satellite data records to uncover the main drivers of monthly vegetation variability at the global scale. Results indicate that water availability is the most dominant factor driving vegetation globally: about 61% of the vegetated surface was primarily water-limited during 1981-2010. This included semiarid climates but also transitional ecoregions. Intra-annually, temperature controls Northern Hemisphere deciduous forests during the growing season, while antecedent precipitation largely dominates vegetation dynamics during the senescence period. The uncovered dependency of global vegetation on water availability is substantially larger than previously reported. This is owed to the ability of the framework to (1) disentangle the co-linearities between radiation/temperature and precipitation, and (2) quantify non-linear impacts of climate on vegetation. Our results reveal a prolonged effect of precipitation anomalies in dry regions: due to the long memory of soil moisture and the cumulative, non-linear, response of vegetation, water-limited regions show sensitivity to the values of precipitation occurring three months earlier. Meanwhile, the impacts of temperature and radiation anomalies are more immediate and dissipate shortly, pointing to a higher resilience of vegetation to these anomalies. Despite being infrequent by definition, hydro-climatic extremes are responsible for up to 10% of the vegetation variability during the 1981-2010 period in certain areas, particularly in water-limited ecosystems. Our approach is a first step towards a quantitative comparison of the resistance and resilience signature of different ecosystems, and can be used to benchmark Earth

  13. NDVI-Based analysis on the influence of human activities on vegetation variation on Hainan Island

    Science.gov (United States)

    Luo, Hongxia; Dai, Shengpei; Xie, Zhenghui; Fang, Jihua

    2018-02-01

    Using the Moderate Resolution Imaging Spectroradiometer-normalized difference vegetation index (NDVI) dataset, we analyzed the predicted NDVI values variation and the influence of human activities on vegetation on Hainan Island during 2001-2015. We investigated the roles of human activities in vegetation variation, particularly from 2002 when implemented the Grain-for-Greenprogram on Hainan Island. The trend analysis, linear regression model and residual analysis were used to analyze the data. The results of the study showed that (1) The predicted vegetation on Hainan Island showed an general upward trend with a linear growth rate of 0.0025/10y (phuman activities. (3) In general, human activities had played a positive role in the vegetation increase on Hainan Island, and the residual NDVI trend of this region showed positive outcomes for vegetation variation after implementing ecological engineering projects. However, it indicated a growing risk of vegetation degradation in the coastal region of Hainan Island as a result of rapid urbanization, land reclamation.

  14. Relationships between vegetation and climate change in Transbaikalia, Siberia

    Energy Technology Data Exchange (ETDEWEB)

    Tchebakova, N.M.; Parfenova, E.I. [V.N. Sukachev Inst. of Forest, Russian Academy of Sciences, Siberian Branch, Akademgorodok, Krasnoyarsk (Russian Federation)

    2002-10-01

    This paper demonstrated how vegetation of the Lake Baikal basin may respond to climate change at a mountain biome (an orobiome over the entire basin) and a stand in a locality. An orobiome vegetation model was developed along with a higher resolution stand model based on climatic parameters. Regional climates were modeled based on physiology and site climates based on topography. Bioclimatic multiple regression models were then developed to predict regional vegetation and forest stand characteristics distribution over a mountain range in Central Transbaikalia under current and future climate scenarios. Bioclimatic models were combined with climatic layers of different resolutions. Tree species composition and wood volume was predicted based on 2 climate indices - temperature sums (base 5 degrees C) and the dryness index. Results indicate that lowland vegetation will shift 250 m upslope and highland vegetation will shift 450 m upslope. This will significantly reduce the tundra and light-needled taiga, and will expand the forest-steppe. Results also indicate that the total phytomass within the entire basin will not change much. Stand phytomass across the basin will, however, increase. The model used in this study does not include climate-forcing factors such as wind, snow and permafrost. The model is open to new development to include a dynamic components that would inject vitality into the model. 13 refs., 2 tabs., 3 figs.

  15. Map of mixed prairie grassland vegetation, Rocky Flats, Colorado

    Energy Technology Data Exchange (ETDEWEB)

    Clark, S J.V.; Webber, P J; Komarkova, V; Weber, W A

    1980-01-01

    A color vegetation map at the scale of 1:12,000 of the area surrounding the Rocky Flats, Rockwell International Plant near Boulder, Colorado, provides a permanent record of baseline data which can be used to monitor changes in both vegetation and environment and thus to contribute to future land management and land-use policies. Sixteen mapping units based on species composition were identified, and characterized by two 10-m/sup 2/ vegetation stands each. These were grouped into prairie, pasture, and valley side on the basis of their species composition. Both the mapping units and these major groups were later confirmed by agglomerative clustering analysis of the 32 vegetation stands on the basis of species composition. A modified Bray and Curtis ordination was used to determine the environmental factor complexes controlling the distribution of vegetation at Rocky flats. Recommendations are made for future policies of environmental management and predictions of the response to environmental change of the present vegetation at the Rocky Flats site.

  16. Large-Scale Mapping and Predictive Modeling of Submerged Aquatic Vegetation in a Shallow Eutrophic Lake

    Directory of Open Access Journals (Sweden)

    Karl E. Havens

    2002-01-01

    Full Text Available A spatially intensive sampling program was developed for mapping the submerged aquatic vegetation (SAV over an area of approximately 20,000 ha in a large, shallow lake in Florida, U.S. The sampling program integrates Geographic Information System (GIS technology with traditional field sampling of SAV and has the capability of producing robust vegetation maps under a wide range of conditions, including high turbidity, variable depth (0 to 2 m, and variable sediment types. Based on sampling carried out in AugustœSeptember 2000, we measured 1,050 to 4,300 ha of vascular SAV species and approximately 14,000 ha of the macroalga Chara spp. The results were similar to those reported in the early 1990s, when the last large-scale SAV sampling occurred. Occurrence of Chara was strongly associated with peat sediments, and maximal depths of occurrence varied between sediment types (mud, sand, rock, and peat. A simple model of Chara occurrence, based only on water depth, had an accuracy of 55%. It predicted occurrence of Chara over large areas where the plant actually was not found. A model based on sediment type and depth had an accuracy of 75% and produced a spatial map very similar to that based on observations. While this approach needs to be validated with independent data in order to test its general utility, we believe it may have application elsewhere. The simple modeling approach could serve as a coarse-scale tool for evaluating effects of water level management on Chara populations.

  17. Large-scale mapping and predictive modeling of submerged aquatic vegetation in a shallow eutrophic lake.

    Science.gov (United States)

    Havens, Karl E; Harwell, Matthew C; Brady, Mark A; Sharfstein, Bruce; East, Therese L; Rodusky, Andrew J; Anson, Daniel; Maki, Ryan P

    2002-04-09

    A spatially intensive sampling program was developed for mapping the submerged aquatic vegetation (SAV) over an area of approximately 20,000 ha in a large, shallow lake in Florida, U.S. The sampling program integrates Geographic Information System (GIS) technology with traditional field sampling of SAV and has the capability of producing robust vegetation maps under a wide range of conditions, including high turbidity, variable depth (0 to 2 m), and variable sediment types. Based on sampling carried out in August-September 2000, we measured 1,050 to 4,300 ha of vascular SAV species and approximately 14,000 ha of the macroalga Chara spp. The results were similar to those reported in the early 1990s, when the last large-scale SAV sampling occurred. Occurrence of Chara was strongly associated with peat sediments, and maximal depths of occurrence varied between sediment types (mud, sand, rock, and peat). A simple model of Chara occurrence, based only on water depth, had an accuracy of 55%. It predicted occurrence of Chara over large areas where the plant actually was not found. A model based on sediment type and depth had an accuracy of 75% and produced a spatial map very similar to that based on observations. While this approach needs to be validated with independent data in order to test its general utility, we believe it may have application elsewhere. The simple modeling approach could serve as a coarse-scale tool for evaluating effects of water level management on Chara populations.

  18. Lidar aboveground vegetation biomass estimates in shrublands: Prediction, uncertainties and application to coarser scales

    Science.gov (United States)

    Li, Aihua; Dhakal, Shital; Glenn, Nancy F.; Spaete, Luke P.; Shinneman, Douglas; Pilliod, David S.; Arkle, Robert; McIlroy, Susan

    2017-01-01

    Our study objectives were to model the aboveground biomass in a xeric shrub-steppe landscape with airborne light detection and ranging (Lidar) and explore the uncertainty associated with the models we created. We incorporated vegetation vertical structure information obtained from Lidar with ground-measured biomass data, allowing us to scale shrub biomass from small field sites (1 m subplots and 1 ha plots) to a larger landscape. A series of airborne Lidar-derived vegetation metrics were trained and linked with the field-measured biomass in Random Forests (RF) regression models. A Stepwise Multiple Regression (SMR) model was also explored as a comparison. Our results demonstrated that the important predictors from Lidar-derived metrics had a strong correlation with field-measured biomass in the RF regression models with a pseudo R2 of 0.76 and RMSE of 125 g/m2 for shrub biomass and a pseudo R2 of 0.74 and RMSE of 141 g/m2 for total biomass, and a weak correlation with field-measured herbaceous biomass. The SMR results were similar but slightly better than RF, explaining 77–79% of the variance, with RMSE ranging from 120 to 129 g/m2 for shrub and total biomass, respectively. We further explored the computational efficiency and relative accuracies of using point cloud and raster Lidar metrics at different resolutions (1 m to 1 ha). Metrics derived from the Lidar point cloud processing led to improved biomass estimates at nearly all resolutions in comparison to raster-derived Lidar metrics. Only at 1 m were the results from the point cloud and raster products nearly equivalent. The best Lidar prediction models of biomass at the plot-level (1 ha) were achieved when Lidar metrics were derived from an average of fine resolution (1 m) metrics to minimize boundary effects and to smooth variability. Overall, both RF and SMR methods explained more than 74% of the variance in biomass, with the most important Lidar variables being associated with vegetation structure

  19. Occurrence and source analysis of typical veterinary antibiotics in manure, soil, vegetables and groundwater from organic vegetable bases, northern China

    International Nuclear Information System (INIS)

    Hu Xiangang; Zhou Qixing; Luo Yi

    2010-01-01

    The residue of antibiotics is becoming an intractable environmental problem in many organic vegetable bases. However, their residual levels and distribution are still obscure. This work systematically analyzed the occurrence and migration of typical veterinary antibiotics in organic vegetable bases, northern China. The results showed that there was no obvious geographical difference in antibiotic distribution between soil and manure. A simple migration model can be easy and quick to predict the accumulation of antibiotics in soil. Antibiotics were mainly taken up through water transport and passive absorption in vegetables. The distribution of antibiotics in a plant was in the sequence leaf > stem > root, and performed biological accumulation. The residues of antibiotics in all samples in winter were significantly higher than those in summer. Overall, this work can lay the foundation for understanding ecological risk of antibiotics and their potential adverse effects on human health by food chain. - The residues of typical veterinary antibiotics from manure were detected and migrated in soil, vegetables and groundwater of organic vegetable bases.

  20. Drought impact on vegetation growth and mortality

    Science.gov (United States)

    Xu, C.; Wang, M.; Allen, C. D.; McDowell, N. G.; Middleton, R. S.

    2017-12-01

    Vegetation is a key regulator of the global carbon cycle via CO2 absorption through photosynthesis and subsequent growth; however, low water availability, heat stress, and disturbances associated with droughts could substantially reduce vegetation growth and increase vegetation mortality. As far as we know, there are few studies have assessed the drought impact on vegetation growth and mortality at regional and global scales. In this study, we analyzed 13 Earth System models (ESMs) to quantify the impact of drought on GPP and linked the remote-sensing based tree mortality to observed drought indices to assess the drought impact on tree mortality in continental US (CONUS). Our analysis of 13 Earth System models (ESMs) shows that the average global gross primary production (GPP) reduction per year associated with extreme droughts over years 2075-2099 is predicted to be 3-5 times larger than that over years 1850-1999. The annual drought-associated reduction in GPP over years 2075-2099 could be 52 and 74 % of annual fossil fuel carbon emission during years 2000-2007. Increasing drought impacts on GPP are driven primarily by the increasing drought frequency. The risks of drought-associated GPP reduction are particularly high for temperate and tropical regions. The consistent prediction of higher drought-associated reduction in NPP across 13 ESMs suggests increasing impacts of drought on the global carbon cycle with atmospheric warming. Our analysis of drought impact on tree mortality showed that drought-associated carbon loss accounts for 12% of forest carbon loss in CONUS for 2000-2014, which is about one-fifth of that resulting from timber harvesting and 1.35 % of average annual fossil fuel emissions in the U.S. for the same period. The carbon stock loss from natural disturbances for 2000-2014 is approximately 75% of the total carbon loss from anthropogenic disturbance (timber harvesting), suggesting that natural disturbances play a very important role on forest

  1. Beryllium-7 deposition to terrestrial vegetation in Tennessee

    Energy Technology Data Exchange (ETDEWEB)

    Mahoney, L.A.

    1984-04-01

    Measurements of natural beryllium-7 (/sup 7/Be) were made in field vegetation and rainwater at the Department of Energy's Oak Ridge Reservation throughout the months of July 1982 to June 1983. Laboratory experiments were also conducted on the adsorption and desorption of /sup 7/Be, cesium-137 (/sup 137/Cs), lead-210 (/sup 210/Pb), and iodine-131 (/sup 131/I) to the foliage of fescue, 3 varieties of beans, and loblolly pine. The field loss of artificially applied /sup 7/Be to field fescue was also measured. The weathering half-life (T/sub W/) was found to be 36.5 days during November-January 1982-1983; no difference was found in the loss of /sup 7/Be during the months March-May 1983, T/sub W/ = 38.5 days. The loss of sulfur-35 (/sup 35/S) was studied concurrently with the spring loss of /sup 7/Be; the T/sub W/ for /sup 35/S was much smaller, equal to 18.4 days. The interception fraction, r, was determined experimentally in the field using the flux of /sup 7/Be in rainwater incident upon clover; the mean value was 0.172. Total deposition velocities were estimated using monthly /sup 7/Be rainwater concentrations and quarterly air concentrations; the yearly average was 1.66 cm/sec. An equation for predicting vegetation concentrations was derived for /sup 7/Be from the US Nuclear Regulatory Commission's Guide 1.109. Generic and site-specific values for deposition rate, interception fraction, effective half-life, exposure time, and biomass density were summarized separately and the derived equation was employed to make predictions of monthly /sup 7/Be vegetation concentrations. These predictions were compared to actual field observations. With the exception of the month of May, both generic and site-specific predictions were found to underestimate the actual /sup 7/Be vegetation concentrations. 44 refs., 9 figs., 15 tabs.

  2. Exploiting differential vegetation phenology for satellite-based mapping of semiarid grass vegetation in the southwestern United States and northern Mexico

    Science.gov (United States)

    Dye, Dennis G.; Middleton, Barry R.; Vogel, John M.; Wu, Zhuoting; Velasco, Miguel G.

    2016-01-01

    We developed and evaluated a methodology for subpixel discrimination and large-area mapping of the perennial warm-season (C4) grass component of vegetation cover in mixed-composition landscapes of the southwestern United States and northern Mexico. We describe the methodology within a general, conceptual framework that we identify as the differential vegetation phenology (DVP) paradigm. We introduce a DVP index, the Normalized Difference Phenometric Index (NDPI) that provides vegetation type-specific information at the subpixel scale by exploiting differential patterns of vegetation phenology detectable in time-series spectral vegetation index (VI) data from multispectral land imagers. We used modified soil-adjusted vegetation index (MSAVI2) data from Landsat to develop the NDPI, and MSAVI2 data from MODIS to compare its performance relative to one alternate DVP metric (difference of spring average MSAVI2 and summer maximum MSAVI2), and two simple, conventional VI metrics (summer average MSAVI2, summer maximum MSAVI2). The NDPI in a scaled form (NDPIs) performed best in predicting variation in perennial C4 grass cover as estimated from landscape photographs at 92 sites (R2 = 0.76, p landscapes of the Southwest, and potentially for monitoring of its response to drought, climate change, grazing and other factors, including land management. With appropriate adjustments, the method could potentially be used for subpixel discrimination and mapping of grass or other vegetation types in other regions where the vegetation components of the landscape exhibit contrasting seasonal patterns of phenology.

  3. Tundra vegetation effects on pan-Arctic albedo

    International Nuclear Information System (INIS)

    Loranty, Michael M; Goetz, Scott J; Beck, Pieter S A

    2011-01-01

    Recent field experiments in tundra ecosystems describe how increased shrub cover reduces winter albedo, and how subsequent changes in surface net radiation lead to altered rates of snowmelt. These findings imply that tundra vegetation change will alter regional energy budgets, but to date the effects have not been documented at regional or greater scales. Using satellite observations and a pan-Arctic vegetation map, we examined the effects of shrub vegetation on albedo across the terrestrial Arctic. We included vegetation classes dominated by low shrubs, dwarf shrubs, tussock-dominated graminoid tundra, and non-tussock graminoid tundra. Each class was further stratified by bioclimate subzones. Low-shrub tundra had higher normalized difference vegetation index values and earlier albedo decline in spring than dwarf-shrub tundra, but for tussock tundra, spring albedo declined earlier than for low-shrub tundra. Our results illustrate how relatively small changes in vegetation properties result in differences in albedo dynamics, regardless of shrub growth, that may lead to differences in net radiation upwards of 50 W m -2 at weekly time scales. Further, our findings imply that changes to the terrestrial Arctic energy budget during this important seasonal transition are under way regardless of whether recent satellite observed productivity trends are the result of shrub expansion. We conclude that a better understanding of changes in vegetation productivity and distribution in Arctic tundra is essential for accurately quantifying and predicting carbon and energy fluxes and associated climate feedbacks.

  4. Climate change and spatial distribution of vegetation in Colombia

    Directory of Open Access Journals (Sweden)

    Juan Carlos Alarcon Hincapie

    2013-12-01

    Full Text Available Vegetation change under two climate change scenarios in different periods of the 21st Century are modeled for Colombia. Vegetation for the years 1970 to 2000 was reproduced using the Holdridge model with climate data with a spatial resolution of 900 meters. The vegetation types that occupied the most territory were sub-humid tropical forest, tropical dry forest and Andean wet forest. These results were validated by comparing with the Colombian ecosystem map (SINA, 2007, which confirmed a high degree of similarity between the modeled spatial vegetation patterns and modern ecosystem distributions. Future vegetation maps were simulated using data generated by a regional climate model under two scenarios (A2 and B2; IPCC, 2007 for the periods 2011-2040 and 2070-2100. Based on our predictions high altitude vegetation will convert to that of lower altitudes and drier provinces with the most dramatic change occurring in the A2 scenario from 2070-2100. The most affected areas are the páramo and other high Andean vegetation types, which in the timeframe of the explored scenarios will disappear by the middle of the 21st Century.

  5. Development of atmosphere-soil-vegetation model for investigation of radioactive materials transport in terrestrial biosphere

    International Nuclear Information System (INIS)

    Katata, Genki; Nagai, Haruyasu; Zhang, Leiming; Held, Andreas; Serca, Dominique; Klemm, Otto

    2010-01-01

    In order to investigate the transport of radionuclides in the terrestrial biosphere we have developed a one-dimensional numerical model named SOLVEG that predicts the transfer of water, heat, and gaseous and particulate matters in atmosphere-soil-vegetation system. The SOLVEG represents atmosphere, soil, and vegetation as an aggregation of several layers. Basic equations used in the model are solved using the finite difference method. Most of predicted variables are interrelated with the source/sink terms of momentum, water, heat, gases, and particles based on mathematically described biophysical processes in atmosphere, soil and vegetation. The SOLVEG can estimate dry, wet and fog deposition of gaseous and particulate matters at each canopy layer. Performance tests of the SOLVEG with several observational sites were carried out. The SOLVEG predicted the observed temporal changes in water vapor, CO 2 , and ozone fluxes over vegetated surfaces. The SOLVEG also reproduced measured fluxes of fog droplets and of fine aerosols over the forest. (author)

  6. Parental food involvement predicts parent and child intakes of fruits and vegetables.

    Science.gov (United States)

    Ohly, Heather; Pealing, Juliet; Hayter, Arabella K M; Pettinger, Clare; Pikhart, Hynek; Watt, Richard G; Rees, Gail

    2013-10-01

    In order to develop successful interventions to improve children's diets, the factors influencing food choice need to be understood. Parental food involvement - the level of importance of food in a person's life - may be one of many important factors. The aim of this study was to determine whether parental food involvement is associated with parents' and children's diet quality. As part of an intervention study, 394 parents with children aged between 18 months and 5 years were recruited from children's centres in Cornwall and Islington, UK. Questionnaires were used to collect data on socio-demographic characteristics, parents' diets, and attitudes towards food including food involvement. Children's diets were assessed using the multiple pass 24 h recall method. Parents reported low intakes of fruits and vegetables and high intakes of sugary items for themselves and their young children. Parental food involvement was strongly correlated with consumption of fruits and vegetables (amount and diversity) for both parents and children. Correlations with consumption of sugary drinks and snacks/foods were not significant. These findings indicate that parental food involvement may influence consumption of fruits and vegetables, more so than sugary items. Further research is needed to investigate how parental food involvement could mediate dietary changes. Copyright © 2013 Elsevier Ltd. All rights reserved.

  7. Predictive Mapping of Dwarf Shrub Vegetation in an Arid High Mountain Ecosystem Using Remote Sensing and Random Forests

    Directory of Open Access Journals (Sweden)

    Kim André Vanselow

    2014-07-01

    Full Text Available In many arid mountains, dwarf shrubs represent the most important fodder and firewood resources; therefore, they are intensely used. For the Eastern Pamirs (Tajikistan, they are assumed to be overused. However, empirical evidence on this issue is lacking. We aim to provide a method capable of mapping vegetation in this mountain desert. We used random forest models based on remote sensing data (RapidEye, ASTER GDEM and 359 plots to predictively map total vegetative cover and the distribution of the most important firewood plants, K. ceratoides and A. leucotricha. These species were mapped as present in 33.8% of the study area (accuracy 90.6%. The total cover of the dwarf shrub communities ranged from 0.5% to 51% (per pixel. Areas with very low cover were limited to the vicinity of roads and settlements. The model could explain 80.2% of the total variance. The most important predictor across the models was MSAVI2 (a spectral vegetation index particularly invented for low-cover areas. We conclude that the combination of statistical models and remote sensing data worked well to map vegetation in an arid mountainous environment. With this approach, we were able to provide tangible data on dwarf shrub resources in the Eastern Pamirs and to relativize previous reports about their extensive depletion.

  8. Assessing food allergy risks from residual peanut protein in highly refined vegetable oil

    NARCIS (Netherlands)

    Blom, W.M.; Kruizinga, A.G.; Rubingh, C.M.; Remington, B.C.; Crevel, R.W.R.; Houben, G.F.

    2017-01-01

    Refined vegetable oils including refined peanut oil are widely used in foods. Due to shared production processes, refined non-peanut vegetable oils can contain residual peanut proteins. We estimated the predicted number of allergic reactions to residual peanut proteins using probabilistic risk

  9. Mapping swamp timothy (Cripsis schenoides) seed productivity using spectral values and vegetation indices in managed wetlands

    Energy Technology Data Exchange (ETDEWEB)

    Rahilly, P.J.A.; Li, D.; Guo, Q.; Zhu, J.; Ortega, R.; Quinn, N.W.T.; Harmon, T.C.

    2010-01-15

    This work examines the potential to predict the seed productivity of a key wetland plant species using spectral reflectance values and spectral vegetation indices. Specifically, the seed productivity of swamp timothy (Cripsis schenoides) was investigated in two wetland ponds, managed for waterfowl habitat, in California's San Joaquin Valley. Spectral reflectance values were obtained and associated spectral vegetation indices (SVI) calculated from two sets of high resolution aerial images (May 11, 2006 and June 9, 2006) and were compared to the collected vegetation data. Vegetation data were collected and analyzed from 156 plots for total aboveground biomass, total aboveground swamp timothy biomass, and total swamp timothy seed biomass. The SVI investigated included the Simple Ratio (SR), Normalized Difference Vegetation Index (NDVI), Soil Adjusted Vegetation Index (SAVI), Transformed Soil Adjusted Vegetation Index (TSAVI), Modified Soil Adjusted Vegetation Index (MSAVI), and Global Environment Monitoring Index (GEMI). We evaluated the correlation of the various SVI with in situ vegetation measurements for linear, quadratic, exponential and power functions. In all cases, the June image provided better predictive capacity relative to May, a result that underscores the importance of timing imagery to coincide with more favorable vegetation maturity. The north pond with the June image using SR and the exponential function (R{sup 2}=0.603) proved to be the best predictor of swamp timothy seed productivity. The June image for the south pond was less predictive, with TSAVI and the exponential function providing the best correlation (R{sup 2}=0.448). This result was attributed to insufficient vegetal cover in the south pond (or a higher percentage of bare soil) due to poor drainage conditions which resulted in a delay in swamp timothy germination. The results of this work suggest that spectral reflectance can be used to estimate seed productivity in managed seasonal

  10. Rendering Future Vegetation Change across Large Regions of the US

    Science.gov (United States)

    Sant'Anna Dias, Felipe; Gu, Yuting; Agarwalla, Yashika; Cheng, Yiwei; Patil, Sopan; Stieglitz, Marc; Turk, Greg

    2015-04-01

    We use two Machine Learning techniques, Decision Trees (DT) and Neural Networks (NN), to provide classified images and photorealistic renderings of future vegetation cover at three large regions in the US. The training data used to generate current vegetation cover include Landsat surface reflectance images, USGS Land Cover maps, 50 years of mean annual temperature and precipitation for the period 1950 - 2000, elevation, aspect and slope data. Present vegetation cover was generated on a 100m grid. Future vegetation cover for the period 2061- 2080 was predicted using the 1 km resolution bias corrected data from the NASA Goddard Institute for Space Studies Global Climate Model E simulation. The three test regions encompass a wide range of climatic gradients, topographic variation, and vegetation cover. The central Oregon site covers 19,182 square km and includes the Ochoco and Malheur National Forest. Vegetation cover is 50% evergreen forest and 50% shrubs and scrubland. The northwest Washington site covers 14,182 square km. Vegetation cover is 60% evergreen forest, 14% scrubs, 7% grassland, and 7% barren land. The remainder of the area includes deciduous forest, perennial snow cover, and wetlands. The third site, the Jemez mountain region of north central New Mexico, covers 5,500 square km. Vegetation cover is 47% evergreen forest, 31% shrubs, 13% grasses, and 3% deciduous forest. The remainder of the area includes developed and cultivated areas and wetlands. Using the above mentioned data sets we first trained our DT and NN models to reproduce current vegetation. The land cover classified images were compared directly to the USGS land cover data. The photorealistic generated vegetation images were compared directly to the remotely sensed surface reflectance maps. For all three sites, similarity between generated and observed vegetation cover was quite remarkable. The three trained models were then used to explore what the equilibrium vegetation would look like for

  11. Predicting Climate Change Impacts to the Canadian Boreal Forest

    Directory of Open Access Journals (Sweden)

    Trisalyn A. Nelson

    2014-03-01

    Full Text Available Climate change is expected to alter temperature, precipitation, and seasonality with potentially acute impacts on Canada’s boreal. In this research we predicted future spatial distributions of biodiversity in Canada’s boreal for 2020, 2050, and 2080 using indirect indicators derived from remote sensing and based on vegetation productivity. Vegetation productivity indices, representing annual amounts and variability of greenness, have been shown to relate to tree and wildlife richness in Canada’s boreal. Relationships between historical satellite-derived productivity and climate data were applied to modelled scenarios of future climate to predict and map potential future vegetation productivity for 592 regions across Canada. Results indicated that the pattern of vegetation productivity will become more homogenous, particularly west of Hudson Bay. We expect climate change to impact biodiversity along north/south gradients and by 2080 vegetation distributions will be dominated by processes of seasonality in the north and a combination of cumulative greenness and minimum cover in the south. The Hudson Plains, which host the world’s largest and most contiguous wetland, are predicted to experience less seasonality and more greenness. The spatial distribution of predicted trends in vegetation productivity was emphasized over absolute values, in order to support regional biodiversity assessments and conservation planning.

  12. Simulated Vegetation Response to Climate Change in California: The Importance of Seasonal Production Patterns

    Science.gov (United States)

    Kim, J. B.; Pitts, B.

    2013-12-01

    MC1 dynamic global vegetation model simulates vegetation response to climate change by simulating vegetation production, soil biogeochemistry, plant biogeography and fire. It has been applied at a wide range of spatial scales, yet the spatio-temporal patterns of simulated vegetation production, which drives the model's response to climate change, has not been examined in detail. We ran MC1 for California at a relatively fine scale, 30 arc-seconds, for the historical period (1895-2006) and for the future (2007-2100), using downscaled data from four CMIP3-based climate projections: A2 and B1 GHG emissions scenarios simulated by PCM and GFDL GCMs. The use of these four climate projections aligns our work with a body of climate change research work commissioned by the California Public Interest Energy Research (PIER) Program. The four climate projections vary not only in terms of changes in their annual means, but in the seasonality of projected climate change. We calibrated MC1 using MODIS NPP data for 2000-2011 as a guide, and adapting a published technique for adjusting simulated vegetation production by increasing the simulated plant rooting depths. We evaluated the simulation results by comparing the model output for the historical period with several benchmark datasets, summarizing by EPA Level 3 Ecoregions. Multi-year summary statistics of model predictions compare moderately well with Kuchler's potential natural vegetation map, National Biomass and Carbon Dataset, Leenhouts' compilation of fire return intervals, and, of course, the MODIS NPP data for 2000-2011. When we compared MC1's monthly NPP values with MODIS monthly GPP data (2000-2011), however, the seasonal patterns compared very poorly, with NPP/GPP ratio for spring (Mar-Apr-May) often exceeding 1, and the NPP/GPP ratio for summer (Jun-Jul-Aug) often flattening to zero. This suggests MC1's vegetation production algorithms are overly biased for spring production at the cost of summer production. We

  13. Application of a plane-stratified emission model to predict the effects of vegetation in passive microwave radiometry

    Directory of Open Access Journals (Sweden)

    K. Lee

    2002-01-01

    Full Text Available This paper reports the application to vegetation canopies of a coherent model for the propagation of electromagnetic radiation through a stratified medium. The resulting multi-layer vegetation model is plausibly realistic in that it recognises the dielectric permittivity of the vegetation matter, the mixing of the dielectric permittivities for vegetation and air within the canopy and, in simplified terms, the overall vertical distribution of dielectric permittivity and temperature through the canopy. Any sharp changes in the dielectric profile of the canopy resulted in interference effects manifested as oscillations in the microwave brightness temperature as a function of canopy height or look angle. However, when Gaussian broadening of the top and bottom of the canopy (reflecting the natural variability between plants was included within the model, these oscillations were eliminated. The model parameters required to specify the dielectric profile within the canopy, particularly the parameters that quantify the dielectric mixing between vegetation and air in the canopy, are not usually available in typical field experiments. Thus, the feasibility of specifying these parameters using an advanced single-criterion, multiple-parameter optimisation technique was investigated by automatically minimizing the difference between the modelled and measured brightness temperatures. The results imply that the mixing parameters can be so determined but only if other parameters that specify vegetation dry matter and water content are measured independently. The new model was then applied to investigate the sensitivity of microwave emission to specific vegetation parameters. Keywords: passive microwave, soil moisture, vegetation, SMOS, retrieval

  14. A method for climate and vegetation reconstruction through the inversion of a dynamic vegetation model

    Energy Technology Data Exchange (ETDEWEB)

    Garreta, Vincent; Guiot, Joel; Hely, Christelle [CEREGE, UMR 6635, CNRS, Universite Aix-Marseille, Europole de l' Arbois, Aix-en-Provence (France); Miller, Paul A.; Sykes, Martin T. [Lund University, Department of Physical Geography and Ecosystems Analysis, Geobiosphere Science Centre, Lund (Sweden); Brewer, Simon [Universite de Liege, Institut d' Astrophysique et de Geophysique, Liege (Belgium); Litt, Thomas [University of Bonn, Paleontological Institute, Bonn (Germany)

    2010-08-15

    Climate reconstructions from data sensitive to past climates provide estimates of what these climates were like. Comparing these reconstructions with simulations from climate models allows to validate the models used for future climate prediction. It has been shown that for fossil pollen data, gaining estimates by inverting a vegetation model allows inclusion of past changes in carbon dioxide values. As a new generation of dynamic vegetation model is available we have developed an inversion method for one model, LPJ-GUESS. When this novel method is used with high-resolution sediment it allows us to bypass the classic assumptions of (1) climate and pollen independence between samples and (2) equilibrium between the vegetation, represented as pollen, and climate. Our dynamic inversion method is based on a statistical model to describe the links among climate, simulated vegetation and pollen samples. The inversion is realised thanks to a particle filter algorithm. We perform a validation on 30 modern European sites and then apply the method to the sediment core of Meerfelder Maar (Germany), which covers the Holocene at a temporal resolution of approximately one sample per 30 years. We demonstrate that reconstructed temperatures are constrained. The reconstructed precipitation is less well constrained, due to the dimension considered (one precipitation by season), and the low sensitivity of LPJ-GUESS to precipitation changes. (orig.)

  15. Covariance and decoupling of floral and vegetative traits in nine Neotropical plants: a re-evaluation of Berg's correlation-pleiades concept.

    Science.gov (United States)

    Armbruster, W S; Di Stilio, V S; Tuxill, J D; Flores, T C; Velásquez Runk, J L

    1999-01-01

    Nearly forty years ago R. L. Berg proposed that plants with specialized pollination ecology evolve genetic and developmental systems that decouple floral morphology from phenotypic variation in vegetative traits. These species evolve separate floral and vegetative trait clusters, or as she termed them, "correlation pleiades." The predictions of this hypothesis have been generally supported, but only a small sample of temperate-zone herb and grass species has been tested. To further evaluate this hypothesis, especially its applicability to plants of other growth forms, we examined the patterns of phenotypic variation and covariation of floral and vegetative traits in nine species of Neotropical plants. We recognized seven specific predictions of Berg's hypothesis. Our results supported some predictions but not others. Species with specialized pollination systems usually had floral traits decoupled (weak correlation; Canna and Eichornia) or buffered (relationship with shallow proportional slope; Calathea and Canna) from variation in vegetative traits. However, the same trend was also observed in three species with unspecialized pollination systems (Echinodorus, Muntingia, and Wedelia). One species with unspecialized pollination (Croton) and one wind-pollinated species (Cyperus) showed no decoupling or buffering, as predicted. While species with specialized pollination usually showed lower coefficients of variation for floral traits than vegetative traits (as predicted), the same was also true of species with unspecialized or wind pollination (unlike our prediction). Species with specialized pollination showed less variation in floral traits than did species with unspecialized or wind pollination, as predicted. However, the same was true of the corresponding vegetative traits, which was unexpected. Also in contrast to our prediction, plants with specialized pollination systems did not exhibit tighter phenotypic integration of floral characters than did species with

  16. Application of a Coupled Vegetation Competition and Groundwater Simulation Model to Study Effects of Sea Level Rise and Storm Surges on Coastal Vegetation

    Directory of Open Access Journals (Sweden)

    Su Yean Teh

    2015-09-01

    Full Text Available Global climate change poses challenges to areas such as low-lying coastal zones, where sea level rise (SLR and storm-surge overwash events can have long-term effects on vegetation and on soil and groundwater salinities, posing risks of habitat loss critical to native species. An early warning system is urgently needed to predict and prepare for the consequences of these climate-related impacts on both the short-term dynamics of salinity in the soil and groundwater and the long-term effects on vegetation. For this purpose, the U.S. Geological Survey’s spatially explicit model of vegetation community dynamics along coastal salinity gradients (MANHAM is integrated into the USGS groundwater model (SUTRA to create a coupled hydrology–salinity–vegetation model, MANTRA. In MANTRA, the uptake of water by plants is modeled as a fluid mass sink term. Groundwater salinity, water saturation and vegetation biomass determine the water available for plant transpiration. Formulations and assumptions used in the coupled model are presented. MANTRA is calibrated with salinity data and vegetation pattern for a coastal area of Florida Everglades vulnerable to storm surges. A possible regime shift at that site is investigated by simulating the vegetation responses to climate variability and disturbances, including SLR and storm surges based on empirical information.

  17. Impact assessment of rainfall-vegetation on sedimentation and predicting erosion-prone region by GIS and RS

    Directory of Open Access Journals (Sweden)

    Mahboob Alam

    2016-03-01

    Full Text Available Water reservoirs are facing universal sedimentation problems worldwide. Land covers, whether natural or manmade, eventually change, and the vegetation cover and rainfall have a great effect on the sediment load. Traditional techniques for analysing this problem are time-consuming and spatially limited. Remote sensing (RS provides a convenient way to observe land cover changes, and geographic information system (GIS provides tools for geographic analysis. This study demonstrates a GIS-based methodology for calculating the impact of vegetation and rainfall on the sediment load using remotely sensed data. Moderate resolution imaging spectroradiometer data were used to observe temporal changes in the vegetation-cover area of the watershed surface. The total drainage area for the reservoir was calculated from shuttle radar topographic mission data. The annual rainfall amount was used to compute the annual available rainwater for the watershed, and the impact of the annual available rainwater on the vegetation-covered area was determined. In addition, areas that were adding sedimentation to the reservoir were identified. An inverse relationship between the rainfall and vegetation cover was observed, clearly showing the triggering of erosion.

  18. Compositional stability of boreal understorey vegetation after overstorey harvesting across a riparian ecotone

    Science.gov (United States)

    Rebecca L. MacDonald; Han Y.H. Chen; Samuel F. Bartels; Brian J. Palik; Ellie E. Prepas; Frank Gilliam

    2015-01-01

    Questions: Understanding factors that contribute to the stability of an ecosystem following harvesting is central to predicting responses of boreal ecosystems to increasing human disturbances.While the response of understorey vegetation to harvesting is well understood for upland sites, little is known about compositional stability of riparian understorey vegetation....

  19. Vegetation monitoring to detect and predict vegetation change: Connecting historical and future shrub/steppe data in Yellowstone National Park

    Science.gov (United States)

    Geneva Chong; David Barnett; Benjamin Chemel; Roy Renkin; Pamela Sikkink

    2011-01-01

    A 2002 National Research Council (NRC) evaluation of ungulate management practices in Yellowstone specifically concluded that previous (1957 to present) vegetation monitoring efforts were insufficient to determine whether climate or ungulates were more influential on shrub/steppe dynamics on the northern ungulate winter range. The NRC further recommended that the...

  20. Assessing allometric models to predict vegetative growth of mango (Mangifera indica; Anacardiaceae) at the current-year branch scale.

    Science.gov (United States)

    Normand, Frédéric; Lauri, Pierre-Éric

    2012-03-01

    Accurate and reliable predictive models are necessary to estimate nondestructively key variables for plant growth studies such as leaf area and leaf, stem, and total biomass. Predictive models are lacking at the current-year branch scale despite the importance of this scale in plant science. We calibrated allometric models to estimate leaf area and stem and branch (leaves + stem) mass of current-year branches, i.e., branches several months old studied at the end of the vegetative growth season, of four mango cultivars on the basis of their basal cross-sectional area. The effects of year, site, and cultivar were tested. Models were validated with independent data and prediction accuracy was evaluated with the appropriate statistics. Models revealed a positive allometry between dependent and independent variables, whose y-intercept but not the slope, was affected by the cultivar. The effects of year and site were negligible. For each branch characteristic, cultivar-specific models were more accurate than common models built with pooled data from the four cultivars. Prediction quality was satisfactory but with data dispersion around the models, particularly for large values. Leaf area and stem and branch mass of mango current-year branches could be satisfactorily estimated on the basis of branch basal cross-sectional area with cultivar-specific allometric models. The results suggested that, in addition to the heteroscedastic behavior of the variables studied, model accuracy was probably related to the functional plasticity of branches in relation to the light environment and/or to the number of growth units composing the branches.

  1. Elemental assessment of vegetation via portable X-ray fluorescence (PXRF) spectrometry.

    Science.gov (United States)

    McGladdery, Candice; Weindorf, David C; Chakraborty, Somsubhra; Li, Bin; Paulette, Laura; Podar, Dorina; Pearson, Delaina; Kusi, Nana Yaw O; Duda, Bogdan

    2018-03-15

    Elemental concentrations in vegetation are of critical importance, whether establishing plant essential element concentrations (toxicity vs. deficiency) or investigating deleterious elements (e.g., heavy metals) differentially extracted from the soil by plants. Traditionally, elemental analysis of vegetation has been facilitated by acid digestion followed by quantification via inductively coupled plasma (ICP) or atomic absorption (AA) spectroscopy. Previous studies have utilized portable X-ray fluorescence (PXRF) spectroscopy to quantify elements in soils, but few have evaluated the vegetation. In this study, a PXRF spectrometer was employed to scan 228 organic material samples (thatch, deciduous leaves, grasses, tree bark, and herbaceous plants) from smelter-impacted areas of Romania, as well as National Institute of Standards and Technology (NIST) certified reference materials, to demonstrate the application of PXRF for elemental determination in vegetation. Samples were scanned in three conditions: as received from the field (moist), oven dry (70 °C), and dried and powdered to pass a 2 mm sieve. Performance metrics of PXRF models relative to ICP atomic emission spectroscopy were developed to asses optimal scanning conditions. Thatch and bark samples showed the highest mean PXRF and ICP concentrations (e.g., Zn, Pb, Cd, Fe), with the exceptions of K and Cl. Validation statistics indicate that the stable validation predictive capacity of PXRF increased in the following order: oven dry intact coefficient of determination, R 2 val 0.86; residual prediction deviation, RPD 2.72) and Cu (R 2 val 0.77; RPD 2.12), while dried and powdered samples allowed for stable validation prediction of Pb (R 2 val 0.90; RPD 3.29), Fe (R 2 val 0.80; RPD 2.29), Cd (R 2 val 0.75; RPD 2.07) and Cu (R 2 val 0.98; RPD of 8.53). Summarily, PXRF was shown to be a useful approach for quickly assessing the elemental concentration in vegetation. Future PXRF/vegetation research should

  2. INFORMATION-ANALYTICAL SYSTEM OF FORECAST VEGETATION FIRES IN NATURAL CONDITIONS

    Directory of Open Access Journals (Sweden)

    R. M. Kogan

    2015-01-01

    Full Text Available A system for spatial prediction for fire danger as function of weather and pyrological vegetation characteristics was constructed. The method of calculating the time conducted vegetable combustible materials in fire condition of each month of the season was suggested. Calculate the probability of fires and danger periods of plant formations in a monsoon climate. The geographic information system was developed, it was tested in the Middle Amur region in the Russian Far East.

  3. Benchmarking LSM root-zone soil mositure predictions using satellite-based vegetation indices

    Science.gov (United States)

    The application of modern land surface models (LSMs) to agricultural drought monitoring is based on the premise that anomalies in LSM root-zone soil moisture estimates can accurately anticipate the subsequent impact of drought on vegetation productivity and health. In addition, the water and energy ...

  4. Remote sensing estimation of vegetation moisture for the prediction of fire hazard

    NARCIS (Netherlands)

    Maffei, C.; Menenti, M.

    2013-01-01

    Various factors contribute to forest fire hazard, and among them vegetation moisture is the one that dictates susceptibility to fire ignition and propagation. The scientific community has developed a number of spectral indexes based on remote sensing measurements in the optical domain for the

  5. Use of vegetation health data for estimation of aus rice yield in bangladesh.

    Science.gov (United States)

    Rahman, Atiqur; Roytman, Leonid; Krakauer, Nir Y; Nizamuddin, Mohammad; Goldberg, Mitch

    2009-01-01

    Rice is a vital staple crop for Bangladesh and surrounding countries, with interannual variation in yields depending on climatic conditions. We compared Bangladesh yield of aus rice, one of the main varieties grown, from official agricultural statistics with Vegetation Health (VH) Indices [Vegetation Condition Index (VCI), Temperature Condition Index (TCI) and Vegetation Health Index (VHI)] computed from Advanced Very High Resolution Radiometer (AVHRR) data covering a period of 15 years (1991-2005). A strong correlation was found between aus rice yield and VCI and VHI during the critical period of aus rice development that occurs during March-April (weeks 8-13 of the year), several months in advance of the rice harvest. Stepwise principal component regression (PCR) was used to construct a model to predict yield as a function of critical-period VHI. The model reduced the yield prediction error variance by 62% compared with a prediction of average yield for each year. Remote sensing is a valuable tool for estimating rice yields well in advance of harvest and at a low cost.

  6. Use of Vegetation Health Data for Estimation of Aus Rice Yield in Bangladesh

    Directory of Open Access Journals (Sweden)

    Mohammad Nizamuddin

    2009-04-01

    Full Text Available Rice is a vital staple crop for Bangladesh and surrounding countries, with interannual variation in yields depending on climatic conditions. We compared Bangladesh yield of aus rice, one of the main varieties grown, from official agricultural statistics with Vegetation Health (VH Indices [Vegetation Condition Index (VCI, Temperature Condition Index (TCI and Vegetation Health Index (VHI] computed from Advanced Very High Resolution Radiometer (AVHRR data covering a period of 15 years (1991–2005. A strong correlation was found between aus rice yield and VCI and VHI during the critical period of aus rice development that occurs during March-April (weeks 8–13 of the year, several months in advance of the rice harvest. Stepwise principal component regression (PCR was used to construct a model to predict yield as a function of critical-period VHI. The model reduced the yield prediction error variance by 62% compared with a prediction of average yield for each year. Remote sensing is a valuable tool for estimating rice yields well in advance of harvest and at a low cost.

  7. Detecting long-term changes to vegetation in northern Canada using the Landsat satellite image archive

    International Nuclear Information System (INIS)

    Fraser, R H; Olthof, I; Carrière, M; Deschamps, A; Pouliot, D

    2011-01-01

    Analysis of coarse resolution (∼1 km) satellite imagery has provided evidence of vegetation changes in arctic regions since the mid-1980s that may be attributable to climate warming. Here we investigate finer-scale changes to northern vegetation over the same period using stacks of 30 m resolution Landsat TM and ETM + satellite images. Linear trends in the normalized difference vegetation index (NDVI) and tasseled cap indices are derived for four widely spaced national parks in northern Canada. The trends are related to predicted changes in fractional shrub and other vegetation covers using regression tree classifiers trained with plot measurements and high resolution imagery. We find a consistent pattern of greening (6.1–25.5% of areas increasing) and predicted increases in vascular vegetation in all four parks that is associated with positive temperature trends. Coarse resolution (3 km) NDVI trends were not detected in two of the parks that had less intense greening. A range of independent studies and observations corroborate many of the major changes observed.

  8. Social Support Is a Primary Influence on Home Fruit, 100% Juice, and Vegetable Availability

    Science.gov (United States)

    Children tend to eat more fruit and vegetables when more are available in the home. We proposed and tested a model that predicts the availability at home (hereinafter termed "home availability") of fruit, 100% juice, and vegetables, using new measures of frequency of food shopping, purchase, and com...

  9. Terrestrial Water Storage and Vegetation Resilience to Drought

    Science.gov (United States)

    Meyer, V.; Reager, J. T., II; Konings, A. G.

    2017-12-01

    The expected increased occurrences of hydrologic extreme events such as droughts in the coming decades motivates studies to better understand and predict the response of vegetation to such extreme conditions. Previous studies have addressed vegetation resilience to drought, defined as its ability to recover from a perturbation (Hirota et al., 2011; Vicente-Serrano et al., 2012), but appear to only focus on precipitation and a couple of vegetation indices, hence lacking a key element: terrestrial water storage (TWS). In this study, we combine and compare multiple remotely-sensed hydro-ecological datasets providing information on climatic and hydrological conditions (Tropical Rainfall Measuring Mission (TRMM), Gravity Recovery and Climate Experiment (GRACE)) and indices characterizing the state of the vegetation (vegetation water content using Vegetation Optical Depth (VOD) from SMAP (Soil Moisture Active and Passive), Gross Primary Production (GPP) from FluxCom and Specific Fluorescence Intensity (SFI, from GOSat)) to assess the ability of vegetation to face and recover from droughts across the globe. Our results suggest that GRACE hydrological data bridge the knowledge gap between precipitation deficit and vegetation response. All products are aggregated at a 0.5º spatial resolution and a monthly temporal resolution to match the GRACE Mascon product. Despite these coarse spatiotemporal resolutions, we find that the relationship between existing remotely-sensed eco-hydrologic data varies spatially, both in terms of strength of relationship and time lag, showing the response time of vegetation characteristics to hydrological changes and highlighting the role of water storage. A special attention is given to the Amazon river basin, where two well documented droughts occurred in 2005 and 2010, and where a more recent drought occurred in 2015/2016. References : Hirota, Marina, et al. "Global resilience of tropical forest and savanna to critical transitions." Science

  10. VEGETATION MAPPING IN WETLANDS

    Directory of Open Access Journals (Sweden)

    F. PEDROTTI

    2004-01-01

    Full Text Available The current work examines the main aspects of wetland vegetation mapping, which can be summarized as analysis of the ecological-vegetational (ecotone gradients; vegetation complexes; relationships between vegetation distribution and geomorphology; vegetation of the hydrographic basin lo which the wetland in question belongs; vegetation monitoring with help of four vegetation maps: phytosociological map of the real and potential vegetation, map of vegetation dynamical tendencies, map of vegetation series.

  11. Canopy Modeling of Aquatic Vegetation: Construction of Submerged Vegetation Index

    Science.gov (United States)

    Ma, Z.; Zhou, G.

    2018-04-01

    The unique spectral characteristics of submerged vegetation in wetlands determine that the conventional terrestrial vegetation index cannot be directly employed to species identification and parameter inversion of submerged vegetation. Based on the Aquatic Vegetation Radiative Transfer model (AVRT), this paper attempts to construct an index suitable for submerged vegetation, the model simulated data and a scene of Sentinel-2A image in Taihu Lake, China are utilized for assessing the performance of the newly constructed indices and the existent vegetation indices. The results show that the angle index composed by 525 nm, 555 nm and 670 nm can resist the effects of water columns and is more sensitive to vegetation parameters such as LAI. Furthermore, it makes a well discrimination between submerged vegetation and water bodies in the satellite data. We hope that the new index will provide a theoretical basis for future research.

  12. The Role of Personality Traits in Young Adult Fruit and Vegetable Consumption.

    Science.gov (United States)

    Conner, Tamlin S; Thompson, Laura M; Knight, Rachel L; Flett, Jayde A M; Richardson, Aimee C; Brookie, Kate L

    2017-01-01

    This project investigated how individual differences in the big-five personality traits (neuroticism, extraversion, openness to experience, conscientiousness, and agreeableness) predicted plant-food consumption in young adults. A total of 1073 participants from two samples of young adults aged 17-25 reported their daily servings of fruits, vegetables, and two unhealthy foods for comparison purposes using an Internet daily diary for 21 or 13 days (micro-longitudinal, correlational design). Participants also completed the Neuroticism, Extraversion, Openness Five Factor Inventory (NEO-FFI) measure of personality, and demographic covariates including gender, age, ethnicity, and body mass index (BMI). Analyses used hierarchical regression to predict average daily fruit and vegetable consumption as separate dependent variables from the demographic covariates (step 1) and the five personality traits (step 2). Results showed that young adults higher in openness and extraversion, and to some extent conscientiousness, ate more fruits and vegetables than their less open, less extraverted, and less conscientious peers. Neuroticism and agreeableness were unrelated to fruit and vegetable consumption. These associations were unique to eating fruit and vegetables and mostly did not extend to unhealthy foods tested. Young adult women also ate more fruit and vegetables than young adult men. Results suggest that traits associated with greater intellect, curiosity, and social engagement (openness and extraversion), and to a lesser extent, discipline (conscientiousness) are associated with greater plant-food consumption in this population. Findings reinforce the importance of personality in establishing healthy dietary habits in young adulthood that could translate into better health outcomes later in life.

  13. Morphodynamic effects of riparian vegetation growth after stream restoration

    NARCIS (Netherlands)

    Vargas-Luna, Andrés; Crosato, Alessandra; Anders, Niels; Hoitink, Antonius J.F.; Keesstra, Saskia D.; Uijttewaal, Wim S.J.

    2018-01-01

    The prediction of the morphological evolution of renaturalized streams is important for the success of restoration projects. Riparian vegetation is a key component of the riverine landscape and is therefore essential for the natural rehabilitation of rivers. This complicates the design of

  14. The interplay of intention, autonomy, and sex with dietary planning: A conditional process model to predict fruit and vegetable intake.

    Science.gov (United States)

    Lange, Daniela; Corbett, Jana; Lippke, Sonia; Knoll, Nina; Schwarzer, Ralf

    2015-11-01

    Dietary intentions are supposed to engender planning processes, which in turn stimulate dietary behaviour change. However, some studies failed to find such mediation effects, which suggest more complex and not yet unravelled relationships between these factors. One explanation may be that mediation works better under certain circumstances or only for specific subgroups. This study addresses this reasoning by examining autonomy beliefs and sex as putative moderators of the hypothesized mediation chain. In a longitudinal design with three measurement points in time (1 week and 1 month apart), 912 women and 214 men were surveyed. Planning, intention, dietary autonomy beliefs, and sex were used to predict fruit and vegetable intake within a conditional process model designed to identify mechanisms of change. The intention-planning-behaviour chain was qualified by a triple interaction involving autonomy beliefs and sex as moderators between intention and planning. Higher dietary autonomy resulted in higher levels of planning fruit and vegetable intake. For men, even in case of higher intention, at least medium levels of autonomy beliefs were necessary to facilitate planning processes. For women, already lower levels of autonomy beliefs can engender postintentional planning strategies and seem to even compensate lower intention. Intention and planning are key predictors of dietary change. However, these variables work better under specific conditions (with a sufficient level of autonomy), and differently in subgroups (men vs. women). These results may explain the inconsistent findings of previous studies on the mediating effect of planning and allow for a better description of the mechanisms by which intentions may influence behaviour. Statement of contribution What is already known on this subject? The adoption of health-enhancing dietary behaviours can be facilitated by intentions and planning. Planning to eat more fruit and vegetable helps to translate intentions into

  15. Prediction of fruit and vegetable intake from biomarkers using individual participant data of diet-controlled intervention studies

    NARCIS (Netherlands)

    Souverein, O.W.; Vries, J.H.M. de; Freese, R.; Watzl, B.; Bub, A.; Miller, E.R., III; Castenmiller, J.J.M.; Pasman, W.J.; Hof, K. van het; Chopra, M.; Karlsen, A.; Dragsted, L.O.; Winkels, R.; Itsiopoulos, C.; Brazionis, L.; O'Dea, K.; Loo-Bouwman, C.A. van; Naber, T.H.J.; Voet, H. van der; Boshuizen, H.C.

    2015-01-01

    Fruit and vegetable consumption produces changes in several biomarkers in blood. The present study aimed to examine the dose-response curve between fruit and vegetable consumption and carotenoid (α-carotene, β-carotene, β-cryptoxanthin, lycopene, lutein and zeaxanthin), folate and vitamin C

  16. Vegetation dynamics and dynamic vegetation science

    NARCIS (Netherlands)

    Van der Maarel, E

    1996-01-01

    his contribution presents a review of the development of the study of vegetation dynamics since 1979, in the framework of a jubilee meeting on progress in the study of vegetation. However, an exhaustive review is both impossible and unnecessary. It is impossible within the few pages available

  17. Vegetation survey: a new focus for Applied Vegetation Science

    NARCIS (Netherlands)

    Chytry, M.; Schaminee, J.H.J.; Schwabe, A.

    2011-01-01

    Vegetation survey is an important research agenda in vegetation science. It defines vegetation types and helps understand differences among them, which is essential for both basic ecological research and applications in biodiversity conservation and environmental monitoring. In this editorial, we

  18. Access to supermarkets and fruit and vegetable consumption.

    Science.gov (United States)

    Aggarwal, Anju; Cook, Andrea J; Jiao, Junfeng; Seguin, Rebecca A; Vernez Moudon, Anne; Hurvitz, Philip M; Drewnowski, Adam

    2014-05-01

    We examined whether supermarket choice, conceptualized as a proxy for underlying personal factors, would better predict access to supermarkets and fruit and vegetable consumption than mere physical proximity. The Seattle Obesity Study geocoded respondents' home addresses and locations of their primary supermarkets. Primary supermarkets were stratified into low, medium, and high cost according to the market basket cost of 100 foods. Data on fruit and vegetable consumption were obtained during telephone surveys. Linear regressions examined associations between physical proximity to primary supermarkets, supermarket choice, and fruit and vegetable consumption. Descriptive analyses examined whether supermarket choice outweighed physical proximity among lower-income and vulnerable groups. Only one third of the respondents shopped at their nearest supermarket for their primary food supply. Those who shopped at low-cost supermarkets were more likely to travel beyond their nearest supermarket. Fruit and vegetable consumption was not associated with physical distance but, with supermarket choice, after adjusting for covariates. Mere physical distance may not be the most salient variable to reflect access to supermarkets, particularly among those who shop by car. Studies on food environments need to focus beyond neighborhood geographic boundaries to capture actual food shopping behaviors.

  19. Access to Supermarkets and Fruit and Vegetable Consumption

    Science.gov (United States)

    Cook, Andrea J.; Jiao, Junfeng; Seguin, Rebecca A.; Vernez Moudon, Anne; Hurvitz, Philip M.; Drewnowski, Adam

    2014-01-01

    Objectives. We examined whether supermarket choice, conceptualized as a proxy for underlying personal factors, would better predict access to supermarkets and fruit and vegetable consumption than mere physical proximity. Methods. The Seattle Obesity Study geocoded respondents’ home addresses and locations of their primary supermarkets. Primary supermarkets were stratified into low, medium, and high cost according to the market basket cost of 100 foods. Data on fruit and vegetable consumption were obtained during telephone surveys. Linear regressions examined associations between physical proximity to primary supermarkets, supermarket choice, and fruit and vegetable consumption. Descriptive analyses examined whether supermarket choice outweighed physical proximity among lower-income and vulnerable groups. Results. Only one third of the respondents shopped at their nearest supermarket for their primary food supply. Those who shopped at low-cost supermarkets were more likely to travel beyond their nearest supermarket. Fruit and vegetable consumption was not associated with physical distance but, with supermarket choice, after adjusting for covariates. Conclusions. Mere physical distance may not be the most salient variable to reflect access to supermarkets, particularly among those who shop by car. Studies on food environments need to focus beyond neighborhood geographic boundaries to capture actual food shopping behaviors. PMID:24625173

  20. Meteorological factors associated with abundance of airborne fungal spores over natural vegetation

    Science.gov (United States)

    Crandall, Sharifa G.; Gilbert, Gregory S.

    2017-08-01

    The abundance of airborne fungal spores in agricultural and urban settings increases with greater air temperature, relative humidity, or precipitation. The same meteorological factors that affect temporal patterns in spore abundance in managed environments also vary spatially across natural habitats in association with differences in vegetation structure. Here we investigated how temporal and spatial variation in aerial spore abundance is affected by abiotic (weather) and biotic (vegetation) factors as a foundation for predicting how fungi may respond to changes in weather and land-use patterns. We measured the phenology of airborne fungal spores across a mosaic of naturally occurring vegetation types at different time scales to describe (1) how spore abundance changes over time, (2) which local meteorological variables are good predictors for airborne spore density, and (3) whether spore abundance differs across vegetation types. Using an air volumetric vacuum sampler, we collected spore samples at 3-h intervals over a 120-h period in a mixed-evergreen forest and coastal prairie to measure diurnal, nocturnal, and total airborne spore abundance across vegetation types. Spore samples were also collected at weekly and monthly intervals in mixed-evergreen forest, redwood forest, and maritime chaparral vegetation types from 12 field sites across two years. We found greater airborne spore densities during the wetter winter months compared to the drier summer months. Mean total spore abundance in the mixed-evergreen forest was twice than in the coastal prairie, but there were no significant differences in total airborne spore abundance among mixed-evergreen forest, redwood forest, and maritime chaparral vegetation types. Weekly and monthly peaks in airborne spore abundance corresponded with rain events and peaks in soil moisture. Overall, temporal patterns in meteorological factors were much more important in determining airborne fungal spore abundance than the

  1. Vegetation dynamics at the upper elevational limit of vascular plants in Himalaya.

    Science.gov (United States)

    Dolezal, Jiri; Dvorsky, Miroslav; Kopecky, Martin; Liancourt, Pierre; Hiiesalu, Inga; Macek, Martin; Altman, Jan; Chlumska, Zuzana; Rehakova, Klara; Capkova, Katerina; Borovec, Jakub; Mudrak, Ondrej; Wild, Jan; Schweingruber, Fritz

    2016-05-04

    A rapid warming in Himalayas is predicted to increase plant upper distributional limits, vegetation cover and abundance of species adapted to warmer climate. We explored these predictions in NW Himalayas, by revisiting uppermost plant populations after ten years (2003-2013), detailed monitoring of vegetation changes in permanent plots (2009-2012), and age analysis of plants growing from 5500 to 6150 m. Plant traits and microclimate variables were recorded to explain observed vegetation changes. The elevation limits of several species shifted up to 6150 m, about 150 vertical meters above the limit of continuous plant distribution. The plant age analysis corroborated the hypothesis of warming-driven uphill migration. However, the impact of warming interacts with increasing precipitation and physical disturbance. The extreme summer snowfall event in 2010 is likely responsible for substantial decrease in plant cover in both alpine and subnival vegetation and compositional shift towards species preferring wetter habitats. Simultaneous increase in summer temperature and precipitation caused rapid snow melt and, coupled with frequent night frosts, generated multiple freeze-thaw cycles detrimental to subnival plants. Our results suggest that plant species responses to ongoing climate change will not be unidirectional upward range shifts but rather multi-dimensional, species-specific and spatially variable.

  2. A model for estimating understory vegetation response to fertilization and precipitation in loblolly pine plantations

    Science.gov (United States)

    Curtis L. VanderSchaaf; Ryan W. McKnight; Thomas R. Fox; H. Lee Allen

    2010-01-01

    A model form is presented, where the model contains regressors selected for inclusion based on biological rationale, to predict how fertilization, precipitation amounts, and overstory stand density affect understory vegetation biomass. Due to time, economic, and logistic constraints, datasets of large sample sizes generally do not exist for understory vegetation. Thus...

  3. Trend shifts in satellite-derived vegetation growth in Central Eurasia, 1982-2013.

    Science.gov (United States)

    Xu, Hao-Jie; Wang, Xin-Ping; Yang, Tai-Bao

    2017-02-01

    Central Eurasian vegetation is critical for the regional ecological security and the global carbon cycle. However, climatic impacts on vegetation growth in Central Eurasia are uncertain. The reason for this uncertainty lies in the fact that the response of vegetation to climate change showed nonlinearity, seasonality and differences among plant functional types. Based on remotely sensed vegetation index and in-situ meteorological data for the years 1982-2013, in conjunction with the latest land cover type product, we analyzed how vegetation growth trend varied across different seasons and evaluated vegetation response to climate variables at regional, biome and pixel scales. We found a persistent increase in the growing season NDVI over Central Eurasia during 1982-1994, whereas this greening trend has stalled since the mid-1990s in response to increased water deficit. The stalled trend in the growing season NDVI was largely attributed by summer and autumn NDVI changes. Enhanced spring vegetation growth after 2002 was caused by rapid spring warming. The response of vegetation to climatic factors varied in different seasons. Precipitation was the main climate driver for the growing season and summer vegetation growth. Changes in temperature and precipitation during winter and spring controlled the spring vegetation growth. Autumn vegetation growth was mainly dependent on the vegetation growth in summer. We found diverse responses of different vegetation types to climate drivers in Central Eurasia. Forests were more responsive to temperature than to precipitation. Grassland and desert vegetation responded more strongly to precipitation than to temperature in summer but more strongly to temperature than to precipitation in spring. In addition, the growth of desert vegetation was more dependent on winter precipitation than that of grasslands. This study has important implications for improving the performance of terrestrial ecosystem models to predict future vegetation

  4. Psychosocial determinants of fruit and vegetable intake in adult population: a systematic review

    Directory of Open Access Journals (Sweden)

    Godin Gaston

    2010-02-01

    Full Text Available Abstract Background Accumulating evidence suggests that fruit and vegetable intake (FVI plays a protective role against major diseases. Despite this protective role and the obesity pandemic context, populations in Western countries usually eat far less than five servings of fruits and vegetables per day. In order to increase the efficiency of interventions, they should be tailored to the most important determinants or mediators of FVI. The objective was to systematically review social cognitive theory-based studies of FVI and to identify its main psychosocial determinants. Methods Published papers were systematically sought using Current Contents (2007-2009 and Medline, Embase, PsycINFO, Proquest and Thesis, as well as Cinhal (1980-2009. Additional studies were identified by a manual search in the bibliographies. Search terms included fruit, vegetable, behaviour, intention, as well as names of specific theories. Only studies predicting FVI or intention to eat fruits and vegetables in the general population and using a social cognitive theory were included. Independent extraction of information was carried out by two persons using predefined data fields, including study quality criteria. Results A total of 23 studies were identified and included, 15 studying only the determinants of FVI, seven studying the determinants of FVI and intention and one studying only the determinants of intention. All pooled analyses were based on random-effects models. The random-effect R2 observed for the prediction of FVI was 0.23 and it was 0.34 for the prediction of intention. Multicomponent theoretical frameworks and the theory of planned behaviour (TPB were most often used. A number of methodological moderators influenced the efficacy of prediction of FVI. The most consistent variables predicting behaviour were habit, motivation and goals, beliefs about capabilities, knowledge and taste; those explaining intention were beliefs about capabilities, beliefs about

  5. Serving vegetables first: A strategy to increase vegetable consumption in elementary school cafeterias.

    Science.gov (United States)

    Elsbernd, S L; Reicks, M M; Mann, T L; Redden, J P; Mykerezi, E; Vickers, Z M

    2016-01-01

    Vegetable consumption in the United States is low despite the wealth of evidence that vegetables play an important role in reducing risk of various chronic diseases. Because eating patterns developed in childhood continue through adulthood, we need to form healthy eating habits in children. The objective of this study was to determine if offering vegetables before other meal components would increase the overall consumption of vegetables at school lunch. We served kindergarten through fifth-grade students a small portion (26-33 g) of a raw vegetable (red and yellow bell peppers) while they waited in line to receive the rest of their lunch meal. They then had the options to take more of the bell peppers, a different vegetable, or no vegetable from the lunch line. We measured the amount of each vegetable consumed by each child. Serving vegetables first greatly increased the number of students eating vegetables. On intervention days most of the vegetables consumed came from the vegetables-first portions. Total vegetable intake per student eating lunch was low because most students chose to not eat vegetables, but the intervention significantly increased this value. Serving vegetables first is a viable strategy to increase vegetable consumption in elementary schools. Long-term implementation of this strategy may have an important impact on healthy eating habits, vegetable consumption, and the health consequences of vegetable intake. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Vegetation-Induced Roughness in Low-Reynold's Number Flows

    Science.gov (United States)

    Piercy, C. D.; Wynn, T. M.

