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LANDSCAPE ECOLOGICAL METHOD TO STUDY AGRICULTURAL VEGETATION: SOME EXAMPLES FROM THE PO VALLEY  

Directory of Open Access Journals (Sweden)

Full Text Available Vegetation is the most important landscape component, as regards to its ability to catch solar energy and to transform it, but also to shape the landscape, to structure the space, to create the fit environment for different animal species, to contribute to the maintenance of a correct metastability level for the landscape, etc. It is a biological system which acts under the constraints of the principles of the System Theory and owns the same properties of any other living system: so, it is a complex adaptive, hierarchical, dynamic, dissipative, self-organizing, self-transcendent, autocatalytic, self-maintaining system and follows the non-equilibrium thermodynamic. Its ecological state can be investigated through the comparison between “gathered data” (pathology and “normal data” (physiology for analogous types of vegetation. The Biological Integrated School of Landscape Ecology provides an integrated methodology to define ecological threshold limits of the different Agricultural Landscape types and applies to agricultural vegetation the specific part of the new methodology already tested to studying forests (the Landscape Biological Survey of Vegetation. Ecological quality, better and worst parameters, biological territorial capacity of vegetated corridors, agricultural field, poplar groves, orchards and woody remnant patches are investigated. Some examples from diverse agricultural landscapes of the Po Valley will be discussed. KEY WORDS: agricultural landscape, vegetation, landscape ecology, landscape health, Biological Integrated Landscape Ecology, Landscape Biological Survey of vegetation.

E. GIGLIO

2006-01-01

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The vegetation of Yucca Mountain: Description and ecology  

International Nuclear Information System (INIS)

Vegetation at Yucca Mountain, Nevada, was monitored over a six-year period, from 1989 through 1994. Yucca Mountain is located at the northern limit of the Mojave Desert and is the only location being studied as a potential repository for high-level nuclear waste. Site characterization consists of a series of multidisciplinary, scientific investigations designed to provide detailed information necessary to assess the suitability of the Yucca Mountain Site as a repository. This vegetation description establishes a baseline for determining the ecological impact of site characterization activities; it porvides input for site characterization research and modeling; and it clarifies vegetation community dynamics and relationships to the physical environment. A companion study will describe the impact of site characterization of vegetation. Cover, density, production, and species composition of vascular plants were monitored at 48 Ecological Study Plots (ESPs) stratified in four vegetation associations. Precipitation, soil moisture, and maximum and minimum temperatures also were measured at each study plot

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The vegetation of Yucca Mountain: Description and ecology  

Energy Technology Data Exchange (ETDEWEB)

Vegetation at Yucca Mountain, Nevada, was monitored over a six-year period, from 1989 through 1994. Yucca Mountain is located at the northern limit of the Mojave Desert and is the only location being studied as a potential repository for high-level nuclear waste. Site characterization consists of a series of multidisciplinary, scientific investigations designed to provide detailed information necessary to assess the suitability of the Yucca Mountain Site as a repository. This vegetation description establishes a baseline for determining the ecological impact of site characterization activities; it porvides input for site characterization research and modeling; and it clarifies vegetation community dynamics and relationships to the physical environment. A companion study will describe the impact of site characterization of vegetation. Cover, density, production, and species composition of vascular plants were monitored at 48 Ecological Study Plots (ESPs) stratified in four vegetation associations. Precipitation, soil moisture, and maximum and minimum temperatures also were measured at each study plot.

NONE

1996-03-29

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Ecological investigations: vegetation studies, preliminary findings  

Energy Technology Data Exchange (ETDEWEB)

The objective of the vegetation studies conducted on the research site is to produce a descriptive data base that can be applied to determinations of carrying capacity of the site and surrounding area. Additional information obtained about parameters that influence vegetation growth and maintenance of soil nutrients, and moisture and temperature regimes help define dynamic relationships that must be understood to effect successful revegetation and habitat rehabilitation. The descriptive vegetation baseline also provides a point of departure for design of future monitoring programs, and predictive models and strategies to be used in dealing with impact mitigation; in turn, monitoring programs and predictive modeling form the bases for making distinctions between natural trends and man-induced perturbations.

Olgeirson, E.R.; Martin, R.B.

1978-09-01

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Alternative Ecology of Human Pathogenic Bacteria in Fruits and Vegetables  

Directory of Open Access Journals (Sweden)

Full Text Available Outbreaks of illness due to human enteric pathogenic bacteria via fresh vegetables warrant intensive research on changing strategies of these bacteria in alterning their hosts for survival. The systemic infection of human pathogenic bacteria in plants and the plant growth stage at which they establish endophytic relationship is poorly understood. The issue is magnified in countries like India where the dietary habits are changing and consumption of fresh fruits and vegetables as salad has become a part in the everyday menu of most people. Most of the human pathogenic enteric bacteria are generally characterized by broad host ranges and these pathogens seem to exploit almost any change in human ecology that provides new opportunities for transmission. Because plants are not traditionally considered as hosts for human enteric pathogens, recent produce-associated outbreaks highlight important deficiencies in our understanding of the ecology of enteric pathogens outside of their human and animal hosts. This review focuses on understanding the human enteric pathogens that have developed abilities to colonize internal tissues of vegetables and fruits popularly consumed as salads, how and when do they enter plants and where do they localize in plant tissues. In addition, we have also highlighted the attempts made in detection and control of these bacteria in plant hosts. This understanding will help develop strategies towards vegetable food safety in a joint effort by agriculturalists, environmentalists, food processing agencies, whole salers and retailers, which will ultimately benefit every consumer.

A. Nithya

2014-01-01

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Arctic Ecological Classifications Derived from Vegetation Community and Satellite Spectral Data  

Directory of Open Access Journals (Sweden)

Full Text Available As a result of the warming observed at high latitudes, there is significant potential for the balance of ecosystem processes to change, i.e., the balance between carbon sequestration and respiration may be altered, giving rise to the release of soil carbon through elevated ecosystem respiration. Gross ecosystem productivity and ecosystem respiration vary in relation to the pattern of vegetation community type and associated biophysical traits (e.g., percent cover, biomass, chlorophyll concentration, etc.. In an arctic environment where vegetation is highly variable across the landscape, the use of high spatial resolution imagery can assist in discerning complex patterns of vegetation and biophysical variables. The research presented here examines the relationship between ecological and spectral variables in order to generate an ecologically meaningful vegetation classification from high spatial resolution remote sensing data. Our methodology integrates ordination and image classifications techniques for two non-overlapping Arctic sites across a 5° latitudinal gradient (approximately 70° to 75°N. Ordination techniques were applied to determine the arrangement of sample sites, in relation to environmental variables, followed by cluster analysis to create ecological classes. The derived classes were then used to classify high spatial resolution IKONOS multispectral data. The results demonstrate moderate levels of success. Classifications had overall accuracies between 69%–79% and Kappa values of 0.54–0.69. Vegetation classes were generally distinct at each site with the exception of sedge wetlands. Based on the results presented here, the combination of ecological and remote sensing techniques can produce classifications that have ecological meaning and are spectrally separable in an arctic environment. These classification schemes are critical for modeling ecosystem processes.

David M. Atkinson

2012-12-01

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PROPOSAL OF A NEW METHOO OF ECOLOGICAL EVALUATION OF VEGETATION: THE CASE STUDY OF THE VEGETATION OF THE VENICE LAGOON LANDSCAPE ANO OF ITS SALT MARSHES  

Directory of Open Access Journals (Sweden)

Full Text Available

In frequent case studies, the heterogeneity of vegetation formation is very high, because of the frequency of both natural and human disturbances. Consequently, the phytosociological approach .and the auto-ecological one are not completely adequate for the evaluation or the ecological state of this vegetation in a landscape.

So, this evaluation needs the integration with a landscape ecological method of vegetation survey through schedules, as indicated by Ingegnoli (2002. Each type of schedule has been designed to check the organisation level and to estimate the metastability of a tessera of a certain type of vegetation, considering both general ecological and landscape ecological characters: (A Landscape e1ement characters (e.g. tessera, corridor, (8 Plant, biomass above ground, (C Ecocoenotope pararneters. (D Relation among the elements and their landscape parameters. There are four evaluation classes, the weights per class depending on an evaluation model designed as shown later on. The principal aim of this research is to design a new schedule, available for the main coenosis of salt marshes vegetation, which allows to complete a preliminary study on the Venice lagoon landscape dynamics, based on its vegetation. The landscape of the Venice lagoon is very complex and articulated, its main vegetation formations are the following: Underwater, Salt marshes. Littoral. Reclamation colonisations, Wet areas. Wooded patches and corridors. Agricultural cultivations, Urban green. The most important typc of vegetation is represented by salt marshes prairies called "barene", especially by Limonietum venetum (Pignani. 1966, This association can be divided into three sub-associations, the first with three facies: but the reality presents a large quantity of tesserae in intermediate or ecotonal states, even mixed with other associations (e,g, Spartinetum maritimae. The design and control of the schedule, the first measure of the community plant biomasses are a part of this study, me results of which will be discussed in this work.

E. GIGLIO

2004-01-01

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Effect of stand types on understory vegetation.  

Science.gov (United States)

The objective of this study was to compare density vegetative cover, basal area, height growth, aboveground biomass production, frequency floristic composition, and species diversity of understory vegetation growing in Hungarian oak (Quercus frainetto Ten.), Oriental beech (Fagus orientalis L.) and a mixed stand of both species (90% Hungarian oak and 10% Oriental beech) with the same crown closure. Understory vegetation was sampled with a quadrat of 0.5 m x 1 m along the 25 m-long transect lines in each stand. A total of seventeen perennial plant species from thirteen different families were found in the three stand types and all of them were present in Hungarian oak stand, eleven in Oriental beech stand, and seven in the mixed stand of Hungarian oak and Oriental beech trees. Results showed that stand types had a statistically significant effect on density, vegetative cover, basal area, height growth, biomass production, frequency floristic composition, and species diversity of understory vegetation. Total understory vegetation density was the highest for Hungarian oak stand with about 136 plants m(-2) and the lowest for the mixed stand of Hungarian oak and Oriental beech with 44 plants m(-2). In addition, the Hungarian oak stand had the most diverse understory vegetation with about 4.3 different plant m(-2), followed by the Oriental beech stand with 3.7 plants m(-2), and the mixed stand of the Hungarian oak and Oriental beech with 2.7 plants m(-2). Species density and diversity were the highest in Hungarian oak stand whereas aboveground biomass production and height growth of understory vegetation were highest in the mixed stand. PMID:20120502

Ister, Sena I; Gokbulak, Ferhat

2009-07-01

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Ecological characteristics of plankton and aquatic vegetation in Lake Qiluhu.  