    2008-12-01

    Wetlands are important ecosystems, providing habitat for wildlife and fish and shellfish production, water storage, erosion control, and water quality improvement and preservation. Models to estimate hydraulic resistance due to vegetation in emergent wetlands are crucial to good wetland design and analysis. The goal of this project is to improve modeling of emergent wetlands by linking properties of the vegetation to flow. Existing resistance equations such as Hoffmann (2004), Kadlec (1990), Moghadam and Kouwen (1997), Nepf (1999), and Stone and Shen (2002) were evaluated. A large outdoor vegetated flume was constructed at the Price's Fork Research Center near Blacksburg, Virginia to measure flow and water surface slope through woolgrass (Scirpus cyperinus), a common native emergent wetland plant. Measurements of clump and stem density, diameter, and volume, blockage factor, and stiffness were made after each set of flume runs. Flow rates through the flume were low (3-4 L/s) resulting in very low stem-Reynold's numbers (15-102). Since experimental flow conditions were in the laminar to transitional range, most of the models considered did not predict velocity or stage accurately except for conditions in which the stem-Reynold's number approached 100. At low stem-Reynold's numbers (drag coefficient is inversely proportional to the Reynold's number and can vary greatly with flow conditions. Most of the models considered assumed a stem-Reynold's number in the 100-105 range in which the drag coefficient is relatively constant and as a result did not predict velocity or stage accurately except for conditions in which the stem-Reynold's number approached 100. The only model that accurately predicted stem layer velocity was the Kadlec (1990) model since it does not make assumptions about flow regime; instead, the parameters are adjusted according to the site conditions. Future work includes relating the parameters used to fit the Kadlec (1990) model to measured vegetation

  7. Predicting outdoor sound

    CERN Document Server

    Attenborough, Keith; Horoshenkov, Kirill

    2014-01-01

    1. Introduction  2. The Propagation of Sound Near Ground Surfaces in a Homogeneous Medium  3. Predicting the Acoustical Properties of Outdoor Ground Surfaces  4. Measurements of the Acoustical Properties of Ground Surfaces and Comparisons with Models  5. Predicting Effects of Source Characteristics on Outdoor Sound  6. Predictions, Approximations and Empirical Results for Ground Effect Excluding Meteorological Effects  7. Influence of Source Motion on Ground Effect and Diffraction  8. Predicting Effects of Mixed Impedance Ground  9. Predicting the Performance of Outdoor Noise Barriers  10. Predicting Effects of Vegetation, Trees and Turbulence  11. Analytical Approximations including Ground Effect, Refraction and Turbulence  12. Prediction Schemes  13. Predicting Sound in an Urban Environment.

  8. Detecting 3D Vegetation Structure with the Galileo Space Probe: Can a Distant Probe Detect Vegetation Structure on Earth?

    Science.gov (United States)

    Doughty, Christopher E; Wolf, Adam

    2016-01-01

    Sagan et al. (1993) used the Galileo space probe data and first principles to find evidence of life on Earth. Here we ask whether Sagan et al. (1993) could also have detected whether life on Earth had three-dimensional structure, based on the Galileo space probe data. We reanalyse the data from this probe to see if structured vegetation could have been detected in regions with abundant photosynthetic pigments through the anisotropy of reflected shortwave radiation. We compare changing brightness of the Amazon forest (a region where Sagan et al. (1993) noted a red edge in the reflectance spectrum, indicative of photosynthesis) as the planet rotates to a common model of reflectance anisotropy and found measured increase of surface reflectance of 0.019 ± 0.003 versus a 0.007 predicted from only anisotropic effects. We hypothesize the difference was due to minor cloud contamination. However, the Galileo dataset had only a small change in phase angle (sun-satellite position) which reduced the observed anisotropy signal and we demonstrate that theoretically if the probe had a variable phase angle between 0-20°, there would have been a much larger predicted change in surface reflectance of 0.1 and under such a scenario three-dimensional vegetation structure on Earth could possibly have been detected. These results suggest that anisotropic effects may be useful to help determine whether exoplanets have three-dimensional vegetation structure in the future, but that further comparisons between empirical and theoretical results are first necessary.

  9. Detecting 3D Vegetation Structure with the Galileo Space Probe: Can a Distant Probe Detect Vegetation Structure on Earth?

    Directory of Open Access Journals (Sweden)

    Christopher E Doughty

    Full Text Available Sagan et al. (1993 used the Galileo space probe data and first principles to find evidence of life on Earth. Here we ask whether Sagan et al. (1993 could also have detected whether life on Earth had three-dimensional structure, based on the Galileo space probe data. We reanalyse the data from this probe to see if structured vegetation could have been detected in regions with abundant photosynthetic pigments through the anisotropy of reflected shortwave radiation. We compare changing brightness of the Amazon forest (a region where Sagan et al. (1993 noted a red edge in the reflectance spectrum, indicative of photosynthesis as the planet rotates to a common model of reflectance anisotropy and found measured increase of surface reflectance of 0.019 ± 0.003 versus a 0.007 predicted from only anisotropic effects. We hypothesize the difference was due to minor cloud contamination. However, the Galileo dataset had only a small change in phase angle (sun-satellite position which reduced the observed anisotropy signal and we demonstrate that theoretically if the probe had a variable phase angle between 0-20°, there would have been a much larger predicted change in surface reflectance of 0.1 and under such a scenario three-dimensional vegetation structure on Earth could possibly have been detected. These results suggest that anisotropic effects may be useful to help determine whether exoplanets have three-dimensional vegetation structure in the future, but that further comparisons between empirical and theoretical results are first necessary.

  10. Satellite assessment of early-season forecasts for vegetation conditions of grazing allotments in Nevada, United States

    Science.gov (United States)

    Fifteen years of enhanced vegetation index data from the MODIS sensor are examined in conjunction with precipitation and the Palmer drought severity index to assess how well growing season conditions for vegetation within grazing allotments of Nevada can be predicted at different times of the year. ...

  11. Estimating Vegetation Height from WorldView-02 and ArcticDEM Data for Broad Ecological Applications

    Science.gov (United States)

    Meddens, A. J.; Vierling, L. A.; Eitel, J.; Jennewein, J. S.; White, J. C.; Wulder, M.

    2017-12-01

    Boreal and arctic regions are warming at an unprecedented rate, and at a rate higher than in other regions across the globe. Ecological processes are highly responsive to temperature and therefore substantial changes in these northern ecosystems are expected. Recently, NASA initiated the Arctic-Boreal Vulnerability Experiment (ABoVE), which is a large-scale field campaign that aims to gain a better understanding of how the arctic responds to environmental change. High-resolution data products that quantify vegetation structure and function will improve efforts to assess these environmental change impacts. Our objective was to develop and test an approach that allows for mapping vegetation height at a 5m grid cell resolution across the ABoVE domain. To accomplish this, we selected three study areas across a north-south gradient in Alaska, representing an area of approximately 130 km2. We developed a RandomForest modeling approach for predicting vegetation height using the ArcticDEM (a digital surface model produced across the Arctic by the Polar Geospatial Center) and high-resolution multispectral satellite data (WorldView-2) in conjunction with aerial lidar data for calibration and validation. Vegetation height was successfully predicted across the three study areas and evaluated using an independent dataset, with R2 ranging from 0.58 to 0.76 and RMSEs ranging from 1.8 to 2.4 m. This predicted vegetation height dataset also led to the development of a digital terrain model using the ArcticDEM digital surface model by removing canopy heights from the surface heights. Our results show potential to establish a high resolution pan-arctic vegetation height map, which will provide useful information to a broad range of ongoing and future ecological research in high northern latitudes.

  12. Predicted Water and Carbon Fluxes as well as Vegetation Distribution on the Korean Peninsula in the Future with the Ecosystem Demography Model version 2

    Science.gov (United States)

    Kim, J. B.; Kim, Y.

    2017-12-01

    This study investigates how the water and carbon fluxes as well as vegetation distribution on the Korean peninsula would vary with climate change. Ecosystem Demography (ED) Model version 2 (ED2) is used in this study, which is an integrated terrestrial biosphere model that can utilize a set of size- and age- structured partial differential equations that track the changing structure and composition of the plant canopy. With using the vegetation distribution data of Jeju Island, located at the southern part of the Korean Peninsula, ED2 is setup and driven for the past 10 years. Then the results of ED2 are evaluated and adjusted with observed forestry data, i.e., growth and mortality, and the flux tower and MODIS satellite data, i.e., evapotranspiration (ET) and gross primary production (GPP). This adjusted ED2 are used to simulate the water and carbon fluxes as well as vegetation dynamics in the Korean Peninsula for the historical period with evaluating the model against the MODIS satellite data. Finally, the climate scenarios of RCP 2.6 and 6.0 are used to predict the fluxes and vegetation distribution of the Korean Peninsula in the future. With using the state-of-art terrestrial ecosystem model, this study would provide us better understanding of the future ecosystem vulnerability of the Korean Peninsula. AcknowledgementsThis work was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT & Future Planning (2015R1C1A2A01054800) and by the Korea Meteorological Administration R&D Program under Grant KMIPA 2015-6180. This work was also supported by the Yonsei University Future-leading Research Initiative of 2015(2016-22-0061).

  13. Past and present vegetation ecology of Laetoli, Tanzania.

    Science.gov (United States)

    Andrews, Peter; Bamford, Marion

    2008-01-01

    -Croton-Lepidotrichilia; and, finally, recent ash falls have produced immature alkaline soils with calcrete formation and short grass vegetation. All of these vegetation associations have been modified by human disturbance to greater or lesser degrees, and we have attempted to allow for this both by basing the associations on the least modified areas and by predicting how the associations, or parts of associations, have been altered by human action. Past land forms at Laetoli have been based on the geology and geomorphology of the area. Past vegetation patterns were estimated by superimposing present distributions of plant associations on equivalent landforms in the past, assuming similar climate to the present. This indicates the overall pattern of vegetation at Laetoli to have been a mosaic of low and tall deciduous woodlands and with riverine woodland and forest associations along water courses. Low woodlands would have been dominated by Acacia species, and tall woodlands by Combretum-Albizia species, with increasing increments of montane species, such as Croton species, to the east of the area. Riverine woodlands would have been dominated by Acacia-Euclea species, with wetter associations (downriver or linked with spring activity) supporting gallery forest with Ficus, Celtis, and Croton species. These are all species associations common in the area today, and with landforms little changed in the past, and assuming similar climate, there is every reason to predict that they would have been present in the past. Moreover, Pliocene environments lack the human disturbance that has destroyed much of the present day vegetation. Presence of woodlands is supported by fossil wood attributed to several of the tree species present in the area today and by similarities in the mammalian community structure between past and present. Having established the pattern for Pliocene vegetation based on climatic variables existing today, we then predict the effects of past variations in climate.

  14. High School Girl's Adherence to 5-a-Day Serving's Fruits and Vegetables: An Application Theory of Planned Behavior

    Directory of Open Access Journals (Sweden)

    Babak Moeini

    2014-09-01

    Full Text Available Introduction: One of the basics of healthy eating is five times consumption of fruits and vegetable a day. Given the importance of recognizing effective factors of consuming fruit and vegetable in this group, the present study aimed to investigate high school girl's adherence to five-time serving fruits and vegetables per day in Hamadan based on the theory of planned behavior application. Materials and Methods: This descriptive-analytical study was performed on 400 girl students from high schools of Hamadan recruited with a multistage cluster sampling method. Participants filled out questionnaires including demographic variables, the theory of planned behavior constructs and a fruit and vegetable consumption measure one week later. Data analysis was performed using SPSS-18 by Chi-square, Pearson correlation and Logistic regression. Results: Fruit and vegetable consumption by female students is 3.4 times daily. Among the demographic variables, family size, mother's education, father's occupation, household income, body mass index and type of school had significant associations with fruit and vegetable consumption (P<0.05. Behavioral intention predicted 35% of the variation in daily fruit and vegetable consumption. Moreover, subjective norms, perceived behavioral control and attitude were able to predict 32% of behavioral intention. Conclusion: Fruit and vegetable consumption in female students is inadequate. The theory of planned behavior may be a useful framework to design a 5-A-Day intervention for female students.

  15. Carbon Inputs From Riparian Vegetation Limit Oxidation of Physically Bound Organic Carbon Via Biochemical and Thermodynamic Processes: OC Oxidation Processes Across Vegetation

    Energy Technology Data Exchange (ETDEWEB)

    Graham, Emily B. [Pacific Northwest National Laboratory, Richland WA USA; Tfaily, Malak M. [Environmental Molecular Sciences Laboratory, Richland WA USA; Crump, Alex R. [Pacific Northwest National Laboratory, Richland WA USA; Goldman, Amy E. [Pacific Northwest National Laboratory, Richland WA USA; Bramer, Lisa M. [Pacific Northwest National Laboratory, Richland WA USA; Arntzen, Evan [Pacific Northwest National Laboratory, Richland WA USA; Romero, Elvira [Pacific Northwest National Laboratory, Richland WA USA; Resch, C. Tom [Pacific Northwest National Laboratory, Richland WA USA; Kennedy, David W. [Pacific Northwest National Laboratory, Richland WA USA; Stegen, James C. [Pacific Northwest National Laboratory, Richland WA USA

    2017-12-01

    In light of increasing terrestrial carbon (C) transport across aquatic boundaries, the mechanisms governing organic carbon (OC) oxidation along terrestrial-aquatic interfaces are crucial to future climate predictions. Here, we investigate biochemistry, metabolic pathways, and thermodynamics corresponding to OC oxidation in the Columbia River corridor. We leverage natural vegetative differences to encompass variation in terrestrial C inputs. Our results suggest that decreases in terrestrial C deposition associated with diminished riparian vegetation induce oxidation of physically-bound (i.e., mineral and microbial) OC at terrestrial-aquatic interfaces. We also find that contrasting metabolic pathways oxidize OC in the presence and absence of vegetation and—in direct conflict with the concept of ‘priming’—that inputs of water-soluble and thermodynamically-favorable terrestrial OC protects bound-OC from oxidation. Based on our results, we propose a mechanistic conceptualization of OC oxidation along terrestrial-aquatic interfaces that can be used to model heterogeneous patterns of OC loss under changing land cover distributions.

  16. Determinants of patchiness of woody vegetation in an African savanna

    NARCIS (Netherlands)

    Veldhuis, Michiel P.; Rozen-Rechels, David; le Roux, Elizabeth; Cromsigt, Joris P.G.M.; Berg, Matheus P.; Olff, Han

    2016-01-01

    How is woody vegetation patchiness affected by rainfall, fire and large herbivore biomass? Can we predict woody patchiness and cover over large-scale environmental gradients? We quantified variation in local patchiness as the lacunarity of woody cover on satellite-derived images. Using Random Forest

  17. Optimization of the trienzyme extraction for the microbiological assay of folate in vegetables.

    Science.gov (United States)

    Chen, Liwen; Eitenmiller, Ronald R

    2007-05-16

    Response surface methodology was applied to optimize the trienzyme digestion for the extraction of folate from vegetables. Trienzyme extraction is a combined enzymatic digestion by protease, alpha-amylase, and conjugase (gamma-glutamyl hydrolase) to liberate the carbohydrate and protein-bound folates from food matrices for total folate analysis. It is the extraction method used in AOAC Official Method 2004.05 for assay of total folate in cereal grain products. Certified reference material (CRM) 485 mixed vegetables was used to represent the matrix of vegetables. Regression and ridge analysis were performed by statistical analysis software. The predicted second-order polynomial model was adequate (R2 = 0.947), without significant lack of fit (p > 0.1). Both protease and alpha-amylase have significant effects on the extraction. Ridge analysis gave an optimum trienzyme digestion time: Pronase, 1.5 h; alpha-amylase, 1.5 h; and conjugase, 3 h. The experimental value for CRM 485 under this optimum digestion was close to the predicted value from the model, confirming the validity and adequacy of the model. The optimized trienzyme digestion condition was applied to five vegetables and yielded higher folate levels than the trienzyme digestion parameters employed in AOAC Official Method 2004.05.

  18. Plant metabolites and nutritional quality of vegetables.

    Science.gov (United States)

    Hounsome, N; Hounsome, B; Tomos, D; Edwards-Jones, G

    2008-05-01

    Vegetables are an important part of the human diet and a major source of biologically active substances such as vitamins, dietary fiber, antioxidants, and cholesterol-lowering compounds. Despite a large amount of information on this topic, the nutritional quality of vegetables has not been defined. Historically, the value of many plant nutrients and health-promoting compounds was discovered by trial and error. By the turn of the century, the application of chromatography, mass spectrometry, infrared spectrometry, and nuclear magnetic resonance allowed quantitative and qualitative measurements of a large number of plant metabolites. Approximately 50000 metabolites have been elucidated in plants, and it is predicted that the final number will exceed 200000. Most of them have unknown function. Metabolites such as carbohydrates, organic and amino acids, vitamins, hormones, flavonoids, phenolics, and glucosinolates are essential for plant growth, development, stress adaptation, and defense. Besides the importance for the plant itself, such metabolites determine the nutritional quality of food, color, taste, smell, antioxidative, anticarcinogenic, antihypertension, anti-inflammatory, antimicrobial, immunostimulating, and cholesterol-lowering properties. This review is focused on major plant metabolites that characterize the nutritional quality of vegetables, and methods of their analysis.

  19. Post-fire vegetation recovery in Portugal based on spot/vegetation data

    Science.gov (United States)

    Gouveia, C.; Dacamara, C. C.; Trigo, R. M.

    2010-04-01

    A procedure is presented that allows identifying large burned scars and the monitoring of vegetation recovery in the years following major fire episodes. The procedure relies on 10-day fields of Maximum Value Composites of Normalized Difference Vegetation Index (MVC-NDVI), with a 1 km×1 km spatial resolution obtained from the VEGETATION instrument. The identification of fire scars during the extremely severe 2003 fire season is performed based on cluster analysis of NDVI anomalies that persist during the vegetative cycle of the year following the fire event. Two regions containing very large burned scars were selected, located in Central and Southwestern Portugal, respectively, and time series of MVC-NDVI analysed before the fire events took place and throughout the post-fire period. It is shown that post-fire vegetation dynamics in the two selected regions may be characterised based on maps of recovery rates as estimated by fitting a monoparametric model of vegetation recovery to MVC-NDVI data over each burned scar. Results indicated that the recovery process in the region located in Central Portugal is mostly related to fire damage rather than to vegetation density before 2003, whereas the latter seems to have a more prominent role than vegetation conditions after the fire episode, e.g. in the case of the region in Southwestern Portugal. These differences are consistent with the respective predominant types of vegetation. The burned area located in Central Portugal is dominated by Pinus Pinaster whose natural regeneration crucially depends on the destruction of seeds present on the soil surface during the fire, whereas the burned scar in Southwestern Portugal was populated by Eucalyptus that may quickly re-sprout from buds after fire. Besides its simplicity, the monoparametric model of vegetation recovery has the advantage of being easily adapted to other low-resolution satellite data, as well as to other types of vegetation indices.

  20. Change in Vegetation Growth and Its Feedback to Climate in the Tibet Plateau

    Science.gov (United States)

    Piao, S.

    2015-12-01

    Vegetation growth is strongly influenced by climate and climate change and can affect the climate system through a number of bio-physical processes. As a result, monitoring, understanding and predicting the response of vegetation growth to global change has been a central activity in Earth system science during the past two decades. The Tibetan Plateau (TP) has experienced a pronounced warming over recent decades. The warming rate of the TP over the period 1960-2009 was about twice the global average warming rate, yet with heterogeneous patterns. In this study, we use satellite derived NDVI data to investigate spatio-temporal change in vegetation growth over the last three decades.

  1. Drought-induced vegetation stress in southwestern North America

    International Nuclear Information System (INIS)

    Zhang Xiaoyang; Goldberg, Mitchell; Tarpley, Dan; Kogan, Felix; Yu Yunyue; Friedl, Mark A; Morisette, Jeffrey

    2010-01-01

    Trends towards earlier greenup and increased average greenness have been widely reported in both humid and dry ecosystems. By analyzing NOAA (National Oceanic and Atmospheric Administration) AVHRR (Advanced Very High Resolution Radiometer) data from 1982 to 2007, we report complex trends in both the growing season amplitude and seasonally integrated vegetation greenness in southwestern North America and further highlight regions consistently experiencing drought stress. In particular, greenness measurements from 1982 to 2007 show an increasing trend in grasslands but a decreasing trend in shrublands. However, vegetation greenness in this period has experienced a strong cycle, increasing from 1982 to 1993 but decreasing from 1993 to 2007. The significant decrease during the last decade has reduced vegetation greenness by 6% in shrublands and 13% in grasslands (16% and 21%, respectively, in the severe drought years). The greenness cycle correlates to both annual precipitation and dry season length derived from NOAA North America Regional Reanalysis data. If drought events continue as predicted by climate models, they will exacerbate ecosystem degradation and reduce carbon uptake.

  2. Study on biomethane production and biodegradability of different leafy vegetables in anaerobic digestion.

    Science.gov (United States)

    Yan, Hu; Zhao, Chen; Zhang, Jiafu; Zhang, Ruihong; Xue, Chunyu; Liu, Guangqing; Chen, Chang

    2017-12-01

    Enormous amounts of vegetable residues are wasted annually, causing many environmental problems due to their high moisture and organic contents. In this study, the methane production potential of 20 kinds of typical leafy vegetable residues in China were explored using a unified method. A connection between the biochemical components and the methane yields of these vegetables was well established which could be used to predict biogas performance in practice. A high volatile solid/total solid (VS/TS) ratio and hemicellulose content exhibited a positive impact on the biogas yield while lignin had a negative impact. In addition, three kinetic models were used to describe the methane production process of these agro-wastes. The systematic comparison of the methane production potentials of these leafy vegetables shown in this study will not only serve as a reference for basic research on anaerobic digestion but also provide useful data and information for agro-industrial applications of vegetable residues in future work.

  3. The Impact of the Rise in Vegetable Prices on Vegetable Producer Behavior–Based on the survey of vegetable producers in Jiayu, Hubei Province

    Directory of Open Access Journals (Sweden)

    Liu Pan

    2015-01-01

    Full Text Available In order to study the impact of the rise in prices of vegetables on vegetable producers, and to increase the revenue of vegetable producers, this paper does a survey by anonymous sampling questionnaire. Results shows that: most vegetable growers think that vegetable prices should rise and would continue to rise, and that vegetable prices would increase their revenue, thus in the coming year they would expand the planting scale of vegetable variety whose increase rate is the largest in this year. But because of the increase of logistics costs and production costs, some farmers benefit very little from the rising trend of vegetable prices. Most farmers expect too much in the trend estimation of the prices of vegetables and also lack of planning and forward-looking in production, thus the planting area of single variety is often decided by the market of previous year. According to analysis of the impact of the rise in vegetable prices on vegetable producer behavior, this paper gives the following suggestions to increase revenue of vegetable producers: change the mode of thinking, improve rural information platform, and increase capital investment for vegetable production base.

  4. Climate-vegetation-soil interactions and long-term hydrologic partitioning: signatures of catchment co-evolution

    Directory of Open Access Journals (Sweden)

    P. A. Troch

    2013-06-01

    Full Text Available Budyko (1974 postulated that long-term catchment water balance is controlled to first order by the available water and energy. This leads to the interesting question of how do landscape characteristics (soils, geology, vegetation and climate properties (precipitation, potential evaporation, number of wet and dry days interact at the catchment scale to produce such a simple and predictable outcome of hydrological partitioning? Here we use a physically-based hydrologic model separately parameterized in 12 US catchments across a climate gradient to decouple the impact of climate and landscape properties to gain insight into the role of climate-vegetation-soil interactions in long-term hydrologic partitioning. The 12 catchment models (with different paramterizations are subjected to the 12 different climate forcings, resulting in 144 10 yr model simulations. The results are analyzed per catchment (one catchment model subjected to 12 climates and per climate (one climate filtered by 12 different model parameterization, and compared to water balance predictions based on Budyko's hypothesis (E/P = ϕ (Ep/P; E: evaporation, P: precipitation, Ep: potential evaporation. We find significant anti-correlation between average deviations of the evaporation index (E/P computed per catchment vs. per climate, compared to that predicted by Budyko. Catchments that on average produce more E/P have developed in climates that on average produce less E/P, when compared to Budyko's prediction. Water and energy seasonality could not explain these observations, confirming previous results reported by Potter et al. (2005. Next, we analyze which model (i.e., landscape filter characteristics explain the catchment's tendency to produce more or less E/P. We find that the time scale that controls subsurface storage release explains the observed trend. This time scale combines several geomorphologic and hydraulic soil properties. Catchments with relatively longer

  5. Research on Vegetable Pest Warning System Based on Multidimensional Big Data

    Directory of Open Access Journals (Sweden)

    Changzhen Zhang

    2018-06-01

    Full Text Available Pest early warning technology is part of the prerequisite for the timely and effective control of pest outbreaks. Traditional pest warning system with artificial mathematical statistics, radar, and remote sensing has some deficiency in many aspects, such as higher cost, weakness of accuracy, low efficiency, and so on. In this study, Pest image data was collected and information about four major vegetable pests (Bemisia tabaci (Gennadius, Phyllotreta striolata (Fabricius, Plutella xylostella (Linnaeus, and Frankliniella occidentalis (Pergande (Thysanoptera, Thripidae in southern China was extracted. A multi-sensor network system was constructed to collect small-scale environmental data on vegetable production sites. The key factors affecting the distribution of pests were discovered by multi-dimensional information, such as soil, environment, eco-climate, and meteorology of vegetable fields, and finally, the vegetable pest warning system that is based on multidimensional big data (VPWS-MBD was implemented. Pest and environmental data from Guangzhou Dongsheng Bio-Park were collected from June 2017 to February 2018. The number of pests is classified as level I (0–56, level II (57–131, level III (132–299, and level IV (above 300 by K-Means algorithm. The Pearson correlation coefficient and the grey relational analysis algorithm were used to calculate the five key influence factors of rainfall, soil temperature, air temperature, leaf surface humidity, and soil moisture. Finally, Back Propagation (BP Neural Network was used for classification prediction. The result shows: I-level warning accuracy was 96.14%, recall rate was 97.56%; II-level pest warning accuracy was 95.34%, the recall rate was 96.45%; III-level pest warning accuracy of 100%, the recall rate was 96.28%; IV-level pest warning accuracy of 100%, recall rate was 100%. It proves that the early warning system can effectively predict vegetable pests and achieve the early warning of

  6. Revealing livestock effects on bunchgrass vegetation with Landsat ETM+ data across a grazing season

    Science.gov (United States)

    Jansen, Vincent S.

    Remote sensing provides monitoring solutions for more informed grazing management. To investigate the ability to detect the effects of cattle grazing on bunchgrass vegetation with Landsat Enhanced Thematic Mapper Plus (ETM+) data, we conducted a study on the Zumwalt Prairie in northeastern Oregon across a gradient of grazing intensities. Biophysical vegetation data was collected on vertical structure, biomass, and cover at three different time periods during the grazing season: June, August, and October 2012. To relate these measures to the remotely sensed Landsat ETM+ data, Pearson's correlations and multiple regression models were computed. Using the best models, predicted vegetation metrics were then mapped across the study area. Results indicated that models using common vegetation indices had the ability to discern different levels of grazing across the study area. Results can be distributed to land managers to help guide grassland conservation by improving monitoring of bunchgrass vegetation for sustainable livestock management.

  7. Fruit and Vegetable Consumption among Special School Students with Mild Intellectual Disability in Hong Kong.

    Science.gov (United States)

    Mok, W K; Ling, T K

    2016-08-01

    The aim of this study was to predict the fruit and vegetable consumption intention of students with mild intellectual disability in Hong Kong by the application of Ajzen's Theory of Planned Behaviour. 50 students with mild intellectual disability (30 male and 20 female), ranging in age from 15 to 38 years, were participated in this study. By means of face-to-face interviews, demographic data, Food Preference and variables of Theory of Planned Behaviour, such as Attitude, Subjective Norm and Perceived Behavioural Control were measured. 20%, 28% and 10% students with mild intellectual disability were rated to be overweight, obese and severely obese respectively. The rest of 10% were classified to be underweight. Regarding the daily intake of fruit and vegetable, 96% students with mild intellectual disability failed to consume sufficient amount. The variables of Theory of Planned Behaviour explained 47.7% of fruit and vegetable consumption intention with significant factors of Attitude, Subjective Norm and Perceived Behavioural Control. Food Preference was found to be a useful construct and further improve the prediction by about 7% after incorporating into the model. Results of this study indicated that Theory of Planned Behaviour is a useful model to predict dietary intention of students with mild intellectual disability in Hong Kong. Food Preference was a significant predictor to model the intention of fruit and vegetable consumption among students other than Attitude, Subjective Norm and Perceived Behavioural Control.

  8. Models for the prediction of the cetane index of biofuels obtained from different vegetable oils using their fatty acid composition

    International Nuclear Information System (INIS)

    Sanchez Borroto, Yisel; Piloto Rodriguez, Ramon; Goyos Perez, Leonardo

    2011-01-01

    The objective of the present work is to obtain a physical-mathematical model that establishes a relationship between the cetane index of biofuels obtained from different vegetable oils and its composition of essential fatty acid. This model is based on experimental data obtained by the authors of the present work and an experimental data reported by different extracted authors of indexed databases. The adjustment of the coefficients of the model is based on the obtaining of residual minima in the capacity of prediction of the model. Starting from these results it is established a very useful tool for the determination of such an important parameter for the fuel diesel as it is the cetane index obtained from an analysis of chemical composition and not obtained from tests in engines banks, to save time and economic resources. (author)

  9. The role of vegetation in shaping dune morphology

    Science.gov (United States)

    Duran Vinent, O.; Moore, L. J.; Young, D.

    2012-12-01

    Aeolian dunes naturally emerge under strong winds and sufficient sand supply. They represent the most dynamical feature of the arid and/or coastal landscape and their evolution has the potential to either increase desertification or reduce coastal vulnerability to storms. Although large-scale dune morphology mainly depends on the wind regime and sand availability, vegetation plays an important role in semiarid and/or coastal areas. It is well known that under certain conditions vegetation is able to stabilize dunes, driving a morphological transformation from un-vegetated mobile crescent dunes to static vegetated "parabolic" dunes, de facto paralyzing desertification and initiating land recovery. Furthermore, vegetation is also the primary ingredient in the formation of coastal foredunes, which determine vulnerability to storms, as low dunes are prone to storm-induced erosion and overwash. In both cases, the coupling of biological and geomorphic (physical) processes, in particular vegetation growth and sand transport, governs the evolution of morphology. These processes were implemented in a computational model as part of a previous effort. It was shown that, for a migrating dune, this coupling leads to a negative feedback for dune motion, where an ever denser vegetation implies ever lesser sand transport. The model also predicted the existence of a "mobility index", defined by the vegetation growth rate to sand erosion rate ratio, that fully characterizes the morphological outcome: for indices above a certain threshold biological processes are dominant and dune motion slows after being covered by plants; for lower indices, the physical processes are the dominant ones and the dune remains mobile while vegetation is buried or rooted out. Here, we extend this model to better understand the formation of coastal dunes. We include new physical elements such as the shoreline and water table, as well as different grass species and potential competition among them

  10. Impacts of vegetation change on groundwater recharge

    Science.gov (United States)

    Bond, W. J.; Verburg, K.; Smith, C. J.

    2003-12-01

    Vegetation change is the accepted cause of increasing river salt concentrations and the salinisation of millions of hectares of farm land in Australia. Replacement of perennial native vegetation by annual crops and pastures following European settlement has altered the water balance causing increased groundwater recharge and mobilising the naturally saline groundwater. The Redesigning Agriculture for Australian Landscapes Program, of which the work described here is a part, was established to develop agricultural practices that are more attuned to the delicate water balance described above. Results of field measurements will be presented that contrast the water balance characteristics of native vegetation with those of conventional agricultural plants, and indicate the functional characteristics required of new agricultural practices to reduce recharge. New agricultural practices may comprise different management of current crops and pastures, or may involve introducing totally new species. In either case, long-term testing is required to examine their impact on recharge over a long enough climate record to encompass the natural variability of rainfall that is characteristic of most Australian farming regions. Field experimentation therefore needs to be complemented and extended by computer simulation. This requires a modelling approach that is more robust than conventional crop modelling because (a) it needs to be sensitive enough to predict small changes in the residual recharge term, (b) it needs to be able to simulate a variety of vegetation in different sequences, (c) it needs to be able to simulate continuously for several decades of input data, and (d) it therefore needs to be able to simulate the period between crops, which often has a critical impact on recharge. The APSIM simulation framework will be used to illustrate these issues and to explore the effect of different vegetation combinations on recharge.

  11. Relations between Vegetation and Geologic Framework in Barrier Island

    Science.gov (United States)

    Smart, N. H.; Ferguson, J. B.; Lehner, J. D.; Taylor, D.; Tuttle, L. F., II; Wernette, P. A.

    2017-12-01

    Barrier islands provide valuable ecosystems and protective services to coastal communities. The longevity of barrier islands is threatened by sea-level rise, human impacts, and extreme storms. The purpose of this research is to evaluate how vegetation dynamics interact with the subsurface and offshore framework geology to influence the beach and dune morphology. Beach and dune morphology can be viewed as free and/or forced behavior, where free systems are stochastic and the morphology is dependent on variations in the storm surge run-up, aeolian sediment supply and transport potential, and vegetation dynamics and persistence. Forced systems are those where patterns in the coastal morphology are determined by some other structural control, such as the underlying and offshore framework geology. Previous studies have documented the effects of geologic framework or vegetation dynamics on the beach and dunes, although none have examined possible control by vegetation dynamics in context of the geologic framework (i.e. combined free and forced behavior). Padre Island National Seashore (PAIS) was used to examine the interaction of free and forced morphology because the subsurface framework geology and surface beach and dune morphology are variable along the island. Vegetation dynamics were assessed by classifying geographically referenced historical aerial imagery into areas with vegetation and areas without vegetation, as well as LiDAR data to verify this imagery. The subsurface geologic structure was assessed using a combination of geophysical surveys (i.e. electromagnetic induction, ground-penetrating radar, and offshore seismic surveys). Comparison of the observed vegetation patterns and geologic framework leads to a series of questions surrounding how mechanistically these two drivers of coastal morphology are related. Upcoming coring and geophysical surveys will enable us to validate new and existing geophysical data. Results of this paper will help us better

  12. Car ownership and the association between fruit and vegetable availability and diet.

    Science.gov (United States)

    Bodor, J Nicholas; Hutchinson, Paul L; Rose, Donald

    2013-12-01

    Nearly all research on the food environment and diet has not accounted for car ownership - a potential key modifying factor. This study examined the modifying effect of car ownership on the relationship between neighborhood fruit and vegetable availability and intake. Data on respondents' (n=760) fruit and vegetable intake, car ownership, and demographics came from the 2008 New Orleans Behavioral Risk Factor Surveillance System. Shelf space data on fresh, frozen, and canned fruits and vegetables were collected in 2008 from a random sample of New Orleans stores (n=114). Availability measures were constructed by summing the amount of fruit and vegetable shelf space in all stores within defined distances from respondent households. Regression analyses controlled for demographics and were run separately for respondents with and without a car. Fruit and vegetable availability was positively associated with intake among non-car owners. An additional 100 m of shelf space within 2 km of a residence was predictive of a half-serving/day increase in fruit and vegetable intake. Availability was not associated with intake among car owners. Future research and interventions to increase neighborhood healthy food options should consider car ownership rates in their target areas as an important modifying factor. © 2013.

  13. European Vegetation Archive (EVA): an integrated database of European vegetation plots

    DEFF Research Database (Denmark)

    Chytrý, M; Hennekens, S M; Jiménez-Alfaro, B

    2015-01-01

    vegetation- plot databases on a single software platform. Data storage in EVA does not affect on-going independent development of the contributing databases, which remain the property of the data contributors. EVA uses a prototype of the database management software TURBOVEG 3 developed for joint management......The European Vegetation Archive (EVA) is a centralized database of European vegetation plots developed by the IAVS Working Group European Vegetation Survey. It has been in development since 2012 and first made available for use in research projects in 2014. It stores copies of national and regional...... data source for large-scale analyses of European vegetation diversity both for fundamental research and nature conservation applications. Updated information on EVA is available online at http://euroveg.org/eva-database....

  14. Abrupt vegetation transitions characterise long-term Amazonian peatland development

    Science.gov (United States)

    Roucoux, K. H.; Baker, T. R.; Gosling, W. D.; Honorio Coronado, E.; Jones, T. D.; Lahteenoja, O.; Lawson, I. T.

    2012-04-01

    woodland with abundant Myrtaceae; (4) Expansion of Mauritia/Mauritiella palm swamp vegetation c. 1000 years ago representing establishment of the present day vegetation community. Our results show that the vegetation at this site has undergone continuous change throughout the period of peat formation. The sequence of vegetation development is not straightforward, being characterised by abrupt transitions between vegetation types and reversals in the apparent trajectory of change. Overall this suggests that the system is highly dynamic on centennial to millennial timescales. This complexity may reflect vegetation responses to a combination of external (physical) and internal (biological) drivers and the presence of thresholds in the system. Future investigations will work towards understanding the processes that drive these vegetation transitions and predicting peatland vegetation responses to future climatic change.

  15. Seasat synthetic aperture radar ( SAR) response to lowland vegetation types in eastern Maryland and Virginia.

    Science.gov (United States)

    Krohn, M.D.; Milton, N.M.; Segal, D.B.

    1983-01-01

    Examination of Seasat SAR images of eastern Maryland and Virginia reveals botanical distinctions between vegetated lowland areas and adjacent upland areas. Radar returns from the lowland areas can be either brighter or darker than returns from the upland forests. Scattering models and scatterometer measurements predict an increase of 6 dB in backscatter from vegetation over standing water. This agrees with the 30-digital number (DN) increase observed in the digital Seasat data. The density, morphology, and relative geometry of the lowland vegetation with respect to standing water can all affect the strength of the return L band signal.-from Authors

  16. Vegetable oil and fat viscosity forecast models based on iodine number and saponification number

    International Nuclear Information System (INIS)

    Toscano, G.; Riva, G.; Foppa Pedretti, E.; Duca, D.

    2012-01-01

    Vegetable oil and fats can be considered as an important renewable source for the energy production. There are many applications where these biofuels are used directly in engines. However, the use of pure vegetable oils causes some problems as consequence of its chemical and physical characteristic. Viscosity is one of the most important parameters affecting several physical and mechanical processes of the operation of the engine. The determination of this parameter at different tis important to determine the behavior of the vegetable oil and fats. In this work we investigated the effects of two analytical chemical parameters (iodine number and saponification number) and forecasting models have been proposed. -- Highlights: ► Vegetable oil and fat viscosity is predicted by mathematical model based on saponification number and iodine number. ► Unsaturated vegetable oils with small size molecules of fatty acids have a lower viscosity values. ► The models proposed show an average error lower than 12%

  17. Impacts of 21st century climate changes on flora and vegetation in Denmark

    International Nuclear Information System (INIS)

    Skov, Flemming; Nygaard, Bettina; Wind, Peter; Floejgaard, Camilla; Borchsenius, Finn; Normand, Signe; Balslev, Henrik; Svenning, Jens-Christian

    2009-01-01

    In this paper we examined the potential impacts of predicted climatic changes on the flora and vegetation in Denmark using data from a digital database on the natural vegetation of Europe. Climate scenarios A2 and B2 were used to find regions with present climatic conditions similar to Denmark's climate in the year 2100. The potential natural vegetation of Denmark today is predominantly deciduous forest that would cover more than 90% of the landscape. Swamps, bogs, and wet forest would be found under moist or wet conditions. Dwarf shrub heaths would be naturally occurring on poor soils along the coast together with dune systems and salt-marsh vegetation. When comparing the natural vegetation of Denmark to the vegetation of five future-climate analogue areas, the most obvious trend is a shift from deciduous to thermophilous broadleaved forest currently found in Southern and Eastern Europe. A total of 983 taxa were recorded for this study of which 539 were found in Denmark. The Soerensen index was used to measure the floristic similarity between Denmark and the five subregions. Deciduous forest, dwarf shrub heath, and coastal vegetation were treated in more detail, focusing on potential new immigrant species to Denmark. Finally, implications for management were discussed. The floristic similarity between Denmark and regions in Europe with a climate similar to what is expected for Denmark in year 2100 was found to vary between 48-78%, decreasing from North to South. Hence, it seems inevitable that climate changes of the magnitudes foreseen will alter the distribution of individual species and the composition of natural vegetation units. Changes, however, will not be immediate. Historic evidence shows a considerable lag in response to climatic change under natural conditions, but little is known about the effects of human land-use and pollution on this process. Facing such uncertainties we suggested that a dynamic strategy based on modeling, monitoring and adaptive

  18. Impacts of 21st century climate changes on flora and vegetation in Denmark

    Science.gov (United States)

    Skov, Flemming; Nygaard, Bettina; Wind, Peter; Borchsenius, Finn; Normand, Signe; Balslev, Henrik; Fløjgaard, Camilla; Svenning, Jens-Christian

    2009-11-01

    In this paper we examined the potential impacts of predicted climatic changes on the flora and vegetation in Denmark using data from a digital database on the natural vegetation of Europe. Climate scenarios A2 and B2 were used to find regions with present climatic conditions similar to Denmark's climate in the year 2100. The potential natural vegetation of Denmark today is predominantly deciduous forest that would cover more than 90% of the landscape. Swamps, bogs, and wet forest would be found under moist or wet conditions. Dwarf shrub heaths would be naturally occurring on poor soils along the coast together with dune systems and salt-marsh vegetation. When comparing the natural vegetation of Denmark to the vegetation of five future-climate analogue areas, the most obvious trend is a shift from deciduous to thermophilous broadleaved forest currently found in Southern and Eastern Europe. A total of 983 taxa were recorded for this study of which 539 were found in Denmark. The Sørensen index was used to measure the floristic similarity between Denmark and the five subregions. Deciduous forest, dwarf shrub heath, and coastal vegetation were treated in more detail, focusing on potential new immigrant species to Denmark. Finally, implications for management were discussed. The floristic similarity between Denmark and regions in Europe with a climate similar to what is expected for Denmark in year 2100 was found to vary between 48-78%, decreasing from North to South. Hence, it seems inevitable that climate changes of the magnitudes foreseen will alter the distribution of individual species and the composition of natural vegetation units. Changes, however, will not be immediate. Historic evidence shows a considerable lag in response to climatic change under natural conditions, but little is known about the effects of human land-use and pollution on this process. Facing such uncertainties we suggested that a dynamic strategy based on modeling, monitoring and adaptive

  19. Impacts of 21st century climate changes on flora and vegetation in Denmark

    Energy Technology Data Exchange (ETDEWEB)

    Skov, Flemming; Nygaard, Bettina; Wind, Peter; Floejgaard, Camilla [Department of Wildlife Ecology and Biodiversity, National Environmental Research Institute, Aarhus University, Grenaavej 14, DK-8410 Roende (Denmark); Borchsenius, Finn; Normand, Signe; Balslev, Henrik; Svenning, Jens-Christian, E-mail: fs@dmu.d [Department of Biological Sciences, Aarhus University, Ny Munkegade 114, DK-8000 Aarhus C (Denmark)

    2009-11-01

    In this paper we examined the potential impacts of predicted climatic changes on the flora and vegetation in Denmark using data from a digital database on the natural vegetation of Europe. Climate scenarios A2 and B2 were used to find regions with present climatic conditions similar to Denmark's climate in the year 2100. The potential natural vegetation of Denmark today is predominantly deciduous forest that would cover more than 90% of the landscape. Swamps, bogs, and wet forest would be found under moist or wet conditions. Dwarf shrub heaths would be naturally occurring on poor soils along the coast together with dune systems and salt-marsh vegetation. When comparing the natural vegetation of Denmark to the vegetation of five future-climate analogue areas, the most obvious trend is a shift from deciduous to thermophilous broadleaved forest currently found in Southern and Eastern Europe. A total of 983 taxa were recorded for this study of which 539 were found in Denmark. The Soerensen index was used to measure the floristic similarity between Denmark and the five subregions. Deciduous forest, dwarf shrub heath, and coastal vegetation were treated in more detail, focusing on potential new immigrant species to Denmark. Finally, implications for management were discussed. The floristic similarity between Denmark and regions in Europe with a climate similar to what is expected for Denmark in year 2100 was found to vary between 48-78%, decreasing from North to South. Hence, it seems inevitable that climate changes of the magnitudes foreseen will alter the distribution of individual species and the composition of natural vegetation units. Changes, however, will not be immediate. Historic evidence shows a considerable lag in response to climatic change under natural conditions, but little is known about the effects of human land-use and pollution on this process. Facing such uncertainties we suggested that a dynamic strategy based on modeling, monitoring and

  20. Explaining fruit and vegetable intake using a consumer marketing tool.

    Science.gov (United States)

    Della, Lindsay J; Dejoy, David M; Lance, Charles E

    2009-10-01

    In response to calls to reinvent the 5 A Day fruit and vegetable campaign, this study assesses the utility of VALS, a consumer-based audience segmentation tool that divides the U.S. population into groups leading similar lifestyles. The study examines whether the impact of theory of planned behavior (TPB) constructs varies across VALS groups in a cross-sectional sample of 1,588 U.S. adults. In a multigroup structural equation model, the VALS audience group variable moderated latent TPB relationships. Attitudes, subjective norms, and perceived behavioral control explained 57% to 70% of the variation in intention to eat fruit and vegetables across 5 different VALS groups. Perceived behavioral control and intention also predicted self-reported consumption behavior (R2 = 20% to 71% across VALS groups). Bivariate z tests were calculated to determine statistical differences in parameter estimates across groups. Nine of the bivariate z tests were statistically significant (p audiences for fruit and vegetable consumption messaging.

  1. Digital soil mapping using remote sensing indices, terrain attributes, and vegetation features in the rangelands of northeastern Iran.

    Science.gov (United States)

    Mahmoudabadi, Ebrahim; Karimi, Alireza; Haghnia, Gholam Hosain; Sepehr, Adel

    2017-09-11

    Digital soil mapping has been introduced as a viable alternative to the traditional mapping methods due to being fast and cost-effective. The objective of the present study was to investigate the capability of the vegetation features and spectral indices as auxiliary variables in digital soil mapping models to predict soil properties. A region with an area of 1225 ha located in Bajgiran rangelands, Khorasan Razavi province, northeastern Iran, was chosen. A total of 137 sampling sites, each containing 3-5 plots with 10-m interval distance along a transect established based on randomized-systematic method, were investigated. In each plot, plant species names and numbers as well as vegetation cover percentage (VCP) were recorded, and finally one composite soil sample was taken from each transect at each site (137 soil samples in total). Terrain attributes were derived from a digital elevation model, different bands and spectral indices were obtained from the Landsat7 ETM+ images, and vegetation features were calculated in the plots, all of which were used as auxiliary variables to predict soil properties using artificial neural network, gene expression programming, and multivariate linear regression models. According to R 2 RMSE and MBE values, artificial neutral network was obtained as the most accurate soil properties prediction function used in scorpan model. Vegetation features and indices were more effective than remotely sensed data and terrain attributes in predicting soil properties including calcium carbonate equivalent, clay, bulk density, total nitrogen, carbon, sand, silt, and saturated moisture capacity. It was also shown that vegetation indices including NDVI, SAVI, MSAVI, SARVI, RDVI, and DVI were more effective in estimating the majority of soil properties compared to separate bands and even some soil spectral indices.

  2. [Quantitative estimation of vegetation cover and management factor in USLE and RUSLE models by using remote sensing data: a review].

    Science.gov (United States)

    Wu, Chang-Guang; Li, Sheng; Ren, Hua-Dong; Yao, Xiao-Hua; Huang, Zi-Jie

    2012-06-01

    Soil loss prediction models such as universal soil loss equation (USLE) and its revised universal soil loss equation (RUSLE) are the useful tools for risk assessment of soil erosion and planning of soil conservation at regional scale. To make a rational estimation of vegetation cover and management factor, the most important parameters in USLE or RUSLE, is particularly important for the accurate prediction of soil erosion. The traditional estimation based on field survey and measurement is time-consuming, laborious, and costly, and cannot rapidly extract the vegetation cover and management factor at macro-scale. In recent years, the development of remote sensing technology has provided both data and methods for the estimation of vegetation cover and management factor over broad geographic areas. This paper summarized the research findings on the quantitative estimation of vegetation cover and management factor by using remote sensing data, and analyzed the advantages and the disadvantages of various methods, aimed to provide reference for the further research and quantitative estimation of vegetation cover and management factor at large scale.

  3. Presence of indicator plant species as a predictor of wetland vegetation integrity

    Science.gov (United States)

    Stapanian, Martin A.; Adams, Jean V.; Gara, Brian

    2013-01-01

    We fit regression and classification tree models to vegetation data collected from Ohio (USA) wetlands to determine (1) which species best predict Ohio vegetation index of biotic integrity (OVIBI) score and (2) which species best predict high-quality wetlands (OVIBI score >75). The simplest regression tree model predicted OVIBI score based on the occurrence of three plant species: skunk-cabbage (Symplocarpus foetidus), cinnamon fern (Osmunda cinnamomea), and swamp rose (Rosa palustris). The lowest OVIBI scores were best predicted by the absence of the selected plant species rather than by the presence of other species. The simplest classification tree model predicted high-quality wetlands based on the occurrence of two plant species: skunk-cabbage and marsh-fern (Thelypteris palustris). The overall misclassification rate from this tree was 13 %. Again, low-quality wetlands were better predicted than high-quality wetlands by the absence of selected species rather than the presence of other species using the classification tree model. Our results suggest that a species’ wetland status classification and coefficient of conservatism are of little use in predicting wetland quality. A simple, statistically derived species checklist such as the one created in this study could be used by field biologists to quickly and efficiently identify wetland sites likely to be regulated as high-quality, and requiring more intensive field assessments. Alternatively, it can be used for advanced determinations of low-quality wetlands. Agencies can save considerable money by screening wetlands for the presence/absence of such “indicator” species before issuing permits.

  4. Post-fire vegetation recovery in Portugal based ewline on spot/vegetation data

    Directory of Open Access Journals (Sweden)

    C. Gouveia

    2010-04-01

    Full Text Available A procedure is presented that allows identifying large burned scars and the monitoring of vegetation recovery in the years following major fire episodes. The procedure relies on 10-day fields of Maximum Value Composites of Normalized Difference Vegetation Index (MVC-NDVI, with a 1 km×1 km spatial resolution obtained from the VEGETATION instrument. The identification of fire scars during the extremely severe 2003 fire season is performed based on cluster analysis of NDVI anomalies that persist during the vegetative cycle of the year following the fire event. Two regions containing very large burned scars were selected, located in Central and Southwestern Portugal, respectively, and time series of MVC-NDVI analysed before the fire events took place and throughout the post-fire period. It is shown that post-fire vegetation dynamics in the two selected regions may be characterised based on maps of recovery rates as estimated by fitting a monoparametric model of vegetation recovery to MVC-NDVI data over each burned scar. Results indicated that the recovery process in the region located in Central Portugal is mostly related to fire damage rather than to vegetation density before 2003, whereas the latter seems to have a more prominent role than vegetation conditions after the fire episode, e.g. in the case of the region in Southwestern Portugal. These differences are consistent with the respective predominant types of vegetation. The burned area located in Central Portugal is dominated by Pinus Pinaster whose natural regeneration crucially depends on the destruction of seeds present on the soil surface during the fire, whereas the burned scar in Southwestern Portugal was populated by Eucalyptus that may quickly re-sprout from buds after fire. Besides its simplicity, the monoparametric model of vegetation recovery has the advantage of being easily adapted to other low-resolution satellite data, as well as to other types of vegetation

  5. Uptake of Organic Contaminants from Soil into Vegetables and Fruits

    DEFF Research Database (Denmark)

    Trapp, Stefan; Legind, Charlotte Nielsen

    2011-01-01

    Contaminants may enter vegetables and fruits by several pathways: by uptake with soil pore water, by diffusion from soil or air, by deposition of soil or airborne particles, or by direct application. The contaminant-specific and plantspecific properties that determine the importance of these path......Contaminants may enter vegetables and fruits by several pathways: by uptake with soil pore water, by diffusion from soil or air, by deposition of soil or airborne particles, or by direct application. The contaminant-specific and plantspecific properties that determine the importance...... of these pathways are described in this chapter. A variety of models have been developed, specific for crop types and with steady-state or dynamic solutions. Model simulations can identify sensitive properties and relevant processes. Persistent, polar (log KOW ... particles, or from air. Volatile contaminants have a low potential for accumulation because they quickly escape to air. Experimental data are listed that support these model predictions, but underline also the high variability of accumulation under field conditions. Plant uptake predictions are uncertain...

  6. The role of water availability in controlling coupled vegetation-atmosphere dynamics

    Science.gov (United States)

    Scanlon, Todd Michael

    This work examines how water availability affects vegetation structure and vegetation-atmosphere exchange of water, carbon, and energy for a savanna ecosystem. The study site is the Kalahari Transect (KT), in southern Africa, which follows a north-south decline in mean annual rainfall from ˜1600 mm/yr to ˜250 mm/yr between the latitudes 12°--26°S. Eddy covariance (EC) flux measurements taken over a time frame of 1--9 days at four sites along the transect during the wet (growing) season revealed that the ecosystem water use efficiency for the sites, defined as the ratio of net carbon flux to evapotranspiration, decreased with increasing mean annual rainfall. EC data were used to parameterize a large eddy simulation model, which was applied over a heterogeneous remotely-sensed surface. Water availability for the vegetation was found to affect the relative controls (structural vs. meteorological) on the spatial distribution of vegetation fluxes. When the spatial distribution of vapor pressure deficit, D, was most predictable (i.e. non water-limiting conditions) it was unimportant in shaping the distribution of the vegetation fluxes, while at times when D was least predictable (i.e. water-limiting conditions) it was most important. This observation is explained by the relative degree of vegetation-atmosphere coupling and the complexity of the non-local effects on D , both of which are dependent upon water availability. Based upon the differing ways in which trees and grass respond to interannual variability in rainfall, a new method was developed to estimate fractional tree, grass, and bare soil cover from a synthesis of satellite and ground-based data. This method was applied to the KT where it was found that tree fractional cover declines with mean annual rainfall, while grass fractional cover peaks near the middle of the gradient. A soil moisture model applied to this data indicated a shift from nutrient- to water-limitation from the mesic to arid portions of

  7. Remote Estimation of Vegetation Fraction and Yield in Oilseed Rape with Unmanned Aerial Vehicle Data

    Science.gov (United States)

    Peng, Y.; Fang, S.; Liu, K.; Gong, Y.

    2017-12-01

    This study developed an approach for remote estimation of Vegetation Fraction (VF) and yield in oilseed rape, which is a crop species with conspicuous flowers during reproduction. Canopy reflectance in green, red, red edge and NIR bands was obtained by a camera system mounted on an unmanned aerial vehicle (UAV) when oilseed rape was in the vegetative growth and flowering stage. The relationship of several widely-used Vegetation Indices (VI) vs. VF was tested and found to be different in different phenology stages. At the same VF when oilseed rape was flowering, canopy reflectance increased in all bands, and the tested VI decreased. Therefore, two algorithms to estimate VF were calibrated respectively, one for samples during vegetative growth and the other for samples during flowering stage. During the flowering season, we also explored the potential of using canopy reflectance or VIs to estimate Flower Fraction (FF) in oilseed rape. Based on FF estimates, rape yield can be estimated using canopy reflectance data. Our model was validated in oilseed rape planted under different nitrogen fertilization applications and in different phenology stages. The results showed that it was able to predict VF and FF accurately in oilseed rape with estimation error below 6% and predict yield with estimation error below 20%.

  8. Evaluation of mathematical methods for predicting optimum dose of gamma radiation in sugarcane (Saccharum sp.)

    International Nuclear Information System (INIS)

    Wu, K.K.; Siddiqui, S.H.; Heinz, D.J.; Ladd, S.L.

    1978-01-01

    Two mathematical methods - the reversed logarithmic method and the regression method - were used to compare the predicted and the observed optimum gamma radiation dose (OD 50 ) in vegetative propagules of sugarcane. The reversed logarithmic method, usually used in sexually propagated crops, showed the largest difference between the predicted and observed optimum dose. The regression method resulted in a better prediction of the observed values and is suggested as a better method for the prediction of optimum dose for vegetatively propagated crops. (author)

  9. Trace metal uptake by tropical vegetables grown on soil amended with urban sewage sludge

    Energy Technology Data Exchange (ETDEWEB)

    Nabulo, G.; Black, C.R. [School of Biosciences, University of Nottingham, University Park, Nottingham, NG7 2RD (United Kingdom); Young, S.D., E-mail: scott.young@nottingham.ac.u [School of Biosciences, University of Nottingham, University Park, Nottingham, NG7 2RD (United Kingdom)

    2011-02-15

    Trace metal uptake was measured for tropical and temperate leafy vegetables grown on soil from an urban sewage disposal farm in the UK. Twenty-four leafy vegetables from East Africa and the UK were assessed and the five vegetable types that showed the greatest Cd concentrations were grown on eight soils differing in the severity of contamination, pH and other physico-chemical properties. The range of Cd concentrations in the edible shoots was greater for tropical vegetables than for temperate types. Metal uptake was modelled as a function of (i) total soil metal concentration, (ii) CaCl{sub 2}-soluble metal, (iii) soil solution concentration and (iv) the activity of metal ions in soil pore water. Tropical vegetables were not satisfactorily modelled as a single generic 'green vegetable', suggesting that more sophisticated approaches to risk assessment may be required to assess hazard from peri-urban agriculture in developing countries. - Research highlights: Cadmium uptake by tropical green vegetables varies greatly between types. Modelling metal uptake works best for Ni, Cd and Zn but is poor for Cu, Ba and Pb. Modelling with dilute CaCl{sub 2} extraction is as good as metal ion activity in pore water. - Trace metal uptake by tropical leaf vegetables can be predicted from dilute CaCl{sub 2} extraction of soil but model parameters are genotype-specific.

  10. Trace metal uptake by tropical vegetables grown on soil amended with urban sewage sludge

    International Nuclear Information System (INIS)

    Nabulo, G.; Black, C.R.; Young, S.D.

    2011-01-01

    Trace metal uptake was measured for tropical and temperate leafy vegetables grown on soil from an urban sewage disposal farm in the UK. Twenty-four leafy vegetables from East Africa and the UK were assessed and the five vegetable types that showed the greatest Cd concentrations were grown on eight soils differing in the severity of contamination, pH and other physico-chemical properties. The range of Cd concentrations in the edible shoots was greater for tropical vegetables than for temperate types. Metal uptake was modelled as a function of (i) total soil metal concentration, (ii) CaCl 2 -soluble metal, (iii) soil solution concentration and (iv) the activity of metal ions in soil pore water. Tropical vegetables were not satisfactorily modelled as a single generic 'green vegetable', suggesting that more sophisticated approaches to risk assessment may be required to assess hazard from peri-urban agriculture in developing countries. - Research highlights: → Cadmium uptake by tropical green vegetables varies greatly between types. → Modelling metal uptake works best for Ni, Cd and Zn but is poor for Cu, Ba and Pb. → Modelling with dilute CaCl 2 extraction is as good as metal ion activity in pore water. - Trace metal uptake by tropical leaf vegetables can be predicted from dilute CaCl 2 extraction of soil but model parameters are genotype-specific.

  11. Estimating vegetation biomass and cover across large plots in shrub and grass dominated drylands using terrestrial lidar and machine learning

    Science.gov (United States)

    Anderson, Kyle E.; Glenn, Nancy F.; Spaete, Lucas P.; Shinneman, Douglas; Pilliod, David S.; Arkle, Robert; McIlroy, Susan; Derryberry, DeWayne R.

    2018-01-01

    Terrestrial laser scanning (TLS) has been shown to enable an efficient, precise, and non-destructive inventory of vegetation structure at ranges up to hundreds of meters. We developed a method that leverages TLS collections with machine learning techniques to model and map canopy cover and biomass of several classes of short-stature vegetation across large plots. We collected high-definition TLS scans of 26 1-ha plots in desert grasslands and big sagebrush shrublands in southwest Idaho, USA. We used the Random Forests machine learning algorithm to develop decision tree models predicting the biomass and canopy cover of several vegetation classes from statistical descriptors of the aboveground heights of TLS points. Manual measurements of vegetation characteristics collected within each plot served as training and validation data. Models based on five or fewer TLS descriptors of vegetation heights were developed to predict the canopy cover fraction of shrubs (R2 = 0.77, RMSE = 7%), annual grasses (R2 = 0.70, RMSE = 21%), perennial grasses (R2 = 0.36, RMSE = 12%), forbs (R2 = 0.52, RMSE = 6%), bare earth or litter (R2 = 0.49, RMSE = 19%), and the biomass of shrubs (R2 = 0.71, RMSE = 175 g) and herbaceous vegetation (R2 = 0.61, RMSE = 99 g) (all values reported are out-of-bag). Our models explained much of the variability between predictions and manual measurements, and yet we expect that future applications could produce even better results by reducing some of the methodological sources of error that we encountered. Our work demonstrates how TLS can be used efficiently to extend manual measurement of vegetation characteristics from small to large plots in grasslands and shrublands, with potential application to other similarly structured ecosystems. Our method shows that vegetation structural characteristics can be modeled without classifying and delineating individual plants, a challenging and time-consuming step common in previous

  12. Accumulation status, sources and phytoavailability of metals in greenhouse vegetable production systems in Beijing, China.

    Science.gov (United States)

    Xu, Li; Lu, Anxiang; Wang, Jihua; Ma, Zhihong; Pan, Ligang; Feng, Xiaoyuan; Luan, Yunxia

    2015-12-01

    The accumulation status, sources and phytoavailability of selected metals in greenhouse vegetable production systems in peri-urban areas of Beijing were investigated. The mean concentrations of As, Cd, Cr, Hg and Pb in greenhouse soils were 8.44, 0.25, 69.0, 0.09 and 22.0 mg kg(-1), dw, respectively. According to principal component analysis, As, Cd, Cr and Hg are mainly from anthropogenic source, but Pb is likely from natural source. Metal concentrations in all vegetable samples were decreased in the order of Cr>As>Pb>Cd>Hg. Compared with root and fruit vegetables, leaf vegetables had relatively high concentrations and transfer factors of heavy metals, except for Cd. By including soil pH, OM and greenhouse soil metals, 10 empirical models were derived using stepwise multiple linear regression analysis to predict heavy metal concentrations in the edible parts of different vegetables. Among the different vegetable groups, the highest intakes of metals occurred through consumption of leaf vegetables for the two age groups, except for Cd. The HI value of the studied metals were all below 1, indicating that consumption of vegetables grown in greenhouse soils was of low risk to consumers in our study area. Copyright © 2015 Elsevier Inc. All rights reserved.

  13. Method of producing vegetable puree

    DEFF Research Database (Denmark)

    2004-01-01

    A process for producing a vegetable puree, comprising the sequential steps of: a)crushing, chopping or slicing the vegetable into pieces of 1 to 30 mm; b) blanching the vegetable pieces at a temperature of 60 to 90°C; c) contacted the blanched vegetable pieces with a macerating enzyme activity; d......) blending the macerated vegetable pieces and obtaining a puree....

  14. Importance of vegetation dynamics for future terrestrial carbon cycling

    International Nuclear Information System (INIS)

    Ahlström, Anders; Smith, Benjamin; Xia, Jianyang; Luo, Yiqi; Arneth, Almut

    2015-01-01

    Terrestrial ecosystems currently sequester about one third of anthropogenic CO 2 emissions each year, an important ecosystem service that dampens climate change. The future fate of this net uptake of CO 2 by land based ecosystems is highly uncertain. Most ecosystem models used to predict the future terrestrial carbon cycle share a common architecture, whereby carbon that enters the system as net primary production (NPP) is distributed to plant compartments, transferred to litter and soil through vegetation turnover and then re-emitted to the atmosphere in conjunction with soil decomposition. However, while all models represent the processes of NPP and soil decomposition, they vary greatly in their representations of vegetation turnover and the associated processes governing mortality, disturbance and biome shifts. Here we used a detailed second generation dynamic global vegetation model with advanced representation of vegetation growth and mortality, and the associated turnover. We apply an emulator that describes the carbon flows and pools exactly as in simulations with the full model. The emulator simulates ecosystem dynamics in response to 13 different climate or Earth system model simulations from the Coupled Model Intercomparison Project Phase 5 ensemble under RCP8.5 radiative forcing. By exchanging carbon cycle processes between these 13 simulations we quantified the relative roles of three main driving processes of the carbon cycle; (I) NPP, (II) vegetation dynamics and turnover and (III) soil decomposition, in terms of their contribution to future carbon (C) uptake uncertainties among the ensemble of climate change scenarios. We found that NPP, vegetation turnover (including structural shifts, wild fires and mortality) and soil decomposition rates explained 49%, 17% and 33%, respectively, of uncertainties in modelled global C-uptake. Uncertainty due to vegetation turnover was further partitioned into stand-clearing disturbances (16%), wild fires (0%), stand

  15. The role of vegetation dynamics in the control of atmospheric CO{sub 2} content

    Energy Technology Data Exchange (ETDEWEB)

    Sitch, Stephen

    2000-04-01

    This thesis contains a description of the Lund-Potsdam-Jena Dynamic Global Vegetation Model (LPJ-DGVM) and its application to infer the role of vegetation dynamics on atmospheric CO{sub 2} content at different time-scales. The model combines vegetation dynamics and biogeochemistry in a modular framework. Individual modules describe ecosystems processes, including vegetation resource competition and production, tissue turnover, growth, fire and mortality, soil and litter biogeochemistry, including the effects of CO{sub 2} on these processes. The model simulates realistic post-disturbance succession in different environments. Seasonal exchange of H{sub 2}O and CO{sub 2} between the terrestrial biosphere and the atmosphere is modelled in reasonable agreement with observation. Global estimates of carbon stocks in soil, litter and vegetation are within their acceptable ranges and the model captures the present-day patterns in vegetation. Fire return intervals are simulated correctly in most regions. Results emphasise the important role of the terrestrial biosphere in both the seasonal cycle and in the inter-annual variability in the growth rate of atmospheric CO{sub 2}. LPJ successfully reproduced both the amplitude and phase of the seasonal cycle of atmospheric CO{sub 2} content as measured at a global network of monitoring stations. The model predicted a small net terrestrial biosphere uptake of CO{sub 2} during the 1980s with a strong CO{sub 2} fertilisation effect, which enhances plant production, reduced by the effects of climate and land use change. Historical land use change and CO{sub 2} fertilisation have been the dominant, albeit opposing factors governing the response of the terrestrial biosphere with respect to carbon storage during the 20th century. LPJ is run using one future climate and atmospheric CO{sub 2} scenario until 2200. Enhanced production due to the CO{sub 2} fertilisation effect eventually reaches an asymptote, and consequently the ability of

  16. Modeling vegetation community responses to sea-level rise on Barrier Island systems: A case study on the Cape Canaveral Barrier Island complex, Florida, USA.

    Directory of Open Access Journals (Sweden)

    Tammy E Foster

    Full Text Available Society needs information about how vegetation communities in coastal regions will be impacted by hydrologic changes associated with climate change, particularly sea level rise. Due to anthropogenic influences which have significantly decreased natural coastal vegetation communities, it is important for us to understand how remaining natural communities will respond to sea level rise. The Cape Canaveral Barrier Island complex (CCBIC on the east central coast of Florida is within one of the most biologically diverse estuarine systems in North America and has the largest number of threatened and endangered species on federal property in the contiguous United States. The high level of biodiversity is susceptible to sea level rise. Our objective was to model how vegetation communities along a gradient ranging from hydric to upland xeric on CCBIC will respond to three sea level rise scenarios (0.2 m, 0.4 m, and 1.2 m. We used a probabilistic model of the current relationship between elevation and vegetation community to determine the impact sea level rise would have on these communities. Our model correctly predicted the current proportions of vegetation communities on CCBIC based on elevation. Under all sea level rise scenarios the model predicted decreases in mesic and xeric communities, with the greatest losses occurring in the most xeric communities. Increases in total area of salt marsh were predicted with a 0.2 and 0.4 m rise in sea level. With a 1.2 m rise in sea level approximately half of CCBIC's land area was predicted to transition to open water. On the remaining land, the proportions of most of the vegetation communities were predicted to remain similar to that of current proportions, but there was a decrease in proportion of the most xeric community (oak scrub and an increase in the most hydric community (salt marsh. Our approach provides a first approximation of the impacts of sea level rise on terrestrial vegetation communities

  17. Modeling vegetation community responses to sea-level rise on Barrier Island systems: A case study on the Cape Canaveral Barrier Island complex, Florida, USA.

    Science.gov (United States)

    Foster, Tammy E; Stolen, Eric D; Hall, Carlton R; Schaub, Ronald; Duncan, Brean W; Hunt, Danny K; Drese, John H

    2017-01-01

    Society needs information about how vegetation communities in coastal regions will be impacted by hydrologic changes associated with climate change, particularly sea level rise. Due to anthropogenic influences which have significantly decreased natural coastal vegetation communities, it is important for us to understand how remaining natural communities will respond to sea level rise. The Cape Canaveral Barrier Island complex (CCBIC) on the east central coast of Florida is within one of the most biologically diverse estuarine systems in North America and has the largest number of threatened and endangered species on federal property in the contiguous United States. The high level of biodiversity is susceptible to sea level rise. Our objective was to model how vegetation communities along a gradient ranging from hydric to upland xeric on CCBIC will respond to three sea level rise scenarios (0.2 m, 0.4 m, and 1.2 m). We used a probabilistic model of the current relationship between elevation and vegetation community to determine the impact sea level rise would have on these communities. Our model correctly predicted the current proportions of vegetation communities on CCBIC based on elevation. Under all sea level rise scenarios the model predicted decreases in mesic and xeric communities, with the greatest losses occurring in the most xeric communities. Increases in total area of salt marsh were predicted with a 0.2 and 0.4 m rise in sea level. With a 1.2 m rise in sea level approximately half of CCBIC's land area was predicted to transition to open water. On the remaining land, the proportions of most of the vegetation communities were predicted to remain similar to that of current proportions, but there was a decrease in proportion of the most xeric community (oak scrub) and an increase in the most hydric community (salt marsh). Our approach provides a first approximation of the impacts of sea level rise on terrestrial vegetation communities, including important

  18. Estimating vegetation dryness to optimize fire risk assessment with spot vegetation satellite data in savanna ecosystems

    Science.gov (United States)

    Verbesselt, J.; Somers, B.; Lhermitte, S.; van Aardt, J.; Jonckheere, I.; Coppin, P.

    2005-10-01

    The lack of information on vegetation dryness prior to the use of fire as a management tool often leads to a significant deterioration of the savanna ecosystem. This paper therefore evaluated the capacity of SPOT VEGETATION time-series to monitor the vegetation dryness (i.e., vegetation moisture content per vegetation amount) in order to optimize fire risk assessment in the savanna ecosystem of Kruger National Park in South Africa. The integrated Relative Vegetation Index approach (iRVI) to quantify the amount of herbaceous biomass at the end of the rain season and the Accumulated Relative Normalized Difference vegetation index decrement (ARND) related to vegetation moisture content were selected. The iRVI and ARND related to vegetation amount and moisture content, respectively, were combined in order to monitor vegetation dryness and optimize fire risk assessment in the savanna ecosystems. In situ fire activity data was used to evaluate the significance of the iRVI and ARND to monitor vegetation dryness for fire risk assessment. Results from the binary logistic regression analysis confirmed that the assessment of fire risk was optimized by integration of both the vegetation quantity (iRVI) and vegetation moisture content (ARND) as statistically significant explanatory variables. Consequently, the integrated use of both iRVI and ARND to monitor vegetation dryness provides a more suitable tool for fire management and suppression compared to other traditional satellite-based fire risk assessment methods, only related to vegetation moisture content.

  19. Unique Microbial Diversity and Metabolic Pathway Features of Fermented Vegetables From Hainan, China

    Science.gov (United States)

    Peng, Qiannan; Jiang, Shuaiming; Chen, Jieling; Ma, Chenchen; Huo, Dongxue; Shao, Yuyu; Zhang, Jiachao

    2018-01-01

    Fermented vegetables are typically traditional foods made of fresh vegetables and their juices, which are fermented by beneficial microorganisms. Herein, we applied high-throughput sequencing and culture-dependent technology to describe the diversities of microbiota and identify core microbiota in fermented vegetables from different areas of Hainan Province, and abundant metabolic pathways in the fermented vegetables were simultaneously predicted. At the genus level, Lactobacillus bacteria were the most abundant. Lactobacillus plantarum was the most abundant species, followed by Lactobacillus fermentum, Lactobacillus pentosaceus, and Weissella cibaria. These species were present in each sample with average absolute content values greater than 1% and were thus defined as core microbiota. Analysis results based on the alpha and beta diversities of the microbial communities showed that the microbial profiles of the fermented vegetables differed significantly based on the regions and raw materials used, and the species of the vegetables had a greater effect on the microbial community structure than the region from where they were harvested. Regarding microbial functional metabolism, we observed an enrichment of metabolic pathways, including membrane transport, replication and repair and translation, which implied that the microbial metabolism in the fermented vegetables tended to be vigorous. In addition, Lactobacillus plantarum and Lactobacillus fermentum were calculated to be major metabolic pathway contributors. Finally, we constructed a network to better explain correlations among the core microbiota and metabolic pathways. This study facilitates an understanding of the differences in microbial profiles and fermentation pathways involved in the production of fermented vegetables, establishes a basis for optimally selecting microorganisms to manufacture high-quality fermented vegetable products, and lays the foundation for better utilizing tropical microbial

  20. Unique Microbial Diversity and Metabolic Pathway Features of Fermented Vegetables From Hainan, China

    Directory of Open Access Journals (Sweden)

    Qiannan Peng

    2018-03-01

    Full Text Available Fermented vegetables are typically traditional foods made of fresh vegetables and their juices, which are fermented by beneficial microorganisms. Herein, we applied high-throughput sequencing and culture-dependent technology to describe the diversities of microbiota and identify core microbiota in fermented vegetables from different areas of Hainan Province, and abundant metabolic pathways in the fermented vegetables were simultaneously predicted. At the genus level, Lactobacillus bacteria were the most abundant. Lactobacillus plantarum was the most abundant species, followed by Lactobacillus fermentum, Lactobacillus pentosaceus, and Weissella cibaria. These species were present in each sample with average absolute content values greater than 1% and were thus defined as core microbiota. Analysis results based on the alpha and beta diversities of the microbial communities showed that the microbial profiles of the fermented vegetables differed significantly based on the regions and raw materials used, and the species of the vegetables had a greater effect on the microbial community structure than the region from where they were harvested. Regarding microbial functional metabolism, we observed an enrichment of metabolic pathways, including membrane transport, replication and repair and translation, which implied that the microbial metabolism in the fermented vegetables tended to be vigorous. In addition, Lactobacillus plantarum and Lactobacillus fermentum were calculated to be major metabolic pathway contributors. Finally, we constructed a network to better explain correlations among the core microbiota and metabolic pathways. This study facilitates an understanding of the differences in microbial profiles and fermentation pathways involved in the production of fermented vegetables, establishes a basis for optimally selecting microorganisms to manufacture high-quality fermented vegetable products, and lays the foundation for better utilizing

  1. Evaluation of vegetation cover using the normalized difference vegetation index (NDVI

    Directory of Open Access Journals (Sweden)

    Gabriela Camargos Lima

    2013-08-01

    Full Text Available Soil loss by water erosion is the main cause of soil degradation in Brazil. However, erosion can be reduced by the presence of vegetation. The Normalized Difference Vegetation Index (NDVI makes it possible to identify the vegetative vigor of crops or natural vegetation which facilities the identification of areas with vegetation covers. This information is very important in identifying the phenomena which might be occurring in a particular area, especially those related to soil degradation by water erosion. Thus, the aim of this work was to assess the canopy cover by using NDVI, checking the image accuracy using the Coverage Index (CI based on the Stocking method, in the Sub-basin of Posses, which belongs to the Cantareira System, located in the Extrema municipality, Minas Gerais, Brazil. Landsat-5 TM images were used. The sub-basin of Posses was very altered in comparison to the surrounding areas. The NDVI technique proved to be a suitable tool to assess the uses that occur in the sub-basin of Posses, as validated by the Stocking methodology. The map derived from NDVI allowed the geographic distribution of different land uses to be observed and allowed for the identification of critical areas in relation to vegetation cover as well. This finding can be used to optimize efforts to recover and protect soil in areas with bare soil and degraded pasture, in order to reduce environmental degradation. The CI has not exceeded 40% for land use classes that occur in the majority of the sub-basin (91%, except in areas of woody vegetation.

  2. Using Google Earth Surface Metrics to Predict Plant Species Richness in a Complex Landscape

    Directory of Open Access Journals (Sweden)

    Sebastián Block

    2016-10-01

    Full Text Available Google Earth provides a freely available, global mosaic of high-resolution imagery from different sensors that has become popular in environmental and ecological studies. However, such imagery lacks the near-infrared band often used in studying vegetation, thus its potential for estimating vegetation properties remains unclear. In this study, we assess the potential of Google Earth imagery to describe and predict vegetation attributes. Further, we compare it to the potential of SPOT imagery, which has additional spectral information. We measured basal area, vegetation height, crown cover, density of individuals, and species richness in 60 plots in the oak forests of a complex volcanic landscape in central Mexico. We modelled each vegetation attribute as a function of surface metrics derived from Google Earth and SPOT images, and selected the best-supported linear models from each source. Total species richness was the best-described and predicted variable: the best Google Earth-based model explained nearly as much variation in species richness as its SPOT counterpart (R2 = 0.44 and 0.51, respectively. However, Google Earth metrics emerged as poor predictors of all remaining vegetation attributes, whilst SPOT metrics showed potential for predicting vegetation height. We conclude that Google Earth imagery can be used to estimate species richness in complex landscapes. As it is freely available, Google Earth can broaden the use of remote sensing by researchers and managers in low-income tropical countries where most biodiversity hotspots are found.

  3. Scale-dependent performances of CMIP5 earth system models in simulating terrestrial vegetation carbon

    Science.gov (United States)

    Jiang, L.; Luo, Y.; Yan, Y.; Hararuk, O.

    2013-12-01

    Mitigation of global changes will depend on reliable projection for the future situation. As the major tools to predict future climate, Earth System Models (ESMs) used in Coupled Model Intercomparison Project Phase 5 (CMIP5) for the IPCC Fifth Assessment Report have incorporated carbon cycle components, which account for the important fluxes of carbon between the ocean, atmosphere, and terrestrial biosphere carbon reservoirs; and therefore are expected to provide more detailed and more certain projections. However, ESMs are never perfect; and evaluating the ESMs can help us to identify uncertainties in prediction and give the priorities for model development. In this study, we benchmarked carbon in live vegetation in the terrestrial ecosystems simulated by 19 ESMs models from CMIP5 with an observationally estimated data set of global carbon vegetation pool 'Olson's Major World Ecosystem Complexes Ranked by Carbon in Live Vegetation: An Updated Database Using the GLC2000 Land Cover Product' by Gibbs (2006). Our aim is to evaluate the ability of ESMs to reproduce the global vegetation carbon pool at different scales and what are the possible causes for the bias. We found that the performance CMIP5 ESMs is very scale-dependent. While CESM1-BGC, CESM1-CAM5, CESM1-FASTCHEM and CESM1-WACCM, and NorESM1-M and NorESM1-ME (they share the same model structure) have very similar global sums with the observation data but they usually perform poorly at grid cell and biome scale. In contrast, MIROC-ESM and MIROC-ESM-CHEM simulate the best on at grid cell and biome scale but have larger differences in global sums than others. Our results will help improve CMIP5 ESMs for more reliable prediction.

  4. Productive vegetation: relationships between net primary productivity, vegetation types and climate change in the Wet Tropics bioregion

    International Nuclear Information System (INIS)

    Ramirez, Vanessa Valdez; Williams, Stephen E.; VanDerWal, Jeremy

    2007-01-01

    Full text: Full text: There is now ample evidence demonstrating the impacts of climate change on biodiversity and human society (Walther ef a/. 2002). Numerous studies have shown climate change is one of the most significant threats to tropical forests, such as the Wet Tropics Heritage Area, due to their high biodiversity and endemism (Pounds ef al. 1999; Hughes 2000; Parmesan and Yohe 2003). Williams ef al. (2003) suggested that small shifts in net primary productivity (NPP) as a result of climate change could lead to potentially massive follow-on effects for the extremely diverse and vulnerable rainforest flora and fauna. It is therefore crucial to explore the relationships between NPP and local biodiversity, especially to create models for different climate change scenarios. Nevertheless, NPP in the Wet Tropics has yet to be estimated. This is the first study to provide a general NPP estimate for the Wet Tropics bioregion using climate surrogates (Schuur 2003). This technique estimates NPP in an accurate, repeatable, and cost-effective way. NPP values were linked to vegetation types and examined under various climatic and environmental conditions. Results show a significant difference in productivity according to vegetation types and climatic variables, with temperature and rainfall seasonality as the most important determining variables. Additionally, lowland and upland vegetations showed a significant difference in productivity patterns throughout the year. Vegetation types located above 1000 metres in altitude had the lowest values of mean annual productivity due to their high rainfall and low temperatures; vegetation types located below 600 metres showed increased productivity values during the wet season (December-March). Net primary productivity will certainly be impacted by changes in temperature and rainfall, due to climate change. Although an increase in NPP values can be predicted for upland areas, the more widely distributed lowlands will drastically

  5. European Vegetation Archive (EVA)

    NARCIS (Netherlands)

    Chytrý, Milan; Hennekens, S.M.; Jiménez-Alfaro, Borja; Schaminée, J.H.J.; Haveman, Rense; Janssen, J.A.M.

    2016-01-01

    The European Vegetation Archive (EVA) is a centralized database of European vegetation plots developed by the IAVS Working Group European Vegetation Survey. It has been in development since 2012 and first made available for use in research projects in 2014. It stores copies of national and

  6. The contribution of vegetation and landscape configuration for predicting environmental change impacts on Iberian birds

    DEFF Research Database (Denmark)

    Triviño, Maria; Thuiller, Wilfried; Cabeza, Mar

    2011-01-01

    of distributions, but they are rarely considered in such assessments. We explore the consequences of using simulated vegetation structure and composition as well as its associated landscape configuration in models projecting global change effects on Iberian bird species distributions. Both present-day and future...

  7. Children and vegetables: strategies to increase children’s liking and intake of vegetables

    NARCIS (Netherlands)

    Wild, de V.W.T.

    2015-01-01

    Background and aim

    Children’s vegetable intake is far below that recommended. Despite increased awareness of the importance of vegetable consumption for health, it remains challenging to improve children’s vegetable intake. Since food preferences are central to

  8. Network based early warning indicators of vegetation changes in a land–atmosphere model

    NARCIS (Netherlands)

    Yin, Z.; Dekker, S.C.; Rietkerk, M.; Hurk, B.J.J.M. van den; Dijkstra, H.A.

    2016-01-01

    Abstract Numerous model studies demonstrate that ecosystems might not shift smoothly with a gradual change in resource concentration. At specific points, vegetation can suddenly shift from one stable state to another. To predict such undesirable shifts, statistical indicators are proposed for early

  9. Runoff measurement and prediction for a watershed under natural vegetation in central Brazil

    Directory of Open Access Journals (Sweden)

    C. L. Silva

    1999-09-01

    Full Text Available This work aimed to measure and analyze total rainfall (P, rainfall intensity and five-day antecedent rainfall effects on runoff (R; to compare measured and simulated R values using the Soil Conservation Service Curve Number method (CN for each rainfall event; and to establish average R/P ratios for observed R values. A one-year (07/01/96 to 06/30/97 rainfall-runoff data study was carried out in the Capetinga watershed (962.4 ha, located at the Federal District of Brazil, 47° 52' longitude West and 15° 52' latitude South. Soils of the watershed were predominantly covered by natural vegetation. Total rainfall and runoff for the period were 1,744 and 52.5 mm, respectively, providing R/P of 3% and suggesting that watershed physical characteristics favored water infiltration into the soil. A multivariate regression analysis for 31 main rainfall-runoff events totaling 781.9 and 51.0 mm, respectively, indicated that the amount of runoff was only dependent upon rainfall volume. Simulated values of total runoff were underestimated about 15% when using CN method and an area-weighted average of the CN based on published values. On the other hand, when average values of CN were calculated for the watershed, total runoff was overestimated about 39%, suggesting that CN method shoud be used with care in areas under natural vegetation.

  10. Preparing Landsat Image Time Series (LITS for Monitoring Changes in Vegetation Phenology in Queensland, Australia

    Directory of Open Access Journals (Sweden)

    Santosh Bhandari

    2012-06-01

    Full Text Available Time series of images are required to extract and separate information on vegetation change due to phenological cycles, inter-annual climatic variability, and long-term trends. While images from the Landsat Thematic Mapper (TM sensor have the spatial and spectral characteristics suited for mapping a range of vegetation structural and compositional properties, its 16-day revisit period combined with cloud cover problems and seasonally limited latitudinal range, limit the availability of images at intervals and durations suitable for time series analysis of vegetation in many parts of the world. Landsat Image Time Series (LITS is defined here as a sequence of Landsat TM images with observations from every 16 days for a five-year period, commencing on July 2003, for a Eucalyptus woodland area in Queensland, Australia. Synthetic Landsat TM images were created using the Spatial and Temporal Adaptive Reflectance Fusion Model (STARFM algorithm for all dates when images were either unavailable or too cloudy. This was done using cloud-free scenes and a MODIS Nadir BRDF Adjusted Reflectance (NBAR product. The ability of the LITS to measure attributes of vegetation phenology was examined by: (1 assessing the accuracy of predicted image-derived Foliage Projective Cover (FPC estimates using ground-measured values; and (2 comparing the LITS-generated normalized difference vegetation index (NDVI and MODIS NDVI (MOD13Q1 time series. The predicted image-derived FPC products (value ranges from 0 to 100% had an RMSE of 5.6. Comparison between vegetation phenology parameters estimated from LITS-generated NDVI and MODIS NDVI showed no significant difference in trend and less than 16 days (equal to the composite period of the MODIS data used difference in key seasonal parameters, including start and end of season in most of the cases. In comparison to similar published work, this paper tested the STARFM algorithm in a new (broadleaf forest environment and also

  11. Vegetative and adaptive traits predict different outcomes for restoration using hybrids

    Directory of Open Access Journals (Sweden)

    Philip Crystal

    2016-11-01

    Full Text Available Abstract – Hybridization has been implicated as a driver of speciation, extinction, and invasiveness, but can also provide resistant breeding stock following epidemics. However, evaluating the appropriateness of hybrids for use in restoration programs is difficult. Past the F1 generation, the proportion of a progenitor’s genome can vary widely, as can the combinations of parental genomes. Detailed genetic analysis can reveal this information, but cannot expose phenotypic alterations due to heterosis, transgressive traits, or changes in metabolism or development. In addition, because evolution is often driven by extreme individuals, decisions based on phenotypic averages of hybrid classes may have unintended results. We demonstrate a strategy to evaluate hybrids for use in restoration by visualizing hybrid phenotypes across selected groups of traits relative to both progenitor species. Specifically, we used discriminant analysis to differentiate among butternut (Juglans cinerea L., black walnut (J. nigra L., and Japanese walnut (J. ailantifolia Carr. var. cordiformis using vegetative characters and then with functional adaptive traits associated with seedling performance. When projected onto the progenitor trait space, naturally occurring hybrids (J. ×bixbyi Rehd. between butternut and Japanese walnut showed introgression towards Japanese walnut at vegetative characters but exhibited a hybrid swarm at functional traits. Both results indicate that hybrids have morphological and ecological phenotypes that distinguish them from butternut, demonstrating a lack of ecological equivalency that should not be carried into restoration breeding efforts. Despite these discrepancies, some hybrids were projected into the space occupied by butternut seedlings’ 95% confidence ellipse, signifying that some hybrids were similar at the measured traits. Determining how to consistently identify these individuals is imperative for future breeding and species

  12. Changes in Vegetation Growth Dynamics and Relations with Climate over China’s Landmass from 1982 to 2011

    Directory of Open Access Journals (Sweden)

    Guang Xu

    2014-04-01

    Full Text Available Understanding how the dynamics of vegetation growth respond to climate change at different temporal and spatial scales is critical to projecting future ecosystem dynamics and the adaptation of ecosystems to global change. In this study, we investigated vegetated growth dynamics (annual productivity, seasonality and the minimum amount of vegetated cover in China and their relations with climatic factors during 1982–2011, using the updated Global Inventory Modeling and Mapping Studies (GIMMS third generation global satellite Advanced Very High Resolution Radiometer (AVHRR Normalized Difference Vegetation Index (NDVI dataset and climate data acquired from the National Centers for Environmental Prediction (NCEP. Major findings are as follows: (1 annual mean NDVI over China significantly increased by about 0.0006 per year from 1982 to 2011; (2 of the vegetated area in China, over 33% experienced a significant positive trend in vegetation growth, mostly located in central and southern China; about 21% experienced a significant positive trend in growth seasonality, most of which occurred in northern China (>35°N; (3 changes in vegetation growth dynamics were significantly correlated with air temperature and precipitation (p < 0.001 at a region scale; (4 at the country scale, changes in NDVI was significantly and positively correlated with annual air temperature (r = 0.52, p < 0.01 and not associated with annual precipitation (p > 0.1; (5 of the vegetated area, about 24% showed significant correlations between annual mean NDVI and air temperature (93% positive and remainder negative, and 12% showed significant correlations of annual mean NDVI with annual precipitation (65% positive and 35% negative. The spatiotemporal variations in vegetation growth dynamics were controlled primarily by temperature and secondly by precipitation. Vegetation growth was also affected by human activities; and (6 monthly NDVI was significantly correlated with the

  13. Irradiation of dehydrated vegetables

    International Nuclear Information System (INIS)

    Esterhuyse, A; Esterhuizen, T.

    1985-01-01

    The reason for radurization was to decreased the microbial count of dehydrated vegetables. The average absorbed irradiation dose range between 2kGy and 15kGy. The product catagories include a) Green vegetables b) White vegetables c) Powders of a) and b). The microbiological aspects were: Declining curves for the different products of T.P.C., Coliforms, E. Coli, Stap. areus, Yeast + Mold at different doses. The organoleptical aspects were: change in taste, flavour, texture, colour and moisture. The aim is the marketing of irradiated dehydrated vegetables national and international basis

  14. [Variation of forest vegetation carbon storage and carbon sequestration rate in Liaoning Province, Northeast China].

    Science.gov (United States)

    Zhen, Wei; Huang, Mei; Zhai, Yin-Li; Chen, Ke; Gong, Ya-Zhen

    2014-05-01

    The forest vegetation carbon stock and carbon sequestration rate in Liaoning Province, Northeast China, were predicted by using Canadian carbon balance model (CBM-CFS3) combining with the forest resource data. The future spatio-temporal distribution and trends of vegetation carbon storage, carbon density and carbon sequestration rate were projected, based on the two scenarios, i. e. with or without afforestation. The result suggested that the total forest vegetation carbon storage and carbon density in Liaoning Province in 2005 were 133.94 Tg and 25.08 t x hm(-2), respectively. The vegetation carbon storage in Quercus was the biggest, while in Robinia pseudoacacia was the least. Both Larix olgensis and broad-leaved forests had higher vegetation carbon densities than others, and the vegetation carbon densities of Pinus tabuliformis, Quercus and Robinia pseudoacacia were close to each other. The spatial distribution of forest vegetation carbon density in Liaoning Province showed a decrease trend from east to west. In the eastern forest area, the future increase of vegetation carbon density would be smaller than those in the northern forest area, because most of the forests in the former part were matured or over matured, while most of the forests in the later part were young. Under the scenario of no afforestation, the future increment of total forest vegetation carbon stock in Liaoning Province would increase gradually, and the total carbon sequestration rate would decrease, while they would both increase significantly under the afforestation scenario. Therefore, afforestation plays an important role in increasing vegetation carbon storage, carbon density and carbon sequestration rate.

  15. Vegetable Genetic Resources in China

    Directory of Open Access Journals (Sweden)

    Haiping WANG

    2018-03-01

    Full Text Available China is recognized as an important region for plant biodiversity based on its vast and historical collection of vegetable germplasm. The aim of this review is to describe the exploration status of vegetable genetic resources in China, including their collection, preservation, evaluation, and utilization. China has established a number of national-level vegetable genetic resources preservation units, including the National Mid-term Genebank for Vegetable Germplasm Resources, the National Germplasm Repository for Vegetatively-Propagated Vegetables, and the National Germplasm Repository for Aquatic Vegetables. In 2015, at least 36 000 accessions were collected and preserved in these units. In the past decade, 44 descriptors and data standards for different species have been published, and most accessions have been evaluated for screening the germplasms for specific important traits such as morphological characteristics, disease resistance, pest resistance, and stress tolerance. Moreover, the genetic diversity and evolution of some vegetable germplasms have been evaluated at the molecular level. Recently, more than 1 000 accessions were distributed to researchers and breeders each year by various means for vegetable research and production. However, additional wild-relative and abroad germplasms from other regions need to be collected and preserved in the units to expand genetic diversity. Furthermore, there is a need to utilize advanced techniques to better understand the background and genetic diversity of a wide range of vegetable genetic resources. This review will provide agricultural scientists’ insights into the genetic diversity in China and provide information on the distribution and potential utilization of these valuable genetic resources. Keywords: vegetable, genetic resource, preservation, evaluation, utilization

  16. Vegetation Patchiness Enhances Hydrological Connectivity in River Deltas Below the Percolation Threshold

    Science.gov (United States)

    Wright, K. A.; Hiatt, M. R.; Passalacqua, P.

    2017-12-01

    The humanitarian and ecological importance of coastal deltas has led many to research the factors influencing their ecogeomorphic evolution, in hopes of predicting the response of these regions to the growing number of natural and anthropogenic threats they face. One area of this effort, in which many unresolved questions remain, concerns the hydrological connectivity between the distributary channels and interdistributary islands, which field observations and numerical modeling have shown to be significant. Island vegetation is known to affect the degree of connectivity, but the effect of the spatial distribution of vegetation on connectivity remains an important question. This research aims to determine to what extent vegetation percent cover, patch size, and plant density affect connectivity in an idealized deltaic system. A 2D hydrodynamic model was used to numerically solve the shallow water equations in an idealized channel-island complex, modeled after Wax Lake Delta in Louisiana. For each model run, vegetation patches were distributed randomly throughout the islands according to a specified percent cover and patch size. Vegetation was modeled as a modified bed roughness, which was varied to represent a range of sparse-to-dense vegetation. To determine the effect of heterogeneity, the results of each patchy scenario were compared to results from a uniform run with the same spatially-averaged roughness. It was found that, while all patchy model runs demonstrated more channel-island connectivity than comparable uniform runs, this was particularly true when vegetation patches were dense and covered distributions in the deltaic islands, which can have implications for the fate and transport of sediment/nutrients. These results indicate that the spatial distribution of vegetation can have a notable impact on our ability to model connectivity in deltaic systems.

  17. Mapping SOC (Soil Organic Carbon) using LiDAR-derived vegetation indices in a random forest regression model

    Science.gov (United States)

    Will, R. M.; Glenn, N. F.; Benner, S. G.; Pierce, J. L.; Spaete, L.; Li, A.

    2015-12-01

    Quantifying SOC (Soil Organic Carbon) storage in complex terrain is challenging due to high spatial variability. Generally, the challenge is met by transforming point data to the entire landscape using surrogate, spatially-distributed, variables like elevation or precipitation. In many ecosystems, remotely sensed information on above-ground vegetation (e.g. NDVI) is a good predictor of below-ground carbon stocks. In this project, we are attempting to improve this predictive method by incorporating LiDAR-derived vegetation indices. LiDAR provides a mechanism for improved characterization of aboveground vegetation by providing structural parameters such as vegetation height and biomass. In this study, a random forest model is used to predict SOC using a suite of LiDAR-derived vegetation indices as predictor variables. The Reynolds Creek Experimental Watershed (RCEW) is an ideal location for a study of this type since it encompasses a strong elevation/precipitation gradient that supports lower biomass sagebrush ecosystems at low elevations and forests with more biomass at higher elevations. Sagebrush ecosystems composed of Wyoming, Low and Mountain Sagebrush have SOC values ranging from .4 to 1% (top 30 cm), while higher biomass ecosystems composed of aspen, juniper and fir have SOC values approaching 4% (top 30 cm). Large differences in SOC have been observed between canopy and interspace locations and high resolution vegetation information is likely to explain plot scale variability in SOC. Mapping of the SOC reservoir will help identify underlying controls on SOC distribution and provide insight into which processes are most important in determining SOC in semi-arid mountainous regions. In addition, airborne LiDAR has the potential to characterize vegetation communities at a high resolution and could be a tool for improving estimates of SOC at larger scales.

  18. Interactions among hydrogeomorphology, vegetation, and nutrient biogeochemistry in floodplain ecosystems

    Science.gov (United States)

    Noe, G.B.

    2013-01-01

    Hydrogeomorphic, vegetative, and biogeochemical processes interact in floodplains resulting in great complexity that provides opportunities to better understand linkages among physical and biological processes in ecosystems. Floodplains and their associated river systems are structured by four dimensional gradients of hydrogeomorphology: longitudinal, lateral, vertical, and temporal components. These four dimensions create dynamic hydrologic and geomorphologic mosaics that have a large imprint on the vegetation and nutrient biogeochemistry of floodplains. Plant physiology, population dynamics, community structure, and productivity are all very responsive to floodplain hydrogeomorphology. The strength of this relationship between vegetation and hydrogeomorphology is evident in the use of vegetation as an indicator of hydrogeomorphic processes. However, vegetation also influences hydrogeomorphology by modifying hydraulics and sediment entrainment and deposition that typically stabilize geomorphic patterns. Nitrogen and phosphorus biogeochemistry commonly influence plant productivity and community composition, although productivity is not limited by nutrient availability in all floodplains. Conversely, vegetation influences nutrient biogeochemistry through direct uptake and storage as well as production of organic matter that regulates microbial biogeochemical processes. The biogeochemistries of nitrogen and phosphorus cycling are very sensitive to spatial and temporal variation in hydrogeomorphology, in particular floodplain wetness and sedimentation. The least studied interaction is the direct effect of biogeochemistry on hydrogeomorphology, but the control of nutrient availability over organic matter decomposition and thus soil permeability and elevation is likely important. Biogeochemistry also has the more documented but indirect control of hydrogeomorphology through regulation of plant biomass. In summary, the defining characteristics of floodplain ecosystems

  19. Heavy metals in green vegetables and soils from vegetable gardens ...

    African Journals Online (AJOL)

    Edible portions of five varieties of green vegetables, namely amaranth, chinese cabbage, cowpea leaves, leafy cabbage and pumpkin leaves, collected from several areas in Dar es Salaam, were analyzed for lead, cadmium, chromium, zinc, nickel and copper. Except for zinc, the levels of heavy metals in the vegetables ...

  20. Interactions of Vegetation and Climate: Remote Observations, Earth System Models, and the Amazon Forest

    Science.gov (United States)

    Quetin, Gregory R.

    The natural composition of terrestrial ecosystems can be shaped by climate to take advantage of local environmental conditions. Ecosystem functioning, e.g. interaction between photosynthesis and temperature, can also acclimate to different climatological states. The combination of these two factors thus determines ecological-climate interactions. The ecosystem functioning also plays a key role in predicting the carbon cycle, hydrological cycle, terrestrial surface energy balance, and the feedbacks in the climate system. Predicting the response of the Earth's biosphere to global warming requires the ability to mechanistically represent the processes controlling ecosystem functioning through photosynthesis, respiration, and water use. The physical environment in a place shapes the vegetation there, but vegetation also has the potential to shape the environment, e.g. increased photosynthesis and transpiration moisten the atmosphere. These two-way ecoclimate interactions create the potential for feedbacks between vegetation at the physical environment that depend on the vegetation and the climate of a place, and can change throughout the year. In Chapter 1, we derive a global empirical map of the sensitivity of vegetation to climate using the response of satellite-observed greenness to interannual variations in temperature and precipitation. We infer mechanisms constraining ecosystem functioning by analyzing how the sensitivity of vegetation to climate varies across climate space. Our analysis yields empirical evidence for multiple physical and biological mediators of the sensitivity of vegetation to climate at large spatial scales. In hot and wet locations, vegetation is greener in warmer years despite temperatures likely exceeding thermally optimum conditions. However, sunlight generally increases during warmer years, suggesting that the increased stress from higher atmospheric water demand is offset by higher rates of photosynthesis. The sensitivity of vegetation

  1. Geosphere-Biosphere interface zone: the role of vegetation in water and element exchanges

    International Nuclear Information System (INIS)

    Vincke, C.

    2007-01-01

    The forest tree vegetation, because of its longevity and high evaporative capacity, has a great influence on the water cycling: it can transpire about 80% of the potential evapotranspiration (PET, mm) under high evaporative demand. The presence of a shallow water table increases the water's availability to root uptake from deep layers. In the scenario of a water table polluted with radionuclides, identifying the sources of water used by the forest vegetation (precipitation vs groundwater) is necessary to correctly predict the rhythm at which radionuclides will be absorbed by trees and further recycled into biosphere. This study aims at understanding and quantifying the forest vegetation and water table interactions. Through the soil-tree-atmosphere continuum, the water fluxes were monitored in parallel to the element cycle, the biomass compartments and the ecophysiological response of a Scots pine stand during 2005 growing season

  2. Accuracy of some simple models for predicting particulate interception and retention in agricultural systems

    International Nuclear Information System (INIS)

    Pinder, J.E. III; McLeod, K.W.; Adriano, D.C.

    1989-01-01

    The accuracy of three radionuclide transfer models for predicting the interception and retention of airborne particles by agricultural crops was tested using Pu-bearing aerosols released to the atmosphere from nuclear fuel facilities on the U.S. Department of Energy's Savannah River Plant, near Aiken, SC. The models evaluated were: (1) NRC, the model defined in U.S. Nuclear Regulatory Guide 1.109; (2) FOOD, a model similar to the NRC model that also predicts concentrations in grains; and (3) AGNS, a model developed from the NRC model for the southeastern United States. Plutonium concentrations in vegetation and grain were predicted from measured deposition rates and compared to concentrations observed in the field. Crops included wheat, soybeans, corn and cabbage. Although predictions of the three models differed by less than a factor of 4, they showed different abilities to predict concentrations observed in the field. The NRC and FOOD models consistently underpredicted the observed Pu concentrations for vegetation. The AGNS model was a more accurate predictor of Pu concentrations for vegetation. Both the FOOD and AGNS models accurately predicted the Pu concentrations for grains

  3. Rescuing and Sharing Historical Vegetation Data for Ecological Analysis: The California Vegetation Type Mapping Project

    Directory of Open Access Journals (Sweden)

    Maggi Kelly

    2016-10-01

    Full Text Available Research efforts that synthesize historical and contemporary ecological data with modeling approaches improve our understanding of the complex response of species, communities, and landscapes to changing biophysical conditions through time and in space. Historical ecological data are particularly important in this respect. There are remaining barriers that limit such data synthesis, and technological improvements that make multiple diverse datasets more readily available for integration and synthesis are needed. This paper presents one case study of the Wieslander Vegetation Type Mapping project in California and highlights the importance of rescuing, digitizing and sharing historical datasets. We review the varied ecological uses of the historical collection: the vegetation maps have been used to understand legacies of land use change and plan for the future; the plot data have been used to examine changes to chaparral and forest communities around the state and to predict community structure and shifts under a changing climate; the photographs have been used to understand changing vegetation structure; and the voucher specimens in combination with other specimen collections have been used for large scale distribution modeling efforts. The digitization and sharing of the data via the web has broadened the scope and scale of the types of analysis performed. Yet, additional research avenues can be pursued using multiple types of VTM data, and by linking VTM data with contemporary data. The digital VTM collection is an example of a data infrastructure that expands the potential of large scale research through the integration and synthesis of data drawn from numerous data sources; its journey from analog to digital is a cautionary tale of the importance of finding historical data, digitizing it with best practices, linking it with other datasets, and sharing it with the research community.

  4. Review of Vegetable Market Development in China

    Institute of Scientific and Technical Information of China (English)

    Chaoping; LUO; Yuandong; NI; Qiong; ZHAI

    2013-01-01

    This paper has reviewed vegetable market development from vegetable circulation system, the develop history of the liberalize vegetable market and the growth of the vegetable wholesale market in China. From the development of vegetables market in China and its characteristics: the development of vegetable market in China is related to vegetable market system, the change of institution, some technology development and infrastructure. this paper has put forward some related measures to perfect the vegetable market and improve the vegetable circulation efficiency in China.

  5. The regional species richness and genetic diversity of Arctic vegetation reflect both past glaciations and current climate

    DEFF Research Database (Denmark)

    Stewart, L.; Alsos, Inger G.; Bay, Christian

    2016-01-01

    Aim The Arctic has experienced marked climatic differences between glacial and interglacial periods and is now subject to a rapidly warming climate. Knowledge of the effects of historical processes on current patterns of diversity may aid predictions of the responses of vegetation to future climate...... species richness of the vascular plant flora of 21 floristic provinces and examined local species richness in 6215 vegetation plots distributed across the Arctic. We assessed levels of genetic diversity inferred from amplified fragment length polymorphism variation across populations of 23 common Arctic...... size compared to the models of bryophyte and lichen richness. Main conclusion Our study suggests that imprints of past glaciations in Arctic vegetation diversity patterns at the regional scale are still detectable today. Since Arctic vegetation is still limited by post-glacial migration lag...

  6. VEGETATION COVER ANALYSIS OF HAZARDOUS WASTE SITES IN UTAH AND ARIZONA USING HYPERSPECTRAL REMOTE SENSING

    Energy Technology Data Exchange (ETDEWEB)

    Serrato, M.; Jungho, I.; Jensen, J.; Jensen, R.; Gladden, J.; Waugh, J.

    2012-01-17

    Remote sensing technology can provide a cost-effective tool for monitoring hazardous waste sites. This study investigated the usability of HyMap airborne hyperspectral remote sensing data (126 bands at 2.3 x 2.3 m spatial resolution) to characterize the vegetation at U.S. Department of Energy uranium processing sites near Monticello, Utah and Monument Valley, Arizona. Grass and shrub species were mixed on an engineered disposal cell cover at the Monticello site while shrub species were dominant in the phytoremediation plantings at the Monument Valley site. The specific objectives of this study were to: (1) estimate leaf-area-index (LAI) of the vegetation using three different methods (i.e., vegetation indices, red-edge positioning (REP), and machine learning regression trees), and (2) map the vegetation cover using machine learning decision trees based on either the scaled reflectance data or mixture tuned matched filtering (MTMF)-derived metrics and vegetation indices. Regression trees resulted in the best calibration performance of LAI estimation (R{sup 2} > 0.80). The use of REPs failed to accurately predict LAI (R{sup 2} < 0.2). The use of the MTMF-derived metrics (matched filter scores and infeasibility) and a range of vegetation indices in decision trees improved the vegetation mapping when compared to the decision tree classification using just the scaled reflectance. Results suggest that hyperspectral imagery are useful for characterizing biophysical characteristics (LAI) and vegetation cover on capped hazardous waste sites. However, it is believed that the vegetation mapping would benefit from the use of 1 higher spatial resolution hyperspectral data due to the small size of many of the vegetation patches (< 1m) found on the sites.

  7. Vegetation Cover Analysis of Hazardous Waste Sites in Utah and Arizona Using Hyperspectral Remote Sensing

    Directory of Open Access Journals (Sweden)

    Mike Serrato

    2012-01-01

    Full Text Available This study investigated the usability of hyperspectral remote sensing for characterizing vegetation at hazardous waste sites. The specific objectives of this study were to: (1 estimate leaf-area-index (LAI of the vegetation using three different methods (i.e., vegetation indices, red-edge positioning (REP, and machine learning regression trees, and (2 map the vegetation cover using machine learning decision trees based on either the scaled reflectance data or mixture tuned matched filtering (MTMF-derived metrics and vegetation indices. HyMap airborne data (126 bands at 2.3 × 2.3 m spatial resolution, collected over the U.S. Department of Energy uranium processing sites near Monticello, Utah and Monument Valley, Arizona, were used. Grass and shrub species were mixed on an engineered disposal cell cover at the Monticello site while shrub species were dominant in the phytoremediation plantings at the Monument Valley site. Regression trees resulted in the best calibration performance of LAI estimation (R2 > 0.80. The use of REPs failed to accurately predict LAI (R2 < 0.2. The use of the MTMF-derived metrics (matched filter scores and infeasibility and a range of vegetation indices in decision trees improved the vegetation mapping when compared to the decision tree classification using just the scaled reflectance. Results suggest that hyperspectral imagery are useful for characterizing biophysical characteristics (LAI and vegetation cover on capped hazardous waste sites. However, it is believed that the vegetation mapping would benefit from the use of higher spatial resolution hyperspectral data due to the small size of many of the vegetation patches ( < 1 m found on the sites.

  8. Vegetation Cover Analysis Of Hazardous Waste Sites In Utah And Arizona Using Hyperspectral Remote Sensing

    International Nuclear Information System (INIS)

    Serrato, M.; Jungho, I.; Jensen, J.; Jensen, R.; Gladden, J.; Waugh, J.

    2012-01-01

    Remote sensing technology can provide a cost-effective tool for monitoring hazardous waste sites. This study investigated the usability of HyMap airborne hyperspectral remote sensing data (126 bands at 2.3 x 2.3 m spatial resolution) to characterize the vegetation at U.S. Department of Energy uranium processing sites near Monticello, Utah and Monument Valley, Arizona. Grass and shrub species were mixed on an engineered disposal cell cover at the Monticello site while shrub species were dominant in the phytoremediation plantings at the Monument Valley site. The specific objectives of this study were to: (1) estimate leaf-area-index (LAI) of the vegetation using three different methods (i.e., vegetation indices, red-edge positioning (REP), and machine learning regression trees), and (2) map the vegetation cover using machine learning decision trees based on either the scaled reflectance data or mixture tuned matched filtering (MTMF)-derived metrics and vegetation indices. Regression trees resulted in the best calibration performance of LAI estimation (R 2 > 0.80). The use of REPs failed to accurately predict LAI (R 2 < 0.2). The use of the MTMF-derived metrics (matched filter scores and infeasibility) and a range of vegetation indices in decision trees improved the vegetation mapping when compared to the decision tree classification using just the scaled reflectance. Results suggest that hyperspectral imagery are useful for characterizing biophysical characteristics (LAI) and vegetation cover on capped hazardous waste sites. However, it is believed that the vegetation mapping would benefit from the use of 1 higher spatial resolution hyperspectral data due to the small size of many of the vegetation patches (< 1m) found on the sites.

  9. Comparison of Modeling Grassland Degradation with and without Considering Localized Spatial Associations in Vegetation Changing Patterns

    Directory of Open Access Journals (Sweden)

    Yuwei Wang

    2018-01-01

    Full Text Available Grassland ecosystems worldwide are confronted with degradation. It is of great importance to understand long-term trajectory patterns of grassland vegetation by advanced analytical models. This study proposes a new approach called a binary logistic regression model with neighborhood interactions, or BLR-NIs, which is based on binary logistic regression (BLR, but fully considers the spatio-temporally localized spatial associations or characterization of neighborhood interactions (NIs in the patterns of grassland vegetation. The BLR-NIs model was applied to a modeled vegetation degradation of grasslands in the Xilin river basin, Inner Mongolia, China. Residual trend analysis on the normalized difference vegetation index (RESTREND-NDVI, which excluded the climatic impact on vegetation dynamics, was adopted as a preprocessing step to derive three human-induced trajectory patterns (vegetation degradation, vegetation recovery, and no significant change in vegetation during two consecutive periods, T1 (2000–2008 and T2 (2007–2015. Human activities, including livestock grazing intensity and transportation accessibility measured by road network density, were included as explanatory variables for vegetation degradation, which was defined for locations if vegetation recovery or no significant change in vegetation in T1 and vegetation degradation in T2 were observed. Our work compared the results of BLR-NIs and the traditional BLR model that did not consider NIs. The study showed that: (1 both grazing intensity and road density had a positive correlation to vegetation degradation based on the traditional BLR model; (2 only road density was found to positively correlate to vegetation degradation by the BLR-NIs model; NIs appeared to be critical factors to predict vegetation degradation; and (3 including NIs in the BLR model improved the model performance substantially. The study provided evidence for the importance of including localized spatial

  10. Monitoring of vegetation dynamics and assessing vegetation response to drought in the Iberian Peninsula

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Haro, F. J.; Moreno, A.; Perez-Hoyos, A.; Gilabert, M. A.; Melia, J.; Belda, F.; Poquet, D.; Martinez, B.; Verger, A.

    2009-07-01

    Monitoring the vegetation activity over long time-scales is necessary to discern ecosystem response to climate variability. Spatial and temporally consistent estimates of the biophysical variables such as fractional vegetation cover (FVC) and leaf area index (LAI) have been obtained in the context of DULCINEA Project. We used long-term monthly climate statistics to build simple climatic indices (SPI, moisture index) at different time scales. From these indices, we estimated that the climatic disturbances affected both the growing season and the total amount of vegetation. This implies that the anomaly of vegetation cover is a good indicator of moisture condition and can be an important data source when used for detecting an monitoring drought in the Iberian Peninsula. The impact of climate variability on the vegetation dynamics has shown not to be the same for every region. We concluded that the relationships between vegetation anomaly and moisture availability are significant for the arid and semiarid areas. (Author) 6 refs.

  11. Monitoring of vegetation dynamics and assessing vegetation response to drought in the Iberian Peninsula

    International Nuclear Information System (INIS)

    Garcia-Haro, F. J.; Moreno, A.; Perez-Hoyos, A.; Gilabert, M. A.; Melia, J.; Belda, F.; Poquet, D.; Martinez, B.; Verger, A.

    2009-01-01

    Monitoring the vegetation activity over long time-scales is necessary to discern ecosystem response to climate variability. Spatial and temporally consistent estimates of the biophysical variables such as fractional vegetation cover (FVC) and leaf area index (LAI) have been obtained in the context of DULCINEA Project. We used long-term monthly climate statistics to build simple climatic indices (SPI, moisture index) at different time scales. From these indices, we estimated that the climatic disturbances affected both the growing season and the total amount of vegetation. This implies that the anomaly of vegetation cover is a good indicator of moisture condition and can be an important data source when used for detecting an monitoring drought in the Iberian Peninsula. The impact of climate variability on the vegetation dynamics has shown not to be the same for every region. We concluded that the relationships between vegetation anomaly and moisture availability are significant for the arid and semiarid areas. (Author) 6 refs.

  12. Ecohydrological drought monitoring and prediction using a land data assimilation system

    Science.gov (United States)

    Sawada, Y.; Koike, T.

    2017-12-01

    Despite the importance of the ecological and agricultural aspects of severe droughts, few drought monitor and prediction systems can forecast the deficit of vegetation growth. To address this issue, we have developed a land data assimilation system (LDAS) which can simultaneously simulate soil moisture and vegetation dynamics. By assimilating satellite-observed passive microwave brightness temperature, which is sensitive to both surface soil moisture and vegetation water content, we can significantly improve the skill of a land surface model to simulate surface soil moisture, root zone soil moisture, and leaf area index (LAI). We run this LDAS to generate a global ecohydrological land surface reanalysis product. In this presentation, we will demonstrate how useful this new reanalysis product is to monitor and analyze the historical mega-droughts. In addition, using the analyses of soil moistures and LAI as initial conditions, we can forecast the ecological and hydrological conditions in the middle of droughts. We will present our recent effort to develop a near real time ecohydrological drought monitoring and prediction system in Africa by combining the LDAS and the atmospheric seasonal prediction.

  13. Vegetation-induced turbulence influencing evapotranspiration-soil moisture coupling: Implications for semiarid regions

    Science.gov (United States)

    Haghighi, E.; Kirchner, J. W.; Entekhabi, D.

    2016-12-01

    The relationship between soil moisture and evapotranspiration (ET) fluxes is an important component of land-atmosphere interactions controlling hydrology-climate feedback processes. Important as this relationship is, it remains empirical and physical mechanisms governing its dynamics are insufficiently studied. This is particularly of importance for semiarid regions (currently comprising about half of the Earth's land surface) where the shallow surface soil layer is the primary source of ET and direct evaporation from bare soil is likely a large component of the total flux. Hence, ET-soil moisture coupling in these regions is hypothesized to be strongly influenced by soil evaporation and associated mechanisms. Motivated by recent progress in mechanistic modeling of localized heat and mass exchange rates from bare soil surfaces covered by cylindrical bluff-body elements, we developed a physically based ET model explicitly incorporating coupled impacts of soil moisture and vegetation-induced turbulence in the near-surface region. Model predictions of ET and its partitioning were in good agreement with measured data and suggest that the strength and nature of ET-soil moisture interactions in sparsely vegetated areas are strongly influenced by aerodynamic (rather than radiative) forcing namely wind speed and near-surface turbulence generation as a function of vegetation type and cover fraction. The results demonstrated that the relationship between ET and soil moisture varies from a nonlinear function (the dual regime behavior) to a single moisture-limited regime (linear relationship) by increasing wind velocity and enhancing turbulence generation in the near-surface region (small-scale woody vegetation species of low cover fraction). Potential benefits of this study for improving accuracy and predictive capabilities of remote sensing techniques when applied to semiarid environments will also be discussed.

  14. Predicting intensity of white-tailed deer herbivory in the Central Appalachian Mountains

    Science.gov (United States)

    Kniowski, Andrew B.; Ford, W. Mark

    2018-01-01

    In eastern North America, white-tailed deer (Odocoileus virginianus) can have profound influences on forest biodiversity and forest successional processes. Moderate to high deer populations in the central Appalachians have resulted in lower forest biodiversity. Legacy effects in some areas persist even following deer population reductions or declines. This has prompted managers to consider deer population management goals in light of policies designed to support conservation of biodiversity and forest regeneration while continuing to support ample recreational hunting opportunities. However, despite known relationships between herbivory intensity and biodiversity impact, little information exists on the predictability of herbivory intensity across the varied and spatially diverse habitat conditions of the central Appalachians. We examined the predictability of browsing rates across central Appalachian landscapes at four environmental scales: vegetative community characteristics, physical environment, habitat configuration, and local human and deer population demographics. In an information-theoretic approach, we found that a model fitting the number of stems browsed relative to local vegetation characteristics received most (62%) of the overall support of all tested models assessing herbivory impact. Our data suggest that deer herbivory responded most predictably to differences in vegetation quantity and type. No other spatial factors or demographic factors consistently affected browsing intensity. Because herbivory, vegetation communities, and productivity vary spatially, we suggest that effective broad-scale herbivory impact assessment should include spatially-balanced vegetation monitoring that accounts for regional differences in deer forage preference. Effective monitoring is necessary to avoid biodiversity impacts and deleterious changes in vegetation community composition that are difficult to reverse and/or may not be detected using traditional deer

  15. Response of the mean global vegetation distribution to interannual climate variability

    Energy Technology Data Exchange (ETDEWEB)

    Notaro, Michael [University of Wisconsin-Madison, Center for Climatic Research, Madison, WI (United States)

    2008-06-15

    The impact of interannual variability in temperature and precipitation on global terrestrial ecosystems is investigated using a dynamic global vegetation model driven by gridded climate observations for the twentieth century. Contrasting simulations are driven either by repeated mean climatology or raw climate data with interannual variability included. Interannual climate variability reduces net global vegetation cover, particularly over semi-arid regions, and favors the expansion of grass cover at the expense of tree cover, due to differences in growth rates, fire impacts, and interception. The area burnt by global fires is substantially enhanced by interannual precipitation variability. The current position of the central United States' ecotone, with forests to the east and grasslands to the west, is largely attributed to climate variability. Among woody vegetation, climate variability supports expanded deciduous forest growth and diminished evergreen forest growth, due to difference in bioclimatic limits, leaf longevity, interception rates, and rooting depth. These results offer insight into future ecosystem distributions since climate models generally predict an increase in climate variability and extremes. (orig.)

  16. Balkan Vegetation Database

    NARCIS (Netherlands)

    Vassilev, Kiril; Pedashenko, Hristo; Alexandrova, Alexandra; Tashev, Alexandar; Ganeva, Anna; Gavrilova, Anna; Gradevska, Asya; Assenov, Assen; Vitkova, Antonina; Grigorov, Borislav; Gussev, Chavdar; Filipova, Eva; Aneva, Ina; Knollová, Ilona; Nikolov, Ivaylo; Georgiev, Georgi; Gogushev, Georgi; Tinchev, Georgi; Pachedjieva, Kalina; Koev, Koycho; Lyubenova, Mariyana; Dimitrov, Marius; Apostolova-Stoyanova, Nadezhda; Velev, Nikolay; Zhelev, Petar; Glogov, Plamen; Natcheva, Rayna; Tzonev, Rossen; Boch, Steffen; Hennekens, Stephan M.; Georgiev, Stoyan; Stoyanov, Stoyan; Karakiev, Todor; Kalníková, Veronika; Shivarov, Veselin; Russakova, Veska; Vulchev, Vladimir

    2016-01-01

    The Balkan Vegetation Database (BVD; GIVD ID: EU-00-019; http://www.givd.info/ID/EU-00- 019) is a regional database that consists of phytosociological relevés from different vegetation types from six countries on the Balkan Peninsula (Albania, Bosnia and Herzegovina, Bulgaria, Kosovo, Montenegro

  17. The MODIS Vegetation Canopy Water Content product

    Science.gov (United States)

    Ustin, S. L.; Riano, D.; Trombetti, M.

    2008-12-01

    Vegetation water stress drives wildfire behavior and risk, having important implications for biogeochemical cycling in natural ecosystems, agriculture, and forestry. Water stress limits plant transpiration and carbon gain. The regulation of photosynthesis creates close linkages between the carbon, water, and energy cycles and through metabolism to the nitrogen cycle. We generated systematic weekly CWC estimated for the USA from 2000-2006. MODIS measures the sunlit reflectance of the vegetation in the visible, near-infrared, and shortwave infrared. Radiative transfer models, such as PROSPECT-SAILH, determine how sunlight interacts with plant and soil materials. These models can be applied over a range of scales and ecosystem types. Artificial Neural Networks (ANN) were used to optimize the inversion of these models to determine vegetation water content. We carried out multi-scale validation of the product using field data, airborne and satellite cross-calibration. An Algorithm Theoretical Basis Document (ATBD) of the product is under evaluation by NASA. The CWC product inputs are 1) The MODIS Terra/Aqua surface reflectance product (MOD09A1/MYD09A1) 2) The MODIS land cover map product (MOD12Q1) reclassified to grassland, shrub-land and forest canopies; 3) An ANN trained with PROSPECT-SAILH; 4) A calibration file for each land cover type. The output is an ENVI file with the CWC values. The code is written in Matlab environment and is being adapted to read not only the 8 day MODIS composites, but also daily surface reflectance data. We plan to incorporate the cloud and snow mask and generate as output a geotiff file. Vegetation water content estimates will help predicting linkages between biogeochemical cycles, which will enable further understanding of feedbacks to atmospheric concentrations of greenhouse gases. It will also serve to estimate primary productivity of the biosphere; monitor/assess natural vegetation health related to drought, pollution or diseases

  18. Spending on vegetable and fruit consumption could reduce all-cause mortality among older adults

    Directory of Open Access Journals (Sweden)

    Lo Yuan-Ting

    2012-12-01

    Full Text Available Abstract Background Few studies have evaluated the linkage between food cost and mortality among older adults. This study considers the hypothesis that greater food expenditure in general, and particularly on more nutritious plant and animal-derived foods, decreases mortality in older adults. Methods This study uses the 1999–2000 Elderly Nutrition and Health Survey in Taiwan and follows the cohort until 2008, collecting 24-hr dietary recall data for 1781 participants (874 men and 907 women aged 65 y or older. Using monthly mean national food prices and 24-hr recall, this study presents an estimate of daily expenditures for vegetable, fruit, animal-derived, and grain food categories. Participants were linked to the national death registry. Results Of the 1781 original participants, 625 died during the 10-y follow-up period. Among the 4 food categories, the fourth and fifth expenditure quintiles for vegetables and for fruits had the highest survival rates. After adjusting for co-variates, higher (Q4 vegetable and higher fruit (Q4 food expenditures referent to Q1 were significantly predictive of reduced mortality (HR = 0.55, 95% CI: 0.39-0.78 and HR = 0.64, 95% CI: 0.42–0.99, respectively and the risk decreased by 12% and 10% for every NT$15 (US$0.50 increase in their daily expenditures. Animal-derived and grain food spending was not predictive of mortality. Conclusion Greater and more achievable vegetable and fruit affordability may improve food security and longevity for older adults.

  19. Social Cognitive Antecedents of Fruit and Vegetable Consumption in Truck Drivers: A Sequential Mediation Analysis.

    Science.gov (United States)

    Hamilton, Kyra; Vayro, Caitlin; Schwarzer, Ralf

    2015-01-01

    To examine a mechanism by which social cognitive factors may predict fruit and vegetable consumption in long-haul truck drivers. Dietary self-efficacy, positive outcome expectancies, and intentions were assessed in 148 Australian truck drivers, and 1 week later they reported their fruit and vegetable consumption. A theory-guided sequential mediation model was specified that postulated self-efficacy and intention as mediators between outcome expectancies and behavior. The hypothesized model was confirmed. A direct effect of outcome expectancies was no longer present when mediators were included, and all indirect effects were significant, including the 2-mediator chain (β = .15; P role of outcome expectancies and self-efficacy are important to consider for understanding and predicting healthy eating intentions in truck drivers. Copyright © 2015 Society for Nutrition Education and Behavior. Published by Elsevier Inc. All rights reserved.

  20. Detection of crop water status in mature olive orchards using vegetation spectral measurements

    Science.gov (United States)

    Rallo, Giovanni; Ciraolo, Giuseppe; Farina, Giuseppe; Minacapilli, Mario; Provenzano, Giuseppe

    2013-04-01

    Leaf/stem water potentials are generally considered the most accurate indicators of crop water status (CWS) and they are quite often used for irrigation scheduling, even if costly and time-consuming. For this reason, in the last decade vegetation spectral measurements have been proposed, not only for environmental monitoring, but also in precision agriculture, to evaluate crop parameters and consequently for irrigation scheduling. Objective of the study was to assess the potential of hyperspectral reflectance (450-2400 nm) data to predict the crop water status (CWS) of a Mediterranean olive orchard. Different approaches were tested and particularly, (i) several standard broad- and narrow-band vegetation indices (VIs), (ii) specific VIs computed on the basis of some key wavelengths, predetermined by simple correlations and finally, (iii) using partial least squares (PLS) regression technique. To this aim, an intensive experimental campaign was carried out in 2010 and a total of 201 reflectance spectra, at leaf and canopy level, were collected with an ASD FieldSpec Pro (Analytical Spectral Devices, Inc.) handheld field spectroradiometer. CWS was contemporarily determined by measuring leaf and stem water potentials with the Scholander chamber. The results indicated that the considered standard vegetation indices were weakly correlated with CWS. On the other side, the prediction of CWS can be improved using VIs pointed to key-specific wavelengths, predetermined with a correlation analysis. The best prediction accuracy, however, can be achieved with models based on PLS regressions. The results confirmed the dependence of leaf/canopy optical features from CWS so that, for the examined crop, the proposed methodology can be considered a promising tool that could also be extended for operational applications using multispectral aerial sensors.

  1. Microbiological Spoilage of Fruits and Vegetables

    Science.gov (United States)

    Barth, Margaret; Hankinson, Thomas R.; Zhuang, Hong; Breidt, Frederick

    Consumption of fruit and vegetable products has dramatically increased in the United States by more than 30% during the past few decades. It is also estimated that about 20% of all fruits and vegetables produced is lost each year due to spoilage. The focus of this chapter is to provide a general background on microbiological spoilage of fruit and vegetable products that are organized in three categories: fresh whole fruits and vegetables, fresh-cut fruits and vegetables, and fermented or acidified vegetable products. This chapter will address characteristics of spoilage microorganisms associated with each of these fruit and vegetable categories including spoilage mechanisms, spoilage defects, prevention and control of spoilage, and methods for detecting spoilage microorganisms.

  2. Assessments of chromium (and other metals) in vegetables and potential bio-accumulations in humans living in areas affected by tannery wastes.

    Science.gov (United States)

    Chen, Hualin; Arocena, Joselito M; Li, Jianbing; Thring, Ronald W; Zhou, Jiangmin

    2014-10-01

    Chromium (Cr) commonly enters the food chain through uptake by vegetables. However, accurate prediction of plant uptake of Cr (and other metals) still remains a challenge. In this study, we evaluated 5 indices of availability for Cr (and other metals) to identify reliable predictors of metal transfer from soils to garlic, onion, bokchoy, radish and celery grown in soils impacted by tannery wastes. The potential bio-accumulation of Cr in humans was calculated from the Cr content of vegetable predicted by the best bio-availability index, amounts of vegetable consumed and recommended daily doses for Cr. Our results show that soil total Cr is the best predictor of Cr transfer from soils to onion (Cr in onion=8.51+0.005 Total Cr) while Cr extractable by Synthetic Precipitation Leaching Procedure at pH 5 correlates very well with Cr uptake by bokchoy (Cr bokchoy=5.86+7.32 SPLP-5 Cr) and garlic (Cr garlic=7.63+2.36 SPLP-5 Cr). The uptake of Cr by radish and celery could not be reliably estimated by any of the 5 indices of availability tested in this study. Potential bio-accumulation of Cr in humans (BA-Cr) increases from soils with low Cr (BA-Cr=11.5) to soil with high total Cr (BA-Cr=31.3). Due to numerous soil factors affecting the behavior of Cr in soils and the physiological differences among vegetables, we suggest that the prediction of the transfer of Cr (and other metals) from soils to plants should be specific to site, metal and vegetable. Potential bio-accumulation of Cr in humans can be derived from a transfer function of Cr from soils to plants and the human consumption of vegetables. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Vegetated dune morphodynamics during recent stabilization of the Mu Us dune field, north-central China

    Science.gov (United States)

    Xu, Zhiwei; Mason, Joseph A.; Lu, Huayu

    2015-01-01

    development of vegetation-stabilized dunes, which should be helpful in better understanding of vegetated dune morphology, model verification and prediction, and guiding practical dune stabilization efforts.

  4. Scales of form roughness on riverbanks with different riparian vegetation

    Science.gov (United States)

    Konsoer, K. M.; Rhoads, B. L.; Best, J.; Langendoen, E. J.; Ursic, M.; Abad, J. D.; Garcia, M. H.

    2013-12-01

    Riverbanks often include topographic irregularities that occur over a range of scales and that are produced by interactions among erosional processes, vegetation, and the geotechnical properties of the banks and floodplains. Irregularity of the bank surface can increase form drag, affecting the overall flow resistance, near-bank shear stresses, and patterns of sediment transport. Understanding how dominant scales of form roughness influence the near-bank flow structure, and thus the shear stress partitioning, is vital for the development of accurate predictive morphodynamic models. In this paper, the scales of bank roughness are examined for two meander bends of a large alluvial river with differing riparian vegetation on the Wabash River near Grayville, Illinois. Detailed measurements of bank topography were obtained using terrestrial LiDAR during low flow events and a multibeam echo sounder (MBES) during bankfull events. These measurements yielded high spatial resolution maps (~5-10 cm) that were used to analyze scales of roughness at different elevations along the banks during both subaerial and subaqueous conditions. The results of these analyses provide insight into the influence of riparian vegetation on form roughness and patterns of near-bank flow structure as documented using acoustic Doppler current profilers (ADCP).

  5. Penalized regression techniques for prediction: a case study for predicting tree mortality using remotely sensed vegetation indices

    NARCIS (Netherlands)

    Lazaridis, D.C.; Verbesselt, J.; Robinson, A.P.

    2011-01-01

    Constructing models can be complicated when the available fitting data are highly correlated and of high dimension. However, the complications depend on whether the goal is prediction instead of estimation. We focus on predicting tree mortality (measured as the number of dead trees) from change

  6. Lake Bathymetric Aquatic Vegetation

    Data.gov (United States)

    Minnesota Department of Natural Resources — Aquatic vegetation represented as polygon features, coded with vegetation type (emergent, submergent, etc.) and field survey date. Polygons were digitized from...

  7. Effects of vegetation structure on biomass accumulation in a Balanced Optimality Structure Vegetation Model (BOSVM v1.0

    Directory of Open Access Journals (Sweden)

    Z. Yin

    2014-05-01

    Full Text Available A myriad of interactions exist between vegetation and local climate for arid and semi-arid regions. Vegetation function, structure and individual behavior have large impacts on carbon–water–energy balances, which consequently influence local climate variability that, in turn, feeds back to the vegetation. In this study, a conceptual vegetation structure scheme is formulated and tested in the new Balanced Optimality Structure Vegetation Model (BOSVM to explore the importance of vegetation structure and vegetation adaptation to water stress on equilibrium biomass states. Surface energy, water and carbon fluxes are simulated for a range of vegetation structures across a precipitation gradient in West Africa and optimal vegetation structures that maximize biomass for each precipitation regime are determined. Two different strategies of vegetation adaptation to water stress are included. Under dry conditions vegetation tries to maximize the water use efficiency and leaf area index as it tries to maximize carbon gain. However, a negative feedback mechanism in the vegetation–soil water system is found as the vegetation also tries to minimize its cover to optimize the surrounding bare ground area from which water can be extracted, thereby forming patches of vertical vegetation. Under larger precipitation, a positive feedback mechanism is found in which vegetation tries to maximize its cover as it then can reduce water loss from bare soil while having maximum carbon gain due to a large leaf area index. The competition between vegetation and bare soil determines a transition between a "survival" state to a "growing" state.

  8. Add More Vegetables to Your Day: 10 Tips to Help You Eat More Vegetables

    Science.gov (United States)

    ... sip on some vegetable soup Heat it and eat it. Try tomato, butternut squash, or garden vegetable soup. Look for reduced- or low-sodium soups. Make your own soups with a low-sodium broth and your favorite vegetables. 8 while you’re out If dinner is away from home, no need to worry. ...

  9. Vegetation index anomaly response to varying lengths of drought across vegetation and climatic gradients in Hawaii

    Science.gov (United States)

    Lucas, M.; Miura, T.; Trauernicht, C.; Frazier, A. G.

    2017-12-01

    A drought which results in prolonged and extended deficit in naturally available water supply and creates multiple stresses across ecosystems is classified as an ecological drought. Detecting and understanding the dynamics and response of such droughts in tropical systems, specifically across various vegetation and climatic gradients is fairly undetermined, yet increasingly important for better understandings of the ecological effects of drought. To understanding the link between what lengths and intensities of known meteorological drought triggers detectable ecological vegetation responses, a landscape scale regression analysis evaluating the response (slope) and relationship strength (R-squared) of several cumulative SPI (standard precipitation index) lengths(1, 3, 6, 12, 18, 24, 36, 48, and 60 month), to various satellite derived monthly vegetation indices anomalies (NDVI, EVI, EVI2, and LSWI) was performed across a matrix of dominant vegetation covers (grassland, shrubland, and forest) and climatic moisture zones (arid, dry, mesic, and wet). The nine different SPI lags across these climactic and vegetation gradients was suggest that stronger relationships and steeper slopes were found in dryer climates (across all vegetation covers) and finer vegetation types (across all moisture zones). Overall NDVI, EVI and EVI2 showed the best utility in these dryer climatic zones across all vegetation types. Within arid and dry areas "best" fits showed increasing lengths of cumulative SPI were with increasing vegetation coarseness respectively. Overall these findings suggest that rainfall driven drought may have a stronger impact on the ecological condition of vegetation in water limited systems with finer vegetation types ecologically responding more rapidly to meteorological drought events than coarser woody vegetation systems. These results suggest that previously and newly documented trends of decreasing rainfall and increasing drought in Hawaiian drylands may have

  10. Vegetation extraction from high-resolution satellite imagery using the Normalized Difference Vegetation Index (NDVI)

    Science.gov (United States)

    AlShamsi, Meera R.