Science.gov (United States)

Investigations of the phytoplankton, zooplankton, zoobenthos and aquatic vegetation in Lake Qiluhu were carried out in February, 2009. Over the whole lake, 13 sampling sites were set up for the analysis of phytoplankton and zooplankton, and 22 profiles for the collection of macrophytes and zoobenthos. In the survey, 7 phyla, 65 algae species were identified. The average abundance of phytoplankton was 7.16 × 10(8) cells/L, and the dominant specie was Limnothrix redekei. No obvious surface accumulation of algae was detected. The concentration of Chlorophyll a ranged from 85 to 101 ?g/L, and the average value was 93 ?g/L. Nineteen species of zooplankton were observed, including 4 species of rotifers, 6 species of cladocerans and 9 species of copepods. Copepods were the dominant species, their abundance reaching 68%, whilst Cladocerans took second place with an abundance proportion of 28%. Six species of submerged vegetation were identified: Potamogeton Pectinatus, Myriophyllum, Elodea Canadensis, Ceratophyllum demersum and Potamogeton crispus. Amongst them, the dominant vegetation was P. Pectinatus, the biomass of which was up to 63% of the total biomass. Emerged macrophytes were cluster distributed across the whole lake, mainly consisting of Scirpus tabernaemontani, phragmites communis and cane shoots. Unfortunately, no living zoobenthos were found at the sites. The results indicated that, in Lake Qiluhu, the abundance of phytoplankton was maintained at a high level. The ecological function of submerged vegetation was gradually being lost because of its low standing crop and coverage, and the benthic animal habitat was severely damaged. PMID:24759520

Mingming, Hu; Huaidong, Zhou; Yuchun, Wang; Yingcai, Wang; Zhen, Wang; Weiju, Wu; Gaofeng, Zhao; Yao, Cheng; Yongding, Liu

2014-01-01

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Next generation dynamic global vegetation models: learning from community ecology (Invited)  

Science.gov (United States)

Dynamic global vegetation models are a powerful tool to project past, current and future vegetation patterns and the associated biogeochemical cycles. However, most models are limited by their representation of vegetation by using static and pre-defined plant functional types and by their simplistic representation of competition. We discuss how concepts from community assembly theory and coexistence theory can help to improve dynamic vegetation models. We present a trait- and individual-based dynamic vegetation model, the aDGVM2, that allows individual plants to adopt a unique combination of trait values. These traits define how individual plants grow, compete and reproduce under the given biotic and abiotic conditions. A genetic optimization algorithm is used to simulate trait inheritance and reproductive isolation between individuals. These model properties allow the assembly of plant communities that are adapted to biotic and abiotic conditions. We show (1) that the aDGVM2 can simulate coarse vegetation patterns in Africa, (2) that changes in the environmental conditions and disturbances strongly influence trait diversity and the assembled plant communities by influencing traits such as leaf phenology and carbon allocation patterns of individual plants and (3) that communities do not necessarily return to the initial state when environmental conditions return to the initial state. The aDGVM2 deals with functional diversity and competition fundamentally differently from current models and allows novel insights as to how vegetation may respond to climate change. We believe that the aDGVM2 approach could foster collaborations between research communities that focus on functional plant ecology, plant competition, plant physiology and Earth system science.

Scheiter, S.; Higgins, S.; Langan, L.

2013-12-01

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Past and present vegetation ecology of Laetoli, Tanzania.  

Science.gov (United States)

We are attempting to set up a new protocol for palaeoecological reconstruction in relation to the fossil hominin site Laetoli, Tanzania. This is based on the premise that habitat variability in the past was at least as great as at present; that this variability at the landscape level is a function of variations in geology, soils, and topography rather than climate; and that vegetation type at the landscape level can be reconstructed from these environmental variables. Measurable variation in climate in tropical Africa today occurs over distances of at least 100 km, so that ranges of habitat variation within the limited area of Laetoli today can be reconstructed in relation to soils and topography, and the effects of climate changes are then estimated in relation to these other factors. In order to document the modern vegetation, we have made voucher collections of plants in the Laetoli region, recorded distributions of plants by habitat, climate, soil, and topography, and mapped the vegetation distributions. Results show that areas of low relief have soils with impeded drainage and dense Acacia drepanolobium woodland, having low canopies when disturbed by human action, higher when not; shallow brown soils on volcanic lavas have four woodland associations, two dominated by Acacia species, two by Combretum-Albizia species; shallow volcanic soils to the east have a woodland association with Croton-Dombeya-Albizia species; elevated land to the east on volcanic soils has two associations of montane-edge species, one with Croton-Celtis-Lepidotrichilia, and the other with Acacia lahai; the eastern highlands above 2,750 m have montane forest; seasonal water channels flowing from east to west have three Acacia riverine woodland associations; three deep valleys to the north of the area have dense riverine woodland with Celtis, Albizia, Euclea, Combretum, Acacia spp.; emergence of springs at Endulen feed a perennial stream with closed gallery forest with Ficus-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. PMID:17765945

Andrews, Peter; Bamford, Marion

2008-01-01

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The integration of GPS, vegetation mapping and GIS in ecological and behavioural studies  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english Global Positioning System (GPS) satellite navigation receivers are increasingly being used in ecological and behavioural studies to track the movements of animals in relation to the environments in which they live and forage. Concurrent recording of the animal's foraging behaviour (e.g. from jaw mov [...] ement recording) allows foraging locations to be determined. By combining the animal GPS movement and foraging data with habitat and vegetation maps using a Geographical Information System (GIS) it is possible to relate animal movement and foraging location to landscape and habitat features and vegetation types. This powerful approach is opening up new opportunities to study the spatial aspects of animal behaviour, especially foraging behaviour, with far greater precision and objectivity than before. Advances in GPS technology now mean that sub-metre precision systems can be used to track animals, extending the range of application of this technology from landscape and habitat scale to paddock and patch scale studies. As well as allowing ecological hypotheses to be empirically tested at the patch scale, the improvements in precision are also leading to the approach being increasing extended from large scale ecological studies to smaller (paddock) scale agricultural studies. The use of sub-metre systems brings both new scientific opportunities and new technological challenges. For example, fitting all of the animals in a group with sub-metre precision GPS receivers allows their relative inter-individual distances to be precisely calculated, and their relative orientations can be derived from data from a digital compass fitted to each receiver. These data, analyzed using GIS, could give new insights into the social behaviour of animals. However, the improvements in precision with which the animals are being tracked also needs equivalent improvements in the precision with which habitat and vegetation are mapped. This needs some degree of automation, as vegetation mapping at a fine spatial scale using the traditional manual approach is far too time consuming. This paper explores these issues, discussing new applications as well as approaches to overcoming some of the associated problems.

Steven Mark, Rutter.

2007-07-01

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Future vegetation types and related main processes for Olkiluoto site  

International Nuclear Information System (INIS)

This working report summarizes current knowledge of the land up-lift induced vegetation succession and future vegetation types on Olkiluoto Island and its surroundings. The report is based on generic literature and site-specific studies concerning Olkiluoto Island. Current vegetation on Olkiluoto Island and typical succession lines on different soil types are described, as well as main factors affecting the succession. Most relevant materials on hand are listed. Some problems and possible areas to be emphasized before using the data in modelling work are pointed out. (orig.)

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Future vegetation types and related main processes for Olkiluoto site  

Energy Technology Data Exchange (ETDEWEB)

This working report summarizes current knowledge of the land up-lift induced vegetation succession and future vegetation types on Olkiluoto Island and its surroundings. The report is based on generic literature and site-specific studies concerning Olkiluoto Island. Current vegetation on Olkiluoto Island and typical succession lines on different soil types are described, as well as main factors affecting the succession. Most relevant materials on hand are listed. Some problems and possible areas to be emphasized before using the data in modelling work are pointed out. (orig.)

Haapanen, R. (Haapanen Forest Consulting, Vanhakylae (FI))

2007-07-15

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The effects of sampling method and vegetation type on the estimated abundance of Ixodes ricinus ticks in forests  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Estimating the spatial and temporal variation in tick abundance is of great economical and ecological importance. Entire-blanket dragging is the most widely used method to sample free-living ixodid ticks. However, this technique is not equally efficient in different vegetation types. The height and structure of the vegetation under study will not only determine the likelihood of a tick-blanket contact, but will also determine the rate of dislodgement. The purpose of this study was therefore t...

Tack, W.; Madder, M.; Frenne, P.; Vanhellemont, M.; Gruwez, R.; Verheyen, K.

2011-01-01

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Effect of vegetation on rock and soil type discrimination  

Science.gov (United States)

The effect of naturally occurring vegetation on the spectral reflectance of earth materials in the wavelength region of 0.45 to 2.4 microns is determined by computer averaging of in situ acquired spectral data. The amount and type of vegetation and the spectral reflectance of the ground are considered. Low albedo materials may be altered beyond recognition with only ten per cent green vegetation cover. Dead or dry vegetation does not greatly alter the shape of the spectral reflectance curve and only changes the albedo with minimum wavelength dependency. With increasing amounts of vegetation the Landsat MSS band ratios 4/6, 4/7, 5/6, and 5/7 are significantly decreased whereas MSS ratios 4/5 and 6/7 remain entirely constant.

Siegal, B. S.; Goetz, A. F. H.

1977-01-01

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Ecological physiological characteristic of some species of natural vegetation in the Poles'e State Radiation Ecological Reservation  

International Nuclear Information System (INIS)

Influence of radiation on important ecological and physiological characteristics of Pinus silvestris L., Phleum pratense L. and Dactylis glomerata L. growing on territory of the Poles'e State Radiation Ecological Reservation has been investigated in 1992-1994. Significant changes in species and quantitative formation of natural vegetation growing on territory contaminated by the Chernobyl accident release were not observed. Positive correlation between the content of protein in needles of Pinus silvestris L., leaves of Agropyron repens L. and specific radioactivity of photosystem was established. Positive correlation between specific radioactivity of overground photosystem and quantity of nucleic acids (DNA+RNA) is leaves of Dactylis glomerata was found. 8 refs., 2 tabs., 2 figs

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Assessing uncertainties in a second-generation dynamic vegetation model caused by ecological scale limitations.  

Science.gov (United States)

*Second-generation Dynamic Global Vegetation Models (DGVMs) have recently been developed that explicitly represent the ecological dynamics of disturbance, vertical competition for light, and succession. Here, we introduce a modified second-generation DGVM and examine how the representation of demographic processes operating at two-dimensional spatial scales not represented by these models can influence predicted community structure, and responses of ecosystems to climate change. *The key demographic processes we investigated were seed advection, seed mixing, sapling survival, competitive exclusion and plant mortality. We varied these parameters in the context of a simulated Amazon rainforest ecosystem containing seven plant functional types (PFTs) that varied along a trade-off surface between growth and the risk of starvation induced mortality. *Varying the five unconstrained parameters generated community structures ranging from monocultures to equal co-dominance of the seven PFTs. When exposed to a climate change scenario, the competing impacts of CO(2) fertilization and increasing plant mortality caused ecosystem biomass to diverge substantially between simulations, with mid-21st century biomass predictions ranging from 1.5 to 27.0 kg C m(-2). *Filtering the results using contemporary observation ranges of biomass, leaf area index (LAI), gross primary productivity (GPP) and net primary productivity (NPP) did not substantially constrain the potential outcomes. We conclude that demographic processes represent a large source of uncertainty in DGVM predictions. PMID:20618912

Fisher, Rosie; McDowell, Nate; Purves, Drew; Moorcroft, Paul; Sitch, Stephen; Cox, Peter; Huntingford, Chris; Meir, Patrick; Woodward, F Ian

2010-08-01

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Characterizing the Seasonal Dynamics of Plant Community Photosynthesis Across a Range of Vegetation Types  

Energy Technology Data Exchange (ETDEWEB)

The seasonal cycle of plant community photosynthesis is one of the most important biotic oscillations to mankind. This study built upon previous efforts to develop a comprehensive framework to studying this cycle systematically with eddy covariance flux measurements. We proposed a new function to represent the cycle and generalized a set of phenological indices to quantify its dynamic characteristics. We suggest that the seasonal variation of plant community photosynthesis generally consists of five distinctive phases in sequence each of which results from the interaction between the inherent biological and ecological processes and the progression of climatic conditions and reflects the unique functioning of plant community at different stages of the growing season. We applied the improved methodology to seven vegetation sites ranging from evergreen and deciduous forests to crop to grasslands and covering both cool-season (vegetation active during cool months, e.g. Mediterranean climate grasslands) and warm-season (vegetation active during warm months, e.g. temperate and boreal forests) vegetation types. Our application revealed interesting phenomena that had not been reported before and pointed to new research directions. We found that for the warm-season vegetation type, the recovery of plant community photosynthesis at the beginning of the growing season was faster than the senescence at the end of the growing season while for the coolseason vegetation type, the opposite was true. Furthermore, for the warm-season vegetation type, the recovery was closely correlated with the senescence such that a faster photosynthetic recovery implied a speedier photosynthetic senescence and vice versa. There was evidence that a similar close correlation could also exist for the cool-season vegetation type, and furthermore, the recovery-senescence relationship may be invariant between the warm-season and cool-season vegetation types up to an offset in the intercept. We also found that while the growing season length affected how much carbon dioxide could be potentially assimilated by a plant community over the course of a growing season, other factors that affect canopy photosynthetic capacity (e.g. nutrients, water) could be more important at this time scale. These results and insights demonstrate that the proposed method of analysis and system of terminology can serve as a foundation for studying the dynamics of plant community photosynthesis and such studies can be fruitful.