    2016-10-01

    Over the past years, there has been various urban development all over the UAE. Dubai is one of the cities that experienced rapid growth in both development and population. That growth can have a negative effect on the surrounding environment. Hence, there has been a necessity to protect the environment from these fast pace changes. One of the major impacts this growth can have is on vegetation. As technology is evolving day by day, there is a possibility to monitor changes that are happening on different areas in the world using satellite imagery. The data from these imageries can be utilized to identify vegetation in different areas of an image through a process called vegetation detection. Being able to detect and monitor vegetation is very beneficial for municipal planning and management, and environment authorities. Through this, analysts can monitor vegetation growth in various areas and analyze these changes. By utilizing satellite imagery with the necessary data, different types of vegetation can be studied and analyzed, such as parks, farms, and artificial grass in sports fields. In this paper, vegetation features are detected and extracted through SAFIY system (i.e. the Smart Application for Feature extraction and 3D modeling using high resolution satellite ImagerY) by using high-resolution satellite imagery from DubaiSat-2 and DEIMOS-2 satellites, which provide panchromatic images of 1m resolution and spectral bands (red, green, blue and near infrared) of 4m resolution. SAFIY system is a joint collaboration between MBRSC and DEIMOS Space UK. It uses image-processing algorithms to extract different features (roads, water, vegetation, and buildings) to generate vector maps data. The process to extract green areas (vegetation) utilize spectral information (such as, the red and near infrared bands) from the satellite images. These detected vegetation features will be extracted as vector data in SAFIY system and can be updated and edited by end-users, such as

  11. Remote sensing captures varying temporal patterns of vegetation between human-altered and natural landscapes.

    Science.gov (United States)

    Leong, Misha; Roderick, George K

    2015-01-01

    Global change has led to shifts in phenology, potentially disrupting species interactions such as plant-pollinator relationships. Advances in remote sensing techniques allow one to detect vegetation phenological diversity between different land use types, but it is not clear how this translates to other communities in the ecosystem. Here, we investigated the phenological diversity of the vegetation across a human-altered landscape including urban, agricultural, and natural land use types. We found that the patterns of change in the vegetation indices (EVI and NDVI) of human-altered landscapes are out of synchronization with the phenology in neighboring natural California grassland habitat. Comparing these findings to a spatio-temporal pollinator distribution dataset, EVI and NDVI were significant predictors of total bee abundance, a relationship that improved with time lags. This evidence supports the importance of differences in temporal dynamics between land use types. These findings also highlight the potential to utilize remote sensing data to make predictions for components of biodiversity that have tight vegetation associations, such as pollinators.

  12. Vegetables and other core food groups

    NARCIS (Netherlands)

    Poelman, Astrid A.M.; Delahunty, Conor M.; Graaf, de Kees

    2017-01-01

    Vegetables are the food category least liked by children. This research investigated the sensory properties of vegetables vis-a-vis other core foods that comprise children's diets, to determine to what degree low acceptance of vegetables can be attributed to sensory properties. Vegetables (n =

  13. 18 CFR 1304.203 - Vegetation management.

    Science.gov (United States)

    2010-04-01

    ... 18 Conservation of Power and Water Resources 2 2010-04-01 2010-04-01 false Vegetation management...-Owned Residential Access Shoreland § 1304.203 Vegetation management. No vegetation management shall be approved on TVA-owned Residential Access Shoreland until a Vegetation Management Plan meeting the...

  14. A landscape model for predicting potential natural vegetation of the Olympic Peninsula USA using boundary equations and newly developed environmental variables.

    Science.gov (United States)

    Jan A. Henderson; Robin D. Lesher; David H. Peter; Chris D. Ringo

    2011-01-01

    A gradient-analysis-based model and grid-based map are presented that use the potential vegetation zone as the object of the model. Several new variables are presented that describe the environmental gradients of the landscape at different scales. Boundary algorithms are conceptualized, and then defined, that describe the environmental boundaries between vegetation...

  15. A submonthly database for detecting changes in vegetation-atmosphere coupling

    Science.gov (United States)

    Zscheischler, Jakob; Orth, René; Seneviratne, Sonia I.

    2016-04-01

    Land-atmosphere coupling and changes in coupling regimes are important for making precise future climate predictions and understanding vegetation-climate feedbacks. Here we introduce the Vegetation-Atmosphere Coupling (VAC) index which identifies regions and times of concurrent strong anomalies in temperature and photosynthetic activity. The different classes of the index determine whether a location is currently in an energy-limited or water-limited regime, and its high temporal resolution allows to investigate how these regimes change over time at the regional scale. We show that the VAC index helps to distinguish different evaporative regimes. It can therefore provide indirect information about the local soil moisture state. We further demonstrate how the index can be used to understand processes leading to and occurring during extreme climate events, using the 2010 heat wave in Russia and the 2010 Amazon drought as examples.

  16. Compressibilities and viscosities of reference, vegetable, and synthetic gear lubricants

    DEFF Research Database (Denmark)

    Regueira Muñiz, Teresa; Lugo, Luis; Fernández, Josefa

    2014-01-01

    Nowadays, one of the primary choices of base oils for environmentally aware lubricants is vegetable oils. This is due to their good natural biodegradability and very low toxicity in combination with very good lubricity characteristics. The development of new vegetable-based lubricants requires...... values of six gear lubricants, two of them reference mineral oils and the other four developed biodegradable oils based in high oleic sunflower oil or in synthetic esters. It was found that all of the lubricants have both similar compressibilities and similar expansivities. Dowson and Higginson, Zhu.......06%. Dowson and Higginson and Zhu and Wen equations of state do not predict well the isothermal compressibilities, with AAD % being around 45% for both equations. Moreover, the viscosities were measured in the temperature range from 278.15 to 373.15 K at atmospheric pressure for these oils, and the viscosity...

  17. Comparison of vegetation roughness descriptions

    NARCIS (Netherlands)

    Augustijn, Dionysius C.M.; Huthoff, Freek; van Velzen, E.H.; Altinakar, M.S.; Kokpinar, M.A.; Aydin, I.; Cokgor, S.; Kirkgoz, S.

    2008-01-01

    Vegetation roughness is an important parameter in describing flow through river systems. Vegetation impedes the flow, which affects the stage-discharge curve and may increase flood risks. Roughness is often used as a calibration parameter in river models, however when vegetation is allowed to

  18. The predictability of phytophagous insect communities: host specialists as habitat specialists.

    Directory of Open Access Journals (Sweden)

    Jörg Müller

    Full Text Available The difficulties specialized phytophagous insects face in finding habitats with an appropriate host should constrain their dispersal. Within the concept of metacommunities, this leads to the prediction that host-plant specialists should sort into local assemblages according to the local environmental conditions, i.e. habitat conditions, whereas assemblages of host-plant generalists should depend also on regional processes. Our study aimed at ranking the importance of local environmental factors and species composition of the vegetation for predicting the species composition of phytophagous moth assemblages with either a narrow or a broad host range. Our database consists of 351,506 specimens representing 820 species of nocturnal Macrolepidoptera sampled between 1980 and 2006 using light traps in 96 strict forest reserves in southern Germany. Species were grouped as specialists or generalists according to the food plants of the larvae; specialists use host plants belonging to one genus. We used predictive canonical correspondence and co-correspondence analyses to rank the importance of local environmental factors, the species composition of the vegetation and the role of host plants for predicting the species composition of host-plant specialists and generalists. The cross-validatory fit for predicting the species composition of phytophagous moths was higher for host-plant specialists than for host-plant generalists using environmental factors as well as the composition of the vegetation. As expected for host-plant specialists, the species composition of the vegetation was a better predictor of the composition of these assemblages than the environmental variables. But surprisingly, this difference for specialized insects was not due to the occurrence of their host plants. Overall, our study supports the idea that owing to evolutionary constraints in finding a host, host-plant specialists and host-plant generalists follow two different models of

  19. Understanding climate impacts on vegetation using a spatiotemporal non-linear Granger causality framework

    Science.gov (United States)

    Papagiannopoulou, Christina; Decubber, Stijn; Miralles, Diego; Demuzere, Matthias; Dorigo, Wouter; Verhoest, Niko; Waegeman, Willem

    2017-04-01

    Satellite data provide an abundance of information about crucial climatic and environmental variables. These data - consisting of global records, spanning up to 35 years and having the form of multivariate time series with different spatial and temporal resolutions - enable the study of key climate-vegetation interactions. Although methods which are based on correlations and linear models are typically used for this purpose, their assumptions for linearity about the climate-vegetation relationships are too simplistic. Therefore, we adopt a recently proposed non-linear Granger causality analysis [1], in which we incorporate spatial information, concatenating data from neighboring pixels and training a joint model on the combined data. Experimental results based on global data sets show that considering non-linear relationships leads to a higher explained variance of past vegetation dynamics, compared to simple linear models. Our approach consists of several steps. First, we compile an extensive database [1], which includes multiple data sets for land surface temperature, near-surface air temperature, surface radiation, precipitation, snow water equivalents and surface soil moisture. Based on this database, high-level features are constructed and considered as predictors in our machine-learning framework. These high-level features include (de-trended) seasonal anomalies, lagged variables, past cumulative variables, and extreme indices, all calculated based on the raw climatic data. Second, we apply a spatiotemporal non-linear Granger causality framework - in which the linear predictive model is substituted for a non-linear machine learning algorithm - in order to assess which of these predictor variables Granger-cause vegetation dynamics at each 1° pixel. We use the de-trended anomalies of Normalized Difference Vegetation Index (NDVI) to characterize vegetation, being the target variable of our framework. Experimental results indicate that climate strongly (Granger

  20. Exploring the contributions of vegetation and dune size to early dune development using unmanned aerial vehicle (UAV) imaging

    Science.gov (United States)

    van Puijenbroek, Marinka E. B.; Nolet, Corjan; de Groot, Alma V.; Suomalainen, Juha M.; Riksen, Michel J. P. M.; Berendse, Frank; Limpens, Juul

    2017-12-01

    Dune development along highly dynamic land-sea boundaries is the result of interaction between vegetation and dune size with sedimentation and erosion processes. Disentangling the contribution of vegetation characteristics from that of dune size would improve predictions of nebkha dune development under a changing climate, but has proven difficult due to the scarcity of spatially continuous monitoring data. This study explored the contributions of vegetation and dune size to dune development for locations differing in shelter from the sea. We monitored a natural nebkha dune field of 8 ha, along the coast of the island Texel, the Netherlands, for 1 year using an unmanned aerial vehicle (UAV) with camera. After constructing a digital surface model and orthomosaic we derived for each dune (1) vegetation characteristics (species composition, vegetation density, and maximum vegetation height), (2) dune size (dune volume, area, and maximum height), (3) degree of shelter (proximity to other nebkha dunes and the sheltering by the foredune). Changes in dune volume over summer and winter were related to vegetation, dune size and degree of shelter. We found that a positive change in dune volume (dune growth) was linearly related to initial dune volume over summer but not over winter. Big dunes accumulated more sand than small dunes due to their larger surface area. Exposed dunes increased more in volume (0.81 % per dune per week) than sheltered dunes (0.2 % per dune per week) over summer, while the opposite occurred over winter. Vegetation characteristics did not significantly affect dune growth in summer, but did significantly affect dune growth in winter. Over winter, dunes dominated by Ammophila arenaria, a grass species with high vegetation density throughout the year, increased more in volume than dunes dominated by Elytrigia juncea, a grass species with lower vegetation density (0.43 vs. 0.42 (m3 m-3) week-1). The effect of species was irrespective of dune size or

  1. Topography and vegetation as predictors of snow water equivalent across the alpine treeline ecotone at Lee Ridge, Glacier National Park, Montana, U.S.A.

    Science.gov (United States)

    Geddes, C.A.; Brown, D.G.; Fagre, D.B.

    2005-01-01

    We derived and implemented two spatial models of May snow water equivalent (SWE) at Lee Ridge in Glacier National Park, Montana. We used the models to test the hypothesis that vegetation structure is a control on snow redistribution at the alpine treeline ecotone (ATE). The statistical models were derived using stepwise and "best" subsets regression techniques. The first model was derived from field measurements of SWE, topography, and vegetation taken at 27 sample points. The second model was derived using GIS-based measures of topography and vegetation. Both the field- (R² = 0.93) and GIS-based models (R² = 0.69) of May SWE included the following variables: site type (based on vegetation), elevation, maximum slope, and general slope aspect. Site type was identified as the most important predictor of SWE in both models, accounting for 74.0% and 29.5% of the variation, respectively. The GIS-based model was applied to create a predictive map of SWE across Lee Ridge, predicting little snow accumulation on the top of the ridge where vegetation is scarce. The GIS model failed in large depressions, including ephemeral stream channels. The models supported the hypothesis that upright vegetation has a positive effect on accumulation of SWE above and beyond the effects of topography. Vegetation, therefore, creates a positive feedback in which it modifies its, environment and could affect the ability of additional vegetation to become established.

  2. The impact of a school-based gardening intervention on intentions and behaviour related to fruit and vegetable consumption in children.

    Science.gov (United States)

    Duncan, Michael J; Eyre, Emma; Bryant, Elizabeth; Clarke, Neil; Birch, Samantha; Staples, Victoria; Sheffield, David

    2015-06-01

    A total of 77 children (34 boys, 43 girls, mean age ± standard deviation = 9 ± 1 years) participated in this study; 46 children (intervention) undertook a 12-week school gardening programme and 31 children acted as controls. Measures of the Theory of Planned Behaviour and fruit and vegetable consumption were taken pre- and post-intervention. Repeated measures analysis of variance and hierarchical regression analysis indicated that the intervention group increased daily consumption of fruits and vegetables and increased intentions, attitudes, norms, and perceived behavioural control related to fruit and vegetable consumption. Attitudes, norms and perceived behavioural control significantly predicted changes in fruit and vegetable consumption. © The Author(s) 2015.

  3. Vegetable Production System (Veggie)

    Data.gov (United States)

    National Aeronautics and Space Administration — The Vegetable Production System (Veggie) was developed to be a simple, easily stowed, high growth volume, low resource facility capable of producing fresh vegetables...

  4. Soil TPH Concentration Estimation Using Vegetation Indices in an Oil Polluted Area of Eastern China

    Science.gov (United States)

    Zhu, Linhai; Zhao, Xuechun; Lai, Liming; Wang, Jianjian; Jiang, Lianhe; Ding, Jinzhi; Liu, Nanxi; Yu, Yunjiang; Li, Junsheng; Xiao, Nengwen; Zheng, Yuanrun; Rimmington, Glyn M.

    2013-01-01

    Assessing oil pollution using traditional field-based methods over large areas is difficult and expensive. Remote sensing technologies with good spatial and temporal coverage might provide an alternative for monitoring oil pollution by recording the spectral signals of plants growing in polluted soils. Total petroleum hydrocarbon concentrations of soils and the hyperspectral canopy reflectance were measured in wetlands dominated by reeds (Phragmites australis) around oil wells that have been producing oil for approximately 10 years in the Yellow River Delta, eastern China to evaluate the potential of vegetation indices and red edge parameters to estimate soil oil pollution. The detrimental effect of oil pollution on reed communities was confirmed by the evidence that the aboveground biomass decreased from 1076.5 g m−2 to 5.3 g m−2 with increasing total petroleum hydrocarbon concentrations ranging from 9.45 mg kg−1 to 652 mg kg−1. The modified chlorophyll absorption ratio index (MCARI) best estimated soil TPH concentration among 20 vegetation indices. The linear model involving MCARI had the highest coefficient of determination (R 2 = 0.73) and accuracy of prediction (RMSE = 104.2 mg kg−1). For other vegetation indices and red edge parameters, the R2 and RMSE values ranged from 0.64 to 0.71 and from 120.2 mg kg−1 to 106.8 mg kg−1 respectively. The traditional broadband normalized difference vegetation index (NDVI), one of the broadband multispectral vegetation indices (BMVIs), produced a prediction (R 2 = 0.70 and RMSE = 110.1 mg kg−1) similar to that of MCARI. These results corroborated the potential of remote sensing for assessing soil oil pollution in large areas. Traditional BMVIs are still of great value in monitoring soil oil pollution when hyperspectral data are unavailable. PMID:23342066

  5. Parental eating behaviours, home food environment and adolescent intakes of fruits, vegetables and dairy foods: longitudinal findings from Project EAT.

    Science.gov (United States)

    Arcan, Chrisa; Neumark-Sztainer, Dianne; Hannan, Peter; van den Berg, Patricia; Story, Mary; Larson, Nicole

    2007-11-01

    To examine longitudinal associations of parental report of household food availability and parent intakes of fruits, vegetables and dairy foods with adolescent intakes of the same foods. This study expands upon the limited research of longitudinal studies examining the role of parents and household food availability in adolescent dietary intakes. Longitudinal study. Project EAT-II followed an ethnically and socio-economically diverse sample of adolescents from 1999 (time 1) to 2004 (time 2). In addition to the Project EAT survey, adolescents completed the Youth Adolescent Food-Frequency Questionnaire in both time periods, and parents of adolescents completed a telephone survey at time 1. General linear modelling was used to examine the relationship between parent intake and home availability and adolescent intake, adjusting for time 1 adolescent intakes. Associations were examined separately for the high school and young adult cohorts and separately for males and females in combined cohorts. The sample included 509 pairs of parents/guardians and adolescents. Vegetables served at dinner significantly predicted adolescent intakes of vegetables for males (P = 0.037), females (P = 0.009), high school (P = 0.033) and young adults (P = 0.05) at 5-year follow-up. Among young adults, serving milk at dinner predicted dairy intake (P = 0.002). Time 1 parental intakes significantly predicted intakes of young adults for fruit (P = 0.044), vegetables (P = 0.041) and dairy foods (P = 0.008). Parental intake predicted intake of dairy for females (P = 0.02). The findings suggest the importance of providing parents of adolescents with knowledge and skills to enhance the home food environment and improve their own eating behaviours.

  6. Hidden vegetables: an effective strategy to reduce energy intake and increase vegetable intake in adults.

    Science.gov (United States)

    Blatt, Alexandria D; Roe, Liane S; Rolls, Barbara J

    2011-04-01

    The overconsumption of energy-dense foods leads to excessive energy intakes. The substitution of low-energy-dense vegetables for foods higher in energy density can help decrease energy intakes but may be difficult to implement if individuals dislike the taste of vegetables. We investigated whether incorporating puréed vegetables to decrease the energy density of entrées at multiple meals reduced daily energy intakes and increased daily vegetable intakes. In this crossover study, 20 men and 21 women ate ad libitum breakfast, lunch, and dinner in the laboratory once a week for 3 wk. Across conditions, entrées at meals varied in energy density from standard versions (100% condition) to reduced versions (85% and 75% conditions) by the covert incorporation of 3 or 4.5 times the amount of puréed vegetables. Entrées were accompanied by unmanipulated side dishes. Participants rated their hunger and fullness before and after meals. Subjects consumed a consistent weight of foods across conditions of energy density; thus, the daily energy intake significantly decreased by 202 ± 60 kcal in the 85% condition (P kcal in the 75% condition (P Daily vegetable consumption significantly increased from 270 ± 17 g of vegetables in the 100% condition to 487 ± 25 g of vegetables in the 75% condition (P < 0.0001). Despite the decreased energy intake, ratings of hunger and fullness did not significantly differ across conditions. Entrées were rated as similar in palatability across conditions. Large amounts of puréed vegetables can be incorporated into various foods to decrease the energy density. This strategy can lead to substantial reductions in energy intakes and increases in vegetable intakes. This trial was registered at clinicaltrials.gov as NCT01165086.

  7. Development of indicators of vegetation recovery based on time series analysis of SPOT Vegetation data

    Science.gov (United States)

    Lhermitte, S.; Tips, M.; Verbesselt, J.; Jonckheere, I.; Van Aardt, J.; Coppin, Pol

    2005-10-01

    Large-scale wild fires have direct impacts on natural ecosystems and play a major role in the vegetation ecology and carbon budget. Accurate methods for describing post-fire development of vegetation are therefore essential for the understanding and monitoring of terrestrial ecosystems. Time series analysis of satellite imagery offers the potential to quantify these parameters with spatial and temporal accuracy. Current research focuses on the potential of time series analysis of SPOT Vegetation S10 data (1999-2001) to quantify the vegetation recovery of large-scale burns detected in the framework of GBA2000. The objective of this study was to provide quantitative estimates of the spatio-temporal variation of vegetation recovery based on remote sensing indicators. Southern Africa was used as a pilot study area, given the availability of ground and satellite data. An automated technique was developed to extract consistent indicators of vegetation recovery from the SPOT-VGT time series. Reference areas were used to quantify the vegetation regrowth by means of Regeneration Indices (RI). Two kinds of recovery indicators (time and value- based) were tested for RI's of NDVI, SR, SAVI, NDWI, and pure band information. The effects of vegetation structure and temporal fire regime features on the recovery indicators were subsequently analyzed. Statistical analyses were conducted to assess whether the recovery indicators were different for different vegetation types and dependent on timing of the burning season. Results highlighted the importance of appropriate reference areas and the importance of correct normalization of the SPOT-VGT data.

  8. The effects of climate, permafrost and fire on vegetation change in Siberia in a changing climate

    Energy Technology Data Exchange (ETDEWEB)

    Tchebakova, N M; Parfenova, E [V N Sukachev Institute of Forest, Siberian Branch of the Russian Academy of Sciences, Academgorodok, Krasnoyarsk, 660036 (Russian Federation); Soja, A J, E-mail: ncheby@forest.akadem.r, E-mail: Amber.J.Soja@nasa.go [National Institute of Aerospace (NIA), NASA Langley Research Center, Climate Sciences, 21 Langley Boulevard, Mail Stop 420, Hampton, VA 23681-2199 (United States)

    2009-10-15

    Observations and general circulation model projections suggest significant temperature increases in Siberia this century that are expected to have profound effects on Siberian vegetation. Potential vegetation change across Siberia was modeled, coupling our Siberian BioClimatic Model with several Hadley Centre climate change scenarios for 2020, 2050 and 2080, with explicit consideration of permafrost and fire activity. In the warmer and drier climate projected by these scenarios, Siberian forests are predicted to decrease and shift northwards and forest-steppe and steppe ecosystems are predicted to dominate over half of Siberia due to the dryer climate by 2080. Despite the large predicted increases in warming, permafrost is not predicted to thaw deep enough to sustain dark (Pinus sibirica, Abies sibirica, and Picea obovata) taiga. Over eastern Siberia, larch (Larix dahurica) taiga is predicted to continue to be the dominant zonobiome because of its ability to withstand continuous permafrost. The model also predicts new temperate broadleaf forest and forest-steppe habitats by 2080. Potential fire danger evaluated with the annual number of high fire danger days (Nesterov index is 4000-10 000) is predicted to increase by 2080, especially in southern Siberia and central Yakutia. In a warming climate, fuel load accumulated due to replacement of forest by steppe together with frequent fire weather promotes high risks of large fires in southern Siberia and central Yakutia, where wild fires would create habitats for grasslands because the drier climate would no longer be suitable for forests.

  9. Dynamic plant ecology: the spectrum of vegetational change in space and time

    Energy Technology Data Exchange (ETDEWEB)

    Delcourt, H R; Delcourt, P A; Webb, T III

    1983-01-01

    Different environmental forcing functions influence vegetational patterns and processes over a wide range of spatial and temporal scales. On the micro-scale (1 year to 5 x 10/sup 3/ years, 1 m/sup 2/ to 10/sup 6/m/sup 2/) natural and anthropogenic disturbances affect establishment and succession of species populations. At the macro-scale (5 x 10/sup 3/ years to 10/sup 6/ years and 10/sup 6/m/sup 2/ to 10/sup 12/m/sup 2/) climatic changes influence regional vegetational processes that include migrations of species as well as displacement of ecosystems. Mega-scale phenomena such as plate tectonics, evolution of the biota and development of global patterns of vegetation occur on the time scale of > 10/sup 6/ years and over areas > 10/sup 12/m/sup 2/. Our knowledge of past vegetational changes resulting from Quaternary climatic change can be used to predict biotic responses to future climatic changes such as global warming that may be induced by increased carbon dioxide (CO/sub 2/) concentrations in the atmosphere. The time scale for future climatic warming may be much more rapid than that characterizing the early- to mid-Holocene, increasing the probability of rapid turnover in species composition, changes in local and regional dominance of important taxa, displacement of species ranges and local extinction of species. Integration of ecological and paleoecological perspectives on vegetational dynamics is fundamental to understanding and managing the biosphere.

  10. Global assessment of experimental climate warming on tundra vegetation: heterogeneity over space and time.

    Science.gov (United States)

    Elmendorf, Sarah C; Henry, Gregory H R; Hollister, Robert D; Björk, Robert G; Bjorkman, Anne D; Callaghan, Terry V; Collier, Laura Siegwart; Cooper, Elisabeth J; Cornelissen, Johannes H C; Day, Thomas A; Fosaa, Anna Maria; Gould, William A; Grétarsdóttir, Járngerður; Harte, John; Hermanutz, Luise; Hik, David S; Hofgaard, Annika; Jarrad, Frith; Jónsdóttir, Ingibjörg Svala; Keuper, Frida; Klanderud, Kari; Klein, Julia A; Koh, Saewan; Kudo, Gaku; Lang, Simone I; Loewen, Val; May, Jeremy L; Mercado, Joel; Michelsen, Anders; Molau, Ulf; Myers-Smith, Isla H; Oberbauer, Steven F; Pieper, Sara; Post, Eric; Rixen, Christian; Robinson, Clare H; Schmidt, Niels Martin; Shaver, Gaius R; Stenström, Anna; Tolvanen, Anne; Totland, Orjan; Troxler, Tiffany; Wahren, Carl-Henrik; Webber, Patrick J; Welker, Jeffery M; Wookey, Philip A

    2012-02-01

    Understanding the sensitivity of tundra vegetation to climate warming is critical to forecasting future biodiversity and vegetation feedbacks to climate. In situ warming experiments accelerate climate change on a small scale to forecast responses of local plant communities. Limitations of this approach include the apparent site-specificity of results and uncertainty about the power of short-term studies to anticipate longer term change. We address these issues with a synthesis of 61 experimental warming studies, of up to 20 years duration, in tundra sites worldwide. The response of plant groups to warming often differed with ambient summer temperature, soil moisture and experimental duration. Shrubs increased with warming only where ambient temperature was high, whereas graminoids increased primarily in the coldest study sites. Linear increases in effect size over time were frequently observed. There was little indication of saturating or accelerating effects, as would be predicted if negative or positive vegetation feedbacks were common. These results indicate that tundra vegetation exhibits strong regional variation in response to warming, and that in vulnerable regions, cumulative effects of long-term warming on tundra vegetation - and associated ecosystem consequences - have the potential to be much greater than we have observed to date. © 2011 Blackwell Publishing Ltd/CNRS.

  11. Does consumption of leafy vegetables grown in peri-urban agriculture pose a risk to human health?

    International Nuclear Information System (INIS)

    Nabulo, G.; Black, C.R.; Craigon, J.; Young, S.D.

    2012-01-01

    Concentrations of potentially toxic elements were measured in soils and five contrasting tropical leafy vegetables grown in a replicated field trial at five contaminated urban agriculture sites in Kampala City, Uganda. Soil contamination at each site could be tentatively ascribed to known waste disposal practices. There was considerable variation in metal uptake between vegetable types. Washing leafy vegetables reduced chromium and lead concentrations but exogenous contamination of leaves also depended on vegetable type, with Gynandropsis gynandra L. showing a marked tendency to accumulate Pb and Cr. For the worst case scenario of children consuming unwashed vegetables, some metal ‘hazard quotient’ (HQ) limits (1.0) were violated at four of the five sites studied. For the 25 ‘site-vegetable’ combinations assessed, the HQ for Pb exceeded 1.0 in 36% of cases. A vegetable-specific site screening tool based on soil extraction with 0.01 M CaCl 2 and extrapolation to provide HQ values was assessed. - Highlights: ► Solubility of toxic metals in soils used for urban agriculture is highly variable. ► Washing leafy vegetables prior to cooking reduces consumption of Cr, Pb, As and Ni. ► Lead (Pb) presents the greatest hazard in produce from agriculture in Kampala City. ► Agriculture in East African cities can be practiced safely with the right choices. ► Soil screening to predict hazard to consumers may be useful in site surveys. - Peri-urban agriculture requires careful consideration of vegetable choice and site characteristics.

  12. Dry deposition to vegetated surfaces: parametric dependencies

    International Nuclear Information System (INIS)

    Underwood, B.Y.

    1987-12-01

    The dry deposition velocity of airborne pollutants to vegetated surfaces depends on the physico-chemical form of the pollutant, on meteorological conditions (windspeed, atmospheric stability) and on characteristics of the surface cover. This report examines these dependencies, drawing on experimental data and on information from theoretical analyses. A canopy model is outlined which uses first-order closure of the equations for turbulent transport of momentum (or matter), with losses of momentum (or matter) to individual canopy elements parameterised in terms of the mean windspeed: the model has previously been tested against experimental data on an artificial 'grass' canopy. The model is used to elucidate the features of the dependence of deposition velocity on windspeed and on whether the pollutant is in gaseous or particulate form: in the former case, the dependence on the molecular diffusivity of the gas is shown; in the latter case, dependencies on particle diameter and density are deduced. The predictions are related to available measurements. Additional hypotheses are introduced to treat the influence of atmospheric stability on deposition, and the analysis is used to shed light on the somewhat confusing picture that has emerged from past experimental studies. In considering the dependence of deposition velocity on the structural properties of the vegetation, it is established that more parameters than the single one conventionally used -aerodynamic roughness length - are needed to characterise the surface cover. Some indications of the extent of variation in deposition velocity from one type of vegetation to another are elicited from the model. (author)

  13. Encouraging children to eat vegetables

    OpenAIRE

    Buh, Alenka

    2014-01-01

    It is important for children to maintain a healthy and balanced diet throughout their childhood and youth. Children tend to skip vegetables in their meals as they are not much liked; the tastes of vegetables are also highly specific and each individual has to get used to them by repeated tasting. The aim of this undergraduate thesis was to analyse how often children eat vegetables, which types of vegetables they like and which they do not, to determine if the executed method of pedagogica...

  14. Special study on vegetative covers

    International Nuclear Information System (INIS)

    1988-11-01

    This report describes the findings of a special study on the use of vegetative covers to stabilize tailings piles for the Uranium Mill Tailings Remedial Action (UMTRA) Project. The principal rationale for using plants would be to establish a dynamic system for controlling water balance. Specifically, vegetation would be used to intercept and transpire precipitation to the atmosphere, rather than allowing water to drain into the tailings and mobilize contaminants. This would facilitate compliance with groundwater standards proposed for the UMTRA Project by the Environmental Protection Agency. The goals of the study were to evaluate the feasibility of using vegetative covers on UMTRA Project piles, define the advantages and disadvantages of vegetative covers, and develop general guidelines for their use when such use seems reasonable. The principal method for the study was to analyze and apply to the UMTRA Project the results of research programs on vegetative covers at other US Department of Energy (DOE) waste management facilities. The study also relied upon observations made of existing stabilized piles at UMTRA Project sites where natural vegetation is growing on the rock-covered surfaces. Water balance and erosion models were also used to quantify the long-term performance of vegetative covers planned for the topslopes of stabilized piles at Grand Junction and Durango, Colorado, two UMTRA Project sites where the decision was made during the course of this special study to use vegetative covers. Elements in the design and construction of the vegetative covers at these two sites are discussed in the report, with explanations of the differing features that reflect differing environmental conditions. 28 refs., 18 figs., 9 tabs

  15. Psychosocial factors and physical activity as predictors of fruit and vegetable intake in college students

    Directory of Open Access Journals (Sweden)

    Rafael Miranda TASSITANO

    2016-04-01

    Full Text Available Objective: To analyze whether psychosocial factors and physical activity are predictors of fruit and vegetable intake in young adults attending college. Methods: This cross-sectional study included a representative sample of students from a public university in the Brazilian Northeast (n=717. Fruit and vegetable intake was measured by a Food Frequency Questionnaire containing 21 items. The psychosocial factors for behavior change, measured by a questionnaire, were: behavior change strategy, self-efficacy, perceived barriers and facilitators in decision making, and social support. The level of physical activity was measured by the International Physical Activity Questionnaire. Multiple linear regression was the intake prediction model using a significance level of 5% (p<0.05. Results: The median fruit and vegetable intake was 2.0 servings/day. In adjusted analysis, behavior change strategy (R²=0.31, self-efficacy (R²=0.03, friends' support (R²=0.02, and physical activity (R²=0.03 explained 39% of the fruit and vegetable intake variance in men. Behavior change strategy (R²=0.03, self-efficacy (R²=0.13, perceived barriers (R²=0.08, and physical activity (R²=0.02 explained 26% of the fruit and vegetable intake variance in women. Fruit and vegetable intake would increase by one serving for every extra 35 and 47 minutes of physical activity men and women, respectively, practice a day. Conclusion: The main predictors of fruit and vegetable intake are behavior change strategies, self-efficacy, and physical activity.

  16. Predicting vegetation type through physiological and environmental interactions with leaf traits: evergreen and deciduous forests in an earth system modeling framework.

    Science.gov (United States)

    Weng, Ensheng; Farrior, Caroline E; Dybzinski, Ray; Pacala, Stephen W

    2017-06-01

    Earth system models are incorporating plant trait diversity into their land components to better predict vegetation dynamics in a changing climate. However, extant plant trait distributions will not allow extrapolations to novel community assemblages in future climates, which will require a mechanistic understanding of the trade-offs that determine trait diversity. In this study, we show how physiological trade-offs involving leaf mass per unit area (LMA), leaf lifespan, leaf nitrogen, and leaf respiration may explain the distribution patterns of evergreen and deciduous trees in the temperate and boreal zones based on (1) an evolutionary analysis of a simple mathematical model and (2) simulation experiments of an individual-based dynamic vegetation model (i.e., LM3-PPA). The evolutionary analysis shows that these leaf traits set up a trade-off between carbon- and nitrogen-use efficiency at the scale of individual trees and therefore determine competitively dominant leaf strategies. As soil nitrogen availability increases, the dominant leaf strategy switches from one that is high in nitrogen-use efficiency to one that is high in carbon-use efficiency or, equivalently, from high-LMA/long-lived leaves (i.e., evergreen) to low-LMA/short-lived leaves (i.e., deciduous). In a region of intermediate soil nitrogen availability, the dominant leaf strategy may be either deciduous or evergreen depending on the initial conditions of plant trait abundance (i.e., founder controlled) due to feedbacks of leaf traits on soil nitrogen mineralization through litter quality. Simulated successional patterns by LM3-PPA from the leaf physiological trade-offs are consistent with observed successional dynamics of evergreen and deciduous forests at three sites spanning the temperate to boreal zones. © 2016 John Wiley & Sons Ltd.

  17. Health Benefits of Fruits and Vegetables1

    Science.gov (United States)

    Slavin, Joanne L.; Lloyd, Beate

    2012-01-01

    Fruits and vegetables are universally promoted as healthy. The Dietary Guidelines for Americans 2010 recommend you make one-half of your plate fruits and vegetables. Myplate.gov also supports that one-half the plate should be fruits and vegetables. Fruits and vegetables include a diverse group of plant foods that vary greatly in content of energy and nutrients. Additionally, fruits and vegetables supply dietary fiber, and fiber intake is linked to lower incidence of cardiovascular disease and obesity. Fruits and vegetables also supply vitamins and minerals to the diet and are sources of phytochemicals that function as antioxidants, phytoestrogens, and antiinflammatory agents and through other protective mechanisms. In this review, we describe the existing dietary guidance on intake of fruits and vegetables. We also review attempts to characterize fruits and vegetables into groups based on similar chemical structures and functions. Differences among fruits and vegetables in nutrient composition are detailed. We summarize the epidemiological and clinical studies on the health benefits of fruits and vegetables. Finally, we discuss the role of fiber in fruits and vegetables in disease prevention. PMID:22797986

  18. Fruits and vegetables (image)

    Science.gov (United States)

    A healthy diet includes adding vegetables and fruit every day. Vegetables like broccoli, green beans, leafy greens, zucchini, cauliflower, cabbage, carrots, and tomatoes are low in calories and high in fiber, vitamins, and minerals. ...

  19. Relishes: The new pickled vegetables

    Directory of Open Access Journals (Sweden)

    Tepić Aleksandra N.

    2006-01-01

    Full Text Available There have been an increasing interest of consumers for a ide variety of pickled vegetable products worldwide. Regarding the regional vegetable supplies and relatively poor assortment of ready-to-use products, the need to broaden the offer of domestic pickled vegetables at the market came out. In this work recipes for different vegetables, spices and condiments were developed. The best graded samples were analyzed for their main chemical composition (dry matter, proteins, oils and fats, total acidity, total sugars, sucrose, starch, cellulose, pH and energy- values.

  20. Analysis of Post-Fire Vegetation Recovery in the Mediterranean Basin using MODIS Derived Vegetation Indices

    Science.gov (United States)

    Hawtree, Daniel; San Miguel, Jesus; Sedano, Fernando; Kempeneers, Pieter

    2010-05-01

    The Mediterranean basin region is highly susceptible to wildfire, with approximately 60,000 individual fires and half a million ha of natural vegetation burnt per year. Of particular concern in this region is the impact of repeated wildfires on the ability of natural lands to return to a pre-fire state, and of the possibility of desertification of semi-arid areas. Given these concerns, understanding the temporal patterns of vegetation recovery is important for the management of environmental resources in the region. A valuable tool for evaluating these recovery patterns are vegetation indices derived from remote sensing data. Previous research on post-fire vegetation recovery conducted in this region has found significant variability in recovery times across different study sites. It is unclear what the primary variables are affecting the differences in the rates of recovery, and if any geographic patterns of behavior exist across the Mediterranean basin. This research has primarily been conducted using indices derived from Landsat imagery. However, no extensive analysis of vegetation regeneration for large regions has been published, and assessment of vegetation recovery on the basis of medium-spatial resolution imagery such as that of MODIS has not yet been analyzed. This study examines the temporal pattern of vegetation recovery in a number of fire sites in the Mediterranean basin, using data derived from MODIS 16 -day composite vegetation indices. The intent is to develop a more complete picture of the temporal sequence of vegetation recovery, and to evaluate what additional factors impact variations in the recovery sequence. In addition, this study evaluates the utility of using MODIS derived vegetation indices for regeneration studies, and compares the findings to earlier studies which rely on Landsat data. Wildfires occurring between the years 2000 and 2004 were considered as potential study sites for this research. Using the EFFIS dataset, all wildfires

  1. To what extent can vegetation change and plant stress be surveyed by remote sensing?

    Energy Technology Data Exchange (ETDEWEB)

    Toemmervik, Hans

    1998-12-31

    Air pollution from the nickel processing industry in the Kola region of Russia accounts for a large part of the environmental problems in the north-eastern parts of Norway and Finland. The objectives of this thesis were to examine if vegetation damage and plant stress can be surveyed by remote sensing and to assess the use of chlorophyll fluorescence measurements to detect plant stress in the field. The study was carried out in the border area between Norway and Russia. Two spaceborne and one airborne sensors were used. Changes in vegetation cover could be monitored with a degree of accuracy varying from 75 to 83%. A hybrid classification method monitored changes in both lichen dominated vegetation and in vegetation cover types dominated by dwarf shrubs and green plants, which were significantly associated with the differences in SO{sub 2} emission during the period from 1973 to 1994. Vegetation indices, change detection maps and prediction maps provided information on biomass and coverage of green vegetation. This was associated with the differences in the SO{sub 2} emissions during the same period. The vegetation and land cover types with the greatest stress and damage had the largest modelled SO{sub 2} concentration levels in the ground air layer while the vegetation cover types with the lowest degree of stress had the lowest. Comparison of the airborne casi map with the previously processed Landsat TM map from the same area showed that the casi map separated the complete vegetation cover into more detail than the Landsat TM map. The casi images indicated a red-edge shift for the medium to heavily damaged vegetation cover types. Problems with using airborne remote sensing by casi include variable clouds, lack of synoptic view, and cost. The variation in chlorophyll fluorescence of 11 plant species at 16 sites was most influenced by precipitation, temperature and continentality. 373 refs., 49 figs., 37 tabs.

  2. Characterization of subarctic vegetation using ground based remote sensing methods

    Science.gov (United States)

    Finnell, D.; Garnello, A.; Palace, M. W.; Sullivan, F.; Herrick, C.; Anderson, S. M.; Crill, P. M.; Varner, R. K.

    2014-12-01

    Stordalen mire is located at 68°21'N and 19°02'E in the Swedish subarctic. Climate monitoring has revealed a warming trend spanning the past 150 years affecting the mires ability to hold stable palsa/hummock mounds. The micro-topography of the landscape has begun to degrade into thaw ponds changing the vegetation cover from ombrothrophic to minerotrophic. Hummocks are ecologically important due to their ability to act as a carbon sinks. Thaw ponds and sphagnum rich transitional zones have been documented as sources of atmospheric CH4. An objective of this project is to determine if a high resolution three band camera (RGB) and a RGNIR camera could detect differences in vegetation over five different site types. Species composition was collected for 50 plots with ten repetitions for each site type: palsa/hummock, tall shrub, semi-wet, tall graminoid, and wet. Sites were differentiated based on dominating species and features consisting of open water presence, sphagnum spp. cover, graminoid spp. cover, or the presence of dry raised plateaus/mounds. A pole based camera mount was used to collect images at a height of ~2.44m from the ground. The images were cropped in post-processing to fit a one-square meter quadrat. Texture analysis was performed on all images, including entropy, lacunarity, and angular second momentum. Preliminary results suggested that site type influences the number of species present. The p-values for the ability to predict site type using a t-test range from use of a stepwise regression of texture variables, actual vs. predicted percent of vegetation coverage provided R squared values of 0.73, 0.71, 0.67, and 0.89 for C. bigelowii, R. chamaemorus, Sphagnum spp., and open water respectively. These data have provided some support to the notion that texture analyses can be used for classification of mire site types. Future work will involve scaling up from the 50 plots through the use of data collected from two unmanned aerial systems (UAS), as

  3. Using NDVI and guided sampling to develop yield prediction maps of processing tomato crop

    Energy Technology Data Exchange (ETDEWEB)

    Fortes, A.; Henar Prieto, M. del; García-Martín, A.; Córdoba, A.; Martínez, L.; Campillo, C.

    2015-07-01

    The use of yield prediction maps is an important tool for the delineation of within-field management zones. Vegetation indices based on crop reflectance are of potential use in the attainment of this objective. There are different types of vegetation indices based on crop reflectance, the most commonly used of which is the NDVI (normalized difference vegetation index). NDVI values are reported to have good correlation with several vegetation parameters including the ability to predict yield. The field research was conducted in two commercial farms of processing tomato crop, Cantillana and Enviciados. An NDVI prediction map developed through ordinary kriging technique was used for guided sampling of processing tomato yield. Yield was studied and related with NDVI, and finally a prediction map of crop yield for the entire plot was generated using two geostatistical methodologies (ordinary and regression kriging). Finally, a comparison was made between the yield obtained at validation points and the yield values according to the prediction maps. The most precise yield maps were obtained with the regression kriging methodology with RRMSE values of 14% and 17% in Cantillana and Enviciados, respectively, using the NDVI as predictor. The coefficient of correlation between NDVI and yield was correlated in the point samples taken in the two locations, with values of 0.71 and 0.67 in Cantillana and Enviciados, respectively. The results suggest that the use of a massive sampling parameter such as NDVI is a good indicator of the distribution of within-field yield variation. (Author)

  4. Consumer attitudes towards vegetable attributes: potential buyers of pesticide-free vegetables in Accra and Kumasi, Ghana.

    Science.gov (United States)

    Probst, Lorenz; Aigelsperger, Lisa; Hauser, Michael

    2010-01-01

    Considering the inappropriate use of synthetic pesticides on vegetables in West Africa, the rationale behind this research was to assess the extent to which consumers can function as demanders of risk reduced vegetables and hence act as innovators towards vegetable safety. Using the cases of Kumasi and Accra in Ghana, the study examined possible consumer responses to product certification that communicates freedom from pesticides (e.g., organic certification). Generally, search attributes such as the fresh and healthy appearance of a vegetable were found to be central to consumer choice. While consumers stress the importance of health value, they are mostly unaware of agro-chemical risks related to vegetable consumption.

  5. Microscale vegetation-soil feedback boosts hysteresis in a regional vegetation-climate system

    NARCIS (Netherlands)

    Janssen, R.H.H.; Meinders, M.B.J.; Nes, van E.H.; Scheffer, M.

    2008-01-01

    It has been hypothesized that a positive feedback between vegetation cover and monsoon circulation may lead to the existence of two alternative stable states in the Sahara region: a vegetated state with moderate precipitation and a desert state with low precipitation. This could explain the sudden

  6. Consumption of a High Quantity and a Wide Variety of Vegetables Are Predicted by Different Food Choice Motives in Older Adults from France, Italy and the UK.

    Science.gov (United States)

    Appleton, Katherine M; Dinnella, Caterina; Spinelli, Sara; Morizet, David; Saulais, Laure; Hemingway, Ann; Monteleone, Erminio; Depezay, Laurence; Perez-Cueto, Frederico J A; Hartwell, Heather

    2017-08-23

    Consumption of a high quantity and wide variety of vegetables is currently recommended for health. Dietary variety can be low, however, particularly for older adults. This study investigated the affective factors associated with the quantity and variety of vegetables consumed by older adults in France, Italy and the UK. Adults aged 65 years plus completed questionnaires on self-reported vegetable intake (quantity and variety), liking for vegetables, attitudes towards intake, and demographic variables. In 497 older adults (France, n = 187, Italy, n = 152, UK, n = 158), higher quantities of vegetables consumed were associated with a higher age, affluence score and liking for vegetables, and a lower importance in consumption of familiarity (smallest β = 0.11, p = 0.03). Greater variety was associated with a higher liking and importance of health benefits, and a lower importance of familiarity (smallest β = -0.11, p foods in vegetable consumption, and a particular role for concern for health benefits in the consumption of a greater variety of vegetables.

  7. Ecosystem properties self-organize in response to a directional fog-vegetation interaction.

    Science.gov (United States)

    Stanton, Daniel E; Armesto, Juan J; Hedin, Lars O

    2014-05-01

    Feedbacks between vegetation and resource inputs can lead to the local, self-organization of ecosystem properties. In particular, feedbacks in response to directional resources (e.g., coastal fog, slope runoff) can create complex spatial patterns, such as vegetation banding. Although similar feedbacks are thought to be involved in the development of ecosystems, clear empirical examples are rare. We created a simple model of a fog-influenced, temperate rainforest in central Chile, which allows the comparison of natural banding patterns to simulations of various putative mechanisms. We show that only feedbacks between plants and fog were able to replicate the characteristic distributions of vegetation, soil water, and soil nutrients observed in field transects. Other processes, such as rainfall, were unable to match these diagnostic distributions. Furthermore, fog interception by windward trees leads to increased downwind mortality, leading to progressive extinction of the leeward edge. This pattern of ecosystem development and decay through self-organized processes illustrates, on a relatively small spatial and temporal scale, the patterns predicted for ecosystem evolution.

  8. Detection and quantification of adulteration of sesame oils with vegetable oils using gas chromatography and multivariate data analysis.

    Science.gov (United States)

    Peng, Dan; Bi, Yanlan; Ren, Xiaona; Yang, Guolong; Sun, Shangde; Wang, Xuede

    2015-12-01

    This study was performed to develop a hierarchical approach for detection and quantification of adulteration of sesame oil with vegetable oils using gas chromatography (GC). At first, a model was constructed to discriminate the difference between authentic sesame oils and adulterated sesame oils using support vector machine (SVM) algorithm. Then, another SVM-based model is developed to identify the type of adulterant in the mixed oil. At last, prediction models for sesame oil were built for each kind of oil using partial least square method. To validate this approach, 746 samples were prepared by mixing authentic sesame oils with five types of vegetable oil. The prediction results show that the detection limit for authentication is as low as 5% in mixing ratio and the root-mean-square errors for prediction range from 1.19% to 4.29%, meaning that this approach is a valuable tool to detect and quantify the adulteration of sesame oil. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Vegetation Description, Rare Plant Inventory, and Vegetation Monitoring for Craig Mountain, Idaho.

    Energy Technology Data Exchange (ETDEWEB)

    Mancuso, Michael; Moseley, Robert

    1994-12-01

    The Craig Mountain Wildlife Mitigation Area was purchased by Bonneville Power Administration (BPA) as partial mitigation for wildlife losses incurred with the inundation of Dworshak Reservoir on the North Fork Clearwater River. Upon completion of the National Environmental Protection Act (NEPA) process, it is proposed that title to mitigation lands will be given to the Idaho Department of Fish and Game (IDFG). Craig Mountain is located at the northern end of the Hells Canyon Ecosystem. It encompasses the plateau and steep canyon slopes extending from the confluence of the Snake and Salmon rivers, northward to near Waha, south of Lewiston, Idaho. The forested summit of Craig Mountain is characterized by gently rolling terrain. The highlands dramatically break into the canyons of the Snake and Salmon rivers at approximately the 4,700 foot contour. The highly dissected canyons are dominated by grassland slopes containing a mosaic of shrubfield, riparian, and woodland habitats. During the 1993 and 1994 field seasons, wildlife, habitat/vegetation, timber, and other resources were systematically inventoried at Craig Mountain to provide Fish and Game managers with information needed to draft an ecologically-based management plan. The results of the habitat/vegetation portion of the inventory are contained in this report. The responsibilities for the Craig Mountain project included: (1) vegetation data collection, and vegetation classification, to help produce a GIS-generated Craig Mountain vegetation map, (2) to determine the distribution and abundance of rare plants populations and make recommendations concerning their management, and (3) to establish a vegetation monitoring program to evaluate the effects of Fish and Game management actions, and to assess progress towards meeting habitat mitigation goals.

  10. Vegetation description, rare plant inventory, and vegetation monitoring for Craig Mountain, Idaho

    International Nuclear Information System (INIS)

    Mancuso, M.; Moseley, R.

    1994-12-01

    The Craig Mountain Wildlife Mitigation Area was purchased by Bonneville Power Administration (BPA) as partial mitigation for wildlife losses incurred with the inundation of Dworshak Reservoir on the North Fork Clearwater River. Upon completion of the National Environmental Protection Act (NEPA) process, it is proposed that title to mitigation lands will be given to the Idaho Department of Fish and Game (IDFG). Craig Mountain is located at the northern end of the Hells Canyon Ecosystem. It encompasses the plateau and steep canyon slopes extending from the confluence of the Snake and Salmon rivers, northward to near Waha, south of Lewiston, Idaho. The forested summit of Craig Mountain is characterized by gently rolling terrain. The highlands dramatically break into the canyons of the Snake and Salmon rivers at approximately the 4,700 foot contour. The highly dissected canyons are dominated by grassland slopes containing a mosaic of shrubfield, riparian, and woodland habitats. During the 1993 and 1994 field seasons, wildlife, habitat/vegetation, timber, and other resources were systematically inventoried at Craig Mountain to provide Fish and Game managers with information needed to draft an ecologically-based management plan. The results of the habitat/vegetation portion of the inventory are contained in this report. The responsibilities for the Craig Mountain project included: (1) vegetation data collection, and vegetation classification, to help produce a GIS-generated Craig Mountain vegetation map, (2) to determine the distribution and abundance of rare plants populations and make recommendations concerning their management, and (3) to establish a vegetation monitoring program to evaluate the effects of Fish and Game management actions, and to assess progress towards meeting habitat mitigation goals

  11. Simulating the effect of vegetation cover on the sediment yield of mediterranean catchments using SHETRAN

    Science.gov (United States)

    Lukey, B. T.; Sheffield, J.; Bathurst, J. C.; Lavabre, J.; Mathys, N.; Martin, C.

    1995-08-01

    The sediment yield of two catchments in southern France was modelled using the newly developed sediment code of SHETRAN. A fire in August 1990 denuded the Rimbaud catchment, providing an opportunity to study the effect of vegetation cover on sediment yield by running the model for both pre-and post-fire cases. Model output is in the form of upper and lower bounds on sediment discharge, reflecting the uncertainty in the erodibility of the soil. The results are encouraging since measured sediment discharge falls largely between the predicted bounds, and simulated sediment yield is dramatically lower for the catchment before the fire which matches observation. SHETRAN is also applied to the Laval catchment, which is subject to Badlands gulley erosion. Again using the principle of generating upper and lower bounds on sediment discharge, the model is shown to be capable of predicting the bulk sediment discharge over periods of months. To simulate the effect of reforestation, the model is run with vegetation cover equivalent to a neighbouring fully forested basin. The results obtained indicate that SHETRAN provides a powerful tool for predicting the impact of environmental change and land management on sediment yield.

  12. Different techniques of multispectral data analysis for vegetation fraction retrieval

    Science.gov (United States)

    Kancheva, Rumiana; Georgiev, Georgi

    2012-07-01

    Vegetation monitoring is one of the most important applications of remote sensing technologies. In respect to farmlands, the assessment of crop condition constitutes the basis of growth, development, and yield processes monitoring. Plant condition is defined by a set of biometric variables, such as density, height, biomass amount, leaf area index, and etc. The canopy cover fraction is closely related to these variables, and is state-indicative of the growth process. At the same time it is a defining factor of the soil-vegetation system spectral signatures. That is why spectral mixtures decomposition is a primary objective in remotely sensed data processing and interpretation, specifically in agricultural applications. The actual usefulness of the applied methods depends on their prediction reliability. The goal of this paper is to present and compare different techniques for quantitative endmember extraction from soil-crop patterns reflectance. These techniques include: linear spectral unmixing, two-dimensional spectra analysis, spectral ratio analysis (vegetation indices), spectral derivative analysis (red edge position), colorimetric analysis (tristimulus values sum, chromaticity coordinates and dominant wavelength). The objective is to reveal their potential, accuracy and robustness for plant fraction estimation from multispectral data. Regression relationships have been established between crop canopy cover and various spectral estimators.

  13. Impact of vegetation dynamics on hydrological processes in a semi-arid basin by using a land surface-hydrology coupled model

    Energy Technology Data Exchange (ETDEWEB)

    Jiao, Yang; Lei, Huimin; Yang, Dawen; Huang, Maoyi; Liu, Dengfeng; Yuan, Xing

    2017-08-01

    Land surface models (LSMs) are widely used to understand the interactions between hydrological processes and vegetation dynamics, which is important for the attribution and prediction of regional hydrological variations. However, most LSMs have large uncertainties in their representations of ecohydrological processes due to deficiencies in hydrological parameterizations. In this study, the Community Land Model version 4 (CLM4) LSM was modified with an advanced runoff generation and flow routing scheme, resulting in a new land surface-hydrology coupled model, CLM-GBHM. Both models were implemented in the Wudinghe River Basin (WRB), which is a semi-arid basin located in the middle reaches of the Yellow River, China. Compared with CLM, CLM-GBHM increased the Nash Sutcliffe efficiency for daily river discharge simulation (1965–1969) from 0.03 to 0.23 and reduced the relative bias in water table depth simulations (2010–2012) from 32.4% to 13.4%. The CLM-GBHM simulations with static, remotely sensed and model-predicted vegetation conditions showed that the vegetation in the WRB began to recover in the 2000s due to the Grain for Green Program but had not reached the same level of vegetation cover as regions in natural eco-hydrological equilibrium. Compared with a simulation using remotely sensed vegetation cover, the simulation with a dynamic vegetation model that considers only climate-induced change showed a 10.3% increase in evapotranspiration, a 47.8% decrease in runoff, and a 62.7% and 71.3% deceleration in changing trend of the outlet river discharge before and after the year 2000, respectively. This result suggests that both natural and anthropogenic factors should be incorporated in dynamic vegetation models to better simulate the eco-hydrological cycle.

  14. Consumer Acceptance Comparison Between Seasoned and Unseasoned Vegetables.

    Science.gov (United States)

    Feng, Yiming; Albiol Tapia, Marta; Okada, Kyle; Castaneda Lazo, Nuria Blanca; Chapman-Novakofski, Karen; Phillips, Carter; Lee, Soo-Yeun

    2018-02-01

    Recent findings show that approximately 87% of the U.S. population fail to meet the vegetable intake recommendations, with unpleasant taste of vegetables being listed as the primary reason for this shortfall. In this study, spice and herb seasoning was used to enhance palatability of vegetables, in order to increase consumer acceptance. In total, 749 panelists were screened and recruited as specific vegetable likers of the vegetable being tested or general vegetable likers. Four sessions were designed to evaluate the effect of seasoning within each type of vegetable, including broccoli, cauliflower, carrot, and green bean. Each panelist was only allowed to participate in one test session to evaluate only one vegetable type, so as to mitigate potential learning effect. Overall, the results showed that seasoned vegetables were significantly preferred over unseasoned vegetables (P trend of seasoned vegetable being preferred remained. The findings from this study demonstrate the effect of seasoning in enhancing consumer liking of vegetables, which may lead to increased consumption to be assessed in future studies. To improve the sensory properties of vegetables, masking the bitter taste of vegetables using spice and herb seasoning are gaining increasing attention. Our findings suggest that the overall liking of vegetables could be improved by incorporating spice and herb seasonings that are specifically formulated for each vegetable. Ultimately, developing and commercializing spice and herb seasonings may aid to increase vegetable consumption, as well as expanding the vegetable seasoning market. © 2018 The Authors Journal of Food Science published by Wiley Periodicals, Inc. on behalf of Institute of Food Technologists.

  15. Evaluation of glucosinolate levels throughout the production chain of Brassica vegetables towards a novel predictive modelling approach

    NARCIS (Netherlands)

    Verkerk, R.

    2002-01-01

    Glucosinolates are a group of plant secondary metabolites, that can have important implications for human health. Vegetables of the Brassica genus, including cabbage, Brussels sprouts, broccoli, cauliflower and kohlrabi contribute almost exclusively to our intake of

  16. [Differences of vegetation phenology monitoring by remote sensing based on different spectral vegetation indices.

    Science.gov (United States)

    Zuo, Lu; Wang, Huan Jiong; Liu, Rong Gao; Liu, Yang; Shang, Rong

    2018-02-01

    Vegetation phenology is a comprehensive indictor for the responses of terrestrial ecosystem to climatic and environmental changes. Remote sensing spectrum has been widely used in the extraction of vegetation phenology information. However, there are many differences between phenology extracted by remote sensing and site observations, with their physical meaning remaining unclear. We selected one tile of MODIS data in northeastern China (2000-2014) to examine the SOS and EOS differences derived from the normalized difference vegetation index (NDVI) and the simple ratio vegetation index (SR) based on both the red and near-infrared bands. The results showed that there were significant differences between NDVI-phenology and SR-phenology. SOS derived from NDVI averaged 18.9 days earlier than that from SR. EOS derived from NDVI averaged 19.0 days later than from SR. NDVI-phenology had a longer growing season. There were significant differences in the inter-annual variation of phenology from NDVI and SR. More than 20% of the pixel SOS and EOS derived from NDVI and SR showed the opposite temporal trend. These results caused by the seasonal curve characteristics and noise resistance differences of NDVI and SR. The observed data source of NDVI and SR were completely consistent, only the mathematical expressions were different, but phenology results were significantly different. Our results indicated that vegetation phenology monitoring by remote sensing is highly dependent on the mathematical expression of vegetation index. How to establish a reliable method for extracting vegetation phenology by remote sensing needs further research.

  17. Handling Procedures of Vegetable Crops

    Science.gov (United States)

    Perchonok, Michele; French, Stephen J.

    2004-01-01

    The National Aeronautics and Space Administration (NASA) is working towards future long duration manned space flights beyond low earth orbit. The duration of these missions may be as long as 2.5 years and will likely include a stay on a lunar or planetary surface. The primary goal of the Advanced Food System in these long duration exploratory missions is to provide the crew with a palatable, nutritious, and safe food system while minimizing volume, mass, and waste. Vegetable crops can provide the crew with added nutrition and variety. These crops do not require any cooking or food processing prior to consumption. The vegetable crops, unlike prepackaged foods, will provide bright colors, textures (crispy), and fresh aromas. Ten vegetable crops have been identified for possible use in long duration missions. They are lettuce, spinach, carrot, tomato, green onion, radish, bell pepper, strawberries, fresh herbs, and cabbage. Whether these crops are grown on a transit vehicle (e.g., International Space Station) or on the lunar or planetary surface, it will be necessary to determine how to safely handle the vegetables while maintaining acceptability. Since hydrogen peroxide degrades into water and oxygen and is generally recognized as safe (GRAS), hydrogen peroxide has been recommended as the sanitizer. The objective of th is research is to determine the required effective concentration of hydrogen peroxide. In addition, it will be determined whether the use of hydrogen peroxide, although a viable sanitizer, adversely affects the quality of the vegetables. Vegetables will be dipped in 1 % hydrogen peroxide, 3% hydrogen peroxide, or 5% hydrogen peroxide. Treated produce and controls will be stored in plastic bags at 5 C for up to 14 days. Sensory, color, texture, and total plate count will be measured. The effect on several vegetables including lettuce, radish, tomato and strawberries has been completed. Although each vegetable reacts to hydrogen peroxide differently, the

  18. An Enhanced TIMESAT Algorithm for Estimating Vegetation Phenology Metrics from MODIS Data

    Science.gov (United States)

    Tan, Bin; Morisette, Jeffrey T.; Wolfe, Robert E.; Gao, Feng; Ederer, Gregory A.; Nightingale, Joanne; Pedelty, Jeffrey A.

    2012-01-01

    An enhanced TIMESAT algorithm was developed for retrieving vegetation phenology metrics from 250 m and 500 m spatial resolution Moderate Resolution Imaging Spectroradiometer (MODIS) vegetation indexes (VI) over North America. MODIS VI data were pre-processed using snow-cover and land surface temperature data, and temporally smoothed with the enhanced TIMESAT algorithm. An objective third derivative test was applied to define key phenology dates and retrieve a set of phenology metrics. This algorithm has been applied to two MODIS VIs: Normalized Difference Vegetation Index (NDVI) and Enhanced Vegetation Index (EVI). In this paper, we describe the algorithm and use EVI as an example to compare three sets of TIMESAT algorithm/MODIS VI combinations: a) original TIMESAT algorithm with original MODIS VI, b) original TIMESAT algorithm with pre-processed MODIS VI, and c) enhanced TIMESAT and pre-processed MODIS VI. All retrievals were compared with ground phenology observations, some made available through the National Phenology Network. Our results show that for MODIS data in middle to high latitude regions, snow and land surface temperature information is critical in retrieving phenology metrics from satellite observations. The results also show that the enhanced TIMESAT algorithm can better accommodate growing season start and end dates that vary significantly from year to year. The TIMESAT algorithm improvements contribute to more spatial coverage and more accurate retrievals of the phenology metrics. Among three sets of TIMESAT/MODIS VI combinations, the start of the growing season metric predicted by the enhanced TIMESAT algorithm using pre-processed MODIS VIs has the best associations with ground observed vegetation greenup dates.

  19. The use of a commercial vegetable juice as a practical means to increase vegetable intake: a randomized controlled trial.

    Science.gov (United States)

    Shenoy, Sonia F; Kazaks, Alexandra G; Holt, Roberta R; Chen, Hsin Ju; Winters, Barbara L; Khoo, Chor San; Poston, Walker S C; Haddock, C Keith; Reeves, Rebecca S; Foreyt, John P; Gershwin, M Eric; Keen, Carl L

    2010-09-17

    Recommendations for daily dietary vegetable intake were increased in the 2005 USDA Dietary Guidelines as consumption of a diet rich in vegetables has been associated with lower risk of certain chronic health disorders including cardiovascular disease. However, vegetable consumption in the United States has declined over the past decade; consequently, the gap between dietary recommendations and vegetable intake is widening. The primary aim of this study is to determine if drinking vegetable juice is a practical way to help meet daily dietary recommendations for vegetable intake consistent with the 2005 Dietary Guidelines and the Dietary Approaches to Stop Hypertension (DASH) diet. The secondary aim is to assess the effect of a vegetable juice on measures of cardiovascular health. We conducted a 12-week, randomized, controlled, parallel-arm study consisting of 3 groups of free-living, healthy volunteers who participated in study visits at the Ragle Human Nutrition Research Center at the University of California, Davis. All subjects received education on the DASH diet and 0, 8 or 16 fluid ounces of vegetable juice daily. Assessments were completed of daily vegetable servings before and after incorporation of vegetable juice and cardiovascular health parameters including blood pressure. Without the juice, vegetable intake in all groups was lower than the 2005 Dietary Guidelines and DASH diet recommendations. The consumption of the vegetable juice helped participants reach recommended intake. In general, parameters associated with cardiovascular health did not change over time. However, in the vegetable juice intervention groups, subjects who were pre-hypertensive at the start of the study showed a significant decrease in blood pressure during the 12-week intervention period. Including 1-2 cups of vegetable juice daily was an effective and acceptable way for healthy adults to close the dietary vegetable gap. Increase in daily vegetable intake was associated with a

  20. The use of a commercial vegetable juice as a practical means to increase vegetable intake: a randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Reeves Rebecca S

    2010-09-01

    Full Text Available Abstract Background Recommendations for daily dietary vegetable intake were increased in the 2005 USDA Dietary Guidelines as consumption of a diet rich in vegetables has been associated with lower risk of certain chronic health disorders including cardiovascular disease. However, vegetable consumption in the United States has declined over the past decade; consequently, the gap between dietary recommendations and vegetable intake is widening. The primary aim of this study is to determine if drinking vegetable juice is a practical way to help meet daily dietary recommendations for vegetable intake consistent with the 2005 Dietary Guidelines and the Dietary Approaches to Stop Hypertension (DASH diet. The secondary aim is to assess the effect of a vegetable juice on measures of cardiovascular health. Methods We conducted a 12-week, randomized, controlled, parallel-arm study consisting of 3 groups of free-living, healthy volunteers who participated in study visits at the Ragle Human Nutrition Research Center at the University of California, Davis. All subjects received education on the DASH diet and 0, 8 or 16 fluid ounces of vegetable juice daily. Assessments were completed of daily vegetable servings before and after incorporation of vegetable juice and cardiovascular health parameters including blood pressure. Results Without the juice, vegetable intake in all groups was lower than the 2005 Dietary Guidelines and DASH diet recommendations. The consumption of the vegetable juice helped participants reach recommended intake. In general, parameters associated with cardiovascular health did not change over time. However, in the vegetable juice intervention groups, subjects who were pre-hypertensive at the start of the study showed a significant decrease in blood pressure during the 12-week intervention period. Conclusion Including 1-2 cups of vegetable juice daily was an effective and acceptable way for healthy adults to close the dietary vegetable

  1. [Correlation analysis on normalized difference vegetation index (NDVI) of different vegetations and climatic factors in Southwest China].