Gu, Lianhong [ORNL; Post, Wilfred M [ORNL; Baldocchi, Dennis [University of California, Berkeley; Black, Andy [University of British Columbia, Vancouver; Suyker, A.E., [University of Nebraska, Lincoln; Verma, Shashi [University of Nebraska; Vesala, Timo [University of Helsinki; Wofsy, Steve [Harvard University

2009-01-01

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Comparison of total polyphenol contents And antioxidant activity in cruciferous vegetables grown in diversified ecological conditions  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Background.The aim of this study was to compare total polyphenol contents and antioxidant activity of three species of cruciferous vegetables grown under diversified ecological conditions for three consecutive years. Material and methods. Methanol extracts were prepared to be used to determine (spectrometrically) the content of total phenolics, using the Folin-Ciocalteau reagent and antioxidant activity by identifying the sam- ple’s ability to extinguish an ABTS•+free radic...

Joanna Kapusta-Duch; Teresa Leszczy?ska; Agnieszka Filipiak-Florkiewicz

2012-01-01

 
 
 
 
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Comparison of total polyphenol contents And antioxidant activity in cruciferous vegetables grown in diversified ecological conditions  

Directory of Open Access Journals (Sweden)

Full Text Available Background.The aim of this study was to compare total polyphenol contents and antioxidant activity of three species of cruciferous vegetables grown under diversified ecological conditions for three consecutive years. Material and methods. Methanol extracts were prepared to be used to determine (spectrometrically the content of total phenolics, using the Folin-Ciocalteau reagent and antioxidant activity by identifying the sam- ple’s ability to extinguish an ABTS•+free radical. Results.All these species of cruciferous vegetables contained similar total polyphenols amounts regardless of its origin. Only red cabbage from organic farms was characterized by significantly higher antioxidant activity compared to vegetables purchased from local retailers in Cracow and similar or those cultivated near the steelworks. In white cabbage from farms located in a former steelworks protection zone a higher antioxidant activity was found than in organically grown vegetables and similar to that in vegetables available in retail. Brussels sprouts was characterised by a similar antioxidant activity regardless of its origin. Conclusions. On the basis of the present study, it cannot be concluded that organically grown cruciferous vegetables generally have higher contents of health-promoting secondary metabolites in comparison with the conventionally cultivated ones.

Joanna Kapusta-Duch

2012-12-01

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Weed vegetation ecology of arable land in Salalah, Southern Oman.  

Science.gov (United States)

This paper applies multivariate statistical methods to a data set of weed relevés from arable fields in two different habitat types of coastal and mountainous escarpments in Southern Oman. The objectives were to test the effect of environmental gradients, crop plants and time on weed species composition, to rank the importance of these particular factors, and to describe the patterns of species composition and diversity associated with these factors. Through the application of TWINSPAN, DCA and CCA programs on data relating to 102 species recorded in 28 plots and farms distributed in the study area, six plant communities were identified: I- Dichanthium micranthum, II- Cynodon dactylon-D. micranthum, III- Convolvulus arvensis, IV- C. dactylon-Sonchus oleraceus, V- Amaranthus viridis and VI- Suaeda aegyptiaca-Achyranthes aspera. The ordination process (CCA) provided a sequence of plant communities and species diversity that correlated with some anthropogenic factors, physiographic variables and crop types. Therefore, length of time since farm construction, disturbance levels and altitude are the most important factors related to the occurrence of the species. The perennial species correlated with the more degraded mountain areas of new farm stands, whereas most of the annuals correlated with old lowland and less disturbed farms. PMID:23961246

El-Sheikh, Mohamed A

2013-07-01

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INFLUENCE OF THE SOIL ON GROWING TYPES OF WOOD VEGETATION  

Directory of Open Access Journals (Sweden)

Full Text Available The article reflects influences of soil conditions on growing types of wood vegetation. The carried-out chemical analyses show quantity of chemical elements which have to arrive to the soil with tree waste, and also acidity of the soil

Irkovsky E. R.

2013-10-01

24

[Influence of three types of riparian vegetation on fluvial erosion control in Pantanos de Centla, Mexico].  

Science.gov (United States)

Wetlands constitute very important ecological areas. The aim of this study was to quantify the soil losses due to fluvial erosion from 2006 to 2008 in two riverbanks under three types of vegetal coverage dominated by Haematoxylum campechianum, Dalbergia brownei and Brachiaria mutica, in the Pantanos de Centla Biosphere Reserve, SE Mexico. The relationship between the texture, organic matter and pH of soils and soil losses was evaluated. We used erosion sticks to estimate soil losses in 18 plots (three plots per type, three vegetation types, two riverbanks). Soil loss decreased in this order: H. campechianum>B. mutica>D. brownei indicating that D. brownei scrubland has the most potential to retain soil. The higher erosive impact within H. campechianum sites can be related with the low density of these trees in the study areas, as well as the lack of association with other types of vegetation that could reinforce the rooting of the soil profile. Furthermore, soil losses in H. campechianum sites were dependent on soil texture. The soils under this type of vegetal coverage were mainly sandy, which are more vulnerable to the erosive action in comparison with fine textured soils or soils with higher clay content, like the ones found in D. brownei and B. mutica sites. Soil losses of 100 % in the second year (B. mutica plots) can be attributed to the distribution of roots in the upper soil layer and also to livestock management along riverbanks. This study recognizes the importance of D. brownei scrublands in riverbank soil retention. Nevertheless it is necessary to consider the role of an entire vegetal community in future research. PMID:20073341

Sepúlveda-Lozada, Alejandra; Geissen, Violette; Ochoa-Gaona, Susana; Jarquín-Sánchez, Aarón; de la Cruz, Simón Hernández; Capetillo, Edward; Zamora-Cornelio, Luis Felipe

2009-12-01

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Soil microbial properties under different vegetation types on Mountain Han.  

Science.gov (United States)

This study investigated the influence of broadleaf and conifer vegetation on soil microbial communities in a distinct vertical distribution belt in Northeast China. Soil samples were taken at 0-5, 5-10 and 10-20 cm depths from four vegetation types at different altitudes, which were characterized by poplar (Populus davidiana) (1250-1300 m), poplar (P. davidiana) mixed with birch (Betula platyphylla) (1370-1550 m), birch (B. platyphylla) (1550-1720 m), and larch (Larix principis-rupprechtii) (1840-1890 m). Microbial biomass and community structure were determined using the fumigation-extraction method and phospholipid fatty acid (PLFA) analysis, and soil fungal community level physiological profiles (CLPP) were characterized using Biolog FF Microplates. It was found that soil properties, especially soil organic carbon and water content, contributed significantly to the variations in soil microbes. With increasing soil depth, the soil microbial biomass, fungal biomass, and fungal catabolic ability diminished; however, the ratio of fungi to bacteria increased. The fungal ratio was higher under larch forests compared to that under poplar, birch, and their mixed forests, although the soil microbial biomass was lower. The direct contribution of vegetation types to the soil microbial community variation was 12%. If the indirect contribution through soil organic carbon was included, variations in the vegetation type had substantial influences on soil microbial composition and diversity. PMID:23737003

Wang, Miao; Qu, Laiye; Ma, Keming; Yuan, Xiu

2013-06-01

26

Vegetation  

DEFF Research Database (Denmark)

• Over the past 30 years (1982-2011), the Normalized Difference Vegetation Index (NDVI), an index of green vegetation, has increased 15.5% in the North American Arctic and 8.2% in the Eurasian Arctic. In the more southern regions of Arctic tundra, the estimated aboveground plant biomass has 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.

Epstein, H.E.; Walker, D.A.

2012-01-01

27

Effects of Mixing Interaction Types on Ecological Community Stability  

CERN Document Server

In the last years, a remarkable theoretical effort has been made in order to understand stability and complexity in ecological communities. The non-random structures of real ecological interaction networks has been recognized as one key ingredient contributing to the coexistence between high complexity and stability in real ecosystems. However most of the theoretical studies have considered communities with only one interaction type (either antagonistic, competitive, or mutualistic). Recently it has been proposed a theoretical analysis on multiple interaction types in ecological systems, concluding that: a) Mixture of antagonistic and mutualistic interactions stabilize the system with respect to the less realistic case of only one interaction type; b) Complexity, measured in terms of the number of interactions and the number of species, increases stability in systems with different types of interactions. By introducing new theoretical investigations and analyzing 21 empirical data sets representing mutualisti...

Suweis, Samir; Maritan, Amos

2013-01-01

28

Forests, savannas and grasslands: bridging the knowledge gap between ecology and Dynamic Global Vegetation Models  

Directory of Open Access Journals (Sweden)

Full Text Available The forest, savanna, and grassland biomes, and the transitions between them, are expected to undergo major changes in the future, due to global climate change. Dynamic Global Vegetation Models (DGVMs are very useful to understand vegetation dynamics under present climate, and to predict its changes under future conditions. However, several DGVMs display high uncertainty in predicting vegetation in tropical areas. Here we perform a comparative analysis of three different DGVMs (JSBACH, LPJ-GUESS-SPITFIRE and aDGVM with regard to their representation of the ecological mechanisms and feedbacks that determine the forest, savanna and grassland biomes, in an attempt to bridge the knowledge gap between ecology and global modelling. Model outcomes, obtained including different mechanisms, are compared to observed tree cover along a mean annual precipitation gradient in Africa. Through these comparisons, and by drawing on the large number of recent studies that have delivered new insights into the ecology of tropical ecosystems in general, and of savannas in particular, we identify two main mechanisms that need an improved representation in the DGVMs. The first mechanism includes water limitation to tree growth, and tree-grass competition for water, which are key factors in determining savanna presence in arid and semi-arid areas. The second is a grass-fire feedback, which maintains both forest and savanna occurrences in mesic areas. Grasses constitute the majority of the fuel load, and at the same time benefit from the openness of the landscape after fires, since they recover faster than trees. Additionally, these two mechanisms are better represented when the models also include tree life stages (adults and seedlings, and distinguish between fire-prone and shade-tolerant savanna trees, and fire-resistant and shade-intolerant forest trees. Including these basic elements could improve the predictive ability of the DGVMs, not only under current climate conditions but also and especially under future scenarios.

M. Baudena

2014-06-01

29

Ecological Factors Affecting the Distribution of Woody Vegetation Near the Arkansas River, Tulsa County  

Directory of Open Access Journals (Sweden)

Full Text Available Ecological factors affecting plant distribution were studied over different rock strata and slope exposures above the Arkansas River, Tulsa County. Here the Wann sandstone caprock is underlain by the Iola limestone formation. The vegetation was analyzed taxonomically by a complete collection throughout one growing season. Belt transects crossing rock strata on all slope exposures permitted computation of parameters summarized by an Importance Percentage for each woody species. Differences in species populations and degree of mesophytism exist on the slope exposures. Sandstone upland dominants are post and blackjack oaks. Smoke-tree, rare in Oklahoma, and chinquapin oak are closely associated in limestone microhabitats, where each occupies a separate niche. The smoke-tree, of disjunct distribution, appears to be a relict of widespread occurrence in past geologic periods. Its survival with limited ecological amplitude is due to the continuance of the microhabitats to which it is so well adapted.

Anne Wanamnaker Long

2004-12-01

30

Ecological trap for Cnemidophorus ocellifer Spix 1825 (Squamata: Teiidae during removal of vegetation  

Directory of Open Access Journals (Sweden)

Full Text Available Animals must anticipate future conditions according to current environmental clues. When habitats are rapidly modified, these signs may not reflect the actual environmental quality, leading to a decreased fitness of an individual and its population. During an activity of faunal rescue and scaring away in the coast of Rio Grande do Norte, Brazil, evidence of an ecological trap for the lizard Cnemidophorus ocellifer was observed. We suggest some actions which can minimize the impact of vegetation removal activities on lizards, such as: i better planning before proceeding with deforestation; and ii capture and release of lizards in appropriate locations.

Lucas Bezerra de Mattos Brito

2012-11-01

31

Ecological study for refrigerator use, salt, vegetable, and fruit intakes, and gastric cancer.  

Science.gov (United States)

We used an ecological approach to determine the correlation between vegetable, fruit and salt intakes, refrigerator use, and gastric cancer mortality in Korean population. Information on fruit and vegetable intakes per capita from the National Health and Nutrition Survey, death certificate data from the National Statistical office, refrigerator per household data from Korean Statistical Information Service, and salt/sodium intake data from a cross-sectional survey were utilized. Correlation coefficients were calculated between vegetable and fruit intakes, refrigerator per household, and gastric cancer mortality and between salt and sodium intakes, and gastric cancer mortality and incidence in the four areas. With 5, 10, and 15 years lag time, refrigerator usage and fruit intake were negatively associated with gastric cancer mortality (p < 0.01), but vegetable intake was not associated with gastric cancer mortality. When estimates of salt/sodium intake evaluated by 24-h urine collection in four areas of Korea were compared to the gastric cancer mortality and incidence in these regions, positive correlation was shown between salt/sodium intake, and gastric cancer incidence and mortality. Negative associations between refrigerator use, fruit intake, and gastric cancer mortality and positive associations between salt/sodium intake and gastric cancer mortality and incidence were suggested. PMID:21805052

Park, Boyoung; Shin, Aesun; Park, Sue K; Ko, Kwang-Pil; Ma, Seung Hyun; Lee, Eun-Ha; Gwack, Jin; Jung, En-Joo; Cho, Lisa Y; Yang, Jae Jeong; Yoo, Keun-Young

2011-11-01

32

Drought offset ecological restoration program-induced increase in vegetation activity in the beijing-tianjin sand source region, china.  

Science.gov (United States)

To improve the ecological conditions, the Chinese government adopted six large-scale ecological restoration programs including 'Three-North Shelterbelt Project', "Grain for Green Project" and "Beijing-Tianjin Sand Source Control Project". Meanwhile, these ecologically vulnerable areas have experienced frequent droughts. However, little attention has been paid to the impact of drought on the effectiveness of these programs. Taking Beijing-Tianjin Sand Source Region (BTSSR) as study area, we investigated the role of droughts and ecological restoration program on trends of vegetation activities and to address the question of a possible "drought signal" in assessing effectiveness of ecological restoration program. The results demonstrate the following: (1) Vegetation activity increased in the BTSSR during 2000-2010, with 58.44% of the study area showing an increased NDVI, of which 11.80% had a significant increase at 0.95 confidential level. The decreasing NDVI trends were mainly concentrated in a southwest-to-northeast strip in the study area. (2) Drought was the main driving force for a decreasing trend of vegetation activity in the southwest-to-northeast regions of the BTSSR at the regional and spatial scales. Summer droughts in 2007 and 2009 contributed to the decreasing trend in NDVI. The severe and extreme droughts in summer reduced the NDVI by approximately 13.06% and 23.55%, respectively. (3) The residual analysis result showed that human acitvities, particularly the ecological restoration programs, have a postive impact on vegetation change. Hence, the decreasing trends in the southwest-to-northeast regions of the BTSSR cannot be explained by the improper ecological restoration program and is partly explained by droughts, especially summer droughts. Therefore, drought offset the ecological restoration program-induced increase in vegetation activity in the BTSSR. PMID:25203241

Wu, Zhitao; Wu, Jianjun; He, Bin; Liu, Jinghui; Wang, Qianfeng; Zhang, Hong; Liu, Yong

2014-10-21

33

The Role of Vegetation on the Ecosystem Radiative Entropy Budget and Trends Along Ecological Succession  

Directory of Open Access Journals (Sweden)

Full Text Available Ecosystem entropy production is predicted to increase along ecological succession and approach a state of maximum entropy production, but few studies have bridged the gap between theory and data. Here, we explore radiative entropy production in terrestrial ecosystems using measurements from 64 Free/Fair-Use sites in the FLUXNET database, including a successional chronosequence in the Duke Forest in the southeastern United States. Ecosystem radiative entropy production increased then decreased as succession progressed in the Duke Forest ecosystems, and did not exceed 95% of the calculated empirical maximum entropy production in the FLUXNET study sites. Forest vegetation, especially evergreen needleleaf forests characterized by low shortwave albedo and close coupling to the atmosphere, had a significantly higher ratio of radiative entropy production to the empirical maximum entropy production than did croplands and grasslands. Our results demonstrate that ecosystems approach, but do not reach, maximum entropy production and that the relationship between succession and entropy production depends on vegetation characteristics. Future studies should investigate how natural disturbances and anthropogenic management—especially the tendency to shift vegetation to an earlier successional state—alter energy flux and entropy production at the surface-atmosphere interface.

Paul C. Stoy

2014-07-01

34

Plant physiological ecology and the global changes / Ecofisiologia vegetal e as mudanças globais  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese As mudanças globais englobam importantes alterações nos padrões normais de processos bioquímicos e biofísicos da Terra. Os reais efeitos e retroalimentações das mudanças globais sobre a vegetação ainda são incertos. Parte das incertezas pode ser atribuída à falta de atenção de cientistas e políticos [...] para a vegetação, enquanto componente do sistema terrestre. Entretanto, algumas questões sobre as mudanças globais poderiam ser mais bem esclarecidas por abordagens mais voltadas à ecofisiologia vegetal. Nesse artigo, alguns pontos relacionados e esses problemas, como as limitações em se abordar a vegetação como um componente estático da atmosfera enquanto outros subsistemas do sistema terrestre são dinâmicos, são discutidos. Dentro dessa perspectiva, essa revisão traz uma reflexão inicial do papel da vegetação, em termos de estrutura e funcionamento, no contexto das mudanças globais. Para isso, foi feita uma revisão das terminologias relacionadas às mudanças globais e ao sistema terrestre, buscou-se ilustrar alguns dos principais temas de pesquisa da ecofisiologia vegetal no contexto das mudanças globais. Foram feitas considerações em relação ao tratamento de plantas como sistemas complexos, o que é importante para o estudo de aspectos relacionados à sensibilidade, estabilidade e vulnerabilidade a variações ambientais. Finalmente, são discutidas alternativas que podem ser utilizadas para incorporar aspectos do funcionamento da vegetação, de forma dinâmica, em estudos de mudanças globais, considerando o desafio de mudança de escalas. Espera-se que essa revisão possa auxiliar pesquisadores subsidiando suas estratégias de identificação e compreensão dos efeitos potenciais das mudanças globais sobre os processos mais vulneráveis da vegetação, da folha ao globo. Abstract in english The global changes are marked by alteration on the normal patterns of important biochemical and biophysical processes of the Earth. However, the real effects as well as the feedbacks of the global changes over vegetation are still unclear. Part of this uncertainty can be attributed to the inattentio [...] n of stakeholders and scientists towards vegetation and its complex interrelations with the environment, which drive plant physiological processes in different space-time scales. Notwithstanding, some key subjects of the global changes could be better elucidated with a more plant physiological ecology approach. We discuss some issues related to this topic, going through some limitations of approaching vegetation as a static component of the biosphere as the other sub-systems of the Earth-system change. With this perspective, this review is an initial reflection towards the assessment of the role and place of vegetation structure and function in the global changes context. We reviewed the Earth-system and global changes terminology; attempted to illustrate key plant physiological ecology researches themes in the global changes context; consider approaching plants as complex systems in order to adequately quantify systems characteristics as sensibility, homeostasis, and vulnerability. Moreover, we propose insights that would allow vegetation studies and scaling procedures in the context of the Earth-system. We hope this review will assist researchers on their strategy to identify, understand and anticipate the potential effects of global changes over the most vulnerable vegetation processes from the leaf to the global levels.

João Paulo Rodrigues Alves Delfino, Barbosa; Serge, Rambal; Angela Maria, Soares; Florent, Mouillot; Joana Messias Pereira, Nogueira; Giordane Augusto, Martins.

2012-06-01

35

Plant physiological ecology and the global changes / Ecofisiologia vegetal e as mudanças globais  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese As mudanças globais englobam importantes alterações nos padrões normais de processos bioquímicos e biofísicos da Terra. Os reais efeitos e retroalimentações das mudanças globais sobre a vegetação ainda são incertos. Parte das incertezas pode ser atribuída à falta de atenção de cientistas e políticos [...] para a vegetação, enquanto componente do sistema terrestre. Entretanto, algumas questões sobre as mudanças globais poderiam ser mais bem esclarecidas por abordagens mais voltadas à ecofisiologia vegetal. Nesse artigo, alguns pontos relacionados e esses problemas, como as limitações em se abordar a vegetação como um componente estático da atmosfera enquanto outros subsistemas do sistema terrestre são dinâmicos, são discutidos. Dentro dessa perspectiva, essa revisão traz uma reflexão inicial do papel da vegetação, em termos de estrutura e funcionamento, no contexto das mudanças globais. Para isso, foi feita uma revisão das terminologias relacionadas às mudanças globais e ao sistema terrestre, buscou-se ilustrar alguns dos principais temas de pesquisa da ecofisiologia vegetal no contexto das mudanças globais. Foram feitas considerações em relação ao tratamento de plantas como sistemas complexos, o que é importante para o estudo de aspectos relacionados à sensibilidade, estabilidade e vulnerabilidade a variações ambientais. Finalmente, são discutidas alternativas que podem ser utilizadas para incorporar aspectos do funcionamento da vegetação, de forma dinâmica, em estudos de mudanças globais, considerando o desafio de mudança de escalas. Espera-se que essa revisão possa auxiliar pesquisadores subsidiando suas estratégias de identificação e compreensão dos efeitos potenciais das mudanças globais sobre os processos mais vulneráveis da vegetação, da folha ao globo. Abstract in english The global changes are marked by alteration on the normal patterns of important biochemical and biophysical processes of the Earth. However, the real effects as well as the feedbacks of the global changes over vegetation are still unclear. Part of this uncertainty can be attributed to the inattentio [...] n of stakeholders and scientists towards vegetation and its complex interrelations with the environment, which drive plant physiological processes in different space-time scales. Notwithstanding, some key subjects of the global changes could be better elucidated with a more plant physiological ecology approach. We discuss some issues related to this topic, going through some limitations of approaching vegetation as a static component of the biosphere as the other sub-systems of the Earth-system change. With this perspective, this review is an initial reflection towards the assessment of the role and place of vegetation structure and function in the global changes context. We reviewed the Earth-system and global changes terminology; attempted to illustrate key plant physiological ecology researches themes in the global changes context; consider approaching plants as complex systems in order to adequately quantify systems characteristics as sensibility, homeostasis, and vulnerability. Moreover, we propose insights that would allow vegetation studies and scaling procedures in the context of the Earth-system. We hope this review will assist researchers on their strategy to identify, understand and anticipate the potential effects of global changes over the most vulnerable vegetation processes from the leaf to the global levels.