    Science.gov (United States)

    Zhang, Yuan-Dong; Zhang, Xiao-He; Liu, Shi-Rong

    2011-02-01

    Based on the 1982-2006 NDVI remote sensing data and meteorological data of Southwest China, and by using GIS technology, this paper interpolated and extracted the mean annual temperature, annual precipitation, and drought index in the region, and analyzed the correlations of the annual variation of NDVI in different vegetation types (marsh, shrub, bush, grassland, meadow, coniferous forest, broad-leaved forest, alpine vegetation, and cultural vegetation) with corresponding climatic factors. In 1982-2006, the NDVI, mean annual temperature, and annual precipitation had an overall increasing trend, and the drought index decreased. Particularly, the upward trend of mean annual temperature was statistically significant. Among the nine vegetation types, the NDVI of bush and mash decreased, and the downward trend was significant for bush. The NDVI of the other seven vegetation types increased, and the upward trend was significant for coniferous forest, meadow, and alpine vegetation, and extremely significant for shrub. The mean annual temperature in the areas with all the nine vegetation types increased significantly, while the annual precipitation had no significant change. The drought index in the areas with marsh, bush, and cultural vegetation presented an increasing trend, that in the areas with meadow and alpine vegetation decreased significantly, and this index in the areas with other four vegetation types had an unobvious decreasing trend. The NDVI of shrub and coniferous forest had a significantly positive correlation with mean annual temperature, and that of shrub and meadow had significantly negative correlation with drought index. Under the conditions of the other two climatic factors unchanged, the NDVI of coniferous forest, broad-leaved forest, and alpine vegetation showed the strongest correlation with mean annual temperature, that of grass showed the strongest correlation with annual precipitation, and the NDVI of mash, shrub, grass, meadow, and cultural

  2. Effects of metals on vegetation

    Energy Technology Data Exchange (ETDEWEB)

    Press, N P

    1972-01-01

    Prospectors have long known that abnormal concentrations of metals in the soil overlying an ore deposit can affect the vegetation rooting in this soil; mineral deposits have even been discovered because of such vegetation changes. Recently, many people have become interested in the possibility of remote sensing such vegetation changes, and perhaps using the results in conjunction with airborne geophysics and photogeological interpretation in integrated prospecting programs.

  3. Vegetation and acidification, Chapter 5

    Science.gov (United States)

    David R. DeWalle; James N. Kochenderfer; Mary Beth Adams; Gary W. Miller

    2006-01-01

    In this chapter, the impact of watershed acidification treatments on WS3 at the Fernow Experimental Forest (FEF) and at WS9 on vegetation is presented and summarized in a comprehensive way for the first time. WS7 is used as a vegetative reference basin for WS3, while untreated plots within WS9 are used as a vegetative reference for WS9. Bioindicators of acidification...

  4. The influence of roadside solid and vegetation barriers on near-road air quality

    Science.gov (United States)

    Ghasemian, Masoud; Amini, Seyedmorteza; Princevac, Marko

    2017-12-01

    The current study evaluates the influence of roadside solid and vegetation barriers on the near-road air quality. Reynolds Averaged Navier-Stokes (RANS) technique coupled with the k - ε realizable turbulence model is utilized to investigate the flow pattern and pollutant concentration. A scalar transport equation is solved for a tracer gas to represent the roadway pollutant emissions. In addition, a broad range of turbulent Schmidt numbers are tested to calibrate the scalar transport equation. Three main scenarios including flat terrain, solid barrier, and vegetative barrier are studied. To validate numerical methodology, predicted pollutant concentration is compared with published wind tunnel data. Results show that the solid barrier induces an updraft motion and lofts the vehicle emission plume. Therefore, the ground-level pollutant concentration decreases compared to the flat terrain. For the vegetation barrier, different sub-scenarios with different vegetation densities ranging from approximately flat terrain to nearly solid barrier are examined. Dense canopies act in a similar manner as a solid barrier and mitigate the pollutant concentration through vertical mixing. On the other hand, the high porosity vegetation barriers reduce the wind speed and lead to a higher pollutant concentration. As the vegetation density increases, i.e. the barrier porosity decreases, the recirculation zone behind the canopy becomes larger and moves toward the canopy. The dense plant canopy with LAD = 3.33m-2m3 can improve the near-road air quality by 10% and high porosity canopy with LAD = 1m-2m3 deteriorates near-road air quality by 15%. The results of this study can be implemented as green infrastructure design strategies by urban planners and forestry organizations.

  5. Pairing vegetables with a liked food and visually appealing presentation: promising strategies for increasing vegetable consumption among preschoolers.

    Science.gov (United States)

    Correia, Danielle C S; O'Connell, Meghan; Irwin, Melinda L; Henderson, Kathryn E

    2014-02-01

    Vegetable consumption among preschool children is below recommended levels. New evidence-based approaches to increase preschoolers' vegetable intake, particularly in the child care setting, are needed. This study tests the effectiveness of two community-based randomized interventions to increase vegetable consumption and willingness to try vegetables: (1) the pairing of a vegetable with a familiar, well-liked food and (2) enhancing the visual appeal of a vegetable. Fifty-seven preschoolers enrolled in a Child and Adult Care Food Program-participating child care center participated in the study; complete lunch and snack data were collected from 43 and 42 children, respectively. A within-subjects, randomized design was used, with order of condition counterbalanced. For lunch, steamed broccoli was served either on the side of or on top of cheese pizza. For a snack, raw cucumber was served either as semicircles with chive and an olive garnish or arranged in a visually appealing manner (in the shape of a caterpillar). Paired t-tests were used to determine differences in consumption of meal components, and McNemar's test was performed to compare willingness to taste. Neither visual appeal enhancement nor pairing with a liked food increased vegetable consumption. Pairing increased willingness to try the vegetable from 79% to 95% of children (p=0.07). Greater vegetable intake occurred at snack than at lunch. Further research should explore the strategy of pairing vegetables with liked foods. Greater consumption at snack underscores snack time as a critical opportunity for increasing preschool children's vegetable intake.

  6. Predicting the impact of vegetations in open channels with different distributaries' operations on water surface profile using artificial neural networks

    International Nuclear Information System (INIS)

    Abdeen, Mostafa A. M.

    2008-01-01

    Most of the open water irrigation channels in Egypt suffer from the infestation of aquatic weeds, especially the submerged ones that cause numerous hydraulic problems for the open channels themselves and their water distributaries such as increasing water losses, obstructing water flow, and reducing channels' water distribution efficiencies. Accurate simulation and prediction of flow behavior in such channels is very essential for water distribution decision makers. Artificial neural networks (ANN) have proven to be very successful in the simulation of several physical phenomena, in general, and in the water research field in particular. Therefore, the current study aims towards introducing the utilization of ANN in simulating the impact of vegetation in main open channel, which supplies water to different distributaries, on the water surface profile in this main channel. Specifically, the study, presented in the current paper utilizes ANN technique for the development of various models to simulate the impact of different submerged weeds' densities, different flow discharges, and different distributaries operation scheduling on the water surface profile in an experimental main open channel that supplies water to different distributaries. In the investigated experiment, the submerged weeds were simulated as branched flexible elements. The investigated experiment was considered as an example for implementing the same methodology and technique in a real open channel system. The results showed that the ANN technique is very successful in simulating the flow behavior of the pre-mentioned open channel experiment with the existence of the submerged weeds. In addition, the developed ANN models were capable of predicting the open channel flow behavior in all the submerged weeds' cases that were considered in the ANN development process

  7. Estimation of Vegetable Crop Parameter by Multi-temporal UAV-Borne Images

    Directory of Open Access Journals (Sweden)

    Thomas Moeckel

    2018-05-01

    Full Text Available 3D point cloud analysis of imagery collected by unmanned aerial vehicles (UAV has been shown to be a valuable tool for estimation of crop phenotypic traits, such as plant height, in several species. Spatial information about these phenotypic traits can be used to derive information about other important crop characteristics, like fresh biomass yield, which could not be derived directly from the point clouds. Previous approaches have often only considered single date measurements using a single point cloud derived metric for the respective trait. Furthermore, most of the studies focused on plant species with a homogenous canopy surface. The aim of this study was to assess the applicability of UAV imagery for capturing crop height information of three vegetables (crops eggplant, tomato, and cabbage with a complex vegetation canopy surface during a complete crop growth cycle to infer biomass. Additionally, the effect of crop development stage on the relationship between estimated crop height and field measured crop height was examined. Our study was conducted in an experimental layout at the University of Agricultural Science in Bengaluru, India. For all the crops, the crop height and the biomass was measured at five dates during one crop growth cycle between February and May 2017 (average crop height was 42.5, 35.5, and 16.0 cm for eggplant, tomato, and cabbage. Using a structure from motion approach, a 3D point cloud was created for each crop and sampling date. In total, 14 crop height metrics were extracted from the point clouds. Machine learning methods were used to create prediction models for vegetable crop height. The study demonstrates that the monitoring of crop height using an UAV during an entire growing period results in detailed and precise estimates of crop height and biomass for all three crops (R2 ranging from 0.87 to 0.97, bias ranging from −0.66 to 0.45 cm. The effect of crop development stage on the predicted crop height was

  8. Toxicología Vegetal

    OpenAIRE

    García Fernández, Antonio Juan

    2010-01-01

    Presentaciones de clase de los temas de Toxicología Vegetal de la licenciatura de Veterinaria de la Universidad de Murcia del curso 2011/12. Presentaciones de Toxicología Vegetal de la asignatura de Toxicología de la Licenciatura de Veterinaria del curso 2011/12

  9. An Analytical Solution for the Impact of Vegetation Changes on Hydrological Partitioning Within the Budyko Framework

    Science.gov (United States)

    Zhang, Shulei; Yang, Yuting; McVicar, Tim R.; Yang, Dawen

    2018-01-01

    Vegetation change is a critical factor that profoundly affects the terrestrial water cycle. Here we derive an analytical solution for the impact of vegetation changes on hydrological partitioning within the Budyko framework. This is achieved by deriving an analytical expression between leaf area index (LAI) change and the Budyko land surface parameter (n) change, through the combination of a steady state ecohydrological model with an analytical carbon cost-benefit model for plant rooting depth. Using China where vegetation coverage has experienced dramatic changes over the past two decades as a study case, we quantify the impact of LAI changes on the hydrological partitioning during 1982-2010 and predict the future influence of these changes for the 21st century using climate model projections. Results show that LAI change exhibits an increasing importance on altering hydrological partitioning as climate becomes drier. In semiarid and arid China, increased LAI has led to substantial streamflow reductions over the past three decades (on average -8.5% in 1990s and -11.7% in 2000s compared to the 1980s baseline), and this decreasing trend in streamflow is projected to continue toward the end of this century due to predicted LAI increases. Our result calls for caution regarding the large-scale revegetation activities currently being implemented in arid and semiarid China, which may result in serious future water scarcity issues here. The analytical model developed here is physically based and suitable for simultaneously assessing both vegetation changes and climate change induced changes to streamflow globally.

  10. VEGETATIVE1 is essential for development of the compound inflorescence in pea

    DEFF Research Database (Denmark)

    Berbel, Ana; Ferrandiz, Cristina; Hecht, Valerie

    2012-01-01

    Unravelling the basis of variation in inflorescence architecture is important to understanding how the huge diversity in plant form has been generated. Inflorescences are divided between simple, as in Arabidopsis, with flowers directly formed at the main primary inflorescence axis, and compound......, as in legumes, where they are formed at secondary or even higher order axes. The formation of secondary inflorescences predicts a novel genetic function in the development of the compound inflorescences. Here we show that in pea this function is controlled by VEGETATIVE1 (VEG1), whose mutation replaces...... secondary inflorescences by vegetative branches. We identify VEG1 as an AGL79-like MADS-box gene that specifies secondary inflorescence meristem identity. VEG1 misexpression in meristem identity mutants causes ectopic secondary inflorescence formation, suggesting a model for compound inflorescence...

  11. Variation of strontium stable isotope ratios and origins of strontium in Japanese vegetables and comparison with Chinese vegetables.

    Science.gov (United States)

    Aoyama, Keisuke; Nakano, Takanori; Shin, Ki-Cheol; Izawa, Atsunobu; Morita, Sakie

    2017-12-15

    To evaluate the utility of 87 Sr/ 86 Sr ratio for determining the geographical provenance of vegetables, we compared 87 Sr/ 86 Sr ratios and Sr concentrations in five vegetable species grown in Japan and China, and we also examined the relationships between 87 Sr/ 86 Sr ratios in vegetables, the soil-exchangeable pool, irrigation water, and fertilizer from 20 Japanese agricultural areas. The vegetable 87 Sr/ 86 Sr ratios in Japan were similar for all species within a given agricultural area, but tended to be low in northeast Japan and high in southwest Japan. The median 87 Sr/ 86 Sr ratio in Japanese vegetables was similar to that in fertilizer, suggesting that in addition to rock-derived Sr, vegetables contain Sr derived from fertilizers. In most cases, the 87 Sr/ 86 Sr ratios for the Japanese and Chinese vegetables differed by approximately 0.710. Linear discriminant analysis using both 87 Sr/ 86 Sr and the Sr concentration allowed more accurate discrimination between vegetables from the two countries. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. The role of ice dynamics in shaping vegetation in flowing waters.

    Science.gov (United States)

    Lind, Lovisa; Nilsson, Christer; Polvi, Lina E; Weber, Christine

    2014-11-01

    Ice dynamics is an important factor affecting vegetation in high-altitude and high-latitude streams and rivers. During the last few decades, knowledge about ice in streams and rivers has increased significantly and a respectable body of literature is now available. Here we review the literature on how ice dynamics influence riparian and aquatic vegetation. Traditionally, plant ecologists have focused their studies on the summer period, largely ignoring the fact that processes during winter also impact vegetation dynamics. For example, the freeze-up period in early winter may result in extensive formation of underwater ice that can restructure the channel, obstruct flow, and cause flooding and thus formation of more ice. In midwinter, slow-flowing reaches develop a surface-ice cover that accumulates snow, protecting habitats under the ice from formation of underwater ice but also reducing underwater light, thus suppressing photosynthesis. Towards the end of winter, ice breaks up and moves downstream. During this transport, ice floes can jam up and cause floods and major erosion. The magnitudes of the floods and their erosive power mainly depend on the size of the watercourse, also resulting in different degrees of disturbance to the vegetation. Vegetation responds both physically and physiologically to ice dynamics. Physical action involves the erosive force of moving ice and damage caused by ground frost, whereas physiological effects - mostly cell damage - happen as a result of plants freezing into the ice. On a community level, large magnitudes of ice dynamics seem to favour species richness, but can be detrimental for individual plants. Human impacts, such as flow regulation, channelisation, agriculturalisation and water pollution have modified ice dynamics; further changes are expected as a result of current and predicted future climate change. Human impacts and climate change can both favour and disfavour riverine vegetation dynamics. Restoration of streams

  13. Vegetable communities and degradation patterns and succession in the vegetation of the Western Hills of Chia, Cundinamarca - Colombia

    International Nuclear Information System (INIS)

    Cortes S, Sandra P; Van der Hammen, Thomas; Rangel Ch, J Orlando

    1999-01-01

    Two physiognomic plant communities were characterized: open vegetation which include the associations Dichondro repentis - Cupheetum serpyllifoliae (meadows), Baccharido rupicolae - Dodonaeetum viscosae (low shrubby vegetation), Andropogono aequatoriensis - Epidendretum elongatae (casmophytic vegetation) and Chaetolepido microphyllae-Espeletiopsietum corymbosae (shrubby vegetation-type with rosette plants). The closed vegetation includes two kinds of forests, Miconio ligustrinae- Weinmannietum tomentosae and Daphnopsio caracasanae - Xylosmetum spiculiferae. According to the floristic composition, depth of the soil, slope climate, relief and the anthropic influence (including degradation and natural succession), two trends in plant succession were defined

  14. Test results of cultivation of vegetables with fish breeding water; Yogyosui riyo ni yoru yasai saibai shiken kekka ni tsuite

    Energy Technology Data Exchange (ETDEWEB)

    Nishida, S. [Hokuriku Electric Power Co. Inc., Toyama (Japan)

    1997-10-28

    Entrails of fish, fowls and domestic animals are mostly incinerated at large expenses, although partly used as foods. This study is to test `possibility of vegetable cultivation with fish breeding water,` where the entrail wastes are used as baits for fish breeding, and fish excretions are used as the fertilizer for vegetable cultivation to purify water for fish breeding. The cultivation bed consists of two sections, one for fish breeding/vegetable cultivation and the other for vegetable cultivation by the normal method. Vegetable grow notably less in the former than in the latter, 54.6 to 79.5 versus 100. Spinach contains slightly higher contents of vitamins A and C by 6 and 13%, when cultivated in the former than in the latter. Quantities of total nitrogen, phosphorus and potassium as the fertilizer components in the former are 49, 49 and 1.7% of those in the latter. It is predicted, judging from growth of the vegetables, that the former gives a harvest comparable with that by the latter, when given a 6 to 13 days longer cultivation period. 3 figs., 2 tabs.

  15. Linking Vital Rates of Landbirds on a Tropical Island to Rainfall and Vegetation Greenness.

    Directory of Open Access Journals (Sweden)

    James F Saracco

    Full Text Available Remote tropical oceanic islands are of high conservation priority, and they are exemplified by range-restricted species with small global populations. Spatial and temporal patterns in rainfall and plant productivity may be important in driving dynamics of these species. Yet, little is known about environmental influences on population dynamics for most islands and species. Here we leveraged avian capture-recapture, rainfall, and remote-sensed habitat data (enhanced vegetation index [EVI] to assess relationships between rainfall, vegetation greenness, and demographic rates (productivity, adult apparent survival of three native bird species on Saipan, Northern Mariana Islands: rufous fantail (Rhipidura rufifrons, bridled white-eye (Zosterops conspicillatus, and golden white-eye (Cleptornis marchei. Rainfall was positively related to vegetation greenness at all but the highest rainfall levels. Temporal variation in greenness affected the productivity of each bird species in unique ways. Predicted productivity of rufous fantail was highest when dry and wet season greenness values were high relative to site-specific 5-year seasonal mean values (i.e., relative greenness; while the white-eye species had highest predicted productivity when relative greenness contrasted between wet and dry seasons. Survival of rufous fantail and bridled white eye was positively related to relative dry-season greenness and negatively related to relative wet-season greenness. Bridled white-eye survival also showed evidence of a positive response to overall greenness. Our results highlight the potentially important role of rainfall regimes in affecting population dynamics of species on oceanic tropical islands. Understanding linkages between rainfall, vegetation, and animal population dynamics will be critical for developing effective conservation strategies in this and other regions where the seasonal timing, extent, and variability of rainfall is expected to change in the

  16. Hiding vegetables to reduce energy density: an effective strategy to increase children's vegetable intake and reduce energy intake.

    Science.gov (United States)

    Spill, Maureen K; Birch, Leann L; Roe, Liane S; Rolls, Barbara J

    2011-09-01

    Strategies are needed to increase children's intake of a variety of vegetables, including vegetables that are not well liked. We investigated whether incorporating puréed vegetables into entrées to reduce the energy density (ED; in kcal/g) affected vegetable and energy intake over 1 d in preschool children. In this crossover study, 3- to 5-y-old children (n = 40) were served all meals and snacks 1 d/wk for 3 wk. Across conditions, entrées at breakfast, lunch, dinner, and evening snack were reduced in ED by increasing the proportion of puréed vegetables. The conditions were 100% ED (standard), 85% ED (tripled vegetable content), and 75% ED (quadrupled vegetable content). Entrées were served with unmanipulated side dishes and snacks, and children were instructed to eat as much as they liked. The daily vegetable intake increased significantly by 52 g (50%) in the 85% ED condition and by 73 g (73%) in the 75% ED condition compared with that in the standard condition (both P daily energy intake decreased by 142 kcal (12%) from the 100% to 75% ED conditions (P daily vegetable intake and decrease the energy intake in young children. This trial was registered at clinicaltrials.gov as NCT01252433.

  17. Estimating riparian and agricultural evapotranspiration by reference crop evapotranspiration and MODIS Enhanced Vegetation Index

    Science.gov (United States)

    Nagler, Pamela L.; Glenn, Edward P.; Nguyen, Uyen; Scott, Russell; Doody, Tania

    2013-01-01

    Dryland river basins frequently support both irrigated agriculture and riparian vegetation and remote sensing methods are needed to monitor water use by both crops and natural vegetation in irrigation districts. We developed an algorithm for estimating actual evapotranspiration (ETa) based on the Enhanced Vegetation Index (EVI) from the Moderate Resolution Imaging Spectrometer (MODIS) sensor on the EOS-1 Terra satellite and locally-derived measurements of reference crop ET (ETo). The algorithm was calibrated with five years of ETa data from three eddy covariance flux towers set in riparian plant associations on the upper San Pedro River, Arizona, supplemented with ETa data for alfalfa and cotton from the literature. The algorithm was based on an equation of the form ETa = ETo [a(1 − e−bEVI) − c], where the term (1 − e−bEVI) is derived from the Beer-Lambert Law to express light absorption by a canopy, with EVI replacing leaf area index as an estimate of the density of light-absorbing units. The resulting algorithm capably predicted ETa across riparian plants and crops (r2 = 0.73). It was then tested against water balance data for five irrigation districts and flux tower data for two riparian zones for which season-long or multi-year ETa data were available. Predictions were within 10% of measured results in each case, with a non-significant (P = 0.89) difference between mean measured and modeled ETa of 5.4% over all validation sites. Validation and calibration data sets were combined to present a final predictive equation for application across crops and riparian plant associations for monitoring individual irrigation districts or for conducting global water use assessments of mixed agricultural and riparian biomes.

  18. Estimating Riparian and Agricultural Actual Evapotranspiration by Reference Evapotranspiration and MODIS Enhanced Vegetation Index

    Directory of Open Access Journals (Sweden)

    Russell L. Scott

    2013-08-01

    Full Text Available Dryland river basins frequently support both irrigated agriculture and riparian vegetation and remote sensing methods are needed to monitor water use by both crops and natural vegetation in irrigation districts. We developed an algorithm for estimating actual evapotranspiration (ETa based on the Enhanced Vegetation Index (EVI from the Moderate Resolution Imaging Spectrometer (MODIS sensor on the EOS-1 Terra satellite and locally-derived measurements of reference crop ET (ETo. The algorithm was calibrated with five years of ETa data from three eddy covariance flux towers set in riparian plant associations on the upper San Pedro River, Arizona, supplemented with ETa data for alfalfa and cotton from the literature. The algorithm was based on an equation of the form ETa = ETo [a(1 − e−bEVI − c], where the term (1 − e−bEVI is derived from the Beer-Lambert Law to express light absorption by a canopy, with EVI replacing leaf area index as an estimate of the density of light-absorbing units. The resulting algorithm capably predicted ETa across riparian plants and crops (r2 = 0.73. It was then tested against water balance data for five irrigation districts and flux tower data for two riparian zones for which season-long or multi-year ETa data were available. Predictions were within 10% of measured results in each case, with a non-significant (P = 0.89 difference between mean measured and modeled ETa of 5.4% over all validation sites. Validation and calibration data sets were combined to present a final predictive equation for application across crops and riparian plant associations for monitoring individual irrigation districts or for conducting global water use assessments of mixed agricultural and riparian biomes.

  19. Reliability and validity of a questionnaire to measure personal, social and environmental correlates of fruit and vegetable intake in 10-11-year-old children in five European countries

    DEFF Research Database (Denmark)

    De Bourdeaudhuij, I; Klepp, K-I; Due, P

    2005-01-01

    To investigate the internal consistency of the scales and the test-retest reliability and predictive validity of behaviour theory-based constructs measuring personal, social and environmental correlates of fruit and vegetable intake in 10-11-year-old children.......To investigate the internal consistency of the scales and the test-retest reliability and predictive validity of behaviour theory-based constructs measuring personal, social and environmental correlates of fruit and vegetable intake in 10-11-year-old children....

  20. Vegetation of the Hantam-Tanqua-Roggeveld subregion, South Africa Part 2: Succulent Karoo Biome related vegetation

    Directory of Open Access Journals (Sweden)

    Helga van der Merwe

    2009-03-01

    Full Text Available The Hantam-Tanqua-Roggeveld subregion lies within the Succulent Karoo Hotspot that stretches along the western side of the Republic of South Africa and Namibia. This project, carried out to document the botanical diversity in the Hantam-Tanqua-Roggeveld subregion, was part of a project identified as a priority during the SKEP (Succulent Karoo Ecosystem Programme initiative in this Hotspot. Botanical surveys were conducted in an area covering over three million hectares. Satellite images of the area and topocadastral, land type and geology maps were used to stratify the area into relatively homogeneous units. An analysis of the floristic data of 390 sample plots identified two major floristic units, i.e. the Fynbos Biome related vegetation and the Succulent Karoo Biome related vegetation. A description of the vegetation related to the Succulent Karoo Biome is presented in this article. Seven associations, 16 subassociations and several mosaic vegetation units, consisting of more than one vegetation unit, were identified and mapped. Various threats to the vegetation in the region were identified during the survey and are briefly discussed.

  1. Interactive Vegetation Phenology, Soil Moisture, and Monthly Temperature Forecasts

    Science.gov (United States)

    Koster, R. D.; Walker, G. K.

    2015-01-01

    The time scales that characterize the variations of vegetation phenology are generally much longer than those that characterize atmospheric processes. The explicit modeling of phenological processes in an atmospheric forecast system thus has the potential to provide skill to subseasonal or seasonal forecasts. We examine this possibility here using a forecast system fitted with a dynamic vegetation phenology model. We perform three experiments, each consisting of 128 independent warm-season monthly forecasts: 1) an experiment in which both soil moisture states and carbon states (e.g., those determining leaf area index) are initialized realistically, 2) an experiment in which the carbon states are prescribed to climatology throughout the forecasts, and 3) an experiment in which both the carbon and soil moisture states are prescribed to climatology throughout the forecasts. Evaluating the monthly forecasts of air temperature in each ensemble against observations, as well as quantifying the inherent predictability of temperature within each ensemble, shows that dynamic phenology can indeed contribute positively to subseasonal forecasts, though only to a small extent, with an impact dwarfed by that of soil moisture.

  2. Vegetation and soils

    Science.gov (United States)

    Burke, M.K.; King, S.L.; Eisenbies, M.H.; Gartner, D.

    2000-01-01

    Intro paragraph: Characterization of bottomland hardwood vegetation in relatively undisturbed forests can provide critical information for developing effective wetland creation and restoration techniques and for assessing the impacts of management and development. Classification is a useful technique in characterizing vegetation because it summarizes complex data sets, assists in hypothesis generation about factors influencing community variation, and helps refine models of community structure. Hierarchical classification of communities is particularly useful for showing relationships among samples (Gauche 1982).

  3. Phenological characteristics of the main vegetation types on the Tibetan Plateau based on vegetation and water indices

    International Nuclear Information System (INIS)

    Peng, D L; Huang, W J; Zhou, B; Li, C J; Wu, Y P; Yang, X H

    2014-01-01

    Plant phenology is considered one of the most sensitive and easily observable natural indicators of climate change, though few studies have focused on the heterogeneities of phenology across the different vegetation types. In this study, we tried to find the phenological characteristics of the main vegetation types on the Tibetan Plateau. MCD12Q1 images over the Tibetan Plateau from 2001 to 2010 were used to extract the main vegetation types. The Normalized Difference Vegetation Index (NDVI), Enhanced Vegetation Index (EVI), and Land Surface Water Index (LSWI) were calculated using surface reflectance values from the blue, red, near-infrared, short-wave infrared (SWIR) 6 (for LSIW6), and SWIR7 (for LSIW7) bands derived from MOD09A1 and used to explore the phenological characteristics of the main vegetation types on the Tibetan Plateau. The results showed that there were eight constant vegetation types on the Tibetan Plateau from 2001 to 2010 demonstrating multiple phenological characteristics. Evergreen needleleaf forest, evergreen broadleaf forest, and permanent wetland had the minimum NDVI values during the summer season, while open shrubland and grassland had the maximum NDVI/EVI values during this period. NDVI and EVI of cropland/natural vegetation had two peaks for their seasonal variations. EVI showed a more significant correlation with LSWI6/LSWI7 than NDVI. Compared to LSWI7, larger EVI values occurred in evergreen needleleaf forest, evergreen broadleaf forest, mixed forest, and permanent wetland, while smaller values occurred in shrubland and barren or sparsely vegetated cover, and nearly equal values occurred in grassland and cropland

  4. Resilience of riverbed vegetation to uprooting by flow

    Science.gov (United States)

    Perona, P.; Crouzy, B.

    2018-03-01

    Riverine ecosystem biodiversity is largely maintained by ecogeomorphic processes including vegetation renewal via uprooting and recovery times to flow disturbances. Plant roots thus heavily contribute to engineering resilience to perturbation of such ecosystems. We show that vegetation uprooting by flow occurs as a fatigue-like mechanism, which statistically requires a given exposure time to imposed riverbed flow erosion rates before the plant collapses. We formulate a physically based stochastic model for the actual plant rooting depth and the time-to-uprooting, which allows us to define plant resilience to uprooting for generic time-dependent flow erosion dynamics. This theory shows that plant resilience to uprooting depends on the time-to-uprooting and that root mechanical anchoring acts as a process memory stored within the plant-soil system. The model is validated against measured data of time-to-uprooting of Avena sativa seedlings with various root lengths under different flow conditions. This allows for assessing the natural variance of the uprooting-by-flow process and to compute the prediction entropy, which quantifies the relative importance of the deterministic and the random components affecting the process.

  5. An application of plot-scale NDVI in predicting carbon dioxide exchange and leaf area index in heterogeneous subarctic tundra

    Energy Technology Data Exchange (ETDEWEB)

    Dagg, J.; Lafleur, P.

    2010-07-01

    This paper reported on a study that examined the flow of carbon into and out of tundra ecosystems. It is necessary to accurately predict carbon dioxide (CO{sub 2}) exchange in the Tundra because of the impacts of climate change on carbon stored in permafrost. Understanding the relationships between the normalized difference vegetation index (NDVI) and vegetation and CO{sub 2} exchange may explain how small-scale variation in vegetation community extends to remotely sensed estimates of landscape characteristics. In this study, CO{sub 2} fluxes were measured with a portable chamber in a range of Tundra vegetation communities. Biomass and leaf area were measured with destructive harvest, and NDVI was obtained using a hand-held infrared camera. There was a weak correlation between NDVI and leaf area index in some vegetation communities, but a significant correlation between NDVI and biomass, including mosses. NDVI was found to be strongly related to photosynthetic activity and net CO{sub 2} uptake in all vegetation groups. However, NDVI related to ecosystem respiration only in wet sedge. It was concluded that at plot scale, the ability of NDVI to predict ecosystem properties and CO{sub 2} exchange in heterogeneous Tundra vegetation is variable.

  6. An application of plot-scale NDVI in predicting carbon dioxide exchange and leaf area index in heterogeneous subarctic tundra

    International Nuclear Information System (INIS)

    Dagg, J.; Lafleur, P.

    2010-01-01

    This paper reported on a study that examined the flow of carbon into and out of tundra ecosystems. It is necessary to accurately predict carbon dioxide (CO 2 ) exchange in the Tundra because of the impacts of climate change on carbon stored in permafrost. Understanding the relationships between the normalized difference vegetation index (NDVI) and vegetation and CO 2 exchange may explain how small-scale variation in vegetation community extends to remotely sensed estimates of landscape characteristics. In this study, CO 2 fluxes were measured with a portable chamber in a range of Tundra vegetation communities. Biomass and leaf area were measured with destructive harvest, and NDVI was obtained using a hand-held infrared camera. There was a weak correlation between NDVI and leaf area index in some vegetation communities, but a significant correlation between NDVI and biomass, including mosses. NDVI was found to be strongly related to photosynthetic activity and net CO 2 uptake in all vegetation groups. However, NDVI related to ecosystem respiration only in wet sedge. It was concluded that at plot scale, the ability of NDVI to predict ecosystem properties and CO 2 exchange in heterogeneous Tundra vegetation is variable.

  7. Co-evolution of Riparian Vegetation and Channel Dynamics in an Aggrading Braided River System, Mount Pinatubo, Philippines

    Science.gov (United States)

    Gran, K. B.; Michal, T.

    2014-12-01

    Increased bank stability by riparian vegetation in braided rivers can decrease bed reworking rates and focus the flow. The magnitude of influence and resulting channel morphology are functions of vegetation strength vs. channel dynamics, a concept encapsulated in a dimensionless ratio between timescales for vegetation growth and channel reworking known as T*. We investigate this relationship in an aggrading braided river at Mount Pinatubo, Philippines, and compare results to numerical and physical models. Gradual reductions in post-eruption sediment loads have reduced bed reworking rates, allowing vegetation to persist year-round and impact channel dynamics on the Pasig-Potrero and Sacobia Rivers. From 2009-2011, we collected data detailing vegetation extent, type, density, and root strength. Incorporating these data into RipRoot and BSTEM models shows cohesion due to roots increased from zero in unvegetated conditions to >10.2 kPa in densely-growing grasses. Field-based parameters were incorporated into a cellular model comparing vegetation growth and sediment mobility effects on braided channel dynamics. The model shows that both low sediment mobility and high vegetation strength lead to less active systems, reflecting trends observed in the field. An estimated T* between 0.8 - 2.3 for the Pasig-Potrero River suggests channels were mobile enough to maintain the braidplain width clear of vegetation and even experience slight gains in area through annual removal of existing vegetation. However, persistent vegetation focused flow and thus aggradation over the unvegetated fraction of braidplain, leading to an aggradational imbalance and transition to a more avulsive state. While physical models predict continued narrowing of the active braidplain as T* declines, the future trajectory of channel-vegetation interactions at Pinatubo as sedimentation rates decline appears more complicated due to strong seasonal variability in precipitation and sediment loads. By 2011

  8. Chapter 3: Status and trends of vegetation

    Science.gov (United States)

    James M. Guldin; Frank R. Thompson; Lynda L. Richards; Kyra C. Harper

    1999-01-01

    This chapter provides information about the vegetation cover of the Assessment area. The types and areal extent of vegetation in the Highlands are of interest for many reasons. Vegetation cover largely determines the availability of habitat for terrestrial animals, plants, and other organisms. Vegetation cover strongly influences what uses {e.g., timber, forage,...

  9. The Role of Personality Traits in Young Adult Fruit and Vegetable Consumption

    OpenAIRE

    Conner, Tamlin S.; Thompson, Laura M.; Knight, Rachel L.; Flett, Jayde A. M.; Richardson, Aimee C.; Brookie, Kate L.

    2017-01-01

    This project investigated how individual differences in the big-five personality traits (neuroticism, extraversion, openness to experience, conscientiousness, and agreeableness) predicted plant-food consumption in young adults. A total of 1073 participants from two samples of young adults aged 17–25 reported their daily servings of fruits, vegetables, and two unhealthy foods for comparison purposes using an Internet daily diary for 21 or 13 days (micro-longitudinal, correlational design). Par...

  10. Investigation on the Patterns of Global Vegetation Change Using a Satellite-Sensed Vegetation Index

    Directory of Open Access Journals (Sweden)

    Ainong Li

    2010-06-01

    Full Text Available The pattern of vegetation change in response to global change still remains a controversial issue. A Normalized Difference Vegetation Index (NDVI dataset compiled by the Global Inventory Modeling and Mapping Studies (GIMMS was used for analysis. For the period 1982–2006, GIMMS-NDVI analysis indicated that monthly NDVI changes show homogenous trends in middle and high latitude areas in the northern hemisphere and within, or near, the Tropic of Cancer and Capricorn; with obvious spatio-temporal heterogeneity on a global scale over the past two decades. The former areas featured increasing vegetation activity during growth seasons, and the latter areas experienced an even greater amplitude in places where precipitation is adequate. The discussion suggests that one should be cautious of using the NDVI time-series to analyze local vegetation dynamics because of its coarse resolution and uncertainties.

  11. An integrated model of soil, hydrology, and vegetation for carbon dynamics in wetland ecosystems

    Science.gov (United States)

    Yu Zhang; Changsheng Li; Carl C. Trettin; Harbin Li; Ge Sun

    2002-01-01

    Wetland ecosystems are an important component in global carbon (C) cycles and may exert a large influence on global clinlate change. Predictions of C dynamics require us to consider interactions among many critical factors of soil, hydrology, and vegetation. However, few such integrated C models exist for wetland ecosystems. In this paper, we report a simulation model...

  12. Prediction of trace gas emissions and their climatic impacts. Some geographical considerations

    Energy Technology Data Exchange (ETDEWEB)

    Nicholson, S E [Florida State Univ., Dept. ofMeteorology, Tallahassee, FL (United States)

    1993-12-31

    This paper examines two major areas of uncertainty in the prediction of the impact of trace gas emissions on climate. The first is socioeconomic factors which determine the rate of such processes as resource use, industrial production or land conversion. The second is the feedback between the earth`s land surface and climate. Since the land surface is the source of trace gas emissions, both natural and anthropogenic changes of vegetation will affect the nature and quantity of emissions. This paper demonstrates large-scale land surface changes which have taken place naturally or from human activities, either intentionally or inadvertently, and describes the dwindling availability of natural resources, using water as an example. Vegetation is also examined as both a response to and a determining factor in climate. Hence, the intricate feedback between vegetation and climate complicates any attempt to predict climatic change. Better quantitative assessment of all relationships and processes is required to achieve realistic forecasts of global change. (au) 31 refs.

  13. Accumulation and health risk of heavy metals in vegetables from harmless and organic vegetable production systems of China.

    Science.gov (United States)

    Chen, Yong; Hu, Wenyou; Huang, Biao; Weindorf, David C; Rajan, Nithya; Liu, Xiaoxiao; Niedermann, Silvana

    2013-12-01

    Heavy metal accumulation in vegetables is a growing concern for public health. Limited studies have elucidated the heavy metal accumulation characteristics and health risk of different vegetables produced in different facilities such as greenhouses and open-air fields and under different management modes such as harmless and organic. Given the concern over the aforementioned factors related to heavy metal accumulation, this study selected four typical greenhouse vegetable production bases, short-term harmless greenhouse vegetable base (SHGVB), middle-term harmless greenhouse vegetable base (MHGVB), long-term harmless greenhouse vegetable base (LHGVB), and organic greenhouse vegetable base (OGVB), in Nanjing City, China to study heavy metal accumulation in different vegetables and their associated health risks. Results showed that soils and vegetables from SHGVB and OGVB apparently accumulated fewer certain heavy metals than those from other bases, probably due to fewer planting years and special management, respectively. Greenhouse conditions significantly increased certain soil heavy metal concentrations relative to open-air conditions. However, greenhouse conditions did not significantly increase concentrations of As, Cd, Cu, Hg, and Zn in leaf vegetables. In fact, under greenhouse conditions, Pb accumulation was effectively reduced. The main source of soil heavy metals was the application of large amounts of low-grade fertilizer. There was larger health risk for producers' children to consume vegetables from the three harmless vegetable bases than those of residents' children. The hazard index (HI) over a large area exceeded 1 for these two kinds of children in the MHGVB and LHGVB. There was also a slight risk in the SHGVB for producers' children solely. However, the HI of the whole area of the OGVB for two kinds of children was below 1, suggesting low risk of heavy metal exposure through the food chain. Notably, the contribution rate of Cu and Zn to the HI were

  14. Studying Vegetation Salinity: From the Field View to a Satellite-Based Perspective

    Directory of Open Access Journals (Sweden)

    Rachel Lugassi

    2017-02-01

    Full Text Available Salinization of irrigated lands in the semi-arid Jezreel Valley, Northern Israel results in soil-structure deterioration and crop damage. We formulated a generic rule for estimating salinity of different vegetation types by studying the relationship between Cl/Na and different spectral slopes in the visible–near infrared–shortwave infrared (VIS–NIR–SWIR spectral range using both field measurements and satellite imagery (Sentinel-2. For the field study, the slope-based model was integrated with conventional partial least squares (PLS analyses. Differences in 14 spectral ranges, indicating changes in salinity levels, were identified across the VIS–NIR–SWIR region (350–2500 nm. Next, two different models were run using PLS regression: (i using spectral slope data across these ranges; and (ii using preprocessed spectral reflectance. The best model for predicting Cl content was based on continuum removal reflectance (R2 = 0.84. Satisfactory correlations were obtained using the slope-based PLS model (R2 = 0.77 for Cl and R2 = 0.63 for Na. Thus, salinity contents in fresh plants could be estimated, despite masking of some spectral regions by water absorbance. Finally, we estimated the most sensitive spectral channels for monitoring vegetation salinity from a satellite perspective. We evaluated the recently available Sentinel-2 imagery’s ability to distinguish variability in vegetation salinity levels. The best estimate of a Sentinel-2-based vegetation salinity index was generated based on a ratio between calculated slopes: the 490–665 nm and 705–1610 nm. This index was denoted as the Sentinel-2-based vegetation salinity index (SVSI (band 4 − band 2/(band 5 + band 11.

  15. Mutation breeding in vegetable crops

    Energy Technology Data Exchange (ETDEWEB)

    Yamaguchi, Takashi

    1984-03-01

    Vegetables breed by seeds and vegetative organs. In main vegetables, the differentiation of clopping types, the adoption of monoculture and year-round production and shipment are carried out, adapting to various socio-economic and cultivation conditions. Protected agriculture has advanced mainly for fruit vegetables, and the seeds for sale have become almost hybrid varieties. Reflecting this situation, the demand for breeding is diversified and characteristic. The present status of mutation breeding of vegetables is not yet well under way, but reports of about 40 raised varieties have been published in the world. The characters introduced by induced mutation and irradiation are compact form, harvesting aptitude, the forms and properties of stems and leaves, anti-lodging property, the size, form and uniformity of fruits, male sterility and so on. The radiation sources used were mostly gamma ray or X-ray, but sometimes, combined irradiation was used. Results obtained in Japan include: burdocks as an example to gamma ray irradiation of seeds; tomatoes as an example of inducing compound resistance against disease injury; and lettuce as an example of internal beta irradiation. (Kako, I.).

  16. Review of Alternative Management Options of Vegetable Crop Residues to Reduce Nitrate Leaching in Intensive Vegetable Rotations

    Directory of Open Access Journals (Sweden)

    Laura Agneessens

    2014-12-01

    Full Text Available Vegetable crop residues take a particular position relative to arable crops due to often large amounts of biomass with a N content up to 200 kg N ha−1 left behind on the field. An important amount of vegetable crops are harvested during late autumn and despite decreasing soil temperatures during autumn, high rates of N mineralization and nitrification still occur. Vegetable crop residues may lead to considerable N losses through leaching during winter and pose a threat to meeting water quality objectives. However, at the same time vegetable crop residues are a vital link in closing the nutrient and organic matter cycle of soils. Appropriate and sustainable management is needed to harness the full potential of vegetable crop residues. Two fundamentally different crop residue management strategies to reduce N losses during winter in intensive vegetable rotations are reviewed, namely (i on-field management options and modifications to crop rotations and (ii removal of crop residues, followed by a useful and profitable application.

  17. CONSIDERATIONS ON ROMANIA’S VEGETABLE MARKET

    Directory of Open Access Journals (Sweden)

    Agatha POPESCU

    2013-12-01

    Full Text Available The paper aimed to present the situation of Romania’s vegetable market in the period 2007-2011 based on the statistical data regarding the main vegetables: tomatoes, onion, garlic, cabbage, green peppers and melons. The vegetable production increased by 33.99 from 3,166.8 tons in 2007 to 4,176.3 tons in 2011.This was due to the yield gain as follows: 58.55 % for melons, 27.62 % for green peppers, 27.05 % for tomatoes, 25.99 % for dry garlic, 24.96 % for dry onion, 12.61 % for white cabbage. In 2011, the contribution of various categories of vegetables to production was: 24.55 % white cabbage, 21.81 % tomatoes, 15.45 % melons, 9.44 % onion, 6.06 % green pepper, 1.59 % garlic and 21.1 % other vegetables. The contribution of the micro regions to vegetable production in 2011 was: 19.46 % South Muntenia, 18.95 % South East Romania, 17.30 % South West Oltenia, 15.92 % North East Romania, 10.43 % West Romania, 8.47 % North West Romania, 6.54 % Central Romania, 2.93 % Bucharest Ilfov. Vegetable production per inhabitant is higher in Romania compared to the average production per capita in the EU. The average consumption increased as a postive aspect reflecting the obtained production and import. Vegetable production should increase in order to cover much better the doestic market needs and support export to the EU market.

  18. Mapping and exploring variation in post-fire vegetation recovery following mixed severity wildfire using airborne LiDAR.

    Science.gov (United States)

    Gordon, Christopher E; Price, Owen F; Tasker, Elizabeth M

    2017-07-01

    There is a public perception that large high-severity wildfires decrease biodiversity and increase fire hazard by homogenizing vegetation composition and increasing the cover of mid-story vegetation. But a growing literature suggests that vegetation responses are nuanced. LiDAR technology provides a promising remote sensing tool to test hypotheses about post-fire vegetation regrowth because vegetation cover can be quantified within different height strata at fine scales over large areas. We assess the usefulness of airborne LiDAR data for measuring post-fire mid-story vegetation regrowth over a range of spatial resolutions (10 × 10 m, 30 × 30 m, 50 × 50 m, 100 × 100 m cell size) and investigate the effect of fire severity on regrowth amount and spatial pattern following a mixed severity wildfire in Warrumbungle National Park, Australia. We predicted that recovery would be more vigorous in areas of high fire severity, because park managers observed dense post-fire regrowth in these areas. Moderate to strong positive associations were observed between LiDAR and field surveys of mid-story vegetation cover between 0.5-3.0 m. Thus our LiDAR survey was an apt representation of on-ground vegetation cover. LiDAR-derived mid-story vegetation cover was 22-40% lower in areas of low and moderate than high fire severity. Linear mixed-effects models showed that fire severity was among the strongest biophysical predictors of mid-story vegetation cover irrespective of spatial resolution. However much of the variance associated with these models was unexplained, presumably because soil seed banks varied at finer scales than our LiDAR maps. Dense patches of mid-story vegetation regrowth were small (median size 0.01 ha) and evenly distributed between areas of low, moderate and high fire severity, demonstrating that high-severity fires do not homogenize vegetation cover. Our results are relevant for ecosystem conservation and fire management because they: indicate

  19. Disaggregating Tropical Disease Prevalence by Climatic and Vegetative Zones within Tropical West Africa.

    Science.gov (United States)

    Beckley, Carl S; Shaban, Salisu; Palmer, Guy H; Hudak, Andrew T; Noh, Susan M; Futse, James E

    2016-01-01

    Tropical infectious disease prevalence is dependent on many socio-cultural determinants. However, rainfall and temperature frequently underlie overall prevalence, particularly for vector-borne diseases. As a result these diseases have increased prevalence in tropical as compared to temperate regions. Specific to tropical Africa, the tendency to incorrectly infer that tropical diseases are uniformly prevalent has been partially overcome with solid epidemiologic data. This finer resolution data is important in multiple contexts, including understanding risk, predictive value in disease diagnosis, and population immunity. We hypothesized that within the context of a tropical climate, vector-borne pathogen prevalence would significantly differ according to zonal differences in rainfall, temperature, relative humidity and vegetation condition. We then determined if these environmental data were predictive of pathogen prevalence. First we determined the prevalence of three major pathogens of cattle, Anaplasma marginale, Babesia bigemina and Theileria spp, in the three vegetation zones where cattle are predominantly raised in Ghana: Guinea savannah, semi-deciduous forest, and coastal savannah. The prevalence of A. marginale was 63%, 26% for Theileria spp and 2% for B. bigemina. A. marginale and Theileria spp. were significantly more prevalent in the coastal savannah as compared to either the Guinea savanna or the semi-deciduous forest, supporting acceptance of the first hypothesis. To test the predictive power of environmental variables, the data over a three year period were considered in best subsets multiple linear regression models predicting prevalence of each pathogen. Corrected Akaike Information Criteria (AICc) were assigned to the alternative models to compare their utility. Competitive models for each response were averaged using AICc weights. Rainfall was most predictive of pathogen prevalence, and EVI also contributed to A. marginale and B. bigemina prevalence

  20. Disaggregating Tropical Disease Prevalence by Climatic and Vegetative Zones within Tropical West Africa.

    Directory of Open Access Journals (Sweden)

    Carl S Beckley

    Full Text Available Tropical infectious disease prevalence is dependent on many socio-cultural determinants. However, rainfall and temperature frequently underlie overall prevalence, particularly for vector-borne diseases. As a result these diseases have increased prevalence in tropical as compared to temperate regions. Specific to tropical Africa, the tendency to incorrectly infer that tropical diseases are uniformly prevalent has been partially overcome with solid epidemiologic data. This finer resolution data is important in multiple contexts, including understanding risk, predictive value in disease diagnosis, and population immunity. We hypothesized that within the context of a tropical climate, vector-borne pathogen prevalence would significantly differ according to zonal differences in rainfall, temperature, relative humidity and vegetation condition. We then determined if these environmental data were predictive of pathogen prevalence. First we determined the prevalence of three major pathogens of cattle, Anaplasma marginale, Babesia bigemina and Theileria spp, in the three vegetation zones where cattle are predominantly raised in Ghana: Guinea savannah, semi-deciduous forest, and coastal savannah. The prevalence of A. marginale was 63%, 26% for Theileria spp and 2% for B. bigemina. A. marginale and Theileria spp. were significantly more prevalent in the coastal savannah as compared to either the Guinea savanna or the semi-deciduous forest, supporting acceptance of the first hypothesis. To test the predictive power of environmental variables, the data over a three year period were considered in best subsets multiple linear regression models predicting prevalence of each pathogen. Corrected Akaike Information Criteria (AICc were assigned to the alternative models to compare their utility. Competitive models for each response were averaged using AICc weights. Rainfall was most predictive of pathogen prevalence, and EVI also contributed to A. marginale and B

  1. Wetland vegetation establishment in L-Lake

    International Nuclear Information System (INIS)

    Kroeger, S.R.

    1990-07-01

    Wetland vegetation was transplanted from PAR Pond to L-Lake between January and August, 1987. Approximately 100,000 individual plants representing over 40 species were transplanted along the southern shoreline. Three zones of vegetation were created: (1) submersed/floating-leaved, (2) emergent, (3) upper emergent/shrub. During the summers of 1987, 1988, 1989, the Savannah River Ecology Laboratory sampled the vegetation in 54 permanent transects located in planted (N=32) and unplanted areas (N=22). The 1989 vegetation data from L-Lake were compared to 1985 data from PAR Pond

  2. Energy budgets and resistances to energy transport in sparsely vegetated rangeland

    Science.gov (United States)

    Nichols, W.D.

    1992-01-01

    Partitioning available energy between plants and bare soil in sparsely vegetated rangelands will allow hydrologists and others to gain a greater understanding of water use by native vegetation, especially phreatophytes. Standard methods of conducting energy budget studies result in measurements of latent and sensible heat fluxes above the plant canopy which therefore include the energy fluxes from both the canopy and the soil. One-dimensional theoretical numerical models have been proposed recently for the partitioning of energy in sparse crops. Bowen ratio and other micrometeorological data collected over phreatophytes growing in areas of shallow ground water in central Nevada were used to evaluate the feasibility of using these models, which are based on surface and within-canopy aerodynamic resistances, to determine heat and water vapor transport in sparsely vegetated rangelands. The models appear to provide reasonably good estimates of sensible heat flux from the soil and latent heat flux from the canopy. Estimates of latent heat flux from the soil were less satisfactory. Sensible heat flux from the canopy was not well predicted by the present resistance formulations. Also, estimates of total above-canopy fluxes were not satisfactory when using a single value for above-canopy bulk aerodynamic resistance. ?? 1992.

  3. Quantifying pollen-vegetation relationships to reconstruct ancient forests using 19th-century forest composition and pollen data

    Science.gov (United States)

    Dawson, Andria; Paciorek, Christopher J.; McLachlan, Jason S.; Goring, Simon; Williams, John W.; Jackson, Stephen T.

    2016-04-01

    Mitigation of climate change and adaptation to its effects relies partly on how effectively land-atmosphere interactions can be quantified. Quantifying composition of past forest ecosystems can help understand processes governing forest dynamics in a changing world. Fossil pollen data provide information about past forest composition, but rigorous interpretation requires development of pollen-vegetation models (PVMs) that account for interspecific differences in pollen production and dispersal. Widespread and intensified land-use over the 19th and 20th centuries may have altered pollen-vegetation relationships. Here we use STEPPS, a Bayesian hierarchical spatial PVM, to estimate key process parameters and associated uncertainties in the pollen-vegetation relationship. We apply alternate dispersal kernels, and calibrate STEPPS using a newly developed Euro-American settlement-era calibration data set constructed from Public Land Survey data and fossil pollen samples matched to the settlement-era using expert elicitation. Models based on the inverse power-law dispersal kernel outperformed those based on the Gaussian dispersal kernel, indicating that pollen dispersal kernels are fat tailed. Pine and birch have the highest pollen productivities. Pollen productivity and dispersal estimates are generally consistent with previous understanding from modern data sets, although source area estimates are larger. Tests of model predictions demonstrate the ability of STEPPS to predict regional compositional patterns.

  4. Quantifying pollen-vegetation relationships to reconstruct ancient forests using 19th-century forest composition and pollen data

    Science.gov (United States)

    Dawson, Andria; Paciorek, Christopher J.; McLachlan, Jason S.; Goring, Simon; Williams, John W.; Jackson, Stephen T.

    2016-01-01

    Mitigation of climate change and adaptation to its effects relies partly on how effectively land-atmosphere interactions can be quantified. Quantifying composition of past forest ecosystems can help understand processes governing forest dynamics in a changing world. Fossil pollen data provide information about past forest composition, but rigorous interpretation requires development of pollen-vegetation models (PVMs) that account for interspecific differences in pollen production and dispersal. Widespread and intensified land-use over the 19th and 20th centuries may have altered pollen-vegetation relationships. Here we use STEPPS, a Bayesian hierarchical spatial PVM, to estimate key process parameters and associated uncertainties in the pollen-vegetation relationship. We apply alternate dispersal kernels, and calibrate STEPPS using a newly developed Euro-American settlement-era calibration data set constructed from Public Land Survey data and fossil pollen samples matched to the settlement-era using expert elicitation. Models based on the inverse power-law dispersal kernel outperformed those based on the Gaussian dispersal kernel, indicating that pollen dispersal kernels are fat tailed. Pine and birch have the highest pollen productivities. Pollen productivity and dispersal estimates are generally consistent with previous understanding from modern data sets, although source area estimates are larger. Tests of model predictions demonstrate the ability of STEPPS to predict regional compositional patterns.

  5. Varying responses of vegetation activity to climate changes on the Tibetan Plateau grassland.

    Science.gov (United States)

    Cong, Nan; Shen, Miaogen; Yang, Wei; Yang, Zhiyong; Zhang, Gengxin; Piao, Shilong

    2017-08-01

    Vegetation activity on the Tibetan Plateau grassland has been substantially enhanced as a result of climate change, as revealed by satellite observations of vegetation greenness (i.e., the normalized difference vegetation index, NDVI). However, little is known about the temporal variations in the relationships between NDVI and temperature and precipitation, and understanding this is essential for predicting how future climate change would affect vegetation activity. Using NDVI data and meteorological records from 1982 to 2011, we found that the inter-annual partial correlation coefficient between growing season (May-September) NDVI and temperature (R NDVI-T ) in a 15-year moving window for alpine meadow showed little change, likely caused by the increasing R NDVI-T in spring (May-June) and autumn (September) and decreasing R NDVI-T in summer (July-August). Growing season R NDVI-T for alpine steppe increased slightly, mainly due to increasing R NDVI-T in spring and autumn. The partial correlation coefficient between growing season NDVI and precipitation (R NDVI-P ) for alpine meadow increased slightly, mainly in spring and summer, and R NDVI-P for alpine steppe increased, mainly in spring. Moreover, R NDVI-T for the growing season was significantly higher in those 15-year windows with more precipitation for alpine steppe. R NDVI-P for the growing season was significantly higher in those 15-year windows with higher temperature, and this tendency was stronger for alpine meadow than for alpine steppe. These results indicate that the impact of warming on vegetation activity of Tibetan Plateau grassland is more positive (or less negative) during periods with more precipitation and that the impact of increasing precipitation is more positive (or less negative) during periods with higher temperature. Such positive effects of the interactions between temperature and precipitation indicate that the projected warmer and wetter future climate will enhance vegetation activity

  6. Development and validation of extensive growth and growth boundary models for psychrotolerant pseudomonads in seafood, meat and vegetable products

    DEFF Research Database (Denmark)

    Martinez Rios, Veronica; Dalgaard, Paw

    Extensive growth and growth boundary models were developed and validated for psychrotolerant pseudomonads growing in seafood, meat and vegetable products. The new models were developed by expanding anexisting cardinal parameter-type model for growth of pseudomonads in milk (Martinez-Rios et al......, when observed and predicted μmax -values were compared. Thus, on average μmax -values for seafood and meat products were overestimated by 14%. Additionally, the reference growth rate parameter μref25˚C was calibrated by fitting the model to 21 μmax -values in vegetable products. This resulted in a μref......25˚C -value of 0.54 1/h. The calibrated vegetable model wassuccessfully validated using 51 μmax -values for psychrotolerant pseudomonads in vegetables. Average bias and accuracy factor values of 1.24 and 1.38 were obtained, respectively. Lag time models were developed by using relative lag times from...

  7. Vegetation physiology controls continental water cycle responses to climate change

    Science.gov (United States)

    Lemordant, L. A.; Swann, A. L. S.; Cook, B.; Scheff, J.; Gentine, P.

    2017-12-01

    Abstract per se:Predicting how climate change will affect the hydrologic cycle is of utmost importance for ecological systems and for human life and activities. A typical perspective is that global warming will cause an intensification of the mean state, the so-called "dry gets drier, wet gets wetter" paradigm. While this result is robust over the oceans, recent works suggest it may be less appropriate for terrestrial regions. Using Earth System Models (ESMs) with decoupled surface (vegetation physiology, PHYS) and atmospheric (radiative, ATMO) CO2 responses, we show that the CO2 physiological response dominates the change in the continental hydrologic cycle compared to radiative and precipitation changes due to increased atmospheric CO2, counter to previous assumptions. Using multiple linear regression analysis, we estimate the individual contribution of each of the three main drivers, precipitation, radiation and physiological CO2 forcing (see attached figure). Our analysis reveals that physiological effects dominate changes for 3 key indicators of dryness and/or vegetation stress (namely LAI, P-ET and EF) over the largest fraction of the globe, except for soil moisture which exhibits a more complex response. This highlights the key role of vegetation in controlling future terrestrial hydrologic response.Legend of the Figure attached:Decomposition along the three main drivers of LAI (a), P-ET (b), EF (c) in the control run. Green quantifies the effect of the vegetation physiology based on the run PHYS; red and blue quantify the contribution of, respectively, net radiation and precipitation, based on multiple linear regression in ATMO. Pie charts show for each variable the fraction (labelled in %) of land under the main influence (more than 50% of the changes is attributed to this driver) of one the three main drivers (green for grid points dominated by vegetation physiology, red for grid points dominated by net radiation, and blue for grid points dominated by the

  8. Cruciferous Vegetables and Cancer Prevention

    Science.gov (United States)

    ... case-control studies have found that people who ate greater amounts of cruciferous vegetables had a lower ... Professionals’ Follow-up Study—showed that women who ate more than 5 servings of cruciferous vegetables per ...

  9. componente vegetal

    Directory of Open Access Journals (Sweden)

    Fabio Moscovich

    2005-01-01

    Full Text Available In order to determine environmental impact, indicators based on vegetation characteristics that would generate the forestry monoculture with the adjacent native forest, 32 sample unit were installed in an area of LIPSIA private enterprise, Esperanza Department, Misiones with those characteristics. The plots of 100 m2 were distributed systematically every 25 meters. The vegetation was divided in stratum: superior (DBH ≥ 10 cm, middle (1,6 cm ≤ DBH > 10 cm and inferior (DBH< cm. There were installed 10 plots in a logged native forest, 10 plots in a 18 years old Pinus elliottii Engelm. with approximately 400 trees/ha., 6 plots in a 10 – 25 years old Araucaria angustifolia (Bertd. Kuntze limiting area with approximately 900 trees/ha., and 6 plots located in this plantation. In the studied area were identified 150 vegetation species. In the inferior stratum there were found differences as function of various floristic diversity indexes. In all the cases the native forest showed larger diversity than plantations, followed by Pinus elliottii, Araucaria plantation and Araucaria limiting area. All the studied forest fitted to a logarithmical series of species distributions, that would indicate the incidence of a environmental factor in this distribution.

  10. Soil-vegetation-atmosphere transfer modeling

    Energy Technology Data Exchange (ETDEWEB)

    Ikonen, J P; Sucksdorff, Y [Finnish Environment Agency, Helsinki (Finland)

    1997-12-31

    In this study the soil/vegetation/atmosphere-model based on the formulation of Deardorff was refined to hour basis and applied to a field in Vihti. The effect of model parameters on model results (energy fluxes, temperatures) was also studied as well as the effect of atmospheric conditions. The estimation of atmospheric conditions on the soil-vegetation system as well as an estimation of the effect of vegetation parameters on the atmospheric climate was estimated. Areal surface fluxes, temperatures and moistures were also modelled for some river basins in southern Finland. Land-use and soil parameterisation was developed to include properties and yearly variation of all vegetation and soil types. One classification was selected to describe the hydrothermal properties of the soils. Evapotranspiration was verified against the water balance method

  11. Soil-vegetation-atmosphere transfer modeling

    Energy Technology Data Exchange (ETDEWEB)

    Ikonen, J.P.; Sucksdorff, Y. [Finnish Environment Agency, Helsinki (Finland)

    1996-12-31

    In this study the soil/vegetation/atmosphere-model based on the formulation of Deardorff was refined to hour basis and applied to a field in Vihti. The effect of model parameters on model results (energy fluxes, temperatures) was also studied as well as the effect of atmospheric conditions. The estimation of atmospheric conditions on the soil-vegetation system as well as an estimation of the effect of vegetation parameters on the atmospheric climate was estimated. Areal surface fluxes, temperatures and moistures were also modelled for some river basins in southern Finland. Land-use and soil parameterisation was developed to include properties and yearly variation of all vegetation and soil types. One classification was selected to describe the hydrothermal properties of the soils. Evapotranspiration was verified against the water balance method

  12. Use of Different Vegetable Products to Increase Preschool-Aged Children's Preference for and Intake of a Target Vegetable

    NARCIS (Netherlands)

    Wild, de Victoire W.T.; Graaf, de Kees; Jager, Gerry

    2017-01-01

    Background: Children's low vegetable consumption requires effective strategies to enhance preference for and intake of vegetables. Objective: The study compared three preparation practices for a target vegetable (spinach) on their effectiveness in increasing preschool-aged children's preference

  13. The potential natural vegetation of eastern Africa distribution, conservation and future changes

    DEFF Research Database (Denmark)

    van Breugel, Paulo

    and sustainable management of the natural environment. There is therefore an urgent need for information that allow us to assess the current status of the region’s natural environment and to predict how this may change under future climates. This thesis aims to improve our knowledge on natural vegetation...... and how this is likely to change under different climate change scenarios. Chapter 4 presents an environmental gap analysis to prioritize conservation efforts in eastern Africa, based on an evaluation of the environmental representativeness of protected areas and an assessment of the level of threat...... distribution in eastern African, examine how this may change under future climates, and how this can be used to identify conservation priorities in the region. Chapter 1 presents a brief overview of the concept of the potential natural vegetation (PNV), synthesizes the general findings and discusses future...

  14. Radiocesium cycling in vegetation and soil

    International Nuclear Information System (INIS)

    Dahlman, R.C.; Francis, C.W.; Tamura, T.

    1975-01-01

    Data on cesium dynamics in vegetation and soils are reviewed. Special emphasis is placed on typical environments in the southeastern United States. Clay minerals of soil, especially micaceous types, effectively fix cesium and remove it from biotic components of ecosystems. Fallout 137 Cs enters food chains principally by direct deposition on vegetation; uptake by the root pathway is usually less than direct contamination of plant foliage. Cesium-137 levels in vegetation of the southeastern U. S. Coastal Plain are estimated on the basis of direct deposition from the atmosphere and root uptake from soil. Estimated concentrations, based on current concepts of 137 Cs dynamics in vegetation and fixation in soil, are in good agreement with observed values of 137 Cs in vegetation collected in 1969 and 1970. Mechanisms of direct deposition and of increased uptake by roots due to the absence of micaceous clays adequately explain the higher levels of 137 Cs in vegetation of the Coastal Plain and thus are responsible for the elevated 137 Cs reported for milk of the Tampa, Fla., milkshed

  15. Habitat features and predictive habitat modeling for the Colorado chipmunk in southern New Mexico

    Science.gov (United States)

    Rivieccio, M.; Thompson, B.C.; Gould, W.R.; Boykin, K.G.

    2003-01-01

    Two subspecies of Colorado chipmunk (state threatened and federal species of concern) occur in southern New Mexico: Tamias quadrivittatus australis in the Organ Mountains and T. q. oscuraensis in the Oscura Mountains. We developed a GIS model of potentially suitable habitat based on vegetation and elevation features, evaluated site classifications of the GIS model, and determined vegetation and terrain features associated with chipmunk occurrence. We compared GIS model classifications with actual vegetation and elevation features measured at 37 sites. At 60 sites we measured 18 habitat variables regarding slope, aspect, tree species, shrub species, and ground cover. We used logistic regression to analyze habitat variables associated with chipmunk presence/absence. All (100%) 37 sample sites (28 predicted suitable, 9 predicted unsuitable) were classified correctly by the GIS model regarding elevation and vegetation. For 28 sites predicted suitable by the GIS model, 18 sites (64%) appeared visually suitable based on habitat variables selected from logistic regression analyses, of which 10 sites (36%) were specifically predicted as suitable habitat via logistic regression. We detected chipmunks at 70% of sites deemed suitable via the logistic regression models. Shrub cover, tree density, plant proximity, presence of logs, and presence of rock outcrop were retained in the logistic model for the Oscura Mountains; litter, shrub cover, and grass cover were retained in the logistic model for the Organ Mountains. Evaluation of predictive models illustrates the need for multi-stage analyses to best judge performance. Microhabitat analyses indicate prospective needs for different management strategies between the subspecies. Sensitivities of each population of the Colorado chipmunk to natural and prescribed fire suggest that partial burnings of areas inhabited by Colorado chipmunks in southern New Mexico may be beneficial. These partial burnings may later help avoid a fire

  16. The influence of El Niño-Southern Oscillation regimes on eastern African vegetation and its future implications under the RCP8.5 warming scenario

    Science.gov (United States)

    Fer, Istem; Tietjen, Britta; Jeltsch, Florian; Wolff, Christian

    2017-09-01

    The El Niño-Southern Oscillation (ENSO) is the main driver of the interannual variability in eastern African rainfall, with a significant impact on vegetation and agriculture and dire consequences for food and social security. In this study, we identify and quantify the ENSO contribution to the eastern African rainfall variability to forecast future eastern African vegetation response to rainfall variability related to a predicted intensified ENSO. To differentiate the vegetation variability due to ENSO, we removed the ENSO signal from the climate data using empirical orthogonal teleconnection (EOT) analysis. Then, we simulated the ecosystem carbon and water fluxes under the historical climate without components related to ENSO teleconnections. We found ENSO-driven patterns in vegetation response and confirmed that EOT analysis can successfully produce coupled tropical Pacific sea surface temperature-eastern African rainfall teleconnection from observed datasets. We further simulated eastern African vegetation response under future climate change as it is projected by climate models and under future climate change combined with a predicted increased ENSO intensity. Our EOT analysis highlights that climate simulations are still not good at capturing rainfall variability due to ENSO, and as we show here the future vegetation would be different from what is simulated under these climate model outputs lacking accurate ENSO contribution. We simulated considerable differences in eastern African vegetation growth under the influence of an intensified ENSO regime which will bring further environmental stress to a region with a reduced capacity to adapt effects of global climate change and food security.

  17. Comparing direct image and wavelet transform-based approaches to analysing remote sensing imagery for predicting wildlife distribution

    NARCIS (Netherlands)

    Murwira, A.; Skidmore, A.K.

    2010-01-01

    In this study we tested the ability to predict the probability of elephant (Loxodonta africana) presence in an agricultural landscape of Zimbabwe based on three methods of measuring the spatial heterogeneity in vegetation cover, where vegetation cover was measured using the Landsat Thematic Mapper

  18. [Effects of road construction on regional vegetation types].

    Science.gov (United States)

    Liu, Shi-Liang; Liu, Qi; Wang, Cong; Yang, Jue-Jie; Deng, Li

    2013-05-01

    As a regional artificial disturbance component, road exerts great effects on vegetation types, and plays a substantial role in defining vegetation distribution to a certain extent. Aiming at the tropical rainforest degradation and artificial forest expansion in Yunnan Province of Southwest China, this paper analyzed the effects of road network extension on regional vegetation types. In the Province, different classes of roads had different effects on the vegetation types, but no obvious regularity was observed in the effects on the patch areas of different vegetation types due to the great variations of road length and affected distance. However, the vegetation patch number was more affected by lower class roads because of their wide distribution. As for different vegetation types, the vegetations on cultivated land were most affected by roads, followed by Castanopsis hystrix and Schima wallichii forests. Road network formation contributed most to the vegetation fragmentation, and there existed significant correlations between the human disturbance factors including village- and road distributions.

  19. Multi-scale predictions of coniferous forest mortality in the northern hemisphere

    Science.gov (United States)

    McDowell, N. G.

    2015-12-01

    Global temperature rise and extremes accompanying drought threaten forests and their associated climatic feedbacks. Our incomplete understanding of the fundamental physiological thresholds of vegetation mortality during drought limits our ability to accurately simulate future vegetation distributions and associated climate feedbacks. Here we integrate experimental evidence with models to show potential widespread loss of needleleaf evergreen trees (NET; ~ conifers) within the Southwest USA by 2100; with rising temperature being the primary cause of mortality. Experimentally, dominant Southwest USA NET species died when they fell below predawn water potential (Ypd) thresholds (April-August mean) beyond which photosynthesis, stomatal and hydraulic conductance, and carbohydrate availability approached zero. Empirical and mechanistic models accurately predicted NET Ypd, and 91% of predictions (10/11) exceeded mortality thresholds within the 21st century due to temperature rise. Completely independent global models predicted >50% loss of northern hemisphere NET by 2100, consistent with the findings for Southwest USA. The global models disagreed with the ecosystem process models in regards to future mortality in Southwest USA, however, highlighting the potential underestimates of future NET mortality as simulated by the global models and signifying the importance of improving regional predictions. Taken together, these results from the validated regional predictions and the global simulations predict global-scale conifer loss in coming decades under projected global warming.

  20. Analysis of ecological context for identifying vegetation and animal conservation planning foci: An example from the arid South-western USA

    Science.gov (United States)

    Hamazaki, T.; Thompson, B.C.; Locke, B.A.; Boykin, K.G.

    2003-01-01

    In developing conservation strategies, it is important to maximize effects of conservation within a specified land tract and to maximize conservation effects on surrounding area (ecological context). The authors proposed two criteria to select biotic entities for conservation foci: (1) the relative occurrence of fauna or flora in a tract is greater than that of an ecological context region; and (2) occurrence of the fauna or flora is relatively limited in the ecological context region. Using extensive spatial data on vegetation and wildlife habitat distribution, the authors identified strategic vegetation and fauna conservation foci for the 400 000 ha Fort Bliss military reservation in New Mexico and Texas relative to a 164 km radius ecological context region intersecting seven ecological zones and the predicted habitat distribution of 616 animal species. The authors set two specific criteria: (1) predicted area of a species' occurrence is 5% (Fort Bliss is 4.2% of the region). These criteria selected one vegetation class and 40 animal species. Further, these vegetation and animal foci were primarily located in two areas of Fort Bliss. Sensitivity analyses with other analytical radii corroborated the context radius used. Conservation of the two areas and associated taxa will maximize the contribution of Fort Bliss's conservation efforts in its ecological proximity. This relatively simple but information-rich process represents economical and defensible preliminary contextual analysis for detailed conservation planning.

  1. The marsh vegetation of Kleinmond Lagoon

    Directory of Open Access Journals (Sweden)

    M. O'Callaghan

    1994-10-01

    Full Text Available The vegetation of Kleinmond Lagoon suggests that this system is in transition from an estuary to a coastal lake. Two major types of vegetation were recognized, one which is subjected to soil and water conditions of marine origin and the other which is subjected to conditions of terrestrial origin. These vegetation types are discussed and compared to the vegetation of other estuarine systems. Artificial manipulations of the mouth seem to have resulted in sediment deposition and a freshening of the system. These unseasonable manipulations also threaten the continued existence of a number of species in the system.

  2. Models of vegetation change for landscape planning: a comparison of FETM, LANDSUM, SIMPPLLE, and VDDT

    Science.gov (United States)

    T. M. Barrett

    2001-01-01

    Landscape assessment and planning often depend on the ability to predict change of vegetation. This report compares four modeling systems (FETM, LANDSUM, SIMPPLLE, and VDDT) that can be used to understand changes resulting from succession, natural disturbance, and management activities. The four models may be useful for regional or local assessments in National Forest...

  3. Empirically Derived and Simulated Sensitivity of Vegetation to Climate Across Global Gradients of Temperature and Precipitation

    Science.gov (United States)

    Quetin, G. R.; Swann, A. L. S.

    2017-12-01

    Successfully predicting the state of vegetation in a novel environment is dependent on our process level understanding of the ecosystem and its interactions with the environment. We derive a global empirical map of the sensitivity of vegetation to climate using the response of satellite-observed greenness and leaf area to interannual variations in temperature and precipitation. Our analysis provides observations of ecosystem functioning; the vegetation interactions with the physical environment, across a wide range of climates and provide a functional constraint for hypotheses engendered in process-based models. We infer mechanisms constraining ecosystem functioning by contrasting how the observed and simulated sensitivity of vegetation to climate varies across climate space. Our analysis yields empirical evidence for multiple physical and biological mediators of the sensitivity of vegetation to climate as a systematic change across climate space. Our comparison of remote sensing-based vegetation sensitivity with modeled estimates provides evidence for which physiological mechanisms - photosynthetic efficiency, respiration, water supply, atmospheric water demand, and sunlight availability - dominate the ecosystem functioning in places with different climates. Earth system models are generally successful in reproducing the broad sign and shape of ecosystem functioning across climate space. However, this general agreement breaks down in hot wet climates where models simulate less leaf area during a warmer year, while observations show a mixed response but overall more leaf area during warmer years. In addition, simulated ecosystem interaction with temperature is generally larger and changes more rapidly across a gradient of temperature than is observed. We hypothesize that the amplified interaction and change are both due to a lack of adaptation and acclimation in simulations. This discrepancy with observations suggests that simulated responses of vegetation to

  4. Using vegetation structure estimates derived from multi-source remote sensing to predict dynamics of a semi-arid ecosystem in the western US

    Science.gov (United States)

    Shrestha, R.; Mitchell, J. J.; Glenn, N. F.; Flores, A. N.

    2014-12-01

    The distribution of species and vegetation types across the western US are expected to shift in response to climate change. Previous studies have documented the change in fire regime and the increasing fire-invasive grass cycle occurring in the western U.S. The change in vegetation structure due to climate change and invasive species alters the fuel load, making these ecosystems vulnerable to high-severity fire. Synergistic remote sensing data, such as hyperspectral data and high-resolution lidar, can be leveraged to capture the composition and structural variability of short-statured semiarid vegetation (e.g. sagebrush, annual grasses). We use a random-forests based fusion technique to integrate multi-source airborne data (hyperspectral and LiDAR) and generate spatially-explicit estimates of vegetation composition and structure (biomass, cover, density, height, LAI) and associated uncertainty across a climate and elevation gradient in southern Idaho. The results will be used to initialize an individual-based terrestrial biosphere model (Ecosystem Demography, ED2) and estimate structural dynamics under future scenarios. This study will provide a basis for understanding feedback mechanisms related to changing climate conditions, fire regimes and patterns of non-native plant invasion. The forthcoming field and remote sensing collection campaigns are also designed for parameterizing a dryland shrub plant functional type in the ED2 model.

  5. Vegetable Grafting: The Implications of a Growing Agronomic Imperative for Vegetable Fruit Quality and Nutritive Value

    Directory of Open Access Journals (Sweden)

    Marios C. Kyriacou

    2017-05-01

    Full Text Available Grafting has become an imperative for intensive vegetable production since chlorofluorocarbon-based soil fumigants were banned from use on grounds of environmental protection. Compelled by this development, research into rootstock–scion interaction has broadened the potential applications of grafting in the vegetable industry beyond aspects of soil phytopathology. Grafting has been increasingly tapped for cultivation under adverse environs posing abiotic and biotic stresses to vegetable crops, thus enabling expansion of commercial production onto otherwise under-exploited land. Vigorous rootstocks have been employed not only in the open field but also under protected cultivation where increase in productivity improves distribution of infrastructural and energy costs. Applications of grafting have expanded mainly in two families: the Cucurbitaceae and the Solanaceae, both of which comprise major vegetable crops. As the main drives behind the expansion of vegetable grafting have been the resistance to soilborne pathogens, tolerance to abiotic stresses and increase in yields, rootstock selection and breeding have accordingly conformed to the prevailing demand for improving productivity, arguably at the expense of fruit quality. It is, however, compelling to assess the qualitative implications of this growing agronomic practice for human nutrition. Problems of impaired vegetable fruit quality have not infrequently been associated with the practice of grafting. Accordingly, the aim of the current review is to reassess how the practice of grafting and the prevalence of particular types of commercial rootstocks influence vegetable fruit quality and, partly, storability. Physical, sensorial and bioactive aspects of quality are examined with respect to grafting for watermelon, melon, cucumber, tomato, eggplant, and pepper. The physiological mechanisms at play which mediate rootstock effects on scion performance are discussed in interpreting the

  6. Soil and vegetation surveillance

    Energy Technology Data Exchange (ETDEWEB)

    Antonio, E.J.

    1995-06-01

    Soil sampling and analysis evaluates long-term contamination trends and monitors environmental radionuclide inventories. This section of the 1994 Hanford Site Environmental Report summarizes the soil and vegetation surveillance programs which were conducted during 1994. Vegetation surveillance is conducted offsite to monitor atmospheric deposition of radioactive materials in areas not under cultivation and onsite at locations adjacent to potential sources of radioactivity.

  7. Mutation breeding in vegetable crops

    International Nuclear Information System (INIS)

    Yamaguchi, Takashi

    1984-01-01

    Vegetables breed by seeds and vegetative organs. In main vegetables, the differentiation of clopping types, the adoption of monoculture and year-round production and shipment are carried out, adapting to various socio-economic and cultivation conditions. Protected agriculture has advanced mainly for fruit vegetables, and the seeds for sale have become almost hybrid varieties. Reflecting the situation like this, the demand for breeding is diversified and characteristic, and the case of applying mutation breeding seems to be many. The present status of the mutation breeding of vegetables is not yet well under way, but about 40 raised varieties have been published in the world. The characters introduced by induced mutation and irradiation were compact form, harvesting aptitude, the forms and properties of stems and leaves, anti-lodging property, the size, form and uniformity of fruits, male sterility and so on. The radiation sources used were mostly gamma ray or X-ray, but sometimes, combined irradiation was used. As the results obtained in Japan, burdocks as an example of gamma ray irradiation to seeds, tomatoes as an example of inducing the compound resistance against disease injury and lettuces as an example of internal beta irradiation are reported. (Kako, I.)

  8. SO/sub 2/ dose-response sensitivity classification data for crops and natural vegetation species

    Energy Technology Data Exchange (ETDEWEB)

    Irving, P.M.; Ballou, S.W.

    1980-09-01

    Over the past several years studies have been made on the interaction of sulfur dioxide (SO/sub 2/) and vegetation by performing field research and by developing analytical procedures for applying field observation data to energy impact assessments. As a result of this work, numerous reports have been prepared on crop-pollutant interactions, such as dose-response data; on the applications of such data to screening approaches for identifying crops at risk; and on models that predict crop yield reductions from point source emissions of SO/sub 2/. Data that were used for these studies, such as the crop-at-risk screening procedure, are presented in this report. Maps are also presented that show the national distribution of SO/sub 2/-sensitive crops and natural vegetation.

  9. The Vegetables Turned:

    DEFF Research Database (Denmark)

    Carter, Dale

    2009-01-01

    in the relationship between creative artists and the Anglo-American popular music industry in the mid-1960s. Finally, and in retrospect, the figure of the vegetable cast into relief the counter-culture's utopian and dystopian dynamics as manifested in these song-writers' personal lives, now rendered as contemporary...... lyricist Van Dyke Parks, the incongruous, semantically complex figure of the vegetable came to illuminate aspects of psychedelic consciousness and - part by design, part by accident - the link between LSD and Anglo-American popular music. It threw light, too, on the scope and limits of changes...

  10. Climatic drivers of vegetation based on wavelet analysis

    Science.gov (United States)

    Claessen, Jeroen; Martens, Brecht; Verhoest, Niko E. C.; Molini, Annalisa; Miralles, Diego

    2017-04-01

    Vegetation dynamics are driven by climate, and at the same time they play a key role in forcing the different bio-geochemical cycles. As climate change leads to an increase in frequency and intensity of hydro-meteorological extremes, vegetation is expected to respond to these changes, and subsequently feed back on their occurrence. This response can be analysed using time series of different vegetation diagnostics observed from space, in the optical (e.g. Normalised Difference Vegetation Index (NDVI), Solar Induced Fluorescence (SIF)) and microwave (Vegetation Optical Depth (VOD)) domains. In this contribution, we compare the climatic drivers of different vegetation diagnostics, based on a monthly global data-cube of 24 years at a 0.25° resolution. To do so, we calculate the wavelet coherence between each vegetation-related observation and observations of air temperature, precipitation and incoming radiation. The use of wavelet coherence allows unveiling the scale-by-scale response and sensitivity of the diverse vegetation indices to their climatic drivers. Our preliminary results show that the wavelet-based statistics prove to be a suitable tool for extracting information from different vegetation indices. Going beyond traditional methods based on linear correlations, the application of wavelet coherence provides information about: (a) the specific periods at which the correspondence between climate and vegetation dynamics is larger, (b) the frequencies at which this correspondence occurs (e.g. monthly or seasonal scales), and (c) the time lag in the response of vegetation to their climate drivers, and vice versa. As expected, areas of high rainfall volumes are characterised by a strong control of radiation and temperature over vegetation. Furthermore, precipitation is the most important driver of vegetation variability over short terms in most regions of the world - which can be explained by the rapid response of leaf development towards available water content

  11. Consumption of a High Quantity and a Wide Variety of Vegetables Are Predicted by Different Food Choice Motives in Older Adults from France, Italy and the UK

    Science.gov (United States)

    Dinnella, Caterina; Spinelli, Sara; Morizet, David; Saulais, Laure; Hemingway, Ann; Monteleone, Erminio; Depezay, Laurence; Perez-Cueto, Federico J. A.; Hartwell, Heather

    2017-01-01

    Background: Consumption of a high quantity and wide variety of vegetables is currently recommended for health. Dietary variety can be low, however, particularly for older adults. This study investigated the affective factors associated with the quantity and variety of vegetables consumed by older adults in France, Italy and the UK. Methods: Adults aged 65 years plus completed questionnaires on self-reported vegetable intake (quantity and variety), liking for vegetables, attitudes towards intake, and demographic variables. Results: In 497 older adults (France, n = 187, Italy, n = 152, UK, n = 158), higher quantities of vegetables consumed were associated with a higher age, affluence score and liking for vegetables, and a lower importance in consumption of familiarity (smallest β = 0.11, p = 0.03). Greater variety was associated with a higher liking and importance of health benefits, and a lower importance of familiarity (smallest β = −0.11, p < 0.01). Higher quantity and variety combined (quantity × variety) was associated with a higher age, liking and importance of health benefits, and a lower importance of familiarity (smallest β = 0.14, p = 0.02). Country-specific effects were also found (smallest β = 0.20, p < 0.01). Conclusions: These findings demonstrate a role for liking and a lower concern for eating familiar foods in vegetable consumption, and a particular role for concern for health benefits in the consumption of a greater variety of vegetables. PMID:28832549

  12. Estimation of Mangrove Forest Aboveground Biomass Using Multispectral Bands, Vegetation Indices and Biophysical Variables Derived from Optical Satellite Imageries: Rapideye, Planetscope and SENTINEL-2

    Science.gov (United States)

    Balidoy Baloloy, Alvin; Conferido Blanco, Ariel; Gumbao Candido, Christian; Labadisos Argamosa, Reginal Jay; Lovern Caboboy Dumalag, John Bart; Carandang Dimapilis, Lee, , Lady; Camero Paringit, Enrico

    2018-04-01

    Aboveground biomass estimation (AGB) is essential in determining the environmental and economic values of mangrove forests. Biomass prediction models can be developed through integration of remote sensing, field data and statistical models. This study aims to assess and compare the biomass predictor potential of multispectral bands, vegetation indices and biophysical variables that can be derived from three optical satellite systems: the Sentinel-2 with 10 m, 20 m and 60 m resolution; RapidEye with 5m resolution and PlanetScope with 3m ground resolution. Field data for biomass were collected from a Rhizophoraceae-dominated mangrove forest in Masinloc, Zambales, Philippines where 30 test plots (1.2 ha) and 5 validation plots (0.2 ha) were established. Prior to the generation of indices, images from the three satellite systems were pre-processed using atmospheric correction tools in SNAP (Sentinel-2), ENVI (RapidEye) and python (PlanetScope). The major predictor bands tested are Blue, Green and Red, which are present in the three systems; and Red-edge band from Sentinel-2 and Rapideye. The tested vegetation index predictors are Normalized Differenced Vegetation Index (NDVI), Soil-adjusted Vegetation Index (SAVI), Green-NDVI (GNDVI), Simple Ratio (SR), and Red-edge Simple Ratio (SRre). The study generated prediction models through conventional linear regression and multivariate regression. Higher coefficient of determination (r2) values were obtained using multispectral band predictors for Sentinel-2 (r2 = 0.89) and Planetscope (r2 = 0.80); and vegetation indices for RapidEye (r2 = 0.92). Multivariate Adaptive Regression Spline (MARS) models performed better than the linear regression models with r2 ranging from 0.62 to 0.92. Based on the r2 and root-mean-square errors (RMSE's), the best biomass prediction model per satellite were chosen and maps were generated. The accuracy of predicted biomass maps were high for both Sentinel-2 (r2 = 0

  13. Influence of vegetation dynamic modeling on the allocation of green and blue waters

    Science.gov (United States)

    Ruiz-Pérez, Guiomar; Francés, Félix

    2015-04-01

    parsimonious dynamic vegetation sub-model which assumes the vegetation biomass as a state variable. Using both models, we estimated the amount of 'blue' water and the amount of 'green' water (according to the previous definitions) in each scenario. Comparing the results, we observed that the static model underestimated the amount of green water in any case (dry, normal or wet year). In fact, the value of the ratio between blue and green water is higher in all scenarios for the static option (0.23 in the dry year, 0.42 in the normal year and 0.96 in the wet year) than the obtained ones for the dynamic model (0.098, 0.29 and 0.76, respectively). It means that we are overestimating the amount of water available for human needs if we assume vegetation as static. This type of error can be very dangerous for water resources predictions with future climates, especially in Mediterranean areas due to their water scarcity.

  14. Kuchler Vegetation

    Data.gov (United States)

    California Natural Resource Agency — Digital version of potential natural plant communites as compiled and published on 'Map of the Natural Vegetation of California' by A. W. Kuchler, 1976. Source map...

  15. Evolution of Well-Being and Happiness After Increases in Consumption of Fruit and Vegetables.

    Science.gov (United States)

    Mujcic, Redzo; J Oswald, Andrew

    2016-08-01

    To explore whether improvements in psychological well-being occur after increases in fruit and vegetable consumption. We examined longitudinal food diaries of 12 385 randomly sampled Australian adults over 2007, 2009, and 2013 in the Household, Income, and Labour Dynamics in Australia Survey. We adjusted effects on incident changes in happiness and life satisfaction for people's changing incomes and personal circumstances. Increased fruit and vegetable consumption was predictive of increased happiness, life satisfaction, and well-being. They were up to 0.24 life-satisfaction points (for an increase of 8 portions a day), which is equal in size to the psychological gain of moving from unemployment to employment. Improvements occurred within 24 months. People's motivation to eat healthy food is weakened by the fact that physical health benefits accrue decades later, but well-being improvements from increased consumption of fruit and vegetables are closer to immediate. Citizens could be shown evidence that "happiness" gains from healthy eating can occur quickly and many years before enhanced physical health.

  16. SPINIFICI-SCAEVOLETEA SERICEAE, A NEW VEGETATION CLASS FOR PSAMMOPHYTIC DUNE VEGETATION IN THAILAND

    Directory of Open Access Journals (Sweden)

    S. PIGNATII

    1996-04-01

    Full Text Available This is a short account on the coastal dune vegetation of the Gulf of Siam in Thailand. Vegetation is mainly composed by succulent creeping plants with herbaceous habit as to Canavalia maritima (Papilionaceae and Iponwea pes-caprae (Convolvulaceae and the robust stoloniferous grass Spinijex littoreus, the last having an important function for the fonnation of coastal dunes.

  17. SPINIFICI-SCAEVOLETEA SERICEAE, A NEW VEGETATION CLASS FOR PSAMMOPHYTIC DUNE VEGETATION IN THAILAND

    Directory of Open Access Journals (Sweden)

    S. PIGNATII

    1996-01-01

    Full Text Available This is a short account on the coastal dune vegetation of the Gulf of Siam in Thailand. Vegetation is mainly composed by succulent creeping plants with herbaceous habit as to Canavalia maritima (Papilionaceae and Iponwea pes-caprae (Convolvulaceae and the robust stoloniferous grass Spinijex littoreus, the last having an important function for the fonnation of coastal dunes.

  18. Oscillations in a simple climate–vegetation model

    Directory of Open Access Journals (Sweden)

    J. Rombouts

    2015-05-01

    Full Text Available We formulate and analyze a simple dynamical systems model for climate–vegetation interaction. The planet we consider consists of a large ocean and a land surface on which vegetation can grow. The temperature affects vegetation growth on land and the amount of sea ice on the ocean. Conversely, vegetation and sea ice change the albedo of the planet, which in turn changes its energy balance and hence the temperature evolution. Our highly idealized, conceptual model is governed by two nonlinear, coupled ordinary differential equations, one for global temperature, the other for vegetation cover. The model exhibits either bistability between a vegetated and a desert state or oscillatory behavior. The oscillations arise through a Hopf bifurcation off the vegetated state, when the death rate of vegetation is low enough. These oscillations are anharmonic and exhibit a sawtooth shape that is characteristic of relaxation oscillations, as well as suggestive of the sharp deglaciations of the Quaternary. Our model's behavior can be compared, on the one hand, with the bistability of even simpler, Daisyworld-style climate–vegetation models. On the other hand, it can be integrated into the hierarchy of models trying to simulate and explain oscillatory behavior in the climate system. Rigorous mathematical results are obtained that link the nature of the feedbacks with the nature and the stability of the solutions. The relevance of model results to climate variability on various timescales is discussed.

  19. Oscillations in a simple climate-vegetation model

    Science.gov (United States)

    Rombouts, J.; Ghil, M.

    2015-05-01

    We formulate and analyze a simple dynamical systems model for climate-vegetation interaction. The planet we consider consists of a large ocean and a land surface on which vegetation can grow. The temperature affects vegetation growth on land and the amount of sea ice on the ocean. Conversely, vegetation and sea ice change the albedo of the planet, which in turn changes its energy balance and hence the temperature evolution. Our highly idealized, conceptual model is governed by two nonlinear, coupled ordinary differential equations, one for global temperature, the other for vegetation cover. The model exhibits either bistability between a vegetated and a desert state or oscillatory behavior. The oscillations arise through a Hopf bifurcation off the vegetated state, when the death rate of vegetation is low enough. These oscillations are anharmonic and exhibit a sawtooth shape that is characteristic of relaxation oscillations, as well as suggestive of the sharp deglaciations of the Quaternary. Our model's behavior can be compared, on the one hand, with the bistability of even simpler, Daisyworld-style climate-vegetation models. On the other hand, it can be integrated into the hierarchy of models trying to simulate and explain oscillatory behavior in the climate system. Rigorous mathematical results are obtained that link the nature of the feedbacks with the nature and the stability of the solutions. The relevance of model results to climate variability on various timescales is discussed.

  20. Estimating fractional vegetation cover and the vegetation index of bare soil and highly dense vegetation with a physically based method

    Science.gov (United States)

    Song, Wanjuan; Mu, Xihan; Ruan, Gaiyan; Gao, Zhan; Li, Linyuan; Yan, Guangjian

    2017-06-01

    Normalized difference vegetation index (NDVI) of highly dense vegetation (NDVIv) and bare soil (NDVIs), identified as the key parameters for Fractional Vegetation Cover (FVC) estimation, are usually obtained with empirical statistical methods However, it is often difficult to obtain reasonable values of NDVIv and NDVIs at a coarse resolution (e.g., 1 km), or in arid, semiarid, and evergreen areas. The uncertainty of estimated NDVIs and NDVIv can cause substantial errors in FVC estimations when a simple linear mixture model is used. To address this problem, this paper proposes a physically based method. The leaf area index (LAI) and directional NDVI are introduced in a gap fraction model and a linear mixture model for FVC estimation to calculate NDVIv and NDVIs. The model incorporates the Moderate Resolution Imaging Spectroradiometer (MODIS) Bidirectional Reflectance Distribution Function (BRDF) model parameters product (MCD43B1) and LAI product, which are convenient to acquire. Two types of evaluation experiments are designed 1) with data simulated by a canopy radiative transfer model and 2) with satellite observations. The root-mean-square deviation (RMSD) for simulated data is less than 0.117, depending on the type of noise added on the data. In the real data experiment, the RMSD for cropland is 0.127, for grassland is 0.075, and for forest is 0.107. The experimental areas respectively lack fully vegetated and non-vegetated pixels at 1 km resolution. Consequently, a relatively large uncertainty is found while using the statistical methods and the RMSD ranges from 0.110 to 0.363 based on the real data. The proposed method is convenient to produce NDVIv and NDVIs maps for FVC estimation on regional and global scales.

  1. Predicting soil acidification trends at Plynlimon using the SAFE model

    Directory of Open Access Journals (Sweden)

    B. Reynolds

    1997-01-01

    Full Text Available The SAFE model has been applied to an acid grassland site, located on base-poor stagnopodzol soils derived from Lower Palaeozoic greywackes. The model predicts that acidification of the soil has occurred in response to increased acid deposition following the industrial revolution. Limited recovery is predicted following the decline in sulphur deposition during the mid to late 1970s. Reducing excess sulphur and NOx deposition in 1998 to 40% and 70% of 1980 levels results in further recovery but soil chemical conditions (base saturation, soil water pH and ANC do not return to values predicted in pre-industrial times. The SAFE model predicts that critical loads (expressed in terms of the (Ca+Mg+K:Alcrit ratio for six vegetation species found in acid grassland communities are not exceeded despite the increase in deposited acidity following the industrial revolution. The relative growth response of selected vegetation species characteristic of acid grassland swards has been predicted using a damage function linking growth to soil solution base cation to aluminium ratio. The results show that very small growth reductions can be expected for 'acid tolerant' plants growing in acid upland soils. For more sensitive species such as Holcus lanatus, SAFE predicts that growth would have been reduced by about 20% between 1951 and 1983, when acid inputs were greatest. Recovery to c. 90% of normal growth (under laboratory conditions is predicted as acidic inputs decline.

  2. Rare Plants of Southeastern Hardwood Forests and the Role of Predictive Modeling

    International Nuclear Information System (INIS)

    Imm, D.W.; Shealy, H.E. Jr.; McLeod, K.W.; Collins, B.

    2001-01-01

    Habitat prediction models for rare plants can be useful when large areas must be surveyed or populations must be established. Investigators developed a habitat prediction model for four species of Southeastern hardwood forests. These four examples suggest that models based on resource and vegetation characteristics can accurately predict habitat, but only when plants are strongly associated with these variables and the scale of modeling coincides with habitat size

  3. Climate and vegetation in a semi-arid savanna: Development of a climate–vegetation response model linking plant metabolic performance to climate and the effects on forage availability for large herbivores

    Directory of Open Access Journals (Sweden)

    Armin H. Seydack

    2012-02-01

    Developing the climate–vegetation response model involved three main components, namely (1 defining indicators of forage availability to herbivores (nitrogen productivity, nitrogen quality, carbon-nutrient quality, (2 identifying herbivore species guilds of similar nutritional requirements with respect to these indicators [bulk feeders with tolerance to fibrous herbage (buffalo, waterbuck, bulk feeders with preference for high nitrogen quality forage (short grass preference grazers: blue wildebeest and zebra and selective feeders where dietary items of relatively high carbon-nutrient quality represented key forage resources (selective grazers: sable antelope, roan antelope, tsessebe, eland] and (3 developing a process model where the expected effects of plant metabolic responses to climate on key forage resources were made explicit. According to the climate–vegetation response model both shorter-term transient temperature acclimation pulses and longer-term shifts in plant metabolic functionality settings were predicted to have occurred in response to temperature trends over the past century. These temperature acclimation responses were expected to have resulted in transient pulses of increased forage availability (increased nitrogen- and carbon-nutrient quality, as well as the progressive long-term decline of the carbon-nutrient quality of forage. Conservation implications: The climate–vegetation response model represents a research framework for further studies contributing towards the enhanced understanding of landscape-scale functioning of savanna systems with reference to the interplay between climate, vegetation and herbivore population dynamics. Gains in such understanding can support sound conservation management.

  4. Assessment of vegetable production practices in Qwaqwa within ...

    African Journals Online (AJOL)

    In this study, the information such as biographical information of the vegetable farmers, information about the vegetable gardens or farms, the current vegetable farming practices, irrigation practices on the vegetable soil and the farmers' physical and financial records were assessed. The assessment was conducted through ...

  5. Radiation and the vegetable industry

    International Nuclear Information System (INIS)

    Roberts, P.B.

    1984-01-01

    The possible uses of irradiation in the vegetable industry are considered. Interest has been increasing because of possible bans on chemical fumigants and clearance of irradiation as an acceptable process, up to certain dose limits, by Codex Alimentarius and the US FDA. Inhibition of sprouting in potatoes and onions would be one possibility for exploitation. However, the main incentive for vegetable irradiation would be as a quarantine treatment for exported products. The shelf-life of a few vegetables could also be increased by combining radiation with heat treatments. Costs in New Zealand and consumer attitudes are briefly considered

  6. Post Fire Vegetation Recovery in Portugal

    Science.gov (United States)

    Gouveia, Celia; Bastos, Ana; DaCamara, Carlos; Trigo, Ricardo M.

    2011-01-01

    Fires in Portugal, as in the Mediterranean ecosystems, have a complex effect on vegetation regeneration due to the different responses of vegetation to the variety of fire regimes and to the complexity of landscape structures. A thorough evaluation of vegetation recovery after fire events becomes therefore crucial in land management. In 2005, Portugal suffered a strong damage from forest fires that damaged an area of 300 000 ha of forest and shrub. This year are particularly interesting because it is associated the severe drought of 2005. The aim of the present study is to identify large burnt scars in Portugal during the 2005 fire seasons and monitoring vegetation behaviour throughout the pre and the post fire periods. The mono-parametric model developed by Gouveia et al. (2010), based on monthly values of NDVI, at the 1km×1km spatial scale, as obtained from the VEGETATION-SPOT5 instrument, from 1999 to 2009, was used.

  7. Vegetable oil spills : oil properties and behaviour

    International Nuclear Information System (INIS)

    Fingas, M.; Fieldhouse, B.; Jokuty, P.

    2001-01-01

    In 1997, the United States Environmental Protection Agency conducted a thorough review of the issue regarding vegetable oil spills. Recent attention has refocused on this issue as a result of an incident where 20 tons of canola oil was spilled in the Vancouver Harbour in 2000. In the past, vegetable oils were suggested to be a useful test material because they were thought to be innocuous. It was even suggested they be used to remove petroleum oil residues from beaches. However, recent studies have shown that spills of vegetable oils can have major environmental consequences, equivalent to those of petroleum oil spills. The spills have devastating effects on birds and intertidal organisms. This paper presented a summary of historical vegetable spills from around the world. In this study, specific behaviour tests were examined for several oils including canola, soy bean, olive, castor and corn oils. Evaporation, water-in-oil emulsification and chemical dispersion were measured and were found to be nearly zero, suggesting that vegetable oil spills are not very soluble in water. The aquatic toxicity of vegetable oil is low, but their fate is quite different from petroleum. Vegetable oils do not evaporate to a significant degree, they do not form water-in-oil emulsions, nor do they disperse in water. The physical properties of vegetable oils were also measured, including density and viscosity. This paper presented the aquatic toxicity of several vegetable oils along with other environmental data including the degradation rates noted in the literature. Most environmental damage reported in the literature is by contact with birds feathers resulting in hypothermia and secondly by smothering of intertidal organisms. The effect of vegetable oil on fish has not been well studied, but it is expected that there will be little destructive effect except where smothering can occur. 35 refs., 3 tabs

  8. Vegetable oil spills : oil properties and behaviour

    Energy Technology Data Exchange (ETDEWEB)

    Fingas, M.; Fieldhouse, B.; Jokuty, P. [Environment Canada, Ottawa, ON (Canada). Emergencies Science Div

    2001-07-01

    In 1997, the United States Environmental Protection Agency conducted a thorough review of the issue regarding vegetable oil spills. Recent attention has refocused on this issue as a result of an incident where 20 tons of canola oil was spilled in the Vancouver Harbour in 2000. In the past, vegetable oils were suggested to be a useful test material because they were thought to be innocuous. It was even suggested they be used to remove petroleum oil residues from beaches. However, recent studies have shown that spills of vegetable oils can have major environmental consequences, equivalent to those of petroleum oil spills. The spills have devastating effects on birds and intertidal organisms. This paper presented a summary of historical vegetable spills from around the world. In this study, specific behaviour tests were examined for several oils including canola, soy bean, olive, castor and corn oils. Evaporation, water-in-oil emulsification and chemical dispersion were measured and were found to be nearly zero, suggesting that vegetable oil spills are not very soluble in water. The aquatic toxicity of vegetable oil is low, but their fate is quite different from petroleum. Vegetable oils do not evaporate to a significant degree, they do not form water-in-oil emulsions, nor do they disperse in water. The physical properties of vegetable oils were also measured, including density and viscosity. This paper presented the aquatic toxicity of several vegetable oils along with other environmental data including the degradation rates noted in the literature. Most environmental damage reported in the literature is by contact with birds feathers resulting in hypothermia and secondly by smothering of intertidal organisms. The effect of vegetable oil on fish has not been well studied, but it is expected that there will be little destructive effect except where smothering can occur. 35 refs., 3 tabs.

  9. Do behavioural health intentions engender health behaviour change? A study on the moderating role of self-affirmation on actual fruit intake versus vegetable intake.

    Science.gov (United States)

    Pietersma, Suzanne; Dijkstra, Arie

    2011-11-01

    The purpose of this persuasion research was to show that self-affirmation (SA) increases intentions in the advocated direction and that these intentions predict actual health behaviour change. That is, these intentions not only serve the function of short-term relief of the threat caused by the persuasive message. We proposed that the effect of SA depends on the level of value-involvement. Participants were randomly assigned to one of two conditions (no SA vs. SA) of a between-subjects design. After the SA manipulation, all participants read a threatening health text about the consequences of insufficient fruit and vegetable intake. At pre-test, value-involvement was determined. Participants included were undergraduate students. The SA manipulation consisted of a writing exercise. After reading the health message, participants reported their intention to eat sufficient fruit and vegetables (N= 537). After 1 week (N= 293) and 4 weeks (N= 261), participants completed self-reports of fruit and vegetable intake. No main effect was found for SA on any outcome measure. We did find that involvement moderated the effect of SA on cooked vegetables consumption. This effect was not present for raw vegetables/salad consumption or for fruit consumption. The moderated effect on cooked vegetable consumption was most evident after 1 week and the effect was mediated by the immediate intentions of participants. SA can lead to genuine intentions that predict actual behaviour, but the effect of SA depends on the type of behaviour and people's value-involvement. ©2011 The British Psychological Society.

  10. Formalized classification of species-poor vegetation: a proposal of a consistent protocol for aquatic vegetation

    Czech Academy of Sciences Publication Activity Database

    Landucci, F.; Tichý, L.; Šumberová, Kateřina; Chytrý, M.

    2015-01-01

    Roč. 26, č. 4 (2015), s. 791-803 ISSN 1100-9233 R&D Projects: GA ČR GB14-36079G Institutional support: RVO:67985939 Keywords : vegetation classification * vegetation database * Coctail method Subject RIV: EF - Botanics Impact factor: 3.151, year: 2015

  11. Effects of gamma radiation on biomass production of ground vegetation under broadleaved forests of northern Wisconsin

    International Nuclear Information System (INIS)

    Zavitkovski, J.; Salmonson, B.J.

    1977-01-01

    Effects of gamma irradiation (10,000-Ci 137 Cs source) for one growing season on biomass production of ground vegetation under northern Wisconsin aspen and maple-aspen-birch forests and on an abandoned logging road were evaluated during and 1 year after irradiation. No significant changes in production were determined during the irradiation year. One year later three distinct zones--semidevastated, herbaceous, and original forest--developed along the radiation gradient. Biomass production under forest canopies decreased significantly in the semidevastated zone, increased significantly in the herbaceous zone (primarily responding to additional light), and remained unchanged under the original forest. Logging-road vegetation responded similarly, but the changes were restricted within higher radiation doses. At comparable levels of radiation, production of species of the logging-road vegetation was affected less than that of species under forest canopies. Such a trend was predictable from the generally smaller interphase chromosome volumes of the species on the logging road and from their ability to survive in severe habitats

  12. Emissions from the burning of vegetative debris in air curtain destructors.

    Science.gov (United States)

    Miller, C Andrew; Lemieux, Paul M

    2007-08-01

    Although air curtain destructors (ACDs) have been used for quite some time to dispose of vegetative debris, relatively little in-depth testing has been conducted to quantify emissions of pollutants other than CO and particulate matter. As part of an effort to prepare for possible use of ACDs to dispose of the enormous volumes of debris generated by Hurricanes Katrina and Rita, the literature on ACD emissions was reviewed to identify potential environmental issues associated with ACD disposal of construction and demolition (C&D) debris. Although no data have been published on emissions from C&D debris combustion in an ACD, a few studies provided information on emissions from the combustion of vegetative debris. These studies are reviewed, and the results compared with studies of open burning of biomass. Combustion of vegetative debris in ACD units results in significantly lower emissions of particulate matter and CO per unit of mass of debris compared with open pile burning. The available data are not sufficient to make general estimates regarding emissions of organic or metal compounds. The highly transient nature of the ACD combustion process, a minimal degree of operational control, and significant variability in debris properties make accurate prediction of ACD emissions impossible in general. Results of scoping tests conducted in preparation for possible in-depth emissions tests demonstrate the challenges associated with sampling ACD emissions and highlight the transient nature of the process. The environmental impacts of widespread use of ACDs for disposal of vegetative debris and their potential use to reduce the volume of C&D debris in future disaster response scenarios remain a considerable gap in understanding the risks associated with debris disposal options.

  13. Wieslander Vegetation

    Data.gov (United States)

    California Natural Resource Agency — Digital version of the 1945 California Vegetation Type Maps by A. E. Wieslander of the U.S. Forest Service. Source scale of maps are 1:100,000. These compiled maps...

  14. Model of Peatland Vegetation Species using HyMap Image and Machine Learning

    Science.gov (United States)

    Dayuf Jusuf, Muhammad; Danoedoro, Projo; Muljo Sukojo, Bangun; Hartono

    2017-12-01

    Species Tumih / Parepat (Combretocarpus-rotundatus Mig. Dancer) family Anisophylleaceae and Meranti (Shorea Belangerang, Shorea Teysmanniana Dyer ex Brandis) family Dipterocarpaceae is a group of vegetation species distribution model. Species pioneer is predicted as an indicator of the succession of ecosystem restoration of tropical peatland characteristics and extremely fragile (unique) in the endemic hot spot of Sundaland. Climate change projections and conservation planning are hot topics of current discussion, analysis of alternative approaches and the development of combinations of species projection modelling algorithms through geospatial information systems technology. Approach model to find out the research problem of vegetation level based on the machine learning hybrid method, wavelet and artificial neural networks. Field data are used as a reference collection of natural resource field sample objects and biodiversity assessment. The testing and training ANN data set iterations times 28, achieve a performance value of 0.0867 MSE value is smaller than the ANN training data, above 50%, and spectral accuracy 82.1 %. Identify the location of the sample point position of the Tumih / Parepat vegetation species using HyMap Image is good enough, at least the modelling, design of the species distribution can reach the target in this study. The computation validation rate above 90% proves the calculation can be considered.

  15. Effects of ozone-vegetation coupling on surface ozone air quality via biogeochemical and meteorological feedbacks

    Science.gov (United States)

    Sadiq, Mehliyar; Tai, Amos P. K.; Lombardozzi, Danica; Martin, Maria Val

    2017-02-01

    Tropospheric ozone is one of the most hazardous air pollutants as it harms both human health and plant productivity. Foliage uptake of ozone via dry deposition damages photosynthesis and causes stomatal closure. These foliage changes could lead to a cascade of biogeochemical and biogeophysical effects that not only modulate the carbon cycle, regional hydrometeorology and climate, but also cause feedbacks onto surface ozone concentration itself. In this study, we implement a semi-empirical parameterization of ozone damage on vegetation in the Community Earth System Model to enable online ozone-vegetation coupling, so that for the first time ecosystem structure and ozone concentration can coevolve in fully coupled land-atmosphere simulations. With ozone-vegetation coupling, present-day surface ozone is simulated to be higher by up to 4-6 ppbv over Europe, North America and China. Reduced dry deposition velocity following ozone damage contributes to ˜ 40-100 % of those increases, constituting a significant positive biogeochemical feedback on ozone air quality. Enhanced biogenic isoprene emission is found to contribute to most of the remaining increases, and is driven mainly by higher vegetation temperature that results from lower transpiration rate. This isoprene-driven pathway represents an indirect, positive meteorological feedback. The reduction in both dry deposition and transpiration is mostly associated with reduced stomatal conductance following ozone damage, whereas the modification of photosynthesis and further changes in ecosystem productivity are found to play a smaller role in contributing to the ozone-vegetation feedbacks. Our results highlight the need to consider two-way ozone-vegetation coupling in Earth system models to derive a more complete understanding and yield more reliable future predictions of ozone air quality.

  16. Alien plant invasion in mixed-grass prairie: Effects of vegetation type and anthropogenic disturbance

    Science.gov (United States)

    Larson, D.L.; Anderson, P.J.; Newton, W.

    2001-01-01

    The ability of alien plant species to invade a region depends not only on attributes of the plant, but on characteristics of the habitat being invaded. Here, we examine characteristics that may influence the success of alien plant invasion in mixed-grass prairie at Theodore Roosevelt National Park, in western North Dakota, USA. The park consists of two geographically separate units with similar vegetation types and management history, which allowed us to examine the effects of native vegetation type, anthropogenic disturbance, and the separate park units on the invasion of native plant communities by alien plant species common to counties surrounding both park units. If matters of chance related to availability of propagules and transient establishment opportunities determine the success of invasion, park unit and anthropogenic disturbance should better explain the variation in alien plant frequency. If invasibility is more strongly related to biotic or physical characteristics of the native plant communities, models of alien plant occurrence should include vegetation type as an explanatory variable. We examined >1300 transects across all vegetation types in both units of the park. Akaike's Information Criterion (AIC) indicated that the fully parameterized model, including the interaction among vegetation type, disturbance, and park unit, best described the distribution of both total number of alien plants per transect and frequency of alien plants on transects where they occurred. Although all vegetation types were invaded by alien plants, mesic communities had both greater numbers and higher frequencies of alien plants than did drier communities. A strong element of stochasticity, reflected in differences in frequencies of individual species between the two park units, suggests that prediction of risk of invasion will always involve uncertainty. In addition, despite well-documented associations between anthropogenic disturbance and alien plant invasion, five of

  17. Interactions Between Wind Erosion, Vegetation Structure, and Soil Stability in Groundwater Dependent Plant Communities

    Science.gov (United States)

    Vest, K. R.; Elmore, A. J.; Okin, G. S.

    2009-12-01

    Desertification is a human induced global phenomenon causing a loss of biodiversity and ecosystem productivity. Semi-arid grasslands are vulnerable to anthropogenic impacts (i.e., groundwater pumping and surface water diversion) that decrease vegetation cover and increase bare soil area leading to a greater probability of soil erosion, potentially enhancing feedback processes associated with desertification. To enhance our understanding of interactions between anthropogenic, physical, and biological factors causing desertification, this study used a combination of modeling and field observations to examine the relationship between chronic groundwater pumping and vegetation cover change and its effects on soil erosion and stability. The work was conducted in Owens Valley California, where a long history of groundwater pumping and surface water diversion has lead to documented vegetation changes. The work examined hydrological, ecological and biogeochemical factors across thirteen sites in Owens Valley. We analyzed soil stability, vegetation and gap size, soil organic carbon, and we also installed Big Spring Number Eight (BSNE) catchers to calculate mass transport of aeolian sediment across sites. Mass transport calculations were used to validate a new wind erosion model that represents the effect of porous vegetation on surface windshear velocity. Results across two field seasons show that the model can be used to predict mass transport, and areas with increased groundwater pumping show a greater susceptibility to erosion. Sediment collected in BSNE catchers was positively correlated with site gap size. Additionally, areas with larger gap sizes have a greater threshold shear velocity and soil stability, yet mass transport was greater at these sites than at sites with smaller gap sizes. Although modeling is complicated by spatial variation in multiple model parameters (e.g., gap size, threshold shear velocity in gaps), our results support the hypothesis that soils

  18. Vegetation - McKenzie Preserve [ds703

    Data.gov (United States)

    California Natural Resource Agency — The California Native Plant Society (CNPS) Vegetation Program produced a vegetation map and classification for approximately 11,600 acres primarily within Millerton...

  19. Combined effects of climate change and forest clearing on the Amazon vegetation: Projections for 2080-2100

    Science.gov (United States)

    Cook, K. H.; Vizy, E. K.

    2007-05-01

    A regional climate model with resolution of 60 km coupled with a potential vegetation model is used to simulate future vegetation distributions over South America. The coupled model, which produces an accurate representation of today's climate and vegetation, is forced with increasing atmospheric CO2 concentrations, sea surface temperature from a global model, and scenarios of future land use practices to predict climate and vegetation distributions for the last 2 decades of the 21st century. When only climate change is considered, under a business-as-usual scenario for global emissions, the extent of the Amazon rainforest is reduced by about 70 per cent by the end of this century, and the shrubland (caatinga) vegetation of Brazil's Nordeste region spreads westward and southward. Reductions in annual mean precipitation are widespread and rainfall becomes insufficient to support the rainforest in these regions, but some areas receive more precipitation. The length of the dry season increases in the central and southern Amazon in association with changes in the large-scale tropical circulation. Without this change in seasonality, local refugia of Amazon vegetation would be preserved and the retreat of the rainforest would be somewhat less extensive. Including various projections of future land use practices in addition to climate change may accelerate the unrecoverable demise of the rainforest and feedback to modify climate on regional space scales. The portions of the rainforest that are most vulnerable to climate change are the same as those that are under the most pressure from human activity, presenting a remarkable competition.

  20. Increasing portion sizes of fruits and vegetables in an elementary school lunch program can increase fruit and vegetable consumption.

    Science.gov (United States)

    Miller, Nicole; Reicks, Marla; Redden, Joseph P; Mann, Traci; Mykerezi, Elton; Vickers, Zata

    2015-08-01

    Increasing portion size can increase children's consumption of food. The goal of this study was to determine whether increasing the portion sizes of fruits and vegetables in an elementary school cafeteria environment would increase children's consumption of them. We measured each child's consumption of the fruit and vegetables served in a cafeteria line on a control day (normal cafeteria procedures) and on two intervention days. When we increased the portion size of 3 of the 4 fruits and vegetables by about 50%, children who took those foods increased their consumption of them. Although this was an effective strategy for increasing fruit and vegetable consumption among students who took those foods, many children chose not to take any fruits or vegetables. Further efforts are needed to increase children's selection and consumption of fruits and vegetables in an environment of competing foods of higher palatability. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. East African Cenozoic vegetation history.

    Science.gov (United States)

    Linder, Hans Peter

    2017-11-01

    The modern vegetation of East Africa is a complex mosaic of rainforest patches; small islands of tropic-alpine vegetation; extensive savannas, ranging from almost pure grassland to wooded savannas; thickets; and montane grassland and forest. Here I trace the evolution of these vegetation types through the Cenozoic. Paleogene East Africa was most likely geomorphologically subdued and, as the few Eocene fossil sites suggest, a woodland in a seasonal climate. Woodland rather than rainforest may well have been the regional vegetation. Mountain building started with the Oligocene trap lava flows in Ethiopia, on which rainforest developed, with little evidence of grass and none of montane forests. The uplift of the East African Plateau took place during the middle Miocene. Fossil sites indicate the presence of rainforest, montane forest and thicket, and wooded grassland, often in close juxtaposition, from 17 to 10 Ma. By 10 Ma, marine deposits indicate extensive grassland in the region and isotope analysis indicates that this was a C 3 grassland. In the later Miocene rifting, first of the western Albertine Rift and then of the eastern Gregory Rift, added to the complexity of the environment. The building of the high strato-volcanos during the later Mio-Pliocene added environments suitable for tropic-alpine vegetation. During this time, the C 3 grassland was replaced by C 4 savannas, although overall the extent of grassland was reduced from the mid-Miocene high to the current low level. Lake-level fluctuations during the Quaternary indicate substantial variation in rainfall, presumably as a result of movements in the intertropical convergence zone and the Congo air boundary, but the impact of these fluctuations on the vegetation is still speculative. I argue that, overall, there was an increase in the complexity of East African vegetation complexity during the Neogene, largely as a result of orogeny. The impact of Quaternary climatic fluctuation is still poorly understood

  2. Contribution of vegetation and water table on isoprene emission from boreal peatland microcosms

    DEFF Research Database (Denmark)

    Tiiva, Päivi; Faubert, Patrick; Räty, Sanna

    2009-01-01

    emission in these naturally wet ecosystems, although water table is predicted to decline due to climate warming. We studied the relative contribution of mosses vs. vascular plants to isoprene emission in boreal peatland microcosms in growth chambers by removing either vascular vegetation or both vascular...... hollows with intact vegetation, 45 ± 6 µg m-2 h-1, was decreased by 25% under water table drawdown. However, water table drawdown reduced net ecosystem carbon dioxide (CO2) exchange more dramatically than isoprene emission. Isoprene emission strongly correlated with both CO2 exchange and methane emission......Boreal peatlands are substantial sources of isoprene, a reactive hydrocarbon. However, it is not known how much mosses, vascular plants and peat each contribute to isoprene emission from peatlands. Furthermore, there is no information on the effects of declining water table depth on isoprene...

  3. A review on vegetation models and applicability to climate simulations at regional scale

    Science.gov (United States)

    Myoung, Boksoon; Choi, Yong-Sang; Park, Seon Ki

    2011-11-01

    The lack of accurate representations of biospheric components and their biophysical and biogeochemical processes is a great source of uncertainty in current climate models. The interactions between terrestrial ecosystems and the climate include exchanges not only of energy, water and momentum, but also of carbon and nitrogen. Reliable simulations of these interactions are crucial for predicting the potential impacts of future climate change and anthropogenic intervention on terrestrial ecosystems. In this paper, two biogeographical (Neilson's rule-based model and BIOME), two biogeochemical (BIOME-BGC and PnET-BGC), and three dynamic global vegetation models (Hybrid, LPJ, and MC1) were reviewed and compared in terms of their biophysical and physiological processes. The advantages and limitations of the models were also addressed. Lastly, the applications of the dynamic global vegetation models to regional climate simulations have been discussed.

  4. Internalisation of microbes in vegetables: microbial load of Ghanaian vegetables and the relationship with different water sources of irrigation.

    Science.gov (United States)

    Donkor, Eric S; Lanyo, R; Kayang, Boniface B; Quaye, Jonathan; Edoh, Dominic A

    2010-09-01

    The occurrence of pathogens in the internal parts of vegetables is usually associated with irrigation water or contaminated soil and could pose risk to consumers as the internalised pathogens are unaffected by external washing. This study was carried out to assess the rate of internalisation of microbes in common Ghanaian vegetables. Standard microbiological methods were employed in microbial enumeration of vegetables collected at the market and farm levels, as well as irrigation water and soil samples. The overall mean counts of vegetables were 4.0 x 10(3) cfu g(-1); 8.1 x 10(2) cfu g(-1); 2.0 x 10(2) cfu g(-1); 3.5 x 10(2) cfu g(-1) for total bacteria, coliform counts, faecal coliform counts and yeast counts, respectively. The rate of internalisation of coliforms in vegetables irrigated with stream/well water was 2.7 times higher than those irrigated with pipe water. The mean coliform counts (4.7 x 10(7) cfu g(-1)) and faecal coliform counts (1.8 x 10(6) cfu g(-1)) of soil samples were similar to those of stream water suggesting both sources exerted similar contamination rates on the vegetables. Generally, there were no significant variations between the rates of internalisation of microbes at the market and farm levels at p vegetables mainly occurred at the farm level. The study has shown that microbial contamination of vegetables in Ghana is not limited to the external surface, but internal vegetable parts could harbour high microbial loads and pose risk to consumers. Safety practices associated with the commodity should therefore not be limited to external washing only. There is the additional need of heating vegetables to eliminate microbes both externally and internally before consumption.

  5. Discharge/Stage Relations in Vegetated Danish Streams

    DEFF Research Database (Denmark)

    Larsen, Torben; Frier, Jens-Ole; Vestergaard, Kristian

    1990-01-01

    This paper describes how the friction in danish streams varies as function of the vegetation. The major species of vegetation are represented. A series of laboratory and field experiments are described, and a hypothesis for the influence of the vegetation on the Manning's n is discussed....

  6. Mapping and characterizing the vegetation types of the Democratic Republic of Congo using SPOT VEGETATION time series

    Science.gov (United States)

    Vancutsem, C.; Pekel, J.-F.; Evrard, C.; Malaisse, F.; Defourny, P.

    2009-02-01

    The need for quantitative and accurate information to characterize the state and evolution of vegetation types at a national scale is widely recognized. This type of information is crucial for the Democratic Republic of Congo, which contains the majority of the tropical forest cover of Central Africa and a large diversity of habitats. In spite of recent progress in earth observation capabilities, vegetation mapping and seasonality analysis in equatorial areas still represent an outstanding challenge owing to high cloud coverage and the extent and limited accessibility of the territory. On one hand, the use of coarse-resolution optical data is constrained by performance in the presence of cloud screening and by noise arising from the compositing process, which limits the spatial consistency of the composite and the temporal resolution. On the other hand, the use of high-resolution data suffers from heterogeneity of acquisition dates, images and interpretation from one scene to another. The objective of the present study was to propose and demonstrate a semi-automatic processing method for vegetation mapping and seasonality characterization based on temporal and spectral information from SPOT VEGETATION time series. A land cover map with 18 vegetation classes was produced using the proposed method that was fed by ecological knowledge gathered from botanists and reference documents. The floristic composition and physiognomy of each vegetation type are described using the Land Cover Classification System developed by the FAO. Moreover, the seasonality of each class is characterized on a monthly basis and the variation in different vegetation indicators is discussed from a phenological point of view. This mapping exercise delivers the first area estimates of seven different forest types, five different savannas characterized by specific seasonality behavior and two aquatic vegetation types. Finally, the result is compared to two recent land cover maps derived from

  7. Global vegetation-fire pattern under different land use and climate conditions

    Science.gov (United States)

    Thonicke, K.; Poulter, B.; Heyder, U.; Gumpenberger, M.; Cramer, W.

    2008-12-01

    Fire is a process of global significance in the Earth System influencing vegetation dynamics, biogeochemical cycling and biophysical feedbacks. Naturally ignited wildfires have long history in the Earth System. Humans have been using fire to shape the landscape for their purposes for many millenia, sometimes influencing the status of the vegetation remarkably as for example in Mediterranean-type ecosystems. Processes and drivers describing fire danger, ignitions, fire spread and effects are relatively well-known for many fire-prone ecosystems. Modeling these has a long tradition in fire-affected regions to predict fire risk and behavior for fire-fighting purposes. On the other hand, the global vegetation community realized the importance of disturbances to be recognized in their global vegetation models with fire being globally most important and so-far best studied. First attempts to simulate fire globally considered a minimal set of drivers, whereas recent developments attempt to consider each fire process separately. The process-based fire model SPITFIRE (SPread and InTensity of FIRE) simulates these processes embedded in the LPJ DGVM. Uncertainties still arise from missing measurements for some parameters in less-studied fire regimes, or from broad PFT classifications which subsume different fire-ecological adaptations and tolerances. Some earth observation data sets as well as fire emission models help to evaluate seasonality and spatial distribution of simulated fire ignitions, area burnt and fire emissions within SPITFIRE. Deforestation fires are a major source of carbon released to the atmosphere in the tropics; in the Amazon basin it is the second-largest contributor to Brazils GHG emissions. How ongoing deforestation affects fire regimes, forest stability and biogeochemical cycling in the Amazon basin under present climate conditions will be presented. Relative importance of fire vs. climate and land use change is analyzed. Emissions resulting from

  8. Assessing the role of access and price on the consumption of fruits and vegetables across New York City using agent-based modeling.

    Science.gov (United States)

    Li, Yan; Zhang, Donglan; Thapa, Janani R; Madondo, Kumbirai; Yi, Stella; Fisher, Elisa; Griffin, Kerry; Liu, Bian; Wang, Youfa; Pagán, José A

    2018-01-01

    Most residents in New York City (NYC) do not consume sufficient fruits and vegetables every day. Difficulties with access and high prices of fruits and vegetables in some neighborhoods contribute to different consumption patterns across NYC neighborhoods. We developed an agent-based model (ABM) to predict dietary behaviors of individuals at the borough and neighborhood levels. Model parameters were estimated from the 2014 NYC Community Health Survey, United States Census data, and the literature. We simulated six hypothetical interventions designed to improve access and reduce the price of fruits and vegetables. We found that all interventions would lead to increases in fruit and vegetable consumption but the results vary substantially across boroughs and neighborhoods. For example, a 10% increase in the number of fruit/vegetable vendors combined with a 10% decrease in the prices of fruits and vegetables would lead to a median increase of 2.28% (range: 0.65%-4.92%) in the consumption of fruits and vegetables, depending on neighborhood. We also found that the impact of increasing the number of vendors on fruit/vegetable consumption is more pronounced in unhealthier local food environments while the impact of reducing prices on fruits/vegetable consumption is more pronounced in neighborhoods with low levels of education. An agent-based model of dietary behaviors that takes into account neighborhood context has the potential to inform how fruit/vegetable access and pricing strategies may specifically work in tandem to increase the consumption of fruits and vegetables at the local level. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. The Hydromechanics of Vegetation for Slope Stabilization

    Science.gov (United States)

    Mulyono, A.; Subardja, A.; Ekasari, I.; Lailati, M.; Sudirja, R.; Ningrum, W.

    2018-02-01

    Vegetation is one of the alternative technologies in the prevention of shallow landslide prevention that occurs mostly during the rainy season. The application of plant for slope stabilization is known as bioengineering. Knowledge of the vegetative contribution that can be considered in bioengineering was the hydrological and mechanical aspects (hydromechanical). Hydrological effect of the plant on slope stability is to reduce soil water content through transpiration, interception, and evapotranspiration. The mechanical impact of vegetation on slope stability is to stabilize the slope with mechanical reinforcement of soils through roots. Vegetation water consumption varies depending on the age and density, rainfall factors and soil types. Vegetation with high ability to absorb water from the soil and release into the atmosphere through a transpiration process will reduce the pore water stress and increase slope stability, and vegetation with deep root anchoring and strong root binding was potentially more significant to maintain the stability of the slope.

  10. New views on changing Arctic vegetation

    Science.gov (United States)

    Kennedy, Robert E.

    2012-03-01

    As climate changes, how will terrestrial vegetation respond? Because the fates of many biogeochemical, hydrological and economic cycles depend on vegetation, this question is fundamental to climate change science but extremely challenging to address. This is particularly true in the Arctic, where temperature change has been most acute globally (IPCC 2007) and where potential feedbacks to carbon, energy and hydrological cycles have important implications for the rest of the Earth system (Chapin et al 2000). It is well known that vegetation is tightly coupled to precipitation and temperature (Whittaker 1975), but predicting the response of vegetation to changes in climate involves much more than invoking the limitations of climate envelopes (Thuiller et al 2008). Models must also consider efficacy of dispersal, soil constraints, ecological interactions, possible CO2 fertilization impacts and the changing impact of other, more proximal anthropogenic effects such as pollution, disturbance, etc (Coops and Waring 2011, Lenihan et al 2008, Scheller and Mladenoff 2005). Given this complexity, a key test will be whether models can match empirical observations of changes that have already occurred. The challenge is finding empirical observations of change that are appropriate to test hypothesized impacts of climate change. As climate gradually changes across broad bioclimatic gradients, vegetation condition may change gradually as well. To capture these gradual trends, observations need at least three characteristics: (1) they must quantify a vegetation attribute that is expected to change, (2) they must measure that attribute in exactly the same way over long periods of time, and (3) they must sample diverse communities at geographic scales commensurate with the scale of expected climatic shifts. Observation networks meeting all three criteria are rare anywhere on the globe, but particularly so in remote areas. For this reason, satellite images have long been used as a

  11. Can riparian vegetation shade mitigate the expected rise in stream temperatures due to climate change during heat waves in a human-impacted pre-alpine river?

    Directory of Open Access Journals (Sweden)

    H. Trimmel

    2018-01-01

    Full Text Available Global warming has already affected European rivers and their aquatic biota, and climate models predict an increase of temperature in central Europe over all seasons. We simulated the influence of expected changes in heat wave intensity during the 21st century on water temperatures of a heavily impacted pre-alpine Austrian river and analysed future mitigating effects of riparian vegetation shade on radiant and turbulent energy fluxes using the deterministic Heat Source model. Modelled stream water temperature increased less than 1.5 °C within the first half of the century. Until 2100, a more significant increase of around 3 °C in minimum, maximum and mean stream temperatures was predicted for a 20-year return period heat event. The result showed clearly that in a highly altered river system riparian vegetation was not able to fully mitigate the predicted temperature rise caused by climate change but would be able to reduce water temperature by 1 to 2 °C. The removal of riparian vegetation amplified stream temperature increases. Maximum stream temperatures could increase by more than 4 °C even in annual heat events. Such a dramatic water temperature shift of some degrees, especially in summer, would indicate a total shift of aquatic biodiversity. The results demonstrate that effective river restoration and mitigation require re-establishing riparian vegetation and emphasize the importance of land–water interfaces and their ecological functioning in aquatic environments.

  12. Can riparian vegetation shade mitigate the expected rise in stream temperatures due to climate change during heat waves in a human-impacted pre-alpine river?

    Science.gov (United States)

    Trimmel, Heidelinde; Weihs, Philipp; Leidinger, David; Formayer, Herbert; Kalny, Gerda; Melcher, Andreas

    2018-01-01

    Global warming has already affected European rivers and their aquatic biota, and climate models predict an increase of temperature in central Europe over all seasons. We simulated the influence of expected changes in heat wave intensity during the 21st century on water temperatures of a heavily impacted pre-alpine Austrian river and analysed future mitigating effects of riparian vegetation shade on radiant and turbulent energy fluxes using the deterministic Heat Source model. Modelled stream water temperature increased less than 1.5 °C within the first half of the century. Until 2100, a more significant increase of around 3 °C in minimum, maximum and mean stream temperatures was predicted for a 20-year return period heat event. The result showed clearly that in a highly altered river system riparian vegetation was not able to fully mitigate the predicted temperature rise caused by climate change but would be able to reduce water temperature by 1 to 2 °C. The removal of riparian vegetation amplified stream temperature increases. Maximum stream temperatures could increase by more than 4 °C even in annual heat events. Such a dramatic water temperature shift of some degrees, especially in summer, would indicate a total shift of aquatic biodiversity. The results demonstrate that effective river restoration and mitigation require re-establishing riparian vegetation and emphasize the importance of land-water interfaces and their ecological functioning in aquatic environments.

  13. A Test of the Optimality Approach to Modelling Canopy gas Exchange by Natural Vegetation

    Science.gov (United States)

    Schymanski, S. J.; Sivapalan, M.; Roderick, M. L.; Beringer, J.; Hutley, L. B.