João Paulo Rodrigues Alves Delfino, Barbosa; Serge, Rambal; Angela Maria, Soares; Florent, Mouillot; Joana Messias Pereira, Nogueira; Giordane Augusto, Martins.

36

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

Science.gov (United States)

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.

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

2014-03-01

37

Sexual differences in microhabitat selection of breeding little bustards Tetrax tetrax: Ecological segregation based on vegetation structure  

Science.gov (United States)

We examined sexual differences in patterns of vegetation structure selection in the sexually dimorphic little bustard. Differences in vegetation structure between male, female and non-used locations during reproduction were examined and used to build a presence/absence model for each sex. Ten variables were measured in each location, extracting two PCA factors (PC1: a visibility-shelter gradient; PC2: a gradient in food availability) used as response variables in GLM explanatory models. Both factors significantly differed between female, male and control locations. Neither study site nor phenology was significant. Logistic regression was used to model male and female presence/absence. Female presence was positively associated to cover of ground by vegetation litter, as well as overall vegetation cover, and negatively to vegetation density over 30 cm above ground. Male presence was positively related to litter cover and short vegetation and negatively to vegetation density over 30 cm above ground. Models showed good global performance and robustness. Female microhabitat selection and distribution seems to be related to the balance between shelter and visibility for surveillance. Male microhabitat selection would be related mainly to the need of conspicuousness for courtship. Accessibility to food resources seems to be equally important for both sexes. Differences suggest ecological sexual segregation resulting from different ecological constraints. These are the first detailed results on vegetation structure selection in both male and female little bustards, and are useful in designing management measures addressing vegetation structure irrespective of landscape composition. Similar microhabitat approaches can be applied to manage the habitat of many declining farmland birds.

Morales, M. B.; Traba, J.; Carriles, E.; Delgado, M. P.; de la Morena, E. L. García

2008-11-01

38

A review of fire effects on vegetation and soils in the Great Basin region: response and ecological site characteristics  

Science.gov (United States)

This review synthesizes the state of knowledge on fire effects on vegetation and soils in semi-arid ecosystems in the Great Basin Region, including the central and northern Great Basin and Range, Columbia River Basin, and the Snake River Plain. We summarize available literature related to: (1) the effects of environmental gradients, ecological site, and vegetation characteristics on resilience to disturbance and resistance to invasive species; (2) the effects of fire on individual plant species and communities, biological soil crusts, seed banks, soil nutrients, and hydrology; and (3) the role of fire severity, fire versus fire surrogate treatments, and post-fire grazing in determining ecosystem response. From this, we identify knowledge gaps and present a framework for predicting plant successional trajectories following wild and prescribed fires and fire surrogate treatments. Possibly the three most important ecological site characteristics that influence a site’s resilience (ability of the ecological site to recover from disturbance) and resistance to invasive species are soil temperature/moisture regimes and the composition and structure of vegetation on the ecological site just prior to the disturbance event.

Miller, Richard F.; Chambers, Jeanne C.; Pyke, David A.; Pierson, Fred B.; Williams, C. Jason

2013-01-01

39

Configuration of water resources for a typical river basin in an arid region of China based on the ecological water requirements (EWRs) of desert riparian vegetation  

Science.gov (United States)

Desert riparian vegetation is a natural cover promoting the stability and development of inland river ecosystems in arid regions. Calculating the ecological water requirements (EWRs) of desert riparian vegetation is an important step in achieving reasonable water utilization. Therefore, this study examined the Tarim River, located in an extremely arid region of China, and collected relevant data on hydrology, weather and vegetation using remote sensing. Subsequently, we analyzed the spatial distribution of the desert riparian vegetation in four sections of the Tarim River and calculated the EWR of the desert riparian vegetation using the phreatic evaporation model; additionally, we determined the required runoffs at five hydrologic stations based on the water balance principle. Ultimately, the necessary protection ranges and goals for desert riparian vegetation were established according to the water resource variations in the Tarim River. Our research showed that the total area of desert riparian vegetation along the Tarim River is 16,285.3 km2; this distribution area gradually decreased as the distance from the river increased, and areas varied in the different river sections. The EWRs of desert riparian vegetation from Sections 1 to 5 are 5.698 × 108, 7.585 × 108, 4.900 × 108, 4.101 × 108 m3 and 1.078 × 108 m3, respectively. Therefore, the total EWR of the study region is 23.362 × 108 m3. In terms of the transpiration law of the "unimodal type", the peak value of EWR of natural vegetation occurs in July, and the decreasing trend appears in the other months. Based on the water balance principle, the required runoffs in Alar, Xinquman, Yingbaza, Wusiman and Qiala were determined to be 47.105 × 108, 35.174 × 108, 22.734 × 108, 15.775 × 108 and 7.707 × 108 m3, respectively. According to the water resource frequency and the EWR of the desert riparian vegetation along the Tarim River, we divided the region into three protection ranges: key protection (8.9-11.8 km from the river), basic protection (15.8-21.8 km from the river) and influence protection (43.0 km from the river). This research not only provides a reasonable calculation method for EWR on the scale of a river basin but also supports the healthy development of the desert riparian vegetation ecosystem and helps to achieve the optimal water allocation for this river.

Ling, Hongbo; Guo, Bin; Xu, Hailiang; Fu, Jinyi

2014-11-01

40

Ecology  

International Nuclear Information System (INIS)

The book turns to the freshment, the teacher, for preparation of ecological topics for lessons, but also to pupils of the secondary stage II, and the main course ecology. The book was knowingly held simple with the restriction to: the ecosystem and its abiotic basic functions, simple articles on population biology, bioceonotic balance ith the questions of niche formation and the life form types coherent with it, of the substance and energy household, the production biology and space-wise and time-wise differentations within an ecological system form the main points. A central role in the volume is given to the illustrations. Their variety is to show and deepen the coherences shown. (orig./HP)

 
 
 
 
41

Koncept ekologických fenomén? v interpretaci st?edoevropské vegetace Ecological phenomena concept: the interpretation of the Central-European vegetation  

Directory of Open Access Journals (Sweden)

Full Text Available A review of literature referring to floristic, vegetation and habitat diversity in Bohemian Massif has resulted to a revision and detailed classification of ecological phenomena. Each phenomenon represents an open nonhierarchical system of lithological, hydrological, topoclimatic and biotic aberrations, that differ from common features of surrounded “zonal“ environment. Two main groups of ecological phenomena have been distinguished: (i large-scale ecological geo-phenomena originated by prominent lithological factors, and (ii meso-scale ecological topo-phenomena produced by local action of hydrology, topoclimate, and air currents. With regard to the first group, the following geo-phenomena play a particular role in the Central European vegetation: (a sandstone, (b limestone and dolomite (karst phenomenon, (c marl (flysch and loess, (d neovolcanic, and (e serpentinite phenomena. With regard to the latter group, the following meso-scale phenomena contribute to the diversity of habitats in landscape scenery: (f river (or valley, (g summit, (h frost hollow, and (i scree (and glacial cirque phenomena. The “insular“ feature of the ecological phenomena in vegetation cover is expressed mainly by the occurrence of treeless ecosystems, such as swamps, bogs, marshes, steppes, rock faces and scree ecosystems, etc. Relatively higher species richness can indicate most of ecological phenomena (they should be detected by the distance from the regional species-area curve, and by the presence of rare plant species, especially by the relic and/or endemic species, which survive on extreme habitats due to the lower competition of prevailing dominant woody or graminoid species.

Tomáš Ku?era

2005-05-01

42

Categorizing Grassland Vegetation with Full-Waveform Airborne Laser Scanning: A Feasibility Study for Detecting Natura 2000 Habitat Types  

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Full Text Available There is increasing demand for reliable, high-resolution vegetation maps covering large areas. Airborne laser scanning data is available for large areas with high resolution and supports automatic processing, therefore, it is well suited for habitat mapping. Lowland hay meadows are widespread habitat types in European grasslands, and also have one of the highest species richness. The objective of this study was to test the applicability of airborne laser scanning for vegetation mapping of different grasslands, including the Natura 2000 habitat type lowland hay meadows. Full waveform leaf-on and leaf-off point clouds were collected from a Natura 2000 site in Sopron, Hungary, covering several grasslands. The LIDAR data were processed to a set of rasters representing point attributes including reflectance, echo width, vegetation height, canopy openness, and surface roughness measures, and these were fused to a multi-band pseudo-image. Random forest machine learning was used for classifying this dataset. Habitat type, dominant plant species and other features of interest were noted in a set of 140 field plots. Two sets of categories were used: five classes focusing on meadow identification and the location of lowland hay meadows, and 10 classes, including eight different grassland vegetation categories. For five classes, an overall accuracy of 75% was reached, for 10 classes, this was 68%. The method delivers unprecedented fine resolution vegetation maps for management and ecological research. We conclude that high-resolution full-waveform LIDAR data can be used to detect grassland vegetation classes relevant for Natura 2000.

András Zlinszky

2014-08-01

43

Using Remote Sensing to Quantify Vegetation Change and Ecological Resilience in a Semi-Arid System  

Directory of Open Access Journals (Sweden)

Full Text Available This research extends upon land cover change studies by incorporating methodological approaches, which are compatible with heterogeneous ecosystems, are able to link landscape changes to system processes, such as climate change, and provide potential linkages to concepts of ecological resilience. The study region in southern Africa experienced a significant climatic shift in the 1970s, resulting in drier conditions. The state of these ecosystems and their response to such climatic shock is quantified in terms of vegetation amount and heterogeneity. We monitor these characteristics pre- and post-disturbance using a Landsat image series and examine the utility of continuous characterizations of land cover for measuring ecosystem resilience. Land cover change is evaluated using a mean-variance analysis in concert with a spatial persistence analysis. This investigation indicates that although the impact of the decreased precipitation is evident in the 1980s, recovery occurred by the 1990s and 2000s. We found the continuous methodological approach used holds potential for studying heterogeneous landscapes within a resilience framework.

Xia Cui

2013-04-01

44

Potential effects of large linear pipeline construction on soil and vegetation in ecologically fragile regions.  

Science.gov (United States)

Long-distance pipeline construction results in marked human disturbance of the regional ecosystem and brings into question the safety of pipeline construction with respect to the environment. Thus, the direct environmental impact and proper handling of such large projects have received much attention. The potential environmental effects, however, have not been fully addressed, particularly for large linear pipeline projects, and the threshold of such effects is unclear. In this study, two typical eco-fragile areas in western China, where large linear construction projects have been conducted, were chosen as the case study areas. Soil quality indices (SQI) and vegetation indices (VI), representing the most important potential effects, were used to analyze the scope of the effect of large pipeline construction on the surrounding environment. These two indices in different buffer zones along the pipeline were compared against the background values. The analysis resulted in three main findings. First, pipeline construction continues to influence the nearby eco-environment even after a 4-year recovery period. During this period, the effect on vegetation due to pipeline construction reaches 300 m beyond the working area, and is much larger in distance than the effect on soil, which is mainly confined to within 30 m either side of the pipeline, indicating that vegetation is more sensitive than soil to this type of human disturbance. However, the effect may not reach beyond 500 m from the pipeline. Second, the scope of the effect in terms of distance on vegetation may also be determined by the frequency of disturbance and the intensity of the pipeline construction. The greater the number of pipelines in an area, the higher the construction intensity and the more frequent the disturbance. Frequent disturbance may expand the effect on vegetation on both sides of the pipeline, but not on soil quality. Third, the construction may eliminate the stable, resident plant community. During the recovery period, the plant community in the work area of the pipeline is replaced by some species that are rare or uncommon in the resident plant community because of human disturbance, thereby increasing the plant diversity in the work area. In terms of plant succession, the duration of the recovery period has a direct effect on the composition and structure of the plant community. The findings provide a theoretical basis and scientific foundation for improving the environmental impact assessment (EIA) of oil and gas pipeline construction as it pertains to the desert steppe ecosystem, and provide a reference point for recovery and management of the eco-environment during the pipeline construction period. PMID:25112841

Xiao, Jun; Wang, Ya-Feng; Shi, Peng; Yang, Lei; Chen, Li-Ding

2014-11-01

45

Pollination ecology of Tabebuia aurea (Manso) Benth. & Hook. and T. ochracea (Cham.) Standl. (Bignoniaceae) in Central Brazil cerrado vegetation  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The pollination ecology and breeding systems of Tabebuia aurea (Manso) Benth. & Hook., and T. ochracea (Cham.) Standl. were investigated in an area of cerrado vegetation in the Federal District of Brazil. These species occur sympatrically, flower massively and synchronously for a month, during the dry season (July to September). Both have diurnal anthesis, with similar floral structures, a yellow tubular corolla and produce nectar. Fourteen species of bees visited both Tabebuia species, but, ...

BARROS MARILUZA GRANJA

2001-01-01

46

Nitrogen deposition effects on Mediterranean-type ecosystems: An ecological assessment  

International Nuclear Information System (INIS)

We review the ecological consequences of N deposition on the five Mediterranean regions of the world. Seasonality of precipitation and fires regulate the N cycle in these water-limited ecosystems, where dry N deposition dominates. Nitrogen accumulation in soils and on plant surfaces results in peaks of availability with the first winter rains. Decoupling between N flushes and plant demand promotes losses via leaching and gas emissions. Differences in P availability may control the response to N inputs and susceptibility to exotic plant invasion. Invasive grasses accumulate as fuel during the dry season, altering fire regimes. California and the Mediterranean Basin are the most threatened by N deposition; however, there is limited evidence for N deposition impacts outside of California. Consequently, more research is needed to determine critical loads for each region and vegetation type based on the most sensitive elements, such as changes in lichen species composition and N cycling. - Highlights: ? N deposition impacts are understudied in Mediterranean ecosystems out of California. ? Dry N deposition is dominant and N flushes are common after rainless periods. ? Water availability and P fertility regulate ecosystem responses to N deposition. ? Research is needed to determine critical loads for each region and vegetation type. - Nitrogen deposition threatens the Mediterranean regions of the world.

47

Nitrogen deposition effects on Mediterranean-type ecosystems: An ecological assessment  

Energy Technology Data Exchange (ETDEWEB)

We review the ecological consequences of N deposition on the five Mediterranean regions of the world. Seasonality of precipitation and fires regulate the N cycle in these water-limited ecosystems, where dry N deposition dominates. Nitrogen accumulation in soils and on plant surfaces results in peaks of availability with the first winter rains. Decoupling between N flushes and plant demand promotes losses via leaching and gas emissions. Differences in P availability may control the response to N inputs and susceptibility to exotic plant invasion. Invasive grasses accumulate as fuel during the dry season, altering fire regimes. California and the Mediterranean Basin are the most threatened by N deposition; however, there is limited evidence for N deposition impacts outside of California. Consequently, more research is needed to determine critical loads for each region and vegetation type based on the most sensitive elements, such as changes in lichen species composition and N cycling. - Highlights: > N deposition impacts are understudied in Mediterranean ecosystems out of California. > Dry N deposition is dominant and N flushes are common after rainless periods. > Water availability and P fertility regulate ecosystem responses to N deposition. > Research is needed to determine critical loads for each region and vegetation type. - Nitrogen deposition threatens the Mediterranean regions of the world.

Ochoa-Hueso, Raul, E-mail: raul.ochoa@ccma.csic.es [Department of Plant Physiology and Ecology, Centro de Ciencias Medioambientales, Consejo Superior de Investigaciones Cientificas, C/Serrano 115 Dpdo., 28006 Madrid (Spain); Allen, Edith B. [Department of Botany and Plant Sciences and Center for Conservation Biology, University of California, Riverside, CA 92521 (United States); Branquinho, Cristina; Cruz, Cristina; Dias, Teresa [Universidade de Lisboa, Faculdade de Ciencias, Centro de Biologia Ambiental, Campo Grande, Bloco C4, 1749-016 Lisboa (Portugal); Fenn, Mark E. [US Department of Agriculture (USDA) Forest Service, Pacific Southwest Research Station, 4955 Canyon Crest Drive, Riverside, CA 92507 (United States); Manrique, Esteban [Department of Plant Physiology and Ecology, Centro de Ciencias Medioambientales, Consejo Superior de Investigaciones Cientificas, C/Serrano 115 Dpdo., 28006 Madrid (Spain); Perez-Corona, M. Esther [Department of Ecology, Faculty of Biology, Universidad Complutense de Madrid, C/Jose Antonio Novais 2, 28040 Madrid (Spain); Sheppard, Lucy J. [Centre of Ecology and Hydrology, Bush Estate, Penicuik EH26 0QB (United Kingdom); Stock, William D. [Centre for Ecosystem Management, School of Natural Sciences, Edith Cowan University, 100 Joondalup Drive, Joondalup, Perth, WA 6027 (Australia)

2011-10-15

48

THE PECULIARITIES OF MORPHOLOGICAL FUNCTIONAL CELL ERYTHRON STATUS OF PERIPHERAL LEVEL TAKING INTO ACCOUNT VEGETATIVE HOMEOSTASIS AT TEENAGERS FROM REGIONS WITH DIFFERENT ECOLOGICAL BALANCES  

Directory of Open Access Journals (Sweden)

Full Text Available The results ofexamination of 267 teenagers who live in various ecological biogeochemical regions are indicated in the work. Vegetative regulation differences of cardiac function and the peculiarities oferythrocytic background have been determined

T.V. Karchinskaja

2008-12-01

49

Measurement and modelling of evapotranspiration in three fynbos vegetation types  

Scientific Electronic Library Online (English)

Full Text Available SciELO South Africa | Language: English Abstract in english Many studies have investigated the water relations of indigenous plants in the fynbos shrublands of the Cape, South Africa. These have mainly focused on understanding the mechanisms by which individual plant species respond to droughts, the frequency and severity of which is expected to increase due [...] to climate change. However, comparatively little information exists on the dynamics of water use by indigenous plants in the region, and, in particular, how water use varies seasonally and between sites. In this study we determined water use by 3 fynbos vegetation types growing at 4 different sites, namely: (i) lowland Atlantis Sand Plain fynbos growing on deep sandy soils, (ii) Kogelberg Sandstone fynbos growing in a riparian zone on deep alluvial soils, (iii) dryland Kogelberg Sandstone fynbos growing on shallow sandy soils at a montane site, and (iv) alluvial Swartland fynbos growing in clayey soils. Evapotranspiration (ET) was quantified at each site during specific periods using a boundary layer scintillometer and energy balance system. A simple dual source model in which the stand ET was calculated as the algebraic sum of outputs from soil evaporation and transpiration sub-models was used to scale up the ET measurements to annual values. The data showed large differences in ET depending on site characteristics and on plant attributes. Dense stands of riparian Sandstone Fynbos had an annual ET of 1 460 mm which exceeded the reference ET of 1 346 mm. Dryland Sandstone Fynbos used only 551 mm of water per year while the Sand Plain Fynbos' annual ET was 1 031 mm, which was similar to the reference ET of 1 059 mm. We conclude that some indigenous plant species use large volumes of water which should be accounted for in, e.g., groundwater recharge estimates, and calculations of incremental water gains after clearing alien invasive plants, among other applications

S, Dzikiti; NZ, Jovanovic; R, Bugan; S, Israel; DC, Le Maitre.

2014-04-03

50

Ecología de la vegetación del desierto chihuahuense / Vegetation ecology of the chihuahuan desert  

Scientific Electronic Library Online (English)

Full Text Available SciELO Mexico | Language: Spanish Abstract in spanish El desierto Chihuahuense (DC), el más grande del Continente Americano, está flanqueado por montañas que impiden el paso de los vientos húmedos: la Sierra Madre Oriental, la Faja Volcánica Trans-mexicana y la Sierra Madre Occidental (en México) y Las Rocallosas (en Estados Unidos); cubre una superfic [...] ie de 507,000 km², desde Nuevo México y Texas en Estados Unidos, hasta porciones de los estados de Chihuahua, Coahuila, Durango, Guanajuato, Hidalgo, Nuevo León, Querétaro, San Luis Potosí, Tamaulipas y Zacatecas, en México. El trabajo en campo consistió en la caracterización cualitativa de los principales tipos de vegetación del DC, con base en su fisonomía y en la recolección de ejemplares vegetales para su posterior identificación. Con los datos de composición y fisonomía se elaboraron perfiles semirrealistas de las principales asociaciones vegetales y de las condiciones fisiográficas y edáficas donde se desarrollaban. Las asociaciones detectadas fueron: matorral micrófilo de Larrea tridentata, matorral rosetófilo de Agave lechuguilla, matorral rosetófilo de Dasylirion spp., pastizal, chaparral, nopalera, mezquital, izotal, vegetación de dunas y vegetación halófita. Abstract in english The Chihuahuan Desert (CD), the largest in the Americas, is flanked by mountains that prevent wet winds from blowing across it; those mountain ranges are the Sierra Madre Oriental, the Trans-Mexican Volcanic Belt and the Sierra Madre Occidental in Mexico, and the Rockies in the United States. The de [...] sert covers an area of 507,000 km2, stretching from New Mexico and Texas in the United States to parts of the states of Chihuahua, Coahuila, Durango, Guanajuato, Hidalgo, Nuevo León, Querétaro, San Luis Potosi, Tamaulipas and Zacatecas in Mexico. Field work consisted of the qualitative characterization of the main vegetation types in the CH, based on their physiognomy and the collection of plant specimens for later identification. With the composition and physiognomy data, semi-realistic profiles were made of the main plant associations and the physiographic and soil conditions where they thrive. The associations detected were: Larrea tridentata microphyll scrub, Agave lechuguilla rosette scrub, Dasylirion spp. rosette scrub, grassland, chaparral, nopalera (a patch of prickly pears), mesquite, yucca, dune vegetation and halophytic vegetation.

Diódoro, Granados-Sánchez; Arturo, Sánchez-González; Ro Linnx, Granados Victorino; Amparo, Borja de la Rosa.

51

Impacts of ecological water conveyance on groundwater dynamics and vegetation recovery in the lower reaches of the Tarim River in northwest China.  

Science.gov (United States)

The ecological water conveyance project (EWCP) in the lower reaches of the Tarim River provided a valuable opportunity to study hydro-ecological processes of desert riparian vegetation. Ecological effects of the EWCP were assessed at large spatial and temporal scales based on 13 years of monitoring data. This study analyzed the trends in hydrological processes and the ecological effects of the EWCP. The EWCP resulted in increased groundwater storage-expressed as a general rise in the groundwater table-and improved soil moisture conditions. The change of water conditions also directly affected vegetative cover and the phenology of herbs, trees, and shrubs. Vegetative cover of herbs was most closely correlated to groundwater depth at the last year-end (R?=?0.81), and trees and shrubs were most closely correlated to annual average groundwater depth (R?=?0.79 and 0.66, respectively). The Normalized Difference Vegetation Index (NDVI) responded to groundwater depth on a 1-year time lag. Although the EWCP improved the NDVI, the study area is still sparsely vegetated. The main limitation of the EWCP is that it can only preserve the survival of existing vegetation, but it does not effectively promote the reproduction and regeneration of natural vegetation. PMID:25074365

Hao, Xingming; Li, Weihong

2014-11-01

52

The use of high altitude remote sensing in determining existing vegetation and monitoring ecological stress  

Science.gov (United States)

High altitude color and multispectral black and white photography was used to survey existing vegetation and soil conditions on the Empire Ranch where large scale development will soon begin. Utilizing stereo pairs of the high altitude color photography, four vegetation classifications were discernable as a function of topography and foliage characteristics. In contrast to the undeveloped Ranch, the same photography was used to detect environmental changes in the Tucson metropolitan area as a result of rapid urbanization. The most prevalent change related to development is the removal of vegetation in high density areas to allow for housing starts. Erosion then occurs where vegetation has been removed.

Foster, K.; Garcia, A.

1972-01-01

53

Analysis of ecological context for identifying vegetation and animal conservation planning foci: An example from the arid South-western USA  

Science.gov (United States)

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.

Hamazaki, T.; Thompson, B.C.; Locke, B.A.; Boykin, K.G.

2003-01-01

54

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

International Nuclear Information System (INIS)

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. Vegettivity 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 decrease their productivity values. Information regarding the variability of net primary productivity across the Wet Tropics bioregion and its possible modifications due to climate change is crucial for management of future scenarios. The results from this study will help management agencies and conservation groups to plan accordingly

55

VEGETATION MAPPING IN WETLANDS  

Directory of Open Access Journals (Sweden)

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.

F. PEDROTTI

2004-01-01

56

Arctic Tundra Vegetation Functional Types Based on Photosynthetic Physiology and Optical Properties  

Science.gov (United States)

Climate change in tundra regions may alter vegetation species composition and ecosystem carbon balance. Remote sensing provides critical tools for monitoring these changes as optical signals provide a way to scale from plot measurements to regional patterns. Gas exchange measurements of pure patches of key vegetation functional types (lichens, mosses, and vascular plants) in sedge tundra at Barrow AK, show three significantly different values of light use efficiency (LUE) with values of 0.013+/-0.001, 0.0018+/-0.0002, and 0.0012 0.0001 mol C/mol absorbed quanta for vascular plants, mosses and lichens, respectively. Further, discriminant analysis of patch reflectance identifies five spectral bands that can separate each vegetation functional type as well as nongreen material (bare soil, standing water, and dead leaves). These results were tested along a 100 m transect where midsummer spectral reflectance and vegetation coverage were measured at one meter intervals. Area-averaged canopy LUE estimated from coverage fractions of the three functional types varied widely, even over short distances. Patch-level statistical discriminant functions applied to in situ hyperspectral reflectance successfully unmixed cover fractions of the vegetation functional types. These functions, developed from the tram data, were applied to 30 m spatial resolution Earth Observing-1 Hyperion imaging spectrometer data to examine regional variability in distribution of the vegetation functional types and from those distributions, the variability of LUE. Across the landscape, there was a fivefold variation in tundra LUE that was correlated to a spectral vegetation index developed to detect vegetation chlorophyll content.

Huemmrich, Karl F.; Gamon, John; Tweedie, Craig; Campbell, Petya P. K.; Landis, David; Middleton, Elizabeth

2012-01-01

57

Satellite observations of high northern latitude vegetation productivity changes between 1982 and 2008: ecological variability and regional differences  

Energy Technology Data Exchange (ETDEWEB)

To assess ongoing changes in high latitude vegetation productivity we compared spatiotemporal patterns in remotely sensed vegetation productivity in the tundra and boreal zones of North America and Eurasia. We compared the long-term GIMMS (Global Inventory Modeling and Mapping Studies) NDVI (Normalized Difference Vegetation Index) to the more recent and advanced MODIS (Moderate Resolution Imaging Spectroradiometer) NDVI data set, and mapped circumpolar trends in a gross productivity metric derived from the former. We then analyzed how temporal changes in productivity differed along an evergreen-deciduous gradient in boreal Alaska, along a shrub cover gradient in Arctic Alaska, and during succession after fire in boreal North America and northern Eurasia. We find that the earlier reported contrast between trends of increasing tundra and decreasing boreal forest productivity has amplified in recent years, particularly in North America. Decreases in boreal forest productivity are most prominent in areas of denser tree cover and, particularly in Alaska, evergreen forest stands. On the North Slope of Alaska, however, increases in tundra productivity do not appear restricted to areas of higher shrub cover, which suggests enhanced productivity across functional vegetation types. Differences in the recovery of post-disturbance vegetation productivity between North America and Eurasia are described using burn chronosequences, and the potential factors driving regional differences are discussed.

Beck, Pieter S A; Goetz, Scott J, E-mail: pbeck@whrc.org [Woods Hole Research Center, 149 Woods Hole Road, Falmouth, MA 02540 (United States)

2011-10-15

58

Satellite observations of high northern latitude vegetation productivity changes between 1982 and 2008: ecological variability and regional differences  

International Nuclear Information System (INIS)

To assess ongoing changes in high latitude vegetation productivity we compared spatiotemporal patterns in remotely sensed vegetation productivity in the tundra and boreal zones of North America and Eurasia. We compared the long-term GIMMS (Global Inventory Modeling and Mapping Studies) NDVI (Normalized Difference Vegetation Index) to the more recent and advanced MODIS (Moderate Resolution Imaging Spectroradiometer) NDVI data set, and mapped circumpolar trends in a gross productivity metric derived from the former. We then analyzed how temporal changes in productivity differed along an evergreen-deciduous gradient in boreal Alaska, along a shrub cover gradient in Arctic Alaska, and during succession after fire in boreal North America and northern Eurasia. We find that the earlier reported contrast between trends of increasing tundra and decreasing boreal forest productivity has amplified in recent years, particularly in North America. Decreases in boreal forest productivity are most prominent in areas of denser tree cover and, particularly in Alaska, evergreen forest stands. On the North Slope of Alaska, however, increases in tundra productivity do not appear restricted to areas of higher shrub cover, which suggests enhanced productivity across functional vegetation types. Differences in the recovery of post-disturbance vegetation productivity between North America and Eurasia are described using burn chronosequences, and the potential factors driving regional differenotential factors driving regional differences are discussed.

59

Bank vegetation of Rimavica River from the perspective of landscape ecology  

International Nuclear Information System (INIS)

The object of our study was 5.3 km long stretch of the river Rimavica with its adjacent ecosystems. The research results show that most of the observed vegetation fulfill its function well in the country. Only certain sections require more human care, in order to strengthen their positive impact on the flow of water and other components of the ecosystem. (authors)

60

Soil Respiration Responses to Variation in Temperature Treatment and Vegetation Type  

Science.gov (United States)

Complex linkages exist between terrestrial vegetation, soil moisture, soil organic matter (SOM), local climate, and soil microorganisms. Thus, large-scale changes in vegetation, such as the woody plant encroachment observed in many historically semiarid and arid grasslands worldwide, could potentially alter the flux of carbon from soil reserves to the atmosphere. Mathematical models that attempt to project the long-term impact of vegetative shifts on soil fluxes largely rely on assumptions such as first-order donor control rather than incorporate the biological aspects of soil respiration such as microbial activity. To examine the impact of vegetation type on soil physicochemical properties and soil microbial respiration and provide experimental data to refine existing predictive models, we compared soil (ground basalt from northern Arizona) in mesocosms established with no vegetation, velvet mesquites (Prosopis velutina; woody shrub), or sideoats gramas (Bouteloua curtipendula; grass) for 2 years, The temperature sensitivity of soil respiration was examined by incubating soil (0-10 and 10-30 cm depth fractions) from each vegetation treatment at 10, 20, 30, and 40 °C for 24 hours. Vegetated soils contained more SOM (~0.1% for mesquite and grass mesocosms) than non-vegetated soils (~0.02%). Respiration rates were generally highest from grass-established soils, intermediate from mesquite-established soils, and lowest from non-vegetated soils. Respiration rates of samples incubated without the addition of substrate peaked at approximately 30 °C, whereas respiration rates of samples incubated with dextrose were highest at 40 °C. Further, the respiration assays suggest that while respiration rates are overall higher in grass-established soils, mesquite-established soils are more temperature sensitive which may have significant implications in the context of global warming and current fire management practices.

Liu, S.; Pavao-zuckerman, M.

2013-12-01

 
 
 
 
61

Crop Type Classification Using Vegetation Indices of RapidEye Imagery  

Science.gov (United States)

Cutting-edge remote sensing technology has a significant role for managing the natural resources as well as the any other applications about the earth observation. Crop monitoring is the one of these applications since remote sensing provides us accurate, up-to-date and cost-effective information about the crop types at the different temporal and spatial resolution. In this study, the potential use of three different vegetation indices of RapidEye imagery on crop type classification as well as the effect of each indices on classification accuracy were investigated. The Normalized Difference Vegetation Index (NDVI), the Green Normalized Difference Vegetation Index (GNDVI), and the Normalized Difference Red Edge Index (NDRE) are the three vegetation indices used in this study since all of these incorporated the near-infrared (NIR) band. RapidEye imagery is highly demanded and preferred for agricultural and forestry applications since it has red-edge and NIR bands. The study area is located in Aegean region of Turkey. Radial Basis Function (RBF) kernel was used here for the Support Vector Machines (SVMs) classification. Original bands of RapidEye imagery were excluded and classification was performed with only three vegetation indices. The contribution of each indices on image classification accuracy was also tested with single band classification. Highest classification accuracy of 87, 46 % was obtained using three vegetation indices. This obtained classification accuracy is higher than the classification accuracy of any dual-combination of these vegetation indices. Results demonstrate that NDRE has the highest contribution on classification accuracy compared to the other vegetation indices and the RapidEye imagery can get satisfactory results of classification accuracy without original bands.

Ustuner, M.; Sanli, F. B.; Abdikan, S.; Esetlili, M. T.; Kurucu, Y.

2014-09-01

62

Catastrophic Shifts in Wetland Geomorphology and Ecology in Response to Hydrology-Vegetation-Sediment Transport Feedbacks (Invited)  

Science.gov (United States)

Coastal marshes and long-hydroperiod floodplain wetlands exhibit strong bi-directional feedback between hydrology, vegetation, and sediment that impacts landscape dynamics and ecosystem services. In these ecosystems, vegetation responds to and also influences the distribution of topography, with effects on habitat provision, biological diversity, landscape connectivity, surface-subsurface exchange, and microbial and redox reactions. Topography evolves both autogenically and allogenically. Autogenically, peat accretes under reducing conditions as a function of local water levels, vegetation community, and nutrient concentrations. Concurrently, an allogenic sediment redistribution feedback process involves erosion of sediment from low, sparsely vegetated areas and deposition of sediment within dense vegetation that resists flow. It is well documented that these feedback processes are dominantly responsible for evolution of tidal marsh morphology and response of coastal marshes to sea level rise. Less well understood is the role these feedbacks play in the evolution of more slowly flowing interior marshes and in the response of these systems to perturbations in flow velocity as well as water level. We developed a cellular automata model that physically simulates both sediment redistribution and differential peat accretion feedbacks. Because of the efficiency of this simplified modeling technique, we ran the model over a broad range of environmental conditions in a generalized sensitivity analysis. As a result of the two feedback processes, simulated landscapes reflected a variety of morphologies found in coastal and interior wetlands worldwide, with differences attributable to relative dominance of physical (e.g., surface-water flow, water level) or biological (e.g., vegetation productivity and colonization) drivers. Significantly, under moderate surface-water flow velocities (4-6 cm s-1), a class of patterned wetlands with regular ridges and sloughs oriented parallel to the dominant flow direction emerged, which mimics the patterned, flow-parallel topography found in the Florida Everglades. Sediment redistribution and differential peat accretion feedbacks constitute the first description of a viable mechanism for formation of this ecologically important landscape structure and provide guidance for restoration efforts. We show that because of vegetative resistance to flow, this patterned landscape structure is prone to shift to an alternate stable state, dominated by a monoculture of emergent vegetation, under changes in surface-water flow velocity or water level. Results suggest that twentieth-century degradation of the Everglades ridge and slough landscape is attributable primarily to changes in water level and, secondarily, to diminished surface-water flow velocities. Because hydrology-vegetation-sediment feedbacks cause hysteresis in landscape evolution trajectories, restoration of historic flow velocities and water levels will not necessarily produce a return to historic landscape structure. Understanding the dynamics of sediment redistribution and differential peat accretion feedbacks will be essential in predicting how wetlands worldwide will respond to changes in climate or water management.