    2005-12-01

    Natural vegetation has co-evolved with its environment over a long period of time and natural selection has led to a species composition that is most suited for the given conditions. Part of this adaptation is the vegetation's water use strategy, which determines the amount and timing of water extraction from the soil. Knowing that water extraction by vegetation often accounts for over 90% of the annual water balance in some places, we need to understand its controls if we want to properly model the hydrologic cycle. Water extraction by roots is driven by transpiration from the canopy, which in turn is an inevitable consequence of CO2 uptake for photosynthesis. Photosynthesis provides plants with their main building material, carbohydrates, and with the energy necessary to thrive and prosper in their environment. Therefore we expect that natural vegetation would have evolved an optimal water use strategy to maximise its `net carbon profit' (the difference between carbon acquired by photosynthesis and carbon spent on maintenance of the organs involved in its uptake). Based on this hypothesis and on an ecophysiological gas exchange and photosynthesis model (Cowan and Farquhar 1977; von Caemmerer 2000), we model the optimal vegetation for a site in Howard Springs (N.T., Australia) and compare the modelled fluxes with measurements by Beringer, Hutley et al. (2003). The comparison gives insights into theoretical and real controls on transpiration and photosynthesis and tests the optimality approach to modelling gas exchange of natural vegetation with unknown properties. The main advantage of the optimality approach is that no assumptions about the particular vegetation on a site are needed, which makes it very powerful for predicting vegetation response to long-term climate- or land use change. Literature: Beringer, J., L. B. Hutley, et al. (2003). "Fire impacts on surface heat, moisture and carbon fluxes from a tropical savanna in northern Australia." International

  14. Multiscale remote sensing analysis to monitor riparian and upland semiarid vegetation

    Science.gov (United States)

    Nguyen, Uyen

    The health of natural vegetation communities is of concern due to observed changes in the climatic-hydrological regime and land cover changes particularly in arid and semiarid regions. Monitoring vegetation at multi temporal and spatial scales can be the most informative approach for detecting change and inferring causal agents of change and remediation strategies. Riparian communities are tightly linked to annual stream hydrology, ground water elevations and sediment transport. These processes are subject to varying magnitudes of disturbance overtime and are candidates for multi-scale monitoring. My first research objective focused on the response of vegetation in the Upper San Pedro River, Arizona, to reduced base flows and climate change. I addressed the correlation between riparian vegetation and hydro-climate variables during the last three decades in one of the remaining undammed rivers in the southwestern U.S. Its riparian forest is threatened by the diminishing base flows, attributed by different studies either to increases in evapotranspiration (ET) due to conversion of grasslands to mesquite shrublands in the adjacent uplands, or to increased regional groundwater pumping to serve growing populations in surrounding urban areas and or to some interactions of those causes. Landsat 5 imagery was acquired for pre- monsoon period, when riparian trees had leafed out but before the arrival of summer monsoon rains in July. The result has showed Normalized Difference Vegetation Index (NDVI) values from both Landsat and Moderate Resolution Imaging Spectrometer (MODIS) had significant decreases which positively correlated to river flows, which decreased over the study period, and negatively correlated with air temperatures, which have increased by about 1.4°C from 1904 to the present. The predictions from other studies that decreased river flows could negatively impact the riparian forest were supported by this study. The pre-monsoon Normalized Different Vegetation

  15. Forest restoration as a strategy to mitigate climate impacts on wildfire, vegetation, and water in semiarid forests.

    Science.gov (United States)

    O'Donnell, Frances C; Flatley, William T; Springer, Abraham E; Fulé, Peter Z

    2018-06-25

    Climate change and wildfire are interacting to drive vegetation change and potentially reduce water quantity and quality in the southwestern United States, Forest restoration is a management approach that could mitigate some of these negative outcomes. However, little information exists on how restoration combined with climate change might influence hydrology across large forest landscapes that incorporate multiple vegetation types and complex fire regimes. We combined spatially explicit vegetation and fire modeling with statistical water and sediment yield models for a large forested landscape (335,000 ha) on the Kaibab Plateau in northern Arizona, USA. Our objective was to assess the impacts of climate change and forest restoration on the future fire regime, forest vegetation, and watershed outputs. Our model results predict that the combination of climate change and high-severity fire will drive forest turnover, biomass declines, and compositional change in future forests. Restoration treatments may reduce the area burned in high-severity fires and reduce conversions from forested to non-forested conditions. Even though mid-elevation forests are the targets of restoration, the treatments are expected to delay the decline of high-elevation spruce-fir, aspen, and mixed conifer forests by reducing the occurrence of high-severity fires that may spread across ecoregions. We estimate that climate-induced vegetation changes will result in annual runoff declines of up to 10%, while restoration reduced or reversed this decline. The hydrologic model suggests that mid-elevation forests, which are the targets of restoration treatments, provide around 80% of runoff in this system and the conservation of mid- to high-elevation forests types provides the greatest benefit in terms of water conservation. We also predict that restoration treatments will conserve water quality by reducing patches of high-severity fire that are associated with high sediment yield. Restoration

  16. Parasitic Contamination of Raw Vegetables in Shahroud, Semnan

    Directory of Open Access Journals (Sweden)

    Saeid Nazemi

    2012-08-01

    Full Text Available Background: Given the importance of healthy vegetables, the present study was conducted to determine parasitic infection of vegetable consumed in Shahroud.Materials and Methods: This cross-sectional study has been conducted on 92 samples of various vegetables collected from 16 vegetable growing farms and 1 vegetable process workshop. Results: Sixty two percent of tested vegetables lacked parasites and the highest amount of parasites observed (34.78% was related to Giardia lamblia. A significant relationship was observed between parasite and having toilets in the farms as well as the extent of farms.Conclusion: safety of fertilizers consumed by farms and healthy fruits can have an effective role in reducing the parasitic infections.

  17. Effects of Telecoupling on Global Vegetation Dynamics

    Science.gov (United States)

    Viña, A.; Liu, J.

    2016-12-01

    With the ever increasing trend in telecoupling processes, such as international trade, all countries around the world are becoming more interdependent. However, the effects of this growing interdependence on vegetation (e.g., shifts in the geographic extent and distribution) remain unknown even though vegetation dynamics are crucially important for food production, carbon sequestration, provision of other ecosystem services, and biodiversity conservation. In this study we evaluate the effects of international trade on the spatio-temporal trajectories of vegetation at national and global scales, using vegetation index imagery collected over more than three decades by the Advanced Very High Resolution Radiometer (AVHRR) satellite sensor series together with concurrent national and international data on international trade (and its associated movement of people, goods, services and information). The spatio-temporal trajectories of vegetation are obtained using the scale of fluctuation technique, which is based on the decomposition of the AVHRR image time series to obtain information on its spatial dependence structure over time. Similar to the correlation length, the scale of fluctuation corresponds to the range over which fluctuations in the vegetation index are spatially correlated. Results indicate that global vegetation has changed drastically over the last three decades. These changes are not uniform across space, with hotspots in active trading countries. This study not only has direct implications for understanding global vegetation dynamics, but also sheds important insights on the complexity of human-nature interactions across telecoupled systems.

  18. 9 CFR 319.311 - Chow mein vegetables with meat, and chop suey vegetables with meat.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Chow mein vegetables with meat, and chop suey vegetables with meat. 319.311 Section 319.311 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE AGENCY ORGANIZATION AND TERMINOLOGY; MANDATORY MEAT AND POULTRY...

  19. Modeling mechanisms of vegetation change due to fire in a semi-arid ecosystem

    Science.gov (United States)

    White, J.D.; Gutzwiller, K.J.; Barrow, W.C.; Randall, L.J.; Swint, P.

    2008-01-01

    Vegetation growth and community composition in semi-arid environments is determined by water availability and carbon assimilation mechanisms specific to different plant types. Disturbance also impacts vegetation productivity and composition dependent on area affected, intensity, and frequency factors. In this study, a new spatially explicit ecosystem model is presented for the purpose of simulating vegetation cover type changes associated with fire disturbance in the northern Chihuahuan Desert region. The model is called the Landscape and Fire Simulator (LAFS) and represents physiological activity of six functional plant types incorporating site climate, fire, and seed dispersal routines for individual grid cells. We applied this model for Big Bend National Park, Texas, by assessing the impact of wildfire on the trajectory of vegetation communities over time. The model was initialized and calibrated based on landcover maps derived from Landsat-5 Thematic Mapper data acquired in 1986 and 1999 coupled with plant biomass measurements collected in the field during 2000. Initial vegetation cover change analysis from satellite data showed shrub encroachment during this time period that was captured in the simulated results. A synthetic 50-year climate record was derived from historical meteorological data to assess system response based on initial landcover conditions. This simulation showed that shrublands increased to the detriment of grass and yucca-ocotillo vegetation cover types indicating an ecosystem-level trajectory for shrub encroachment. Our analysis of simulated fires also showed that fires significantly reduced site biomass components including leaf area, stem, and seed biomass in this semi-arid ecosystem. In contrast to other landscape simulation models, this new model incorporates detailed physiological responses of functional plant types that will allow us to simulated the impact of increased atmospheric CO2 occurring with climate change coupled with fire

  20. Ecosystems past: prehistory of California vegetation

    Science.gov (United States)

    C.I. Millar; W.B. Woolfenden

    2016-01-01

    The history of California's vegetation, from origins in the Mesozoic through Quaternary is outlined. Climatic and geologic history and the processes driving changes in vegetation over time are also described. 

  1. Landscape change in the Holocene transition Development of a predictive model of vegetation cover in the Asón Valley (Cantabria

    Directory of Open Access Journals (Sweden)

    García Moreno, Alejandro

    2007-12-01

    Full Text Available The spatial distribution of prehistoric vegetation, and its evolution during the Pleistocene-Holocene transition, is essential for understanding the changes in the settlement patterns that took place at the end of the Upper Palaeolithic. To calculate this distribution, we have use a predictive model based on the weighted values method, according to the forest vegetation’s ecological requirements, analizing its evolution in the Asón river valley (Cantabria and its relationship with Palaeolithic sites.

    El conocimiento de la distribución espacial de la vegetación prehistórica, y su evolución a lo largo de la transición al Holoceno, es fundamental para entender los cambios en los patrones de explotación del territorio y de asentamiento que se producen en los grupos de cazadores-recolectores del final del Paleolítico Superior. Para calcular dicha distribución, se emplea un modelo predictivo basado en el método de weighted values (valores ponderados, a partir de los requerimientos ecológicos de la vegetación arbórea, analizando su evolución en el Valle del Asón (Cantabria y su relación con los yacimientos paleolíticos que allí existen.

  2. Simulating vegetation dynamics in Chile from 21ka BP to present: Effects of climate change on vegetation functions and cover

    Science.gov (United States)

    Werner, Christian; Liakka, Johan; Schmid, Manuel; Fuentes, Juan-Pablo; Ehlers, Todd A.; Hickler, Thomas

    2017-04-01

    Vegetation composition and establishment is strongly dependent on climate conditions but also a result of vegetation dynamics (competition for light, water and nutrients). In addition, vegetation exerts control over the development of landscapes as it mediates the climatic and hydrological forces shaping the terrain via hillslope and fluvial processes. At the same time, topography as well as soil texture and soil depth affect the microclimate, soil water storage and rooting space that is defining the environmental envelope for vegetation development. Within the EarthShape research program (www.earthshape.net) we evaluate these interactions by simulating the co-evolution of landscape and vegetation with a dynamic vegetation model (LPJ-GUESS) and a landscape evolution model (LandLab). LPJ-GUESS is a mechanistic model driven by daily or monthly weather data and explicitly simulates vegetation physiology, succession, competition and water and nutrient cycling. Here we present the results of first transient vegetation simulations from 21kyr BP to present-day using the TraCE-21ka climate dataset for four focus sites along the coastal cordillera of Chile that are exposed to a substantial meridional climate gradient (ranging from hyper-arid to humid-temperate conditions). We show that the warming occurring in the region from LGM to present, in addition to the increase of atmospheric CO2 concentrations, led to a shift in vegetation composition and surface cover. Future work will show how these changes resonate in the dynamics of hillslope and fluvial erosion and ultimately bi-directional feedback mechanisms of vegetation development and landscape evolution/ soil formation (see also companion presentation by Schmid et al., this session).

  3. Seasonally asymmetric enhancement of northern vegetation productivity

    Science.gov (United States)

    Park, T.; Myneni, R.

    2017-12-01

    Multiple evidences of widespread greening and increasing terrestrial carbon uptake have been documented. In particular, enhanced gross productivity of northern vegetation has been a critical role leading to observed carbon uptake trend. However, seasonal photosynthetic activity and its contribution to observed annual carbon uptake trend and interannual variability are not well understood. Here, we introduce a multiple-source of datasets including ground, atmospheric and satellite observations, and multiple process-based global vegetation models to understand how seasonal variation of land surface vegetation controls a large-scale carbon exchange. Our analysis clearly shows a seasonally asymmetric enhancement of northern vegetation productivity in growing season during last decades. Particularly, increasing gross productivity in late spring and early summer is obvious and dominant driver explaining observed trend and variability. We observe more asymmetric productivity enhancement in warmer region and this spatially varying asymmetricity in northern vegetation are likely explained by canopy development rate, thermal and light availability. These results imply that continued warming may facilitate amplifying asymmetric vegetation activity and cause these trends to become more pervasive, in turn warming induced regime shift in northern land.

  4. Vegetation - San Felipe Valley [ds172

    Data.gov (United States)

    California Natural Resource Agency — This Vegetation Map of the San Felipe Valley Wildlife Area in San Diego County, California is based on vegetation samples collected in the field in 2002 and 2005 and...

  5. Vegetation exerts a greater control on litter decomposition than climate warming in peatlands.

    Science.gov (United States)

    Ward, Susan E; Orwin, Kate H; Ostle, Nicholas J; Briones, J I; Thomson, Bruce C; Griffiths, Robert I; Oakley, Simon; Quirk, Helen; Bardget, Richard D

    2015-01-01

    Historically, slow decomposition rates have resulted in the accumulation of large amounts of carbon in northern peatlands. Both climate warming and vegetation change can alter rates of decomposition, and hence affect rates of atmospheric CO2 exchange, with consequences for climate change feedbacks. Although warming and vegetation change are happening concurrently, little is known about their relative and interactive effects on decomposition processes. To test the effects of warming and vegetation change on decomposition rates, we placed litter of three dominant species (Calluna vulgaris, Eriophorum vaginatum, Hypnum jutlandicum) into a peatland field experiment that combined warming.with plant functional group removals, and measured mass loss over two years. To identify potential mechanisms behind effects, we also measured nutrient cycling and soil biota. We found that plant functional group removals exerted a stronger control over short-term litter decomposition than did approximately 1 degrees C warming, and that the plant removal effect depended on litter species identity. Specifically, rates of litter decomposition were faster when shrubs were removed from the plant community, and these effects were strongest for graminoid and bryophyte litter. Plant functional group removals also had strong effects on soil biota and nutrient cycling associated with decomposition, whereby shrub removal had cascading effects on soil fungal community composition, increased enchytraeid abundance, and increased rates of N mineralization. Our findings demonstrate that, in addition to litter quality, changes in vegetation composition play a significant role in regulating short-term litter decomposition and belowground communities in peatland, and that these impacts can be greater than moderate warming effects. Our findings, albeit from a relatively short-term study, highlight the need to consider both vegetation change and its impacts below ground alongside climatic effects when

  6. Vegetation study in support of the design and optimization of vegetative soil covers, Sandia National Laboratories, Albuquerque, New Mexico.

    Energy Technology Data Exchange (ETDEWEB)

    Peace, Gerald (Jerry) L.; Goering, Timothy James (GRAM inc., Albuquerque, NM); Knight, Paul J. (Marron and Associates, Albuquerque, NM); Ashton, Thomas S. (Marron and Associates, Albuquerque, NM)

    2004-11-01

    A vegetation study was conducted in Technical Area 3 at Sandia National Laboratories, Albuquerque, New Mexico in 2003 to assist in the design and optimization of vegetative soil covers for hazardous, radioactive, and mixed waste landfills at Sandia National Laboratories/New Mexico and Kirtland Air Force Base. The objective of the study was to obtain site-specific, vegetative input parameters for the one-dimensional code UNSAT-H and to identify suitable, diverse native plant species for use on vegetative soil covers that will persist indefinitely as a climax ecological community with little or no maintenance. The identification and selection of appropriate native plant species is critical to the proper design and long-term performance of vegetative soil covers. Major emphasis was placed on the acquisition of representative, site-specific vegetation data. Vegetative input parameters measured in the field during this study include root depth, root length density, and percent bare area. Site-specific leaf area index was not obtained in the area because there was no suitable platform to measure leaf area during the 2003 growing season due to severe drought that has persisted in New Mexico since 1999. Regional LAI data was obtained from two unique desert biomes in New Mexico, Sevilletta Wildlife Refuge and Jornada Research Station.

  7. On the characterization of vegetation recovery after fire disturbance using Fisher-Shannon analysis and SPOT/VEGETATION Normalized Difference Vegetation Index (NDVI) time series

    Science.gov (United States)

    Lasaponara, Rosa; Lanorte, Antonio; Lovallo, Michele; Telesca, Luciano

    2015-04-01

    Time series can fruitfully support fire monitoring and management from statistical analysis of fire occurrence (Tuia et al. 2008) to danger estimation (lasaponara 2005), damage evaluation (Lanorte et al 2014) and post fire recovery (Lanorte et al. 2014). In this paper, the time dynamics of SPOT-VEGETATION Normalized Difference Vegetation Index (NDVI) time series are analyzed by using the statistical approach of the Fisher-Shannon (FS) information plane to assess and monitor vegetation recovery after fire disturbance. Fisher-Shannon information plane analysis allows us to gain insight into the complex structure of a time series to quantify its degree of organization and order. The analysis was carried out using 10-day Maximum Value Composites of NDVI (MVC-NDVI) with a 1 km × 1 km spatial resolution. The investigation was performed on two test sites located in Galizia (North Spain) and Peloponnese (South Greece), selected for the vast fires which occurred during the summer of 2006 and 2007 and for their different vegetation covers made up mainly of low shrubland in Galizia test site and evergreen forest in Peloponnese. Time series of MVC-NDVI have been analyzed before and after the occurrence of the fire events. Results obtained for both the investigated areas clearly pointed out that the dynamics of the pixel time series before the occurrence of the fire is characterized by a larger degree of disorder and uncertainty; while the pixel time series after the occurrence of the fire are featured by a higher degree of organization and order. In particular, regarding the Peloponneso fire, such discrimination is more evident than in the Galizia fire. This suggests a clear possibility to discriminate the different post-fire behaviors and dynamics exhibited by the different vegetation covers. Reference Lanorte A, R Lasaponara, M Lovallo, L Telesca 2014 Fisher-Shannon information plane analysis of SPOT/VEGETATION Normalized Difference Vegetation Index (NDVI) time series to

  8. Exploring vegetation in the fourth dimension.

    Science.gov (United States)

    Mitchell, Fraser J G

    2011-01-01

    Much ecological research focuses on changes in vegetation on spatial scales from stands to landscapes; however, capturing data on vegetation change over relevant timescales remains a challenge. Pollen analysis offers unrivalled access to data with global coverage over long timescales. Robust techniques have now been developed that enable pollen data to be converted into vegetation data in terms of individual taxa, plant communities or biomes, with the possibility of deriving from those data a range of plant attributes and ecological indicators. In this review, I discuss how coupling pollen with macrofossil, charcoal and genetic data opens up the extensive pollen databases to investigation of the drivers of vegetation change over time and also provides extensive data sets for testing hypotheses with wide ecological relevance. © 2010 Elsevier Ltd. All rights reserved.

  9. Detection of heavy metal Cd in polluted fresh leafy vegetables by laser-induced breakdown spectroscopy.

    Science.gov (United States)

    Yao, Mingyin; Yang, Hui; Huang, Lin; Chen, Tianbing; Rao, Gangfu; Liu, Muhua

    2017-05-10

    In seeking a novel method with the ability of green analysis in monitoring toxic heavy metals residue in fresh leafy vegetables, laser-induced breakdown spectroscopy (LIBS) was applied to prove its capability in performing this work. The spectra of fresh vegetable samples polluted in the lab were collected by optimized LIBS experimental setup, and the reference concentrations of cadmium (Cd) from samples were obtained by conventional atomic absorption spectroscopy after wet digestion. The direct calibration employing intensity of single Cd line and Cd concentration exposed the weakness of this calibration method. Furthermore, the accuracy of linear calibration can be improved a little by triple Cd lines as characteristic variables, especially after the spectra were pretreated. However, it is not enough in predicting Cd in samples. Therefore, partial least-squares regression (PLSR) was utilized to enhance the robustness of quantitative analysis. The results of the PLSR model showed that the prediction accuracy of the Cd target can meet the requirement of determination in food safety. This investigation presented that LIBS is a promising and emerging method in analyzing toxic compositions in agricultural products, especially combined with suitable chemometrics.

  10. Hyperspectral-based predictive modelling of grapevine water status in the Portuguese Douro wine region

    Science.gov (United States)

    Pôças, Isabel; Gonçalves, João; Costa, Patrícia Malva; Gonçalves, Igor; Pereira, Luís S.; Cunha, Mario

    2017-06-01

    In this study, hyperspectral reflectance (HySR) data derived from a handheld spectroradiometer were used to assess the water status of three grapevine cultivars in two sub-regions of Douro wine region during two consecutive years. A large set of potential predictors derived from the HySR data were considered for modelling/predicting the predawn leaf water potential (Ψpd) through different statistical and machine learning techniques. Three HySR vegetation indices were selected as final predictors for the computation of the models and the in-season time trend was removed from data by using a time predictor. The vegetation indices selected were the Normalized Reflectance Index for the wavelengths 554 nm and 561 nm (NRI554;561), the water index (WI) for the wavelengths 900 nm and 970 nm, and the D1 index which is associated with the rate of reflectance increase in the wavelengths of 706 nm and 730 nm. These vegetation indices covered the green, red edge and the near infrared domains of the electromagnetic spectrum. A large set of state-of-the-art analysis and statistical and machine-learning modelling techniques were tested. Predictive modelling techniques based on generalized boosted model (GBM), bagged multivariate adaptive regression splines (B-MARS), generalized additive model (GAM), and Bayesian regularized neural networks (BRNN) showed the best performance for predicting Ψpd, with an average determination coefficient (R2) ranging between 0.78 and 0.80 and RMSE varying between 0.11 and 0.12 MPa. When cultivar Touriga Nacional was used for training the models and the cultivars Touriga Franca and Tinta Barroca for testing (independent validation), the models performance was good, particularly for GBM (R2 = 0.85; RMSE = 0.09 MPa). Additionally, the comparison of Ψpd observed and predicted showed an equitable dispersion of data from the various cultivars. The results achieved show a good potential of these predictive models based on vegetation indices to support

  11. Heavy Metals Accumulation Characteristics of Vegetables in Hangzhou City, China

    Directory of Open Access Journals (Sweden)

    GU Yan-qing

    2015-08-01

    Full Text Available A field survey of heavy metal concentrations in soils and vegetables grown in 30 vegetable farmlands of Hangzhou City were carried out. Through calculating the bioconcentration factor(BCFand transfer factor(TFfor different heavy metals(Cu, Zn, Cd, Cr and Pbin 27 kinds of different vegetables which belong to leafy vegetables, root vegetables or eggplant fruit vegetables, assessing their accumulation characteristics of heavy metals according to the differences of the bio-concentration factor, the reasonable proposals were put forward to optimize the planting structure of vegetables in mild and middle-level heavy metal contamination soils. The experimental results were as follows: In soils with mild and middle-level heavy metal contamination, leafy vegetables, such as crown daisy, cabbage, celery and Chinese long cabbage, had relatively low enrichment ability of heavy metals, so as the root and fruit vegetables like white radish, carrot, tomatoes, hence these vegetables could be planted preferentially. In contrast, some kinds of vegetables, including white amaranth, red amaranth, tatsoi, broccoli, gynura, brassica juncea and lettuce of leafy vegetables, lactuca sativa, taro, red radish and cherry radish of rhizome vegetables and sweet pepper of fruit vegetables, had relatively high accumulation ability of heavy metal, which should be avoided to be planted in soils with mild and middle-level heavy metal contamination.

  12. Nigerian women reap benefits from indigenous vegetables | IDRC ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    2016-06-06

    Jun 6, 2016 ... Demand for fresh indigenous vegetables in Nigeria has increased ... greater returns from indigenous vegetables compared to conventional vegetables. ... In Kolli Hills, Tamil Nadu, monocropping of a single, non-edible variety ...

  13. Towards quantifying uncertainty in predictions of Amazon 'dieback'.

    Science.gov (United States)

    Huntingford, Chris; Fisher, Rosie A; Mercado, Lina; Booth, Ben B B; Sitch, Stephen; Harris, Phil P; Cox, Peter M; Jones, Chris D; Betts, Richard A; Malhi, Yadvinder; Harris, Glen R; Collins, Mat; Moorcroft, Paul

    2008-05-27

    Simulations with the Hadley Centre general circulation model (HadCM3), including carbon cycle model and forced by a 'business-as-usual' emissions scenario, predict a rapid loss of Amazonian rainforest from the middle of this century onwards. The robustness of this projection to both uncertainty in physical climate drivers and the formulation of the land surface scheme is investigated. We analyse how the modelled vegetation cover in Amazonia responds to (i) uncertainty in the parameters specified in the atmosphere component of HadCM3 and their associated influence on predicted surface climate. We then enhance the land surface description and (ii) implement a multilayer canopy light interception model and compare with the simple 'big-leaf' approach used in the original simulations. Finally, (iii) we investigate the effect of changing the method of simulating vegetation dynamics from an area-based model (TRIFFID) to a more complex size- and age-structured approximation of an individual-based model (ecosystem demography). We find that the loss of Amazonian rainforest is robust across the climate uncertainty explored by perturbed physics simulations covering a wide range of global climate sensitivity. The introduction of the refined light interception model leads to an increase in simulated gross plant carbon uptake for the present day, but, with altered respiration, the net effect is a decrease in net primary productivity. However, this does not significantly affect the carbon loss from vegetation and soil as a consequence of future simulated depletion in soil moisture; the Amazon forest is still lost. The introduction of the more sophisticated dynamic vegetation model reduces but does not halt the rate of forest dieback. The potential for human-induced climate change to trigger the loss of Amazon rainforest appears robust within the context of the uncertainties explored in this paper. Some further uncertainties should be explored, particularly with respect to the

  14. The impact of geoengineering on vegetation in experiment G1 of the GeoMIP

    Science.gov (United States)

    Glienke, Susanne; Irvine, Peter J.; Lawrence, Mark G.

    2015-10-01

    Solar Radiation Management (SRM) has been proposed as a mean to partly counteract global warming. The Geoengineering Model Intercomparison Project (GeoMIP) has simulated the climate consequences of a number of SRM techniques. Thus far, the effects on vegetation have not yet been thoroughly analyzed. Here the vegetation response to the idealized GeoMIP G1 experiment from eight fully coupled Earth system models (ESMs) is analyzed, in which a reduction of the solar constant counterbalances the radiative effects of quadrupled atmospheric CO2 concentrations (abrupt4 × CO2). For most models and regions, changes in net primary productivity (NPP) are dominated by the increase in CO2, via the CO2 fertilization effect. As SRM will reduce temperatures relative to abrupt4 × CO2, in high latitudes this will offset increases in NPP. In low latitudes, this cooling relative to the abrupt4 × CO2 simulation decreases plant respiration while having little effect on gross primary productivity, thus increasing NPP. In Central America and the Mediterranean, generally dry regions which are expected to experience increased water stress with global warming, NPP is highest in the G1 experiment for all models due to the easing of water limitations from increased water use efficiency at high-CO2 concentrations and the reduced evaporative demand in a geoengineered climate. The largest differences in the vegetation response are between models with and without a nitrogen cycle, with a much smaller CO2 fertilization effect for the former. These results suggest that until key vegetation processes are integrated into ESM predictions, the vegetation response to SRM will remain highly uncertain.

  15. Stem breakage of salt marsh vegetation under wave forcing: A field and model study

    Science.gov (United States)

    Vuik, Vincent; Suh Heo, Hannah Y.; Zhu, Zhenchang; Borsje, Bas W.; Jonkman, Sebastiaan N.

    2018-01-01

    One of the services provided by coastal ecosystems is wave attenuation by vegetation, and subsequent reduction of wave loads on flood defense structures. Therefore, stability of vegetation under wave forcing is an important factor to consider. This paper presents a model which determines the wave load that plant stems can withstand before they break or fold. This occurs when wave-induced bending stresses exceed the flexural strength of stems. Flexural strength was determined by means of three-point-bending tests, which were carried out for two common salt marsh species: Spartina anglica (common cord-grass) and Scirpus maritimus (sea club-rush), at different stages in the seasonal cycle. Plant stability is expressed in terms of a critical orbital velocity, which combines factors that contribute to stability: high flexural strength, large stem diameter, low vegetation height, high flexibility and a low drag coefficient. In order to include stem breakage in the computation of wave attenuation by vegetation, the stem breakage model was implemented in a wave energy balance. A model parameter was calibrated so that the predicted stem breakage corresponded with the wave-induced loss of biomass that occurred in the field. The stability of Spartina is significantly higher than that of Scirpus, because of its higher strength, shorter stems, and greater flexibility. The model is validated by applying wave flume tests of Elymus athericus (sea couch), which produced reasonable results with regards to the threshold of folding and overall stem breakage percentage, despite the high flexibility of this species. Application of the stem breakage model will lead to a more realistic assessment of the role of vegetation for coastal protection.

  16. Comparison of single questions and brief questionnaire with longer validated food frequency questionnaire to assess adequate fruit and vegetable intake.

    Science.gov (United States)

    Cook, Amelia; Roberts, Kia; O'Leary, Fiona; Allman-Farinelli, Margaret Anne

    2015-01-01

    The aim of this study was to determine if a single question (SQ) for fruit and a SQ or five-item questionnaire for vegetable consumption (VFQ) could replace a longer food frequency questionnaire (FFQ) to screen for inadequate versus adequate intakes in populations. Participants (109) completed three test screeners: fruit SQ, vegetable SQ, and a five-item VFQ followed by the reference 74-item FFQ (version 2 of the Dietary Questionnaire for Epidemiological Studies [DQESv2]) including 13 fruit and 25 vegetable items. The five-item VFQ asked about intake of salad vegetables, cooked vegetables, white potatoes, legumes, and vegetable juice. The screeners were compared with the reference (DQESv2 FFQ) for sensitivity, specificity, and positive and negative predictive powers (PPV, NPV) to detect intakes of two or more servings of fruit and three or more servings of vegetables. Relative validity was examined using Bland-Altman statistics. The fruit SQ showed a PPV of 56% and an NPV of 83%. The PPV for the vegetable SQ was 30% and the NPV was 89%. For the five-item VFQ, the PPV was 39% and the NPV was 85%. Bland-Altman plots and linear regression equations showed that although the screener showed good agreement for fruit (unstandardized b1 coefficient = 0.04) for vegetable intake the difference between methods increased at higher intake levels (unstandardized b1 coefficients = -0.3 for the SQ, b1 = -0.6 for five-item VFQ). The fruit SQ and the five-item VFQ are suitable replacements for longer FFQs to detect inadequate intake and assess population mean but not individual intakes. Copyright © 2015 Elsevier Inc. All rights reserved.

  17. Selection of vegetation indices for mapping the sugarcane condition around the oil and gas field of North West Java Basin, Indonesia

    Science.gov (United States)

    Muji Susantoro, Tri; Wikantika, Ketut; Saepuloh, Asep; Handoyo Harsolumakso, Agus

    2018-05-01

    Selection of vegetation indices in plant mapping is needed to provide the best information of plant conditions. The methods used in this research are the standard deviation and the linear regression. This research tried to determine the vegetation indices used for mapping the sugarcane conditions around oil and gas fields. The data used in this study is Landsat 8 OLI/TIRS. The standard deviation analysis on the 23 vegetation indices with 27 samples has resulted in the six highest standard deviations of vegetation indices, termed as GRVI, SR, NLI, SIPI, GEMI and LAI. The standard deviation values are 0.47; 0.43; 0.30; 0.17; 0.16 and 0.13. Regression correlation analysis on the 23 vegetation indices with 280 samples has resulted in the six vegetation indices, termed as NDVI, ENDVI, GDVI, VARI, LAI and SIPI. This was performed based on regression correlation with the lowest value R2 than 0,8. The combined analysis of the standard deviation and the regression correlation has obtained the five vegetation indices, termed as NDVI, ENDVI, GDVI, LAI and SIPI. The results of the analysis of both methods show that a combination of two methods needs to be done to produce a good analysis of sugarcane conditions. It has been clarified through field surveys and showed good results for the prediction of microseepages.

  18. Changes in Remotely Sensed Vegetation Growth Trend in the Heihe Basin of Arid Northwestern China.

    Directory of Open Access Journals (Sweden)

    Wenchao Sun

    Full Text Available The Heihe River Basin (HRB is the second largest inland river basin in China, characterized by high diversity in geomorphology and irrigated agriculture in middle reaches. To improve the knowledge about the relationship between biotic and hydrological processes, this study used Global Inventory Modeling and Mapping Studies Normalized Difference Vegetation Index (NDVI data (1982-2006 to analyze spatiotemporal variations in vegetation growth by using the Mann-Kendall test together with Sen's slope estimator. The results indicate that 10.1% and 1.6% of basin area exhibit statistically significant (p < 0.05 upward and downward trends, and maximum magnitude is 0.066/10a and 0.026/10a, respectively. More specifically, an increasing trend was observed in the Qilian Mountains and Hexi Corridor and a decreasing trend detected in the transitional region between them. Increases in precipitation and temperature may be one possible reason for the changes of vegetation growth in the Qilian Mountains. And decreasing trend in transitional region may be driven by the changes in precipitation. Increases of irrigation contribute to the upward trend of NDVI for cropland in the Hexi Corridor, reflecting that agricultural development becomes more intensive. Our study demonstrates the complexity of the response of vegetation growth in the HRB to climate change and anthropogenic activities and correspondingly adopting mechanistic ecological models capable of describing both factors is favorable for reasonable predictions of future vegetation growth. It is also indicated that improving irrigation water use efficiency is one practical strategy to balance water demand between human and natural ecosystems in the HRB.

  19. Determination of zinc contents in vegetables

    International Nuclear Information System (INIS)

    Salah-ud-Din; Salariya, A.M.; Yasin, M.

    1996-01-01

    Zinc content of three groups of vegetables (roots and tuber, leaves and fruits) collected from local markets was determined and are reported here. The determination was made by Atomic Absorption Spectrophotometer. The results obtained show that the zinc content of different vegetables ranged from 6.26-36.80 ppm, 8.80-70-70 ppm and 7.20-35.10 ppm for roots and tubers, fruits of vegetables respectively on dry weight basis. Generally, the values obtained in majority are not above, the maximum permissible limits. (author)

  20. Radionuclide interception and loss processes in vegetation

    International Nuclear Information System (INIS)

    Proehl, G.; Hoffman, F.O.

    1996-01-01

    Data available since the Chernobyl accident have strengthened the view that the transfer of radionuclides from air to vegetation is a primary area of uncertainty in the estimation of the contamination of food chains leading to human exposure. The processes affecting the overall transfer from air to vegetation involve wet and dry deposition, interception and initial retention, and post-deposition retention of radioactive substances by vegetation. During the growing season, the time-integrated concentrations of radionuclides on vegetation in the first few months after initial deposition are dominated by the direct foliar interception of deposited material. Chapter 2 contains a review of data for modelling the direct foliar interception and initial retention of radioactivity deposited by dry and wet processes, together with data on the factors affecting post-deposition retention of radioactivity on the vegetation. 82 refs, 9 figs, 11 tabs

  1. Using RapidEye and MODIS Data Fusion to Monitor Vegetation Dynamics in Semi-Arid Rangelands in South Africa

    Directory of Open Access Journals (Sweden)

    Andreas Tewes

    2015-05-01

    Full Text Available Image time series of high temporal and spatial resolution capture land surface dynamics of heterogeneous landscapes. We applied the ESTARFM (Enhanced Spatial and Temporal Adaptive Reflectance Fusion Model algorithm to multi-spectral images covering two semi-arid heterogeneous rangeland study sites located in South Africa. MODIS 250 m resolution and RapidEye 5 m resolution images were fused to produce synthetic RapidEye images, from June 2011 to July 2012. We evaluated the performance of the algorithm by comparing predicted surface reflectance values to real RapidEye images. Our results show that ESTARFM predictions are accurate, with a coefficient of determination for the red band 0.80 < R2 < 0.92, and for the near-infrared band 0.83 < R2 < 0.93, a mean relative bias between 6% and 12% for the red band and 4% to 9% in the near-infrared band. Heterogeneous vegetation at sub-MODIS resolution is captured adequately: A comparison of NDVI time series derived from RapidEye and ESTARFM data shows that the characteristic phenological dynamics of different vegetation types are reproduced well. We conclude that the ESTARFM algorithm allows us to produce synthetic remote sensing images at high spatial combined with high temporal resolution and so provides valuable information on vegetation dynamics in semi-arid, heterogeneous rangeland landscapes.

  2. Predicting fire severity using surface fuels and moisture

    Science.gov (United States)

    Pamela G. Sikkink; Robert E. Keane

    2012-01-01

    Fire severity classifications have been used extensively in fire management over the last 30 years to describe specific environmental or ecological impacts of fire on fuels, vegetation, wildlife, and soils in recently burned areas. New fire severity classifications need to be more objective, predictive, and ultimately more useful to fire management and planning. Our...

  3. Mineral composition of non-conventional leafy vegetables.

    Science.gov (United States)

    Barminas, J T; Charles, M; Emmanuel, D

    1998-01-01

    Six non-conventional leafy vegetables consumed largely by the rural populace of Nigeria were analyzed for mineral composition. Mineral contents appeared to be dependent on the type of vegetables. Amaranthus spinosus and Adansonia digitata leaves contained the highest level of iron (38.4 mg/100 g and 30.6 mg/100 g dw, respectively). These values are low compared to those for common Nigerian vegetables but higher than those for other food sources. All the vegetables contained high levels of calcium compared to common vegetables, thus they could be a rich source of this mineral. Microelement content of the leaves varied appreciably. Zinc content was highest in Moringa oleifera, Adansonia digitata and Cassia tora leaves (25.5 mg/100 g, 22.4 mg/100 g and 20.9 mg/100 g dw, respectively) while the manganese content was comparatively higher in Colocasia esculenta. The concentrations of the mineral elements in the vegetables per serving portion are presented and these values indicate that the local vegetables could be valuable and important contributors in the diets of the rural and urban people of Nigeria. The mean daily intake of P, Mg, Ca, Fe, Cu and Zn were lower than their recommended dietary allowances (RDAs). However, the manganese daily intake was found not to differ significantly (p = 0.05) from the RDA value.

  4. Transfer of 137Cs to wild vegetables

    International Nuclear Information System (INIS)

    Ito, Nobuhiko; Natsuhori, Masahiro; Mezawa, Akane; Kawakami, Akira

    1998-01-01

    For the evaluation of internal radiation dose, it is needed to estimate the amount of radionuclide incorporated to human body using a simulation model. 137 Cesium (Cs) is easily transferred associating with food intake as well as potassium and so, Cs is an important nuclide for evaluation of internal radiation. 137 Cs concentrations in wild vegetables are higher than those of cultured vegetables and milk. Therefore, the transfer coefficients of 137 Cs from soil to wild vegetables were estimated in this study. Wild vegetables and soils of their farms were collected in the Hakkoda Mountain range of Aomori Prefecture. The levels of 137 Cs in wild vegetables were 0.42-18.35 (Bq/kg), whereas those in cabbage and spinach were 0.08 and 0.01 (Bq/kg), respectively, indicating that the Cs level is dozens to several hundreds times higher in wild vegetables than cultured ones. And the transfer coefficient was estimated as 0.003-0.94 for the former and 0.001-0.8 for the latter. On the other hand, 1 37 Cs levels of the soils on which wild vegetables grew was 28.0 Bq/kg and it was 3.9 Bq/kg for the farm soil. Furthermore, the effects of water content and pH of the soil on the transfer coefficient were studied. (M.N.)

  5. The relative importance of climate and vegetation properties on patterns of North American breeding bird species richness

    International Nuclear Information System (INIS)

    Goetz, Scott J; Sun, Mindy; Zolkos, Scott; Hansen, Andy; Dubayah, Ralph

    2014-01-01

    Recent advances in remote sensing and ecological modeling warrant a timely and robust investigation of the ecological variables that underlie large-scale patterns of breeding bird species richness, particularly in the context of intensifying land use and climate change. Our objective was to address this need using an array of bioclimatic and remotely sensed data sets representing vegetation properties and structure, and other aspects of the physical environment. We first build models of bird species richness across breeding bird survey (BBS) routes, and then spatially predict richness across the coterminous US at moderately high spatial resolution (1 km). Predictor variables were derived from various sources and maps of species richness were generated for four groups (guilds) of birds with different breeding habitat affiliation (forest, grassland, open woodland, scrub/shrub), as well as all guilds combined. Predictions of forest bird distributions were strong (R 2 = 0.85), followed by grassland (0.76), scrub/shrub (0.63) and open woodland (0.60) species. Vegetation properties were generally the strongest determinants of species richness, whereas bioclimatic and lidar-derived vertical structure metrics were of variable importance and dependent upon the guild type. Environmental variables (climate and the physical environment) were also frequently selected predictors, but canopy structure variables were not as important as expected based on more local to regional scale studies. Relatively sparse sampling of canopy structure metrics from the satellite lidar sensor may have reduced their importance relative to other predictor variables across the study domain. We discuss these results in the context of the ecological drivers of species richness patterns, the spatial scale of bird diversity analyses, and the potential of next generation space-borne lidar systems relevant to vegetation and ecosystem studies. This study strengthens current understanding of bird species–climate–vegetation

  6. Vegetation geographical patterns as a key to the past, with emphasis on the dry vegetation types of South Africa

    Directory of Open Access Journals (Sweden)

    M. J. A. Werger

    1983-11-01

    Full Text Available Southern Africa is characterized by a highly diversified vegetational cover with extremes as contrasting as desert, tropical forest, alpine grassland, or mediterranean type scrub, and many other types in between. This vegetational pattern is strongly correlated to the climatological pattern. It is therefore likely that past changes in climate can still be partly traced in the vegetational pattern, particularly in geographical anomalies, and that study of these patterns provides complementary evidence to palynological research. The following anomalies in the vegetational pattern are briefly discussed: 1. island-wise occurrence of Afro-montane vegetation on mesic, sheltered sites in the southern Sudano- Zambezian Region, in particular in the Highveld grassland/False Karoo transition area; 2. similar westward occurrence of Sudano-Zambezian scrub patches in the Karoo-Namib Region near the Orange/Vaal confluence; 3. scattered occurrence of Sudano-Zambezian woody species in a matrix of Karoo-Namib vegetation in the marginal Karoo-Namib Region; 4. island-wise occurrence of frost-tolerant, dry, karroid dwarf shrub vegetation of predominantly C,-plants on isolated peaks in the winter rainfall area of Namaqualand; 5. peculiar patchy distribution of some succulents in wide areas of climatically rather homogeneous, succulent dwarf shrub vegetation of predominantly CAM-plants in the escarpment area of Namaqualand. a pattern reminiscent of that in many Cape fynbos species. Interpretation of these patterns logically leads to the conclusion that these result from a previously wetter, a previously cooler, or a previously wetter and cooler climate, respectively, over the parts of southern Africa under discussion. This conclusion is compared with published palynological views.

  7. Australian consumer awareness of health benefits associated with vegetable consumption.

    Science.gov (United States)

    Rekhy, Reetica; Khan, Aila; Eason, Jocelyn; Mactavish-West, Hazel; Lister, Carolyn; Mcconchie, Robyn

    2017-04-01

    The present study investigated the perceived health benefits of specific vegetable consumption to guide the use of nutrition and health claims on vegetable marketing collateral. Free elicitation and consumer ranking data were collected through an online survey of 1000 adults from across Australia and analysed for the perceived importance of vegetables in the daily diet, number of serves consumed per day, knowledge about health-related benefits of specific vegetables and perceived health benefits of vegetable consumption. The importance of vegetables in the diet and daily vegetable consumption was higher in people from an English-speaking background, females, people aged 45 years and over and people living in non-metropolitan areas. Digestion was selected as the major health benefit from consumption of specific vegetables. However, understanding of the health benefits of specific vegetable consumption was relatively low among consumers. Half of the respondents were not sure of the health benefits associated with specific vegetables, except for carrots and spinach. Some respondents volunteered nutrient content or other information. There was no clear indication that consumers understand the specific health benefits conferred by consumption of vegetables. Nutrient and health benefit labelling therefore has the capacity to enhance knowledge of vegetable consumers. It is recommended that health benefit labelling be tailored to promote greater consumption of vegetables in those demographic groups where vegetable consumption was lower. The present study assists the Australian vegetable industry in helping consumers make more informed consumption choices. © 2016 Dietitians Association of Australia.

  8. A Modeling Approach for Evaluating the Coupled Riparian Vegetation-Geomorphic Response to Altered Flow Regimes

    Science.gov (United States)

    Manners, R.; Wilcox, A. C.; Merritt, D. M.

    2016-12-01

    The ecogeomorphic response of riparian ecosystems to a change in hydrologic properties is difficult to predict because of the interactions and feedbacks among plants, water, and sediment. Most riparian models of community dynamics assume a static channel, yet geomorphic processes strongly control the establishment and survival of riparian vegetation. Using a combination of approaches that includes empirical relationships and hydrodynamic models, we model the coupled vegetation-topographic response of three cross-sections on the Yampa and Green Rivers in Dinosaur National Monument, to a shift in the flow regime. The locations represent the variable geomorphology and vegetation composition of these canyon-bound rivers. We account for the inundation and hydraulic properties of vegetation plots surveyed over three years within International River Interface Cooperative (iRIC) Fastmech, equipped with a vegetation module that accounts for flexible stems and plant reconfiguration. The presence of functional groupings of plants, or those plants that respond similarly to environmental factors such as water availability and disturbance are determined from flow response curves developed for the Yampa River. Using field measurements of vegetation morphology, distance from the channel centerline, and dominant particle size and modeled inundation properties we develop an empirical relationship between these variables and topographic change. We evaluate vegetation and channel form changes over decadal timescales, allowing for the integration of processes over time. From our analyses, we identify thresholds in the flow regime that alter the distribution of plants and reduce geomorphic complexity, predominately through side-channel and backwater infilling. Simplification of some processes (e.g., empirically-derived sedimentation) and detailed treatment of others (e.g., plant-flow interactions) allows us to model the coupled dynamics of riparian ecosystems and evaluate the impact of

  9. [Storages and distributed patterns of soil organic carbon and total nitrogen during the succession of artificial sand-binding vegetation in arid desert ecosystem].

    Science.gov (United States)

    Jia, Xiao-Hong; Li, Xin-Rong; Zhou, Yu-Yan; Li, Yuan-Shou

    2012-03-01

    Soil carbon pool acts as the largest one of carbon pools in the terrestrial ecosystem. The storages and distributed patterns of soil organic carbon (SOC) and total nitrogen (TN) evaluated accurately are helpful to predict the feedback between the terrestrial ecosystem and climate changes. Based on the data about bulk density, content of SOC and TN at 0-100 cm soil profile, the density of SOC and TN at the temporal (chronosequence of artificial vegetation) and spatial (vertical) distributed patterns have been estimated. The results indicated that storages of SOC and TN at 0-100 cm depth increased with the chronosequence of artificial vegetation. The storages of SOC and TN showed the same tendency with the succession time of artificial vegetation. Storages of SOC and TN significantly increased at the early stage of banding sand by artificially vegetation ( 25 a). The variation of storages mainly occurred in the 0-20 cm depth. The storages decreased with the soil vertical depth. At the early stage of banding sand, increase in storage included every depth (0-100 cm). Whereas, at the later stage, increase in storage at 0-20 cm depth was main, and increase in the 20-100 cm was inconspicuous. The accumulation of storage at the shallow soil depth was more notability with the succession of artificial vegetation. The distributed pattern of storage in SOC and TN has been confirmed in arid desert regions below 200 mm annual precipitation. This was beneficial to understand the carbon cycle and to predict the feedback relationship between desert ecosystem and climate changes.

  10. Identification of Distribution Channels to Create Sustainable Vegetable Prices

    Directory of Open Access Journals (Sweden)

    Aflit Nuryulia Praswati

    2017-12-01

    Full Text Available The price of vegetables has a role as a contributor to the rate of inflation. Currently the number of vegetable production in Boyolali region can no longer meet the needs of local communities. The limited amount of vegetable production and the inhibition of the vegetable distribution channel creates a scarcity of vegetables that result in price increases. This study aims to identify the distribution channel and the formation of vegetable prices derived from Boyolali area. The method used in this research is quantitative and qualitative. Respondents from this study consisted of farmers, wholesalers, small trader and end consumers. The type of distribution channel prevailing in Boyolali area are traditional and modern distribution channels. Intermediate distribution channels play a greater role in determining vegetable prices. If farmers want to improve their economic condition, it needs innovation and creativity in the process of planting, harvesting, packaging and marketing vegetable products.

  11. Effects of repeated exposure to either vegetables or fruits on infant's vegetable and fruit acceptance at the beginning of weaning

    NARCIS (Netherlands)

    Barends, C.; Vries, de J.; Mojet, J.; Graaf, de C.

    2013-01-01

    This study investigated the effects of repeated exposure to either vegetables or fruits on an infant's vegetable and fruit acceptance during the first 18 days of weaning. We hypothesized that repeated exposure to a type of vegetable or fruit, would increase its intake. Furthermore, we expected that

  12. A morphometric analysis of vegetation patterns in dryland ecosystems

    Science.gov (United States)

    Mander, Luke; Dekker, Stefan C.; Li, Mao; Mio, Washington; Punyasena, Surangi W.; Lenton, Timothy M.

    2017-02-01

    Vegetation in dryland ecosystems often forms remarkable spatial patterns. These range from regular bands of vegetation alternating with bare ground, to vegetated spots and labyrinths, to regular gaps of bare ground within an otherwise continuous expanse of vegetation. It has been suggested that spotted vegetation patterns could indicate that collapse into a bare ground state is imminent, and the morphology of spatial vegetation patterns, therefore, represents a potentially valuable source of information on the proximity of regime shifts in dryland ecosystems. In this paper, we have developed quantitative methods to characterize the morphology of spatial patterns in dryland vegetation. Our approach is based on algorithmic techniques that have been used to classify pollen grains on the basis of textural patterning, and involves constructing feature vectors to quantify the shapes formed by vegetation patterns. We have analysed images of patterned vegetation produced by a computational model and a small set of satellite images from South Kordofan (South Sudan), which illustrates that our methods are applicable to both simulated and real-world data. Our approach provides a means of quantifying patterns that are frequently described using qualitative terminology, and could be used to classify vegetation patterns in large-scale satellite surveys of dryland ecosystems.

  13. Parasitic Contamination of Raw Vegetables in Zanjan Markets, Iran

    Directory of Open Access Journals (Sweden)

    Negin Torabi

    2016-09-01

    Full Text Available Background: Complex surface of vegetables facilitate attachment and transmission of several pathogens. No previous study has been conducted in survey of parasitic contamination of vegetables in Zanjan. This study aimed to detect the parasitic contamination in common raw vegetables in Zanjan markets. Methods: A total of 352 raw vegetable samples, including leek, parsley, basil, mint, radish, cress and dill were collected from grocery stores using cluster sampling in different regions of the city during 2014. The edible parts of vegetables were separated and immersed in normal saline solution. Floating vegetables were removed and the solution was allowed to sediment at room temperature for 24 hours. The pellet was examined following sedimentation and floatation methods. Results:Various Organisms were detected in 54% (190 of the 352 samples, but only 2.8% of samples had pathogenic parasites including; Trichostrongylus eggs (3, Hookworm eggs (2, Eimeria oocysts (2, Sarcocystis oocyst (1, Strongyloides larvae (1, and Fasciola eggs (1. The contamination rate of vegetables was highest (90.4% in the fall (p˂0.05. Conclusion: Vegetable contamination with parasitic organisms in this area was low, maybe due to irrigation of vegetables with sources other than sewage water, but it is still necessary to improve sanitary conditions of vegetables.

  14. Farming of Vegetables in Space-Limited Environments

    Science.gov (United States)

    He, Jie

    2015-10-01

    Vegetables that contain most of the essential components of human nutrition are perishable and cannot be stocked. To secure vegetable supply in space limited cities such as Singapore, there are different farming methods to produce vegetables. These include low-cost urban community gardening and innovative rooftop and vertical farms integrated with various technologies such as hydroponics, aquaponics and aeroponics. However, for large-scale vegetable production in space-limited Singapore, we need to develop farming systems that not only increase productivity many-fold per unit of land but also produce all types of vegetable, all year-round for today and the future. This could be resolved through integrated vertical aeroponic farming system. Manipulation of root-zone (RZ) environments such as cooling the RZ, modifying mineral nutrients and introducing elevated RZ CO2 using aeroponics can further boost crop productivity beyond what can be achieved from more efficient use of land area. We could also adopt energy saving light emitting diodes (LEDs) for vertical aeroponic farming system to promote uniform growth and to improve the utilisation of limited space via shortening the growth cycle, thus improving vegetable production in a cost-effective manner.

  15. Estimation of tritiated water concentration in vegetables and milk around argentine nuclear power plants obtained from discharge sites and meteorological data

    International Nuclear Information System (INIS)

    Amado, Valeria A.; Lopez, Fabio O.; Sartori, Francisco M.

    2009-01-01

    The present work shows a methodology to assess the concentration of tritiated water in vegetation and milk. Calculations are depending on the release rate and the meteorological data of the nuclear installations. Methodology is based on existing models that had been modified taking in account available data and specific conditions in the vicinity of the nuclear power plants in Argentina. The predictions of the models are compared with the measurements of tritium concentrations in sampling of vegetables and milk occurred monthly during 2007, near of the plants. (author) [es

  16. Curtimento de peles de peixe com taninos vegetal e sintético = Tanning fish skins using vegetable and synthetic tannins

    Directory of Open Access Journals (Sweden)

    Ariana Martins Vieira

    2008-07-01

    Full Text Available No presente experimento objetivou-se avaliar a resistência das peles de peixes submetidas ao curtimento com taninos vegetal e sintético. As peles foram distribuídas em um delineamento inteiramente casualizado, com seis tratamentos aplicados na etapa decurtimento (T1 = 10% tanino vegetal; T2=10% tanino sintético; T3 = 5% tanino vegetal + 5% sintético; T4 = 12% tanino vegetal; T5 = 12% tanino sintético; T6 = 6% tanino vegetal + 6% sintético e dez repetições por tratamento, sendo o couro a unidade experimental.Para os testes de resistência à tração, alongamento e rasgamento, foi utilizado o dinamômetro EMIC. O curtimento com tanino vegetal, sintético e/ou sua combinação, assim como os níveis utilizados dentro de cada técnica de curtimento, interferiu no teste de tração, no entanto não influenciou No teste de alongamento e rasgamento progressivo. Portanto, a técnica de curtimento interfere na resistência dos couros de peixes. As peles de tilápia, quando curtidas e recurtidas apenas com tanino sintético, independentemente da concentração (10 ou 12%, apresentaram pior resistência à tração. Quando comparados com os que receberam 10% de taninos (vegetal e a combinação dos taninos, esses couros não apresentaram diferença na resistência.The objective of the present experiment was to evaluate the resistance of fish skins submitted to tanning using vegetable and synthetic tannins. Skins were distributed in a completelyrandomized design, with six treatments applied in the tanning stage (T1 = 10% vegetable tannin; T2 = 10% synthetic tannin; T3 = 5% vegetable tannin + 5% synthetic tannin; T4 = 12% vegetable tannin; T5 = 12% synthetic tannin; T6 = 6% vegetable tannin + 6% synthetic. Ten repetitions per treatment were conducted, and the leather was theexperimental unit. For the tests of tensile strength, lengthening and progressive tearing resistance, an EMIC dynamometer was used. Tanning with vegetable tannin, synthetic

  17. Understanding the interaction between wild fire and vegetation distribution within the NCAR CESM framework

    Science.gov (United States)

    Seo, H.; Kim, Y.; Kim, H. J.

    2017-12-01

    Every year wild fire brings about 400Mha of land burned therefore 2Pg of carbon emissions from the surface occur. In this way fire not only affects the carbon circulation but also has an effect on the terrestrial ecosystems. This study aims to understand role of fire on the geographic vegetation distribution and the terrestrial carbon balances within the NCAR CESM framework, specifically with the CLM-BGC and CLM-BGC-DV. Global climate data from Climate Research Unit (CRU)-National Centers for Environmental Prediction (NCEP) data ranging from 1901 to 2010 are used to drive the land models. First, by comparing fire-on and fire-off simulations with the CLM-BGC-DV, the fire impacts in dynamic vegetation are quantified by the fractional land areas of the different plant functional types. In addition, we examine how changes in vegetation distribution affect the total sum of the burned areas and the carbon balances. This study would provide the limits of and suggestions for the fire and dynamic vegetation modules of the CLM-BGC. AcknowledgementsThis work was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT & Future Planning (2015R1C1A2A01054800) and by the Korea Meteorological Administration R&D Program under Grant KMIPA 2015-6180. This work was also supported by the Yonsei University Future-leading Research Initiative of 2015(2016-22-0061).

  18. Nutritional potentials of some tropical vegetable leaf meals ...

    African Journals Online (AJOL)

    Three tropical vegetable species (Talium triangulare, Amaranthus cruentus and Telfairia occidentalis) were selected based on their availability and agronomic desirability. The freshly harvested vegetable leaves were subjected to 2 processing techniques (shredding and sundrying) before milling into the vegetable leaf ...

  19. Terrestrial transect study on driving mechanism of vegetation changes

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    In terms of Chinese climate-vegetation model based on the classification of plant functional types, to- gether with climatic data from 1951 to 1980 and two future climatic scenarios (SRES-A2 and SRES-B2) in China from the highest and the lowest emission scenarios of greenhouse gases, the distribution patterns of vegetation types and their changes along the Northeast China Transect (NECT) and the North-South Transect of Eastern China (NSTEC) were simulated in order to understand the driving mechanisms of vegetation changes under climatic change. The results indicated that the vegetation distribution patterns would change significantly under future climate, and the major factors driving the vegetation changes were water and heat. However, the responses of various vegetation types to the changes in water and heat factors were obviously different. The vegetation changes were more sensi- tive to heat factors than to water factors. Thus, in the future climate warming will significantly affect vegetation distribution patterns.

  20. Vegetated Ditches for the Mitigation of Pesticides Runoff in the Po Valley.

    Directory of Open Access Journals (Sweden)

    Stefan Otto

    Full Text Available In intensive agricultural systems runoff is one of the major potential diffuse pollution pathways for pesticides and poses a risk to surface water. Ditches are common in the Po Valley and can potentially provide runoff mitigation for the protection of watercourses. The effectiveness depends on ditch characteristics, so there is an urgent need for site-specific field trials. The use of a fugacity model (multimedia model can allows recognition of the mitigation main processes. A field experiment was conducted in order to evaluate the mitigation capacity of a typical vegetated ditch, and results were compared with predictions by a fugacity model. To evaluate herbicide mitigation after an extreme runoff, the ditch was flooded with water containing mesotrione, S-metolachlor and terbuthylazine. Two other subsequent floods with uncontaminated water were applied 27 and 82 days later to evaluate herbicides release. Results show that the ditch can immediately reduce runoff concentration of herbicides by at least 50% even in extreme flooding conditions. The half-distances were about 250 m. As a general rule, a runoff of 1 mm from 5 ha is mitigated by 99% in 100 m of vegetated ditch. Herbicides retention in the vegetated ditch was reversible, and the second flood mobilized 0.03-0.2% of the previous one, with a concentration below the drinking water limit of 0.1 μg L(-1. No herbicide was detected in the third flood, because the residual amount in the ditch was too low. Fugacity model results show that specific physical-chemical parameters may be used and a specific soil-sediment-plant compartment included for modelling herbicides behaviour in a vegetated ditch, and confirm that accumulation is low or negligible for herbicides with a half-life of 40 days or less. Shallow vegetated ditches can thus be included in a general agri-environment scheme for the mitigation of pesticides runoff together with wetlands and linear buffer strips. These structures are

  1. Vegetated Ditches for the Mitigation of Pesticides Runoff in the Po Valley.

    Science.gov (United States)

    Otto, Stefan; Pappalardo, Salvatore E; Cardinali, Alessandra; Masin, Roberta; Zanin, Giuseppe; Borin, Maurizio

    2016-01-01

    In intensive agricultural systems runoff is one of the major potential diffuse pollution pathways for pesticides and poses a risk to surface water. Ditches are common in the Po Valley and can potentially provide runoff mitigation for the protection of watercourses. The effectiveness depends on ditch characteristics, so there is an urgent need for site-specific field trials. The use of a fugacity model (multimedia model) can allows recognition of the mitigation main processes. A field experiment was conducted in order to evaluate the mitigation capacity of a typical vegetated ditch, and results were compared with predictions by a fugacity model. To evaluate herbicide mitigation after an extreme runoff, the ditch was flooded with water containing mesotrione, S-metolachlor and terbuthylazine. Two other subsequent floods with uncontaminated water were applied 27 and 82 days later to evaluate herbicides release. Results show that the ditch can immediately reduce runoff concentration of herbicides by at least 50% even in extreme flooding conditions. The half-distances were about 250 m. As a general rule, a runoff of 1 mm from 5 ha is mitigated by 99% in 100 m of vegetated ditch. Herbicides retention in the vegetated ditch was reversible, and the second flood mobilized 0.03-0.2% of the previous one, with a concentration below the drinking water limit of 0.1 μg L(-1). No herbicide was detected in the third flood, because the residual amount in the ditch was too low. Fugacity model results show that specific physical-chemical parameters may be used and a specific soil-sediment-plant compartment included for modelling herbicides behaviour in a vegetated ditch, and confirm that accumulation is low or negligible for herbicides with a half-life of 40 days or less. Shallow vegetated ditches can thus be included in a general agri-environment scheme for the mitigation of pesticides runoff together with wetlands and linear buffer strips. These structures are present in the

  2. Modelling post-fire vegetation recovery in Portugal

    Science.gov (United States)

    Bastos, A.; Gouveia, C. M.; Dacamara, C. C.; Trigo, R. M.

    2011-12-01

    Wildfires in Mediterranean Europe have been increasing in number and extension over the last decades and constitute one of the major disturbances of these ecosystems. Portugal is the country with more burnt area in the last decade and the years of 2003 and 2005 were particularly devastating, the total burned areas of 425 000 and 338 000 ha being several times higher than the corresponding average. The year of 2005 further coincided with one of the most severe droughts since early 20th century. Due to different responses of vegetation to diverse fire regimes and to the complexity of landscape structures, fires have complex effects on vegetation recovery. Remote sensing has revealed to be a powerful tool in studying vegetation dynamics and in monitoring post-fire vegetation recovery, which is crucial to land-management and to prevent erosion. The main goals of the present work are (i) to assess the accuracy of a vegetation recovery model previously developed by the authors; (ii) to assess the model's performance, namely its sensitivity to initial conditions, to the temporal length of the input dataset and to missing data; (iii) to study vegetation recovery over two selected areas that were affected by two large wildfire events in the fire seasons of 2003 and 2005, respectively. The study relies on monthly values of NDVI over 11 years (1998-2009), at 1 km × 1 km spatial resolution, as obtained by the VEGETATION instrument. According to results from sensitivity analysis, the model is robust and able to provide good estimations of recovery times of vegetation when the regeneration process is regular, even when missing data is present. In respect to the two selected burnt scars, results indicate that fire damage is a determinant factor of regeneration, as less damaged vegetation recovers more rapidly, which is mainly justified by the high coverage of Pinus pinaster over the area, and by the fact that coniferous forests tend to recover slower than transitional woodland

  3. Comparing the utility of the theory of planned behavior between boys and girls for predicting snack food consumption: implications for practice.

    Science.gov (United States)

    Branscum, Paul; Sharma, Manoj

    2014-01-01

    The purpose of this study was to use the theory of planned behavior to explain two types of snack food consumption among boys and girls (girls n = 98; boys n = 69), which may have implications for future theory-based health promotion interventions. Between genders, there was a significant difference for calorie-dense/nutrient-poor snacks (p = .002), but no difference for fruit and vegetable snacks. Using stepwise multiple regression, attitudes, perceived behavioral control, and subjective norms accounted for a large amount of the variance of intentions (girls = 43.3%; boys = 55.9%); however, for girls, subjective norms accounted for the most variance, whereas for boys, attitudes accounted for the most variance. Calories from calorie-dense/nutrient-poor snacks and fruit and vegetable snacks were also predicted by intentions. For boys, intentions predicted 6.4% of the variance for fruit and vegetable snacks (p = .03) but was not significant for calorie-dense/nutrient-poor snacks, whereas for girls, intentions predicted 6.0% of the variance for fruit and vegetable snacks (p = .007), and 7.2% of the variance for calorie-dense/nutrient-poor snacks (p = .004). Results suggest that the theory of planned behavior is a useful framework for predicting snack foods among children; however, there are important differences between genders that should be considered in future health promotion interventions.

  4. Projected future vegetation changes for the northwest United States and southwest Canada at a fine spatial resolution using a dynamic global vegetation model.

    Science.gov (United States)

    Shafer, Sarah; Bartlein, Patrick J.; Gray, Elizabeth M.; Pelltier, Richard T.

    2015-01-01

    Future climate change may significantly alter the distributions of many plant taxa. The effects of climate change may be particularly large in mountainous regions where climate can vary significantly with elevation. Understanding potential future vegetation changes in these regions requires methods that can resolve vegetation responses to climate change at fine spatial resolutions. We used LPJ, a dynamic global vegetation model, to assess potential future vegetation changes for a large topographically complex area of the northwest United States and southwest Canada (38.0–58.0°N latitude by 136.6–103.0°W longitude). LPJ is a process-based vegetation model that mechanistically simulates the effect of changing climate and atmospheric CO2 concentrations on vegetation. It was developed and has been mostly applied at spatial resolutions of 10-minutes or coarser. In this study, we used LPJ at a 30-second (~1-km) spatial resolution to simulate potential vegetation changes for 2070–2099. LPJ was run using downscaled future climate simulations from five coupled atmosphere-ocean general circulation models (CCSM3, CGCM3.1(T47), GISS-ER, MIROC3.2(medres), UKMO-HadCM3) produced using the A2 greenhouse gases emissions scenario. Under projected future climate and atmospheric CO2 concentrations, the simulated vegetation changes result in the contraction of alpine, shrub-steppe, and xeric shrub vegetation across the study area and the expansion of woodland and forest vegetation. Large areas of maritime cool forest and cold forest are simulated to persist under projected future conditions. The fine spatial-scale vegetation simulations resolve patterns of vegetation change that are not visible at coarser resolutions and these fine-scale patterns are particularly important for understanding potential future vegetation changes in topographically complex areas.

  5. Suppression of vegetation in LANDSAT ETM+ remote sensing images

    Science.gov (United States)

    Yu, Le; Porwal, Alok; Holden, Eun-Jung; Dentith, Michael

    2010-05-01

    Vegetation cover is an impediment to the interpretation of multispectral remote sensing images for geological applications, especially in densely vegetated terrains. In order to enhance the underlying geological information in such terrains, it is desirable to suppress the reflectance component of vegetation. One form of spectral unmixing that has been successfully used for vegetation reflectance suppression in multispectral images is called "forced invariance". It is based on segregating components of the reflectance spectrum that are invariant with respect to a specific spectral index such as the NDVI. The forced invariance method uses algorithms such as software defoliation. However, the outputs of software defoliation are single channel data, which are not amenable to geological interpretations. Crippen and Blom (2001) proposed a new forced invariance algorithm that utilizes band statistics, rather than band ratios. The authors demonstrated the effectiveness of their algorithms on a LANDSAT TM scene from Nevada, USA, especially in open canopy areas in mixed and semi-arid terrains. In this presentation, we report the results of our experimentation with this algorithm on a densely to sparsely vegetated Landsat ETM+ scene. We selected a scene (Path 119, Row 39) acquired on 18th July, 2004. Two study areas located around the city of Hangzhou, eastern China were tested. One of them covers uninhabited hilly terrain characterized by low rugged topography, parts of the hills are densely vegetated; another one covers both inhabited urban areas and uninhabited hilly terrain, which is densely vegetated. Crippen and Blom's algorithm is implemented in the following sequential steps: (1) dark pixel correction; (2) vegetation index calculation; (3) estimation of statistical relationship between vegetation index and digital number (DN) values for each band; (4) calculation of a smooth best-fit curve for the above relationships; and finally, (5) selection of a target average DN

  6. Regional vegetation dynamics and its response to climate change—a case study in the Tao River Basin in Northwestern China

    International Nuclear Information System (INIS)

    Li, Changbin; Yang, Linshan; Wang, Shuaibing; Yang, Wenjin; Zhu, Gaofeng; Qi, Jiaguo; Zou, Songbing; Zhang, Feng

    2014-01-01

    The 30-year normalized-difference vegetation index (NDVI) time series from AVHRR/MODIS satellite sensors was used in this study to assess the regional vegetation dynamic changes in the Tao River Basin, which cuts across the Eastern Tibetan Plateau (ETP) and the Southwestern Loess Plateau (SLP). First, principal component and correlation analyses were carried out to determine the key climatic variables driving ecological change in the region. Then, regression models were tested to correlate NDVI with the selected climatic variables to determine their predictive power. Finally, Sen’s slope method was used to determine how terrestrial vegetation has responded to regional climate change in the region. The results indicated an average winter season NDVI value of 0.14 in the ETP but only 0.04 in the SLP. Primarily driven by increasing temperature, vegetation growth has generally been enhanced since 1981; spring NDVI increased by 0.03 every 10 years in the ETP and 0.02 in the SLP. Further, results from trend analyses suggest vegetation growth in the ETP shifted to earlier-start and earlier-end dates, however in the SLP, the growing season has been extended with an earlier-start and later-end date. The precipitation threshold for vegetation germination, measured by the cumulative spring rainfall, was found to be 44 mm for both the ETP and SLP. (paper)

  7. Can radiocaesium be used as a tracer for vegetal nutrients?

    International Nuclear Information System (INIS)

    Anjos, R. M.; Mosquera, B.; Carvalho, C.; Sanches, N.; Bastos, J.; Macario, K.; Vezzone, M.; Gomes, P.R.S.