Larsen, L. G.; Harvey, J. W.

2010-12-01

63

Experimental restoration of a salt marsh with some comments on ecological restoration of coastal vegetated ecosystems in Korea  

Science.gov (United States)

Since the 1980s, the coastal wetlands in Korea have been rapidly degraded and destroyed mainly due to reclamation and landfills for coastal development. In order to recover damaged coastal environments and to develop wetland restoration technologies, a 4-year study on ecological the restoration of coastal vegetated ecosystems was started in 1998. As one of a series of studies, a small-scale experiment on salt marsh restoration was carried out from April 2000 to August 2001. The experiment was designed to find effective means of ecological restoration through a comparison of the changes in environmental components and species structure between two different experimental plots created using sediment fences, one with and one without small canals. Temporal variation in surface elevation, sedimentary facies, and benthic species were measured seasonally in each plot and in the adjacent natural reference sites. Monthly exposure occurred from 330 cm to mean sea level, which represents the critical tidal level (CTL) at which salt marsh plants colonize. Vegetation, especially Suaeda japonica, colonized the site the following spring and recovered to a similar extent in the natural marshes 16 months later. The sedimentary results indicated that the sediment fences had effects on particle size and sediment accumulation, especially in the plot with small canals. This experiment also showed that tidal height, especially that exceeding the CTL, is an important factor in the recovery of the benthic fauna of salt marshes. From these results, we suggested that designs for the restoration of salt marsh ecosystems must consider the inclusion of a tidal height exceeding CTL, as this may allow reconstruction of the previous natural ecosystem without artificial transplanting.

Koo, Bon Joo; Je, Jong Geel; Woo, Han Jun

2011-03-01

64

Assessment of the transfer of 137Cs in three types of vegetables consumed in Hong Kong  

International Nuclear Information System (INIS)

A dynamic food chain model has been built for the modeling of the transfer of 137Cs in three types of vegetables consumed in Hong Kong, namely, white flowering cabbage (Brassica chinensis), head lettuce (Lactuca sativa) and celery (Apium graveolens). Some parameters have been estimated from the experimental data obtained in this work. The experimental data include the transfer factors of 137Cs from soil to the different vegetable species which are determined through high resolution gamma spectrometry, maximum crop biomasses for the vegetable species, the dry-to-fresh ratios for the vegetable species, the bulk density of soil layers and the average concentration of 137Cs in air. The derived parameters include the deposition rate and the root uptake rate, information for tillage, the logistic growth model and radionuclide concentrations in vegetables. The dynamic food chain model is solved by the Birchall-James algorithm to give the 137Cs concentration in subsurface soil, from the 0.1-25 cm soil layer, and the 137Cs concentration in harvested and unwashed vegetables. As validation of the model and parameters, the concentrations obtained experimentally and from the model are compared and are found to be in good agreement

65

Vegetation ecological restoration during geothermic exploratory perforation: A case study in Mexico  

Energy Technology Data Exchange (ETDEWEB)

At Las Tres Virgenes, B.C.S., Mexico developed the Geothermic exploratory drilling of the area. One of the main recommendations of our Environmental Impact Assessment Study includes transplantation of the plant individuals found in the zones of roads and drilling platforms. In this work we describe the methodologies used to transplant the vegetal individuals found in such zones. We listed the species selected and the survivorship rate obtained for every one of them. From a total of 4,266 transplanted individuals, including many endemic species, a total of 2349 survived. Members of the Agavaceae and Cactaceae families show the maximum survivorship rate, meanwhile the members of the Burseraceae, Euphorbiaceae and Fouqueriaceae families exhibited the minimum survivorship rate (between 12.7% and 20%).

Ortega-Rubio, A.; Salinas, F.; Naranjo, A. [and others

1997-12-31

66

Anaerobic digestion and co-digestion processes of vegetable and fruit residues: process and microbial ecology.  

Science.gov (United States)

This study evaluated the feasibility of methane production from fruit and vegetable waste (FVW) obtained from the central food distribution market in Mexico City using an anaerobic digestion (AD) process. Batch systems showed that pH control and nitrogen addition had significant effects on biogas production, methane yield, and volatile solids (VS) removal from the FVW (0.42 m(biogas)(3)/kg VS, 50%, and 80%, respectively). Co-digestion of the FVW with meat residues (MR) enhanced the process performance and was also evaluated in a 30 L AD system. When the system reached stable operation, its methane yield was 0.25 (m(3)/kg TS), and the removal of the organic matter measured as the total chemical demand (tCOD) was 65%. The microbial population (general Bacteria and Archaea) in the 30 L system was also determined and characterized and was closely correlated with its potential function in the AD system. PMID:21865034

Garcia-Peña, E I; Parameswaran, P; Kang, D W; Canul-Chan, M; Krajmalnik-Brown, R

2011-10-01

67

An ecological approach to the assessment of vegetation cover on inactive uranium mill tailings sites  

International Nuclear Information System (INIS)

Vascular plants have been collected from abandoned or inactive uranium mill tailings in three mining areas in Canada. The collection was evaluated to determine some characteristics of vegetation development and to identify the plants which will persist on the sites. A total of 170 species were identified. Many of the species are widely distributed in North America, none has been reported as rare in any of the locations from which they were collected. Species richness was highest on Bancroft sites and lowest on Uranium City sites, though values were variable between sites. Forty-four per cent of the total number of species were found on only a single site. Only seven species occurred on more than half of the tailings sites and in all three mining areas. There was no difference between amended and unamended sites in terms of either species richness or species composition. There was no apparent relationship between species richness and either site size, site age or amendment history. The results of this survey suggest that the uranium mill tailings sites are at an early stage of colonization where the seed input from surrounding areas and the heterogeneity of the sites are factors determining species composition and species richness. The fate of an individual once it has reached the site will be determined by its ability to establish on the sites. A perennial growth habit and the ability to expand clonally are important characteristics of the species on the tailings. The species on the tailings are commonly found in a variety of habitats. Consistent with the observation that the tailings sites are at a stage of early colonization, we find that the few species widely distributed across sites are all characteristic pioneering species with wide environmental tolerances. These species included Populus tremuloides, P. balsamifera, Scirpus cyperinus, Equisetum arvense, Betula papyrifera, Achillea millefolium and Typha spp. The vegetation on the tailings is likely to be characterized by these species for a long period of time. (author)

68

Physical activity, fruit and vegetable intake and the built environment: ecological and epidemiological studies among youth  

DEFF Research Database (Denmark)

Since the 1990’s, there has been increasing scientific interest in investigating place effects on dietary and exercise behaviors. The two overall aims of this dissertation are designed to investigate at an area level and at an individual level, how food and physical activity resources are spatially distributed by socioeconomic indicators, and whether these associations can be observed between aspects of the built environment and: a) fruit and vegetable intake, and b) vigorous physical activity in individuals. Specifically, this involves operationalization of geographical measures of exposure within neighborhood environments, with development and validation of data used to describe characteristics of exercise and dietary resources. The concept of deprivation amplification is also investigated, which suggests that individual or household deprivation is further enhanced or comprised by the lack of resources in the neighborhood, and could manifest itself in poor health behaviors. This concept is first studied at the neighborhood level, by examining the socioeconomic patterning of food and exercise resources. Next, at the individual level, I examine the combined effects of socioeconomic status and the built environment, and report on how these associations affect individual dietary and exercise behavior. Data drawn for the individually-based analyses stem from the Danish contribution to the Health Behavior in School-aged Children Study (HBSC), an international, cross-sectional population-based study investigating the health and health behaviors of 11-to-15-year old school children. Outcome measures for these studies were infrequent less than daily intake of fruit and vegetables (Paper II) and frequent vigorous physical activity of one hour or more per day (Paper IV). The individual dataset was appended with a validated and cross-referenced objected database built for these studies and contained location information about supermarkets, fast food outlets, and various exercise-supportive resources (public open space, sports facilities, street connectivity, and total length of cycling and walking paths). The neighborhood-based analyses uses validated and cross-referenced objective data about food and physical activity resources in each of the 400 neighborhoods in Copenhagen and combines them with area-level socioeconomic and demographic data derived from The National Statistics Bank of Denmark. Outcome measures for these studies were also defined as the number of supermarkets and fast food outlets in each neighborhood (Paper I) and high exposure (top 25%) to resources supportive of physical activity. Study findings are expressed as either relative risk (RR) or odds ratios (OR), with 95% confidence intervals (CI). In general, study findings indicate no clear socioeconomic patterning of food or physical activity resources by examining neighborhood units alone. For example, there was no association between areal income and supermarket exposure in Copenhagen, while low income areas were more likely to be exposed to fewer fast food outlets than high-income neighborhoods (RR = 0.66; CI: 0.46-0.97). Areas with a high proportion of residents lacking a high school diploma had greater exposure to physical activity resources such as, public open space (OR = 1.90; CI: 1.15-3.15), cycling and walking paths (OR = 3.46; CI: 1.86-6.42) and one or more sports facilities (OR = 2.05; CI: 1.36-3.10) than the referent. Areas with high proportions of children were less likely to have exposure to connected streets (OR = 0.51; 0.31-0.83) than areas with low proportions of children. Results from individual-level studies generally show that while socioeconomic status remains an important individual predictor for diet and exercise behavior, the exposure to resources in the neighborhood environment may differentially affect children according to social class background. Children from low social class backgrounds attending schools with low exposure to supermarkets had the greatest odds of infrequent vegetable (OR = 1.50; CI: 1.03-2.20) and fruit (OR = 1.43

Svastisalee, Chalida

2011-01-01

69

Cost Effectiveness of Vegetative Filter Strips and Instream Half-logs for Ecological Restoration  

Science.gov (United States)

This paper presents the results of cost effectiveness (CE) analysis of vegetative filter strips (VFS) and instream half-logs as tools for recovering scores on a fish Index of Biotic Integrity (IBI) in the upper Wabash River watershed (UW) in Indiana. Three assumptions were made about recovery time for IBI scores (5, 15, and 30 years) and social discount rates (1, 3, and 5 percent), which were tested for sensitivity of the estimated CE ratios. Effectiveness of VFS was estimated using fish IBIs and riparian forest cover from 49 first-order to fifth-order stream reaches. Half-log structures had been installed for approximately two years in the UW prior to the study and provided a basis for estimates of cost and maintenance. Cost effectiveness ratios for VFS decreased from 387 to 277 per 100 m for a 1 percent increase in IBI scores from first- to fifthorder streams with 3 percent discount and 30-year recovery. This cost weighted by proportion of stream orders was $360. The ratio decreased with decreasing time of recovery and discount rate. Based on installation costs and an assumption of equal recovery rates, half-logs were two-thirds to one-half as cost-effective as VFS. Half-logs would be a cost-effective supplement to VFS in low order streams if they can be proven to recover IBI scores faster than VFS do. This study provides baseline data and a framework for planning and determining the cost of stream restoration.

Frimpong, Emmanuel A.; Lee, John G.; Sutton, Trent M.

2006-10-01

70

Hydrologic and Ecologic Responses to Diminished Spring Discharge; Surface-Water/Groundwater and Vegetation Modeling, Grand Canyon, Arizona  

Science.gov (United States)

Numerous springs discharge from the regional Redwall-Muav aquifer of the Coconino Plateau along the South Rim of the Grand