    2007-01-01

    In recent years, there has been a growing interest in the evaluation of nutrient fluxes and radioactive contaminants in forest and agricultural ecosystems. Several studies on forest ecosystems have been carried out, mostly in Europe, after the Chernobyl accident. These studies have been performed mainly in the development of models for predicting the radiocaesium behavior in the soil and plant compartments of forest systems. However, research on the use of radiocaesium as a tracer for vegetal nutrients has shown that, despite the fact that caesium is a weakly hydrated alkaline metal and has chemical similarities to potassium and ammonium, this is still a complex problem requiring, then, more experimental results. Additionally, very little is known about the mechanisms involved in the radionuclide uptake and retention by tropical plants. In order to contribute to the understanding of the relative behavior of caesium, potassium and ammonium and to investigate whether radiocaesium can be used as a tracer for vegetal nutrients, the Laboratory of Radioecology (LARA) of the Federal Fluminense University has been performing analysis of 137 Cs, 40 K and NH 4 concentrations in several vegetal compartments of agricultural tropical plants, such as guava (Psidium guajava), mango (Mangifera indica), avocado (Persea americana), pomegranate (Punica granatum), papaya (Carica Papaya), banana (Musa paradisiaca), manioc (Manihot Esculenta), and chili pepper (Capsicum fructescens) trees. Measurements of 137 Cs, 40 K and NH 4 concentrations show that these elements can be very mobile within a plant, exhibiting the highest values of concentration in the growing parts of the trees: fruits, leaves, twigs, barks and the outer growth layers. On the other hand, our results indicate that for wood trees (such as guava, mango, avocado, pomegranate and chili pepper trees) do both caesium and the vegetal nutrients have simultaneously higher concentrations in the youngest rather than in the oldest

  8. Vegetative buffer strips for reducing herbicide transport in runoff: effects of buffer width, vegetation, and season

    Science.gov (United States)

    The effect of vegetative buffer strip (VBS) width, vegetation, and season of the year on herbicide transport in runoff has not been well documented for runoff prone soils. A multi-year replicated plot-scale study was conducted on an eroded claypan soil with the following objectives: 1) assess the ef...

  9. Temperature and snowfall trigger alpine vegetation green-up on the world's roof.

    Science.gov (United States)

    Chen, Xiaoqiu; An, Shuai; Inouye, David W; Schwartz, Mark D

    2015-10-01

    Rapid temperature increase and its impacts on alpine ecosystems in the Qinghai-Tibetan Plateau, the world's highest and largest plateau, are a matter of global concern. Satellite observations have revealed distinctly different trend changes and contradicting temperature responses of vegetation green-up dates, leading to broad debate about the Plateau's spring phenology and its climatic attribution. Large uncertainties in remote-sensing estimates of phenology significantly limit efforts to predict the impacts of climate change on vegetation growth and carbon balance in the Qinghai-Tibetan Plateau, which are further exacerbated by a lack of detailed ground observation calibration. Here, we revealed the spatiotemporal variations and climate drivers of ground-based herbaceous plant green-up dates using 72 green-up datasets for 22 herbaceous plant species at 23 phenological stations, and corresponding daily mean air temperature and daily precipitation data from 19 climate stations across eastern and southern parts of the Qinghai-Tibetan Plateau from 1981 to 2011. Results show that neither the continuously advancing trend from 1982 to 2011, nor a turning point in the mid to late 1990s as reported by remote-sensing studies can be verified by most of the green-up time series, and no robust evidence for a warmer winter-induced later green-up dates can be detected. Thus, chilling requirements may not be an important driver influencing green-up responses to spring warming. Moreover, temperature-only control of green-up dates appears mainly at stations with relatively scarce preseason snowfall and lower elevation, while coupled temperature and precipitation controls of green-up dates occur mostly at stations with relatively abundant preseason snowfall and higher elevation. The diversified interactions between snowfall and temperature during late winter to early spring likely determine the spatiotemporal variations of green-up dates. Therefore, prediction of vegetation growth

  10. The technology of fish-vegetable feed production

    Directory of Open Access Journals (Sweden)

    Mukatova M. D.

    2016-09-01

    Full Text Available Perspective direction of the Volga-Caspian basin fisheries is increasing the productivity of aquaculture production which requires the availability of sufficient quantities of feed. The cutting waste of carp and crucian carp, crayfish processing (cephalothorax, wheat bran, soy isolate, freshwater plants – pondweed perfoliate, fish-vegetable ration, produced feeding staffs have been investigated. In researching samples of manufactured pelleted feeds the standard methods adopted in the animal feed industry have been used. The number of nitrogen-free extractives and energy value has been determined by calculation. The composition of fish-vegetable ration has been worked out. Some manufacturing inspection of fish-vegetable feed technology using proofing process has been carried out. The possibility of manufacturing on the basis of crushed fish waste of the company LLC "VES" and dry ingredients of fish-vegetable feed has been determined; the output of feed at water content of not more than 10 % is 43 % of feed mix based on the mass of directed waste equal to 84 %. The pilot batch of dry fish-vegetable feed has been investigated to establish quality indicators. It has been determined that fish-vegetable feed meets the requirements of GOST 10385–2014 "Combined feeding staffs for fishes. General specifications" as for main quality indicators and refers to economic grower for catfish and carp fish weighing more than 50 g. This reveals good palatability of the experimental batch of floating feed by carp fish species and African catfish. Thus, fish-vegetable feed manufacturing technology can be implemented in the production for processing secondary raw materials: waste from butchering fish by grinding, cooking, mixing with selected vegetable fillings which is waste of flour or grain processing industries and freshwater plants mowed annually during the reclamation works on the Volga delta.

  11. Predictive occurrence models for coastal wetland plant communities: Delineating hydrologic response surfaces with multinomial logistic regression

    Science.gov (United States)

    Snedden, Gregg A.; Steyer, Gregory D.

    2013-02-01

    Understanding plant community zonation along estuarine stress gradients is critical for effective conservation and restoration of coastal wetland ecosystems. We related the presence of plant community types to estuarine hydrology at 173 sites across coastal Louisiana. Percent relative cover by species was assessed at each site near the end of the growing season in 2008, and hourly water level and salinity were recorded at each site Oct 2007-Sep 2008. Nine plant community types were delineated with k-means clustering, and indicator species were identified for each of the community types with indicator species analysis. An inverse relation between salinity and species diversity was observed. Canonical correspondence analysis (CCA) effectively segregated the sites across ordination space by community type, and indicated that salinity and tidal amplitude were both important drivers of vegetation composition. Multinomial logistic regression (MLR) and Akaike's Information Criterion (AIC) were used to predict the probability of occurrence of the nine vegetation communities as a function of salinity and tidal amplitude, and probability surfaces obtained from the MLR model corroborated the CCA results. The weighted kappa statistic, calculated from the confusion matrix of predicted versus actual community types, was 0.7 and indicated good agreement between observed community types and model predictions. Our results suggest that models based on a few key hydrologic variables can be valuable tools for predicting vegetation community development when restoring and managing coastal wetlands.

  12. Effect of Organic Dust Exposure on Pulmonary Functions in Workers of Vegetable Market with Special Reference to its Microbial Content.

    Science.gov (United States)

    Goel, Arun; Omar, Balram Ji; Kathrotia, Rajesh; Patil, Prashant M; Mittal, Sunita

    2018-01-01

    Wholesale vegetable market is a rich source of generation of organic dust as loads of fruits and vegetables are loaded and unloaded here daily. Thus, regular workers are exposed to this organic dust for a considerable period of time depending on their work schedule. This study was planned to determine the microbial status of organic dust and to explore its association with pulmonary functions in the workers of wholesale vegetable market in Rishikesh. It was a cross-sectional exploratory/observational study. Thirty-five apparently healthy adult males were selected from vegetable market having no history of any chronic illness. Smokers and alcoholic were excluded from the study. The same number of age- and sex-matched controls with the same exclusion criteria were recruited from workers not working in the vegetable market and also not exposed to any other kinds of organic dust. Microbial culture of air in the vegetable market was done. It was compared with the microbial status of air in the working place of controls. Pulmonary functions of all the workers were performed with the help of digital spirometer (Helios 401). Bacterial and fungal concentration was found to be significantly higher in the air of vegetable market as compared to air in the workplace of controls (such as coagulase-negative staphylococci >25 colony-forming unit (CFU) at incubation temperature vs. 10-12 CFU at incubation temperature, significant growth of Mucor , Aspergillus niger , and Candida nonalbicans in vegetable market as compared to workplace of controls). Pulmonary function parameters (percentage forced expiratory volume in 1 st s (FEV 1 ), percentage predicted forced expiratory flow in mid-half of expiration, and FEV 1 ) of workers exposed to organic dust in vegetable market were also significantly lower ( P < 0.05). Exposure of organic dust is associated with compromised pulmonary functions and there is a need of formulation of safety guidelines.

  13. Man-influenced vegetation of North Korea

    Czech Academy of Sciences Publication Activity Database

    Kolbek, Jiří; Jarolímek, I.

    2008-01-01

    Roč. 40, č. 1 (2008), s. 381-404 ISSN 0253-116X R&D Projects: GA ČR(CZ) GA206/05/0119 Institutional research plan: CEZ:AV0Z60050516 Keywords : vegetation classification * weed communities * man-depending vegetation Subject RIV: EF - Botanics

  14. Natural Vegetation of the Flora area

    DEFF Research Database (Denmark)

    Sebsebe, Demissew; Friis, Ib

    2009-01-01

    A review article summarising the recent ideas about the natural vegetation in the area covered by the Flora of Ethiopia and Eritrea......A review article summarising the recent ideas about the natural vegetation in the area covered by the Flora of Ethiopia and Eritrea...

  15. Serving large portions of vegetable soup at the start of a meal affected children's energy and vegetable intake.

    Science.gov (United States)

    Spill, Maureen K; Birch, Leann L; Roe, Liane S; Rolls, Barbara J

    2011-08-01

    This study tested whether varying the portion of low-energy-dense vegetable soup served at the start of a meal affects meal energy and vegetable intakes in children. Subjects were 3- to 5-year-olds (31 boys and 41 girls) in daycare facilities. Using a crossover design, children were served lunch once a week for four weeks. On three occasions, different portions of tomato soup (150, 225, and 300 g) were served at the start of the meal, and on one occasion no soup was served. Children had 10 min to consume the soup before being served the main course. All foods were consumed ad libitum. The primary outcomes were soup intake as well as energy and vegetable intake at the main course. A mixed linear model tested the effect of soup portion size on intake. Serving any portion of soup reduced entrée energy intake compared with serving no soup, but total meal energy intake was only reduced when 150 g of soup was served. Increasing the portion size increased soup and vegetable intake. Serving low-energy-dense, vegetable soup as a first course is an effective strategy to reduce children's intake of a more energy-dense main entrée and increase vegetable consumption at the meal. Copyright © 2011 Elsevier Ltd. All rights reserved.

  16. Forest Vegetation Simulator translocation techniques with the Bureau of Land Management's Forest Vegetation Information system database

    Science.gov (United States)

    Timothy A. Bottomley

    2008-01-01

    The BLM uses a database, called the Forest Vegetation Information System (FORVIS), to store, retrieve, and analyze forest resource information on a majority of their forested lands. FORVIS also has the capability of easily transferring appropriate data electronically into Forest Vegetation Simulator (FVS) for simulation runs. Only minor additional data inputs or...

  17. Plant functional diversity affects climate-vegetation interaction

    Science.gov (United States)

    Groner, Vivienne P.; Raddatz, Thomas; Reick, Christian H.; Claussen, Martin

    2018-04-01

    We present how variations in plant functional diversity affect climate-vegetation interaction towards the end of the African Humid Period (AHP) in coupled land-atmosphere simulations using the Max Planck Institute Earth system model (MPI-ESM). In experiments with AHP boundary conditions, the extent of the green Sahara varies considerably with changes in plant functional diversity. Differences in vegetation cover extent and plant functional type (PFT) composition translate into significantly different land surface parameters, water cycling, and surface energy budgets. These changes have not only regional consequences but considerably alter large-scale atmospheric circulation patterns and the position of the tropical rain belt. Towards the end of the AHP, simulations with the standard PFT set in MPI-ESM depict a gradual decrease of precipitation and vegetation cover over time, while simulations with modified PFT composition show either a sharp decline of both variables or an even slower retreat. Thus, not the quantitative but the qualitative PFT composition determines climate-vegetation interaction and the climate-vegetation system response to external forcing. The sensitivity of simulated system states to changes in PFT composition raises the question how realistically Earth system models can actually represent climate-vegetation interaction, considering the poor representation of plant diversity in the current generation of land surface models.

  18. Fruits, vegetables, 100% juices, and cognitive function.

    Science.gov (United States)

    Lamport, Daniel J; Saunders, Caroline; Butler, Laurie T; Spencer, Jeremy Pe

    2014-12-01

    Although reviews of the association between polyphenol intake and cognition exist, research examining the cognitive effects of fruit, vegetable, and juice consumption across epidemiological and intervention studies has not been previously examined. For the present review, critical inclusion criteria were human participants, a measure of fruit, vegetable, or 100% juice consumption, an objective measure of cognitive function, and a clinical diagnosis of neuropsychological disease. Studies were excluded if consumption of fruits, vegetables, or juice was not assessed in isolation from other food groups, or if there was no statistical control for education or IQ. Seventeen of 19 epidemiological studies and 3 of 6 intervention studies reported significant benefits of fruit, vegetable, or juice consumption for cognitive performance. The data suggest that chronic consumption of fruits, vegetables, and juices is beneficial for cognition in healthy older adults. The limited data from acute interventions indicate that consumption of fruit juices can have immediate benefits for memory function in adults with mild cognitive impairment; however, as of yet, acute benefits have not been observed in healthy adults. Conclusions regarding an optimum dietary intake for fruits, vegetables, and juices are difficult to quantify because of substantial heterogeneity in the categorization of consumption of these foods. © 2014 International Life Sciences Institute.

  19. Fruit and vegetable consumption: benefits and barriers.

    Science.gov (United States)

    Maclellan, Debbie L; Gottschall-Pass, Katherine; Larsen, Roberta

    2004-01-01

    Few people on Prince Edward Island meet the goal of consuming five or more servings of vegetables and fruit a day. The main objective of this qualitative study was to explore the perceptions of the nutritional benefits and barriers to vegetable and fruit intake among adult women in Prince Edward Island. Participants were 40 women aged 20-49, with or without children at home, who were or were not currently meeting the objective of eating five or more fruit and vegetable servings a day. In-home, one-on-one interviews were used for data collection. Thematic analysis was conducted on the transcribed interviews. Data were examined for trustworthiness in the context of credibility, transferability, and dependability. Most participants identified one or more benefits of eating fruit and vegetables; however, comments tended to be non-specific. The main barriers that participants identified were effort, lack of knowledge, sociopsychological and socioenvironmental factors, and availability. Internal influences, life events, and food rules were identified as encouraging women to include vegetables and fruit in their diets. Given the challenges of effecting meaningful dietary change, dietitians must look for broader dietary behavioural interventions that are sensitive to women's perceptions of benefits and barriers to fruit and vegetable intake.

  20. Wind dispersal of alien plant species into remnant natural vegetation from adjacent agricultural fields

    Directory of Open Access Journals (Sweden)

    Chika Egawa

    2017-07-01

    Full Text Available Knowledge regarding the seed dispersal of alien species is crucial to manage invasion risk in fragmented natural habitats. Focusing on wind dispersal, this study assessed the spatial and quantitative extents to which a remnant natural fen receives the seeds of alien species dispersed from adjacent hay meadows in Hokkaido, northern Japan. I established a total of 80 funnel seed traps in the fen at distances of 1, 2, 5, 10, 20, 30, 50, and 100 m from the meadows. The proportion of alien species in the seed rain at each distance was quantified, and the 99th-percentile dispersal distance from the meadows was estimated for each alien species by constructing dispersal kernels. Despite the presence of a marginal ditch and an elevational difference between the fen and the meadows, five alien species, including four grasses that do not have modified seed structures for wind dispersal, dispersed their seeds into the fen. These alien species accounted for up to 65.9% of the seed rain in terms of quantity. The 99th-percentile dispersal distances of the alien species ranged from 3.8 m to 309.3 m, and these distances were longer than the values predicted on the basis of their functional traits, such as terminal velocity. The results of this study demonstrated that numerous seeds of farmland-derived alien species were transported into the remnant vegetation via wind dispersal, and that simple predictions of dispersal distance based on functional traits could underestimate the potential area that alien species can reach. Continuous management both in farmland (to reduce seed escape and in remnant vegetation (to prevent the establishment of alien species is necessary to protect native vegetation from biological invasion in agricultural landscapes.

  1. Beyond Precipitation: Physiographic Gradients Dictate the Relative Importance of Environmental Drivers on Savanna Vegetation

    Science.gov (United States)

    Campo-Bescós, Miguel A.; Muñoz-Carpena, Rafael; Kaplan, David A.; Southworth, Jane; Zhu, Likai; Waylen, Peter R.

    2013-01-01

    Background Understanding the drivers of large-scale vegetation change is critical to managing landscapes and key to predicting how projected climate and land use changes will affect regional vegetation patterns. This study aimed to improve our understanding of the role, magnitude and spatial distribution of the key environmental factors driving vegetation change in southern African savanna, and how they vary across physiographic gradients. Methodology/Principal Findings We applied Dynamic Factor Analysis (DFA), a multivariate times series dimension reduction technique to ten years of monthly remote sensing data (MODIS-derived normalized difference vegetation index, NDVI) and a suite of environmental covariates: precipitation, mean and maximum temperature, soil moisture, relative humidity, fire and potential evapotranspiration. Monthly NDVI was described by cyclic seasonal variation with distinct spatiotemporal patterns in different physiographic regions. Results support existing work emphasizing the importance of precipitation, soil moisture and fire on NDVI, but also reveal overlooked effects of temperature and evapotranspiration, particularly in regions with higher mean annual precipitation. Critically, spatial distributions of the weights of environmental covariates point to a transition in the importance of precipitation and soil moisture (strongest in grass-dominated regions with precipitation950 mm). Conclusions/Significance We quantified the combined spatiotemporal effects of an available suite of environmental drivers on NDVI across a large and diverse savanna region. The analysis supports known drivers of savanna vegetation but also uncovers important roles of temperature and evapotranspiration. Results highlight the utility of applying the DFA approach to remote sensing products for regional analyses of landscape change in the context of global environmental change. With the dramatic increase in global change research, this methodology augurs well for

  2. Vegetation

    DEFF Research Database (Denmark)

    Epstein, H.E.; Walker, D.A.; Bhatt, U.S.

    2012-01-01

    increased 20-26%. • Increasing shrub growth and range extension throughout the Low Arctic are related to winter and early growing season temperature increases. Growth of other tundra plant types, including graminoids and forbs, is increasing, while growth of mosses and lichens is decreasing. • Increases...... in vegetation (including shrub tundra expansion) and thunderstorm activity, each a result of Arctic warming, have created conditions that favor a more active Arctic fire regime....

  3. Carbon Inputs From Riparian Vegetation Limit Oxidation of Physically Bound Organic Carbon Via Biochemical and Thermodynamic Processes

    Science.gov (United States)

    Graham, Emily B.; Tfaily, Malak M.; Crump, Alex R.; Goldman, Amy E.; Bramer, Lisa M.; Arntzen, Evan; Romero, Elvira; Resch, C. Tom; Kennedy, David W.; Stegen, James C.

    2017-12-01

    In light of increasing terrestrial carbon (C) transport across aquatic boundaries, the mechanisms governing organic carbon (OC) oxidation along terrestrial-aquatic interfaces are crucial to future climate predictions. Here we investigate the biochemistry, metabolic pathways, and thermodynamics corresponding to OC oxidation in the Columbia River corridor using ultrahigh-resolution C characterization. We leverage natural vegetative differences to encompass variation in terrestrial C inputs. Our results suggest that decreases in terrestrial C deposition associated with diminished riparian vegetation induce oxidation of physically bound OC. We also find that contrasting metabolic pathways oxidize OC in the presence and absence of vegetation and—in direct conflict with the "priming" concept—that inputs of water-soluble and thermodynamically favorable terrestrial OC protect bound-OC from oxidation. In both environments, the most thermodynamically favorable compounds appear to be preferentially oxidized regardless of which OC pool microbiomes metabolize. In turn, we suggest that the extent of riparian vegetation causes sediment microbiomes to locally adapt to oxidize a particular pool of OC but that common thermodynamic principles govern the oxidation of each pool (i.e., water-soluble or physically bound). Finally, we propose a mechanistic conceptualization of OC oxidation along terrestrial-aquatic interfaces that can be used to model heterogeneous patterns of OC loss under changing land cover distributions.

  4. Assessment of human impacts on landuse and vegetation cover ...

    African Journals Online (AJOL)

    This paper is an assessment of the impact of man's activities on the landuse and vegetation cover of Mubi region. Landsat MSS Landuse/vegetation image of 1978 and Spot XS landuse/vegetation image of 1995 were used to study the landuse/vegetation cover changes of the region between 1978 and 1995 – a period of 17 ...

  5. Conveyance estimation in channels with emergent bank vegetation ...

    African Journals Online (AJOL)

    Emergent vegetation along the banks of a river channel influences its conveyance considerably. The total channel discharge can be estimated as the sum of the discharges of the vegetated and clear channel zones calculated separately. The vegetated zone discharge is often negligible, but can be estimated using ...

  6. Rapid responses of permafrost and vegetation to experimentally increased snow cover in sub-arctic Sweden

    International Nuclear Information System (INIS)

    Johansson, Margareta; Bosiö, Julia; Akerman, H Jonas; Jackowicz-Korczynski, Marcin; Christensen, Torben R; Callaghan, Terry V

    2013-01-01

    Increased snow depth already observed, and that predicted for the future are of critical importance to many geophysical and biological processes as well as human activities. The future characteristics of sub-arctic landscapes where permafrost is particularly vulnerable will depend on complex interactions between snow cover, vegetation and permafrost. An experimental manipulation was, therefore, set up on a lowland peat plateau with permafrost, in northernmost Sweden, to simulate projected future increases in winter precipitation and to study their effects on permafrost and vegetation. After seven years of treatment, statistically significant differences between manipulated and control plots were found in mean winter ground temperatures, which were 1.5 ° C higher in manipulated plots. During the winter, a difference in minimum temperatures of up to 9 ° C higher could be found in individual manipulated plots compared with control plots. Active layer thicknesses increased at the manipulated plots by almost 20% compared with the control plots and a mean surface subsidence of 24 cm was recorded in the manipulated plots compared to 5 cm in the control plots. The graminoid Eriophorum vaginatum has expanded in the manipulated plots and the vegetation remained green longer in the season. (letter)

  7. Utility of Rice Bran Mixed with Fermentation Extract of Vegetable Waste Unconditioned as Probiotics from Vegetable Market

    Directory of Open Access Journals (Sweden)

    Cahya Setya Utama

    2013-06-01

    Full Text Available The aimed of the study was to enhance utilization of Lactobacillus Sp. and Saccharomyces sp. as starter for fermentation of waste cabbage and green mustard to enhance the utility of rice bran as an ingredient of poultry feed. The first stage of the study was to characterize the extract of fermented wasted vegetable with difference concentration of glucose and different period of time for incubation. Completely randomized design using 3 x 3 factorial with three replications was used for the first stage of the study. The second stage of the study was to evaluate the effectiveness of the extract of fermented wasted vegetable to improve the quality and utility of rice bran. Completely randomized design with four treatments and 4 replications. The third stage of the study was to obtain the value of nitrogen, calcium and phosphorus retention, as well as metabolic energy of rice bran after fermentation in broiler hatching. The third stage analysis was conducted by t-test analysis. The results of the study showed that the microbial characteristics on the extract of fermented wasted vegetable in two days incubation time and 2% concentration of glucose was able to produce pH of 3.80, log of total lactic acid bacteria 7.38 and types of microbes that grow predominantly were Lactobacillus Sp. and Saccharomyces Sp. The effectiveness of the extract fermented wasted vegetable for the fermentation of rice bran were shown in additional concentration of extract wasted vegetable of 40% with a moisture content of  toluene 65.24%, 13.36% ash, 14.93% protein, 7.61% crude fat, 12.39% crude fiber, nitrogen free extract material (NFE 51.59% and 0.07% biomass. The biological value and the availability of fermented rice bran were higher than unfermented rice bran on the broiler chickens after hatching. The values were justified from nitrogen, calcium and phosphorus retention also metabolic energy. The study concluded that the benefits and utility of rice bran could

  8. Serving large portions of vegetable soup at the start of a meal affected children’s energy and vegetable intake

    Science.gov (United States)

    Spill, Maureen K.; Birch, Leann L.; Roe, Liane S.; Rolls, Barbara J.

    2011-01-01

    This study tested whether varying the portion of low-energy-dense vegetable soup served at the start of a meal affects meal energy and vegetable intakes in children. Subjects were 3- to 5-year-olds (31 boys and 41 girls) in daycare facilities. Using a crossover design, children were served lunch once a week for four weeks. On three occasions, different portions of tomato soup (150, 225, and 300 g) were served at the start of the meal, and on one occasion no soup was served. Children had 10 minutes to consume the soup before being served the main course. All foods were consumed ad libitum. The primary outcomes were soup intake as well as energy and vegetable intake at the main course. A mixed linear model tested the effect of soup portion size on intake. Serving any portion of soup reduced entrée energy intake compared with serving no soup, but total meal energy intake was only reduced when 150 g of soup was served. Increasing the portion size increased soup and vegetable intake. Serving low-energy-dense, vegetable soup as a first course is an effective strategy to reduce children’s intake of a more energy-dense main entrée and increase vegetable consumption at the meal. PMID:21596073

  9. Water quality function of an extensive vegetated roof.

    Science.gov (United States)

    Todorov, Dimitar; Driscoll, Charles T; Todorova, Svetoslava; Montesdeoca, Mario

    2018-06-01

    In this paper we present the results of a four-year study of water quality in runoff from an extensive, sedum covered, vegetated roof on an urban commercial building. Monitoring commenced seven months after the roof was constructed, with the first growing season. Stormwater drainage quality function of the vegetated roof was compared to a conventional (impermeable, high-albedo) membrane roof in addition to paired measurements of wet and bulk depositions at the study site. We present concentrations and fluxes of nutrients and major solutes. We discuss seasonal and year-to-year variation in water quality of drainage from the vegetated roof and how it compares with atmospheric deposition and drainage from the impermeable roof. Drainage waters from the vegetated roof exhibited a high concentration of nutrients compared to atmospheric deposition, particularly during the warm temperature growing season. However, nutrient losses were generally low because of the strong retention of water by the vegetated roof. There was marked variation in the retention of nutrients by season due to variations in concentrations in drainage from the vegetated roof. The vegetated roof was a sink of nitrogen, total phosphorus and chloride, and a source of phosphate and dissolved inorganic and organic carbon. Chloride exhibited elevated inputs and leaching during the winter. The drainage from the vegetated and impermeable roofs met the United States Environmental Protection Agency freshwater standards for all parameters, except for total phosphorus. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Listeria monocytogenes - Danger for health safety vegetable production.

    Science.gov (United States)

    Kljujev, Igor; Raicevic, Vera; Jovicic-Petrovic, Jelena; Vujovic, Bojana; Mirkovic, Milica; Rothballer, Michael

    2018-04-22

    The microbiologically contaminated vegetables represent a risk for consumers, especially vegetables without thermal processing. It is known that human pathogen bacteria, such as Listeria monocytogenes, could exist on fresh vegetables. The fresh vegetables could become Listeria-contaminated if they come in touch with contaminated soil, manure, irrigation water. The aim of this work was to investigate the presence of Listeria spp. and L. monocytogenes in different kind of vegetables grown in field and greenhouse condition as well as surface and endophytic colonization plant roots of different vegetables species by L. monocytogenes in laboratory conditions. The detection of Listeria spp. and L. monocytogenes in vegetable samples was done using ISO and PCR methods. The investigation of colonization vegetable roots and detection Listeria-cells inside plant root tissue was done using Fluorescence in situ hybridization (FISH) method in combination with confocal laser scanning microscopy (CLSM). The results showed that 25.58% vegetable samples were positive for Listeria spp. and only one sample (carrot) was positive for L. monocytogenes out of 43 samples in total collected from field and greenhouse. The strain L. monocytogenes EGD-E surface and endophytic colonized carrot root in highest degree while strain L. monocytogenes SV4B was the most represented at leafy vegetable plants, such at lettuce (1.68 × 10 6  cells/mm 3 absolutely dry root) and spinach (1.39 × 10 6  cells/mm 3 absolutely dry root) root surface. The cells of L. monocytogenes SV4B were visible as single cells in interior tissue of plant roots (celery and sweet corn roots) as well as in the interior of the plant root cell at sweet corn root. The cells of L. monocytogenes EGD-E bind to the surface of the plant root and they were less commonly found out on root hair. In the inner layers of the root, those bacterial cells were inhabited intercellular spaces mainly as single cells very close to the

  11. 24 GHz cmWave Radio Propagation Through Vegetation

    DEFF Research Database (Denmark)

    Rodriguez, Ignacio; Abreu, Renato Barbosa; Portela Lopes de Almeida, Erika

    2016-01-01

    This paper presents a measurement-based analysis of cm-wave radio propagation through vegetation at 24 GHz. A set of dedicated directional measurements were performed with horn antennas located close to street level inside a densely-vegetated area illuminated from above. The full azimuth was exam......This paper presents a measurement-based analysis of cm-wave radio propagation through vegetation at 24 GHz. A set of dedicated directional measurements were performed with horn antennas located close to street level inside a densely-vegetated area illuminated from above. The full azimuth...

  12. Investigation of NPK in fertilized and unfertilized vegetables

    International Nuclear Information System (INIS)

    Deeba, F.; Butt, M.T.; Iqubal, K.; Shafiq, T.

    2010-01-01

    Contents of selected minerals and moisture in Ridge Gourd, Gourd and Brinjal vegetables, collected from house and market of different localities, were determined. In house vegetables from kitchen garden of PCSIR colony the moisture contents were high (90%) as compared to market vegetables of Taj Bagh, Railway workshop Mandy and Singpura Lahore Mandy was 87%, 86.5% and 87.5% respectively. Regarding nitrogen, nitrate, nitrite, phosphate, sodium and potassium was high in market vegetables as compared to house samples due to the accumulation of nutrients in soil and crop. (author)

  13. Ecogeomorphology of Sand Dunes Shaped by Vegetation

    Science.gov (United States)

    Tsoar, H.

    2014-12-01

    Two dune types associated with vegetation are known: Parabolic and Vegetated Linear Dunes (VLDs), the latters are the dominant dune type in the world deserts. Parabolic dunes are formed in humid, sub-humid and semi-arid environments (rather than arid) where vegetation is nearby. VLDs are known today in semiarid and arid lands where the average yearly rainfall is ≥100 mm, enough to support sparse cover of vegetation. These two dune types are formed by unidirectional winds although they demonstrate a different form and have a distinct dynamics. Conceptual and mathematical models of dunes mobility and stability, based on three control parameters: wind power (DP), average annual precipitation (p), and the human impact parameter (μ) show that where human impact is negligible the effect of wind power (DP) on vegetative cover is substantial. The average yearly rainfall of 60-80 mm is the threshold of annual average rainfall for vegetation growth on dune sand. The model is shown to follow a hysteresis path, which explains the bistability of active and stabilized dunes under the same climatic conditions with respect to wind power. We have discerned formation of parabolic dunes from barchans and transverse dunes in the coastal plain of Israel where a decrease in human activity during the second half of the 20th century caused establishment of vegetation on the crest of the dunes, a process that changed the dynamics of these barchans and transverse dunes and led to a change in the shape of the windward slope from convex to concave. These dunes gradually became parabolic. It seems that VLDs in Australia or the Kalahari have always been vegetated to some degree, though the shrubs were sparser in colder periods when the aeolian erosion was sizeable. Those ancient conditions are characterized by higher wind power and lower rainfall that can reduce, but not completely destroy, the vegetation cover, leading to the formation of lee (shadow) dunes behind each shrub. Formation of

  14. Modelling post-fire vegetation recovery in Portugal

    Directory of Open Access Journals (Sweden)

    A. Bastos

    2011-12-01

    Full Text Available Wildfires in Mediterranean Europe have been increasing in number and extension over the last decades and constitute one of the major disturbances of these ecosystems. Portugal is the country with more burnt area in the last decade and the years of 2003 and 2005 were particularly devastating, the total burned areas of 425 000 and 338 000 ha being several times higher than the corresponding average. The year of 2005 further coincided with one of the most severe droughts since early 20th century. Due to different responses of vegetation to diverse fire regimes and to the complexity of landscape structures, fires have complex effects on vegetation recovery. Remote sensing has revealed to be a powerful tool in studying vegetation dynamics and in monitoring post-fire vegetation recovery, which is crucial to land-management and to prevent erosion.

    The main goals of the present work are (i to assess the accuracy of a vegetation recovery model previously developed by the authors; (ii to assess the model's performance, namely its sensitivity to initial conditions, to the temporal length of the input dataset and to missing data; (iii to study vegetation recovery over two selected areas that were affected by two large wildfire events in the fire seasons of 2003 and 2005, respectively.

    The study relies on monthly values of NDVI over 11 years (1998–2009, at 1 km × 1 km spatial resolution, as obtained by the VEGETATION instrument. According to results from sensitivity analysis, the model is robust and able to provide good estimations of recovery times of vegetation when the regeneration process is regular, even when missing data is present. In respect to the two selected burnt scars, results indicate that fire damage is a determinant factor of regeneration, as less damaged vegetation recovers more rapidly, which is mainly justified by the high coverage of Pinus pinaster over the area, and by the fact that coniferous forests tend to

  15. Semi-Dried Fruits and Vegetables

    Directory of Open Access Journals (Sweden)

    Gamze Uysal Seçkin

    2015-12-01

    Full Text Available Since ancient times, the preservation of fruit and vegetables is an ancient method of drying. Sun drying method has been used more widely. In general, consumer-ready products are dried fruits, while the dried vegetables are the foods subjected to the rehydration processes such as boiling, heating and baking before consumption. In recent years, new products with high eating quality have been attempted to achieve without losing characteristic of raw material. With the improving of food technology, using developed methods (pH reduction with reducing aw, slight heating, preservatives use etc. as protective agent, and using a combination of a low rate as an alternative to traditional food preservation process, products have been obtained without changing original characteristics of food. ‘Semi-dried 'or 'medium moist 'products with little difference between the taste and texture of the product with a damp have gained importance in recent years in terms of consumer preferences. Vegetables or fruits, which have water activity levels between 0.50 and 0.95 and the moisture content of between 26% and 60%, are called 'medium moist fruit or vegetables'. Two different manufacturing process to obtain a semi-dried or intermediate moisture products are applied. First, fully dried fruits and vegetables to be rehydrated with water are brought to the desired level of their moisture content. Second, in the first drying process, when the product moisture content is reduced to the desired level, the drying process is finished. The semi-dried products are preferred by consumers because they have a softer texture in terms of eating quality and like fresh products texture.

  16. Ecological Impacts of the Cerro Grande Fire: Predicting Elk Movement and Distribution Patterns in Response to Vegetative Recovery through Simulation Modeling October 2005

    Energy Technology Data Exchange (ETDEWEB)

    Rupp, Susan P. [Texas Tech Univ., Lubbock, TX (United States)

    2005-10-01

    In May 2000, the Cerro Grande Fire burned approximately 17,200 ha in north-central New Mexico as the result of an escaped prescribed burn initiated by Bandelier National Monument. The interaction of large-scale fires, vegetation, and elk is an important management issue, but few studies have addressed the ecological implications of vegetative succession and landscape heterogeneity on ungulate populations following large-scale disturbance events. Primary objectives of this research were to identify elk movement pathways on local and landscape scales, to determine environmental factors that influence elk movement, and to evaluate movement and distribution patterns in relation to spatial and temporal aspects of the Cerro Grande Fire. Data collection and assimilation reflect the collaborative efforts of National Park Service, U.S. Forest Service, and Department of Energy (Los Alamos National Laboratory) personnel. Geographic positioning system (GPS) collars were used to track 54 elk over a period of 3+ years and locational data were incorporated into a multi-layered geographic information system (GIS) for analysis. Preliminary tests of GPS collar accuracy indicated a strong effect of 2D fixes on position acquisition rates (PARs) depending on time of day and season of year. Slope, aspect, elevation, and land cover type affected dilution of precision (DOP) values for both 2D and 3D fixes, although significant relationships varied from positive to negative making it difficult to delineate the mechanism behind significant responses. Two-dimensional fixes accounted for 34% of all successfully acquired locations and may affect results in which those data were used. Overall position acquisition rate was 93.3% and mean DOP values were consistently in the range of 4.0 to 6.0 leading to the conclusion collar accuracy was acceptable for modeling purposes. SAVANNA, a spatially explicit, process-oriented ecosystem model, was used to simulate successional dynamics. Inputs to the

  17. Vegetation Change in Blue Oak Woodlands in California

    Science.gov (United States)

    Barbara A. Holzman; Barbara H. Allen-Diaz

    1991-01-01

    A preliminary report of a statewide project investigating vegetation change in blue oak (Quercus douglasii) woodlands in California is presented. Vegetation plots taken in the 1930s, as part of a statewide vegetation mapping project, were relocated and surveyed. Species composition, cover and tree stand structure data from the earlier study were...

  18. The importance of vegetation change in the prediction of future tropical cyclone flood statistics

    Science.gov (United States)

    Irish, J. L.; Resio, D.; Bilskie, M. V.; Hagen, S. C.; Weiss, R.

    2015-12-01

    Global sea level rise is a near certainty over the next century (e.g., Stocker et al. 2013 [IPCC] and references therein). With sea level rise, coastal topography and land cover (hereafter "landscape") is expected to change and tropical cyclone flood hazard is expected to accelerate (e.g., Irish et al. 2010 [Ocean Eng], Woodruff et al. 2013 [Nature], Bilskie et al. 2014 [Geophys Res Lett], Ferreira et al. 2014 [Coast Eng], Passeri et al. 2015 [Nat Hazards]). Yet, the relative importance of sea-level rise induced landscape change on future tropical cyclone flood hazard assessment is not known. In this paper, idealized scenarios are used to evaluate the relative impact of one class of landscape change on future tropical cyclone extreme-value statistics in back-barrier regions: sea level rise induced vegetation migration and loss. The joint probability method with optimal sampling (JPM-OS) (Resio et al. 2009 [Nat Hazards]) with idealized surge response functions (e.g., Irish et al. 2009 [Nat Hazards]) is used to quantify the present-day and future flood hazard under various sea level rise scenarios. Results are evaluated in terms of their impact on the flood statistics (a) when projected flood elevations are included directly in the JPM analysis (Figure 1) and (b) when represented as additional uncertainty within the JPM integral (Resio et al. 2013 [Nat Hazards]), i.e., as random error. Findings are expected to aid in determining the level of effort required to reasonably account for future landscape change in hazard assessments, namely in determining when such processes are sufficiently captured by added uncertainty and when sea level rise induced vegetation changes must be considered dynamically, via detailed modeling initiatives. Acknowledgements: This material is based upon work supported by the National Science Foundation under Grant No. CMMI-1206271 and by the National Sea Grant College Program of the U.S. Department of Commerce's National Oceanic and

  19. ROOT VEGETABLES, BREEDING TRENDS, RESULTS

    Directory of Open Access Journals (Sweden)

    M. I. Fedorova

    2017-01-01

    Full Text Available The main advantage of root vegetables is their unique specificity and high economic importance. The benefits and medicinal properties of root vegetables being highly demanded by the market requirements to the commodity are highlighted in the article. The main directions of breeding program for root vegetable crops, including species of Apiaceae family with carrot, parsnips; Chenopodioideae family with red beet; Brassicaceae family with radish, Daikon, Raphanus sativus L. var. lobo Sazonova & Stank, turnip and rutabaga. Initial breeding accessions of carrot, red beet, radish, Daikon, Raphanus sativus L. var. lobo Sazonova & Stank, turnip and rutabaga have been selected out to be used for breeding program for heterosis. The mf and ms breeding lines were developed, and with the use of them the new gene pool was created. Variety supporting breeding program and methods were also proposed. 

  20. Temporal reflectance changes in vegetables

    DEFF Research Database (Denmark)

    Dissing, Bjørn Skovlund; Clemmensen, Line Katrine Harder; Ersbøll, Bjarne Kjær

    2009-01-01

    Quality control in the food industry is often performed by measuring various chemical compounds of the food involved. We propose an imaging concept for acquiring high quality multispectral images to evaluate changes of carrots and celeriac over a period of 14 days. Properties originating...... in the surface chemistry of vegetables may be captured in an integrating sphere illumination which enables the creation of detailed surface chemistry maps with a good combination of spectral and spatial resolutions. Prior to multispectral image recording, the vegetables were prefried and frozen at -30Â......°C for four months. During the 14 days of image recording, the vegetables were kept at +5°C in refrigeration. In this period, surface changes and thereby reflectance properties were very subtle. To describe this small variation we employed advanced statistical techniques to search a large featurespace...

  1. NEW GREENHOUSE TECHNOLOGIES FOR VEGETABLE PRODUCTION

    Directory of Open Access Journals (Sweden)

    S. M. Sirota

    2016-01-01

    Full Text Available First decade of XXI century is characterized by significant augmentation in vegetable world’s production. Average annual vegetable production has been 346 million tons, and it has exceeded the average annual potato production (318 million tons. It has occurred due to the use of up-to-date technologies for vegetable production and, particularly, in greenhouses. In Russian Federation, the total production of vegetables was 5 275.6 thousand tons in 2015 that was 13.3% more than in 2014. But the total vegetable production in greenhouses was only 722.8 thousand tons, that was 0.7% less than in 2014 (728.1 thousand tons. It can be explained that the old technologies have been used for many greenhouses around Russia. Up-to-date technologies for greenhouses are described in the article. Small-volume hydroponics. Plants are grown in mineral wadding, packed up in the special chutes. Mineral nutrition and water are supplied through special pipe with many branch pipes toward each plant. Advantage: pH and nutrition are maintained, consumption of water and mineral nutrition are optimized, and that improves plants grow control. Expenditures of labor decreased, quality of fruit became better and the yield increased significantly by 45-50 kg/m2 comparing with growing on the soil (25-30 kg/m2. Hydroponics with flowing water (salad production lines. Conveyor for salad and vegetable growing on horizontal moving chutes with flowing water and nutrition was developed. Advantage: high level of automation and mechanization of all processes of growing increased the effectiveness of the use of greenhouse areas (we can place 30% plants more at the same area. Seedling production lines. Production lines for seedlings enable to grow vegetables and leafy vegetables on stationary benches, being furnished with periodical nutrition and water supply at times. Advantage: 700 seedlings additionally on each m2 a year. Future technologies are

  2. Where to Combat Shrub Encroachment in Alpine Timberline Ecosystems: Combining Remotely-Sensed Vegetation Information with Species Habitat Modelling.

    Directory of Open Access Journals (Sweden)

    Veronika Braunisch

    Full Text Available In many cultural landscapes, the abandonment of traditional grazing leads to encroachment of pastures by woody plants, which reduces habitat heterogeneity and impacts biodiversity typical of semi-open habitats. We developed a framework of mutually interacting spatial models to locate areas where shrub encroachment in Alpine treeline ecosystems deteriorates vulnerable species' habitat, using black grouse Tetrao tetrix (L. in the Swiss Alps as a study model. Combining field observations and remote-sensing information we 1 identified and located the six predominant treeline vegetation types; 2 modelled current black grouse breeding habitat as a function thereof so as to derive optimal habitat profiles; 3 simulated from these profiles the theoretical spatial extension of breeding habitat when assuming optimal vegetation conditions throughout; and used the discrepancy between (2 and (3 to 4 locate major aggregations of homogeneous shrub vegetation in otherwise suitable breeding habitat as priority sites for habitat restoration. All six vegetation types (alpine pasture, coniferous forest, Alnus viridis (Chaix, Rhododendron-dominated, Juniperus-dominated and mixed heathland were predicted with high accuracy (AUC >0.9. Breeding black grouse preferred a heterogeneous mosaic of vegetation types, with none exceeding 50% cover. While 15% of the timberline belt currently offered suitable breeding habitat, twice that fraction (29% would potentially be suitable when assuming optimal shrub and ground vegetation conditions throughout the study area. Yet, only 10% of this difference was attributed to habitat deterioration by shrub-encroachment of dense heathland (all types 5.2% and Alnus viridis (4.8%. The presented method provides both a general, large-scale assessment of areas covered by dense shrub vegetation as well as specific target values and priority areas for habitat restoration related to a selected target organism. This facilitates optimizing the

  3. Changes of Vegetation Distribution in the East Dongting Lake After the Operation of the Three Gorges Dam, China

    Directory of Open Access Journals (Sweden)

    Jia-Yu Hu

    2018-05-01

    Full Text Available Water regime is regarded as the primary factor influencing the vegetation distribution in natural wetland ecosystems. However, the effect of water regime change induced by large-scale hydraulic engineering on vegetation distribution is still unclear. In this study, multi-temporal TM/ETM+/OLI images and hydrological data from 1995 to 2015 were used to elucidate how the change in water regime influenced the vegetation distribution in the East Dongting Lake (EDTL, especially after the operation of the Three Gorges Dam (TGD in 2003. Using unsupervised and supervised classification methods, three types of land cover were identified in the study area: Water and Mudflat, Grass, and Reed and Forest. Results showed that the total vegetation area in EDTL increased by approximately 78 km2 during 1995–2015. The areas of Reed and Forest and Grass exhibited a contrasting trend, dramatic increase in Reed and Forest but sharp decrease in Grass, particularly after the operation of TGD. The lowest distribution elevations of Grass and Reed and Forest decreased by 0.61 and 0.52 m, respectively. As a result of water level variation, submergence duration increased at 20–21 m and 28 m elevations (1–13 days, but significantly decreased at 22–27 m and 29–30 m elevations (-3 to -31 days. The submergence duration of Grass and Reed and Forest was 246 and 177 days, respectively. This study indicated that wetland vegetation pattern significantly changed after the operation of TGD, mainly as a result of changes in submergence condition. Submergence duration might be an effective indicator to predict the shift of vegetation distribution in EDTL, and which could provide scientific guidance for vegetation restoration and wetland management in this lake.

  4. Spatial and Temporal Variation in Primary Productivity (NDVI) of Coastal Alaskan Tundra: Decreased Vegetation Growth Following Earlier Snowmelt

    Science.gov (United States)

    Gamon, John A.; Huemmrich, K. Fred; Stone, Robert S.; Tweedie, Craig E.

    2015-01-01

    In the Arctic, earlier snowmelt and longer growing seasons due to warming have been hypothesized to increase vegetation productivity. Using the Normalized Difference Vegetation Index (NDVI) from both field and satellite measurements as an indicator of vegetation phenology and productivity, we monitored spatial and temporal patterns of vegetation growth for a coastal wet sedge tundra site near Barrow, Alaska over three growing seasons (2000-2002). Contrary to expectation, earlier snowmelt did not lead to increased productivity. Instead, productivity was associated primarily with precipitation and soil moisture, and secondarily with growing degree days, which, during this period, led to reduced growth in years with earlier snowmelt. Additional moisture effects on productivity and species distribution, operating over a longer time scale, were evident in spatial NDVI patterns associated with microtopography. Lower, wetter regions dominated by graminoids were more productive than higher, drier locations having a higher percentage of lichens and mosses, despite the earlier snowmelt at the more elevated sites. These results call into question the oft-stated hypothesis that earlier arctic growing seasons will lead to greater vegetation productivity. Rather, they agree with an emerging body of evidence from recent field studies indicating that early-season, local environmental conditions, notably moisture and temperature, are primary factors determining arctic vegetation productivity. For this coastal arctic site, early growing season conditions are strongly influenced by microtopography, hydrology, and regional sea ice dynamics, and may not be easily predicted from snowmelt date or seasonal average air temperatures alone. Our comparison of field to satellite NDVI also highlights the value of in-situ monitoring of actual vegetation responses using field optical sampling to obtain detailed information on surface conditions not possible from satellite observations alone.

  5. Where to Combat Shrub Encroachment in Alpine Timberline Ecosystems: Combining Remotely-Sensed Vegetation Information with Species Habitat Modelling.

    Science.gov (United States)

    Braunisch, Veronika; Patthey, Patrick; Arlettaz, Raphaël

    2016-01-01

    In many cultural landscapes, the abandonment of traditional grazing leads to encroachment of pastures by woody plants, which reduces habitat heterogeneity and impacts biodiversity typical of semi-open habitats. We developed a framework of mutually interacting spatial models to locate areas where shrub encroachment in Alpine treeline ecosystems deteriorates vulnerable species' habitat, using black grouse Tetrao tetrix (L.) in the Swiss Alps as a study model. Combining field observations and remote-sensing information we 1) identified and located the six predominant treeline vegetation types; 2) modelled current black grouse breeding habitat as a function thereof so as to derive optimal habitat profiles; 3) simulated from these profiles the theoretical spatial extension of breeding habitat when assuming optimal vegetation conditions throughout; and used the discrepancy between (2) and (3) to 4) locate major aggregations of homogeneous shrub vegetation in otherwise suitable breeding habitat as priority sites for habitat restoration. All six vegetation types (alpine pasture, coniferous forest, Alnus viridis (Chaix), Rhododendron-dominated, Juniperus-dominated and mixed heathland) were predicted with high accuracy (AUC >0.9). Breeding black grouse preferred a heterogeneous mosaic of vegetation types, with none exceeding 50% cover. While 15% of the timberline belt currently offered suitable breeding habitat, twice that fraction (29%) would potentially be suitable when assuming optimal shrub and ground vegetation conditions throughout the study area. Yet, only 10% of this difference was attributed to habitat deterioration by shrub-encroachment of dense heathland (all types 5.2%) and Alnus viridis (4.8%). The presented method provides both a general, large-scale assessment of areas covered by dense shrub vegetation as well as specific target values and priority areas for habitat restoration related to a selected target organism. This facilitates optimizing the spatial

  6. Coastwide Reference Monitoring System (CRMS) Vegetation Volume Index: An assessment tool for marsh habitat focused on the three-dimensional structure at CRMS vegetation monitoring stations

    Science.gov (United States)

    Wood, William B.; Visser, Jenneke M.; Piazza, Sarai C.; Sharp, Leigh A.; Hundy, Laura C.; McGinnis, Tommy E.

    2015-12-04

    A Vegetation Volume (VV) variable and Vegetation Volume Index (VVI) have been developed for the Coastwide Reference Monitoring System (CRMS). The VV is a measure of the amount of three-dimensional vegetative structure present at each CRMS site and is based on vegetation data collected annually. The VV uses 10 stations per CRMS site to quantify four vegetation layers: carpet, herbaceous, shrub, and tree. For each layer an overall live vegetation percent cover and height are collected to create a layer volume; the individual layer volumes are then summed to generate a site vegetation volume profile. The VV uses the two-dimensional area of live vegetative cover (in square meters) multiplied by the height (in meters) of each layer to produce a volume (in cubic meters) for each layer present in a 2-meter by 2-meter station. These layers are additive, yielding a total volume for each of the 10 herbaceous vegetation stations and an overall CRMS marsh site average.

  7. A qualitative and quantitative analysis of vegetable pricing in supermarket

    Science.gov (United States)

    Miranda, Suci

    2017-06-01

    The purpose of this study is to analyze the variables affecting the determination of the sale price of vegetable which is constant over time in a supermarket qualitatively and quantitavely. It focuses on the non-organic vegetable with a fixed selling price over time such as spinach, beet, and parsley. In qualitative analysis, the sale price determination is influenced by the vegetable characteristics: (1) vegetable segmentation (low to high daily consumed); (2) vegetable age (how long it can last related to freshness); which both characteristic relates to the inventory management and ultimately to the sale price in supermarket. While quantitatively, the vegetables are divided into two categories: the leaf vegetable group that the leaves are eaten as a vegetable with the aging product (a) = 0 and the shelf life (t) = 0, and the non-leafy vegetable group with the aging group (a) = a+1 and the shelf life (t) = t+1. The vegetable age (a) = 0 means they only last for one day when they are ordered then they have to terminate. Whereas a+1 is that they have a longer life for more than a day such as beet, white radish, and string beans. The shelf life refers to how long it will be placed in a shelf in supermarket in line with the vegetable age. According to the cost plus pricing method using full price costing approach, production costs, non-production costs, and markup are adjusted differently for each category. There is a holding cost added to the sale price of the non-leafy vegetable, yet it is assumed a 0 holding cost for the leafy vegetable category. The amount of expected margin of each category is correlated to the vegetable characteristics.

  8. New options for conversion of vegetable oils to alternative fuels

    Energy Technology Data Exchange (ETDEWEB)

    Demirbas, A.; Kara, H. [Selcuk University, Konya (Turkey). Department of Chemical Engineering

    2006-05-15

    Biodiesel from transesterification of vegetable oils is an excellent alternative fuel. There is, however, a need to develop a direct process for conversion of vegetable oils into gasoline-competitive biodiesel and other petroleum products. Methyl esters of vegetable oils have several outstanding advantages among other new-renewable and clean engine fuel alternatives. The purpose of the transesterification process is to lower the viscosity of vegetable oil. Compared to No. 2 diesel fuel, all of the vegetable oils are much more viscous, whereas methyl esters of vegetable oils are slightly more viscous. The methyl esters are more volatile than those of the vegetable oils. Conversion of vegetable oils to useful fuels involves the pyrolysis and catalytic cracking of the oils into lower molecular products. Pyrolysis produces more biogasoline than biodiesel fuel. Soap pyrolysis products of vegetable oils can be used as alternative diesel engine fuel. The soaps obtained from the vegetable oils can be pyrolyzed into hydrocarbon-rich products. Zinc chloride catalyst contributed greatly to high amounts of hydrocarbons in the liquid product. The yield of ZnCl2 catalytic conversion of the soybean oil reached the maximum 79.9% at 660 K. (author)

  9. Temperature and substrate controls on intra-annual variation in ecosystem respiration in two subarctic vegetation types

    DEFF Research Database (Denmark)

    Grogan, Paul; Jonasson, Sven Evert

    2005-01-01

    significantly to ecosystem respiration during most phases of winter and summer in the two vegetation types. Ecosystem respiration rates through the year did not differ significantly between vegetation types despite substantial differences in biomass pools, soil depth and temperature regime. Most (76...... contributions of bulk soil organic matter and plant-associated carbon pools to ecosystem respiration is critical to predicting the response of arctic ecosystem net carbon balance to climate change. In this study, we determined the variation in ecosystem respiration rates from birch forest understory and heath......-92%) of the intra-annual variation in ecosystem respiration rates from these two common mesic subarctic ecosystems was explained using a first-order exponential equation relating respiration to substrate chemical quality and soil temperature. Removal of plants and their current year's litter significantly reduced...

  10. Does urban vegetation mitigate air pollution in northern conditions?

    International Nuclear Information System (INIS)

    Setälä, Heikki; Viippola, Viljami; Rantalainen, Anna-Lea; Pennanen, Arto; Yli-Pelkonen, Vesa

    2013-01-01

    It is generally accepted that urban vegetation improves air quality and thereby enhances the well-being of citizens. However, empirical evidence on the potential of urban trees to mitigate air pollution is meager, particularly in northern climates with a short growing season. We studied the ability of urban park/forest vegetation to remove air pollutants (NO 2 , anthropogenic VOCs and particle deposition) using passive samplers in two Finnish cities. Concentrations of each pollutant in August (summer; leaf-period) and March (winter, leaf-free period) were slightly but often insignificantly lower under tree canopies than in adjacent open areas, suggesting that the role of foliage in removing air pollutants is insignificant. Furthermore, vegetation-related environmental variables (canopy closure, number and size of trees, density of understorey vegetation) did not explain the variation in pollution concentrations. Our results suggest that the ability of urban vegetation to remove air pollutants is minor in northern climates. -- Highlights: ► The ability of northern urban vegetation to remove air pollutants is minor. ► Vegetation-related environmental variables had no effect on air pollution levels. ► The ability of vegetation to clean air did not differ between summer and winter. ► Dry deposition passive samplers proved applicable in urban air pollution study. -- The ability of urban vegetation to remove air pollutants seems to be minor in northern climates

  11. Disentangling the Effects of Water Stress on Carbon Acquisition, Vegetative Growth, and Fruit Quality of Peach Trees by Means of the QualiTree Model

    Directory of Open Access Journals (Sweden)

    Mitra Rahmati

    2018-01-01

    Full Text Available Climate change projections predict warmer and drier conditions. In general, moderate to severe water stress reduce plant vegetative growth and leaf photosynthesis. However, vegetative and reproductive growths show different sensitivities to water deficit. In fruit trees, water restrictions may have serious implications not only on tree growth and yield, but also on fruit quality, which might be improved. Therefore, it is of paramount importance to understand the complex interrelations among the physiological processes involved in within-tree carbon acquisition and allocation, water uptake and transpiration, organ growth, and fruit composition when affected by water stress. This can be studied using process-based models of plant functioning, which allow assessing the sensitivity of various physiological processes to water deficit and their relative impact on vegetative growth and fruit quality. In the current study, an existing fruit-tree model (QualiTree was adapted for describing the water stress effects on peach (Prunus persica L. Batsch vegetative growth, fruit size and composition. First, an energy balance calculation at the fruit-bearing shoot level and a water transfer formalization within the plant were integrated into the model. Next, a reduction function of vegetative growth according to tree water status was added to QualiTree. Then, the model was parameterized and calibrated for a late-maturing peach cultivar (“Elberta” under semi-arid conditions, and for three different irrigation practices. Simulated vegetative and fruit growth variability over time was consistent with observed data. Sugar concentrations in fruit flesh were well simulated. Finally, QualiTree allowed for determining the relative importance of photosynthesis and vegetative growth reduction on carbon acquisition, plant growth and fruit quality under water constrains. According to simulations, water deficit impacted vegetative growth first through a direct effect on

  12. Disentangling the Effects of Water Stress on Carbon Acquisition, Vegetative Growth, and Fruit Quality of Peach Trees by Means of the QualiTree Model.

    Science.gov (United States)

    Rahmati, Mitra; Mirás-Avalos, José M; Valsesia, Pierre; Lescourret, Françoise; Génard, Michel; Davarynejad, Gholam H; Bannayan, Mohammad; Azizi, Majid; Vercambre, Gilles

    2018-01-01

    Climate change projections predict warmer and drier conditions. In general, moderate to severe water stress reduce plant vegetative growth and leaf photosynthesis. However, vegetative and reproductive growths show different sensitivities to water deficit. In fruit trees, water restrictions may have serious implications not only on tree growth and yield, but also on fruit quality, which might be improved. Therefore, it is of paramount importance to understand the complex interrelations among the physiological processes involved in within-tree carbon acquisition and allocation, water uptake and transpiration, organ growth, and fruit composition when affected by water stress. This can be studied using process-based models of plant functioning, which allow assessing the sensitivity of various physiological processes to water deficit and their relative impact on vegetative growth and fruit quality. In the current study, an existing fruit-tree model (QualiTree) was adapted for describing the water stress effects on peach ( Prunus persica L. Batsch) vegetative growth, fruit size and composition. First, an energy balance calculation at the fruit-bearing shoot level and a water transfer formalization within the plant were integrated into the model. Next, a reduction function of vegetative growth according to tree water status was added to QualiTree. Then, the model was parameterized and calibrated for a late-maturing peach cultivar ("Elberta") under semi-arid conditions, and for three different irrigation practices. Simulated vegetative and fruit growth variability over time was consistent with observed data. Sugar concentrations in fruit flesh were well simulated. Finally, QualiTree allowed for determining the relative importance of photosynthesis and vegetative growth reduction on carbon acquisition, plant growth and fruit quality under water constrains. According to simulations, water deficit impacted vegetative growth first through a direct effect on its sink strength

  13. Diesel fuel from vegetable oil via transesterification and soap pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Demirbas, A.

    2002-09-15

    Transesterifications of 6 vegetable oil samples in supercritical methanol (SC MeOH) were studied without using any catalyst. Methyl esters of vegetable oils have several outstanding advantages among other new-renewable and clean engine fuel alternatives. The variables affecting the methyl ester yielded during the transesterification reaction, such as the molar ratio of alcohol to vegetable oil and reaction temperature, were investigated. Compared to No. 2 diesel fuel, all of the vegetable oils are much more viscous, while methyl esters of vegetable oils are the slightly more viscous. The methyl esters are more volatile than those of the vegetable oils. The soaps obtained from the vegetable oils can be pyrolyzed into hydrocarbon-rich products. (author)

  14. Dynamics of climatic characteristics influencing vegetation in Siberia

    International Nuclear Information System (INIS)

    Shulgina, Tamara M; Genina, Elena Yu; Gordov, Evgeny P

    2011-01-01

    The spatiotemporal pattern of the dynamics of surface air temperature and precipitation and those bioclimatic indices that are based upon factors which control vegetation cover are investigated. Surface air temperature and precipitation data are retrieved from the ECMWF ERA Interim reanalysis and APHRODITE JMA datasets, respectively, which were found to be the closest to the observational data. We created an archive of bioclimatic indices for further detailed studies of interrelations between local climate and vegetation cover changes, which include carbon uptake changes related to changes of vegetation types and amount, as well as with spatial shifts of vegetation zones. Meanwhile, analysis reveals significant positive trends of the growing season length accompanied by a statistically significant increase of the sums of the growing degree days and precipitation over the south of West Siberia. The trends hint at a tendency for an increase of vegetation ecosystems' productivity across the south of West Siberia (55°–60°N, 59°–84°E) in the past several decades and (if sustained) may lead to a future increase of vegetation productivity in this region.

  15. GLS-Finder: A Platform for Fast Profiling of Glucosinolates in Brassica Vegetables.

    Science.gov (United States)

    Sun, Jianghao; Zhang, Mengliang; Chen, Pei

    2016-06-01

    Mass spectrometry combined with related tandem techniques has become the most popular method for plant secondary metabolite characterization. We introduce a new strategy based on in-database searching, mass fragmentation behavior study, formula predicting for fast profiling of glucosinolates, a class of important compounds in brassica vegetables. A MATLAB script-based expert system computer program, "GLS-Finder", was developed. It is capable of qualitative and semi-quantitative analyses of glucosinolates in samples using data generated by ultrahigh-performance liquid chromatography-high-resolution accurate mass with multi-stage mass fragmentation (UHPLC-HRAM/MS(n)). A suite of bioinformatic tools was integrated into the "GLS-Finder" to perform raw data deconvolution, peak alignment, glucosinolate putative assignments, semi-quantitation, and unsupervised principal component analysis (PCA). GLS-Finder was successfully applied to identify intact glucosinolates in 49 commonly consumed Brassica vegetable samples in the United States. It is believed that this work introduces a new way of fast data processing and interpretation for qualitative and quantitative analyses of glucosinolates, where great efficacy was improved in comparison to identification manually.

  16. Integrated monitoring of hydrogeomorphic, vegetative, and edaphic conditions in riparian ecosystems of Great Basin National Park, Nevada

    Science.gov (United States)

    Beever, Erik A.; Pyke, D.A.

    2004-01-01

    In semiarid regions such as the Great Basin, riparian areas function as oases of cooler and more stable microclimates, greater relative humidity, greater structural complexity, and a steady flow of water and nutrients relative to upland areas. These qualities make riparian areaʼs attractive not only to resident and migratory wildlife, but also to visitors in recreation areas such as Great Basin National Park in the Snake Range, east-central Nevada. To expand upon the system of ten permanent plots sampled in 1992 (Smith et al. 1994) and 2001 (Beever et al. in press), we established a collection of 31 cross-sectional transects of 50-m width across the mainstems of Strawberry, Lehman, Baker, and Snake creeks. Our aims in this research were threefold: a) map riparian vegetative communities in greater detail than had been done by past efforts; b) provide a monitoring baseline of hydrogeomorphology; structure, composition, and function of upland- and riparianassociated vegetation; and edaphic properties potentially sensitive to management; and c) test whether instream conditions or physiographic variables predicted vegetation patterns across the four target streams.

  17. Simulations of Vegetation Impacts on Arctic Climate

    Science.gov (United States)

    Bonfils, C.; Phillips, T. J.; Riley, W. J.; Post, W. M.; Torn, M. S.

    2009-12-01

    Because global warming disproportionately influences high-latitude climate, changes in arctic vegetation are in progress. These land-cover changes include redistribution of local vegetation types as well as northward migration of lower-latitude species in response to the increasing warming. The resulting displacement of low-lying tundra vegetation by shrubs and trees darkens the surface, thus accelerating regional warming. As participants in the U.S. Department of Energy IMPACTS Project, we are investigating the potential for abrupt arctic climatic change resulting from such variations in vegetation, among other mechanisms. To estimate the relative magnitudes of effects to be expected from changes in high-latitude land cover, we are conducting several numerical experiments with the Community Climate System Model (CCSM). These experiments include: 1) A “present-day-climate” control experiment with current atmospheric greenhouse-gas concentrations and climatological monthly sea surface temperatures and sea ice extents prescribed, and with “standard” CLM plant functional types (PFTs) specified; 2) A “changed-vegetation-type” experiment that is the same as 1), except that the “standard” PFTs are augmented by additional vegetation types (forbs, sedges, shrubs, mosses, and lichens) that are not presently represented in CLM. This experiment will require information on the location, fractional cover, and physiological parameterizations of these new PFTs. 3) A “changed-vegetation-extent experiment” that is the same as 2), except that the spatial extents of selected PFTs (e.g. shrubs or boreal forest PFTs) are shifted northward from their present locations in the CLM. We will report on the atmospheric climate and land-surface feedbacks associated with these vegetation changes, with emphasis on local and regional surface energy and moisture fluxes and near-surface temperature, humidity, and clouds. Acknowledgments This work was performed under the auspices

  18. Biota - 2009 Vegetation Inventory - Lake Ashtabula, ND

    Data.gov (United States)

    Army Corps of Engineers, Department of the Army, Department of Defense — 2009 Vegetation Classification for Lake Ashtabula, ND Vegetation Project Report, OMBIL Environmental Stewardship - Level 1 Inventory, U.S. Army Corps of Engineers...

  19. Biota - 2011 Vegetation Inventory - Marsh Lake, MN

    Data.gov (United States)

    Army Corps of Engineers, Department of the Army, Department of Defense — 2011 Vegetation Classification for Marsh Lake, MN Vegetation Project Report, OMBIL Environmental Stewardship - Level 1 Inventory. Marsh Lake is located on the...

  20. Marketing African Leafy Vegetables: Challenges and Opportunities ...

    African Journals Online (AJOL)

    Marketing African Leafy Vegetables: Challenges and Opportunities in the Kenyan Context. ... The market share of ALVs vis-à-vis other vegetable species, particularly kales, cabbages and ... EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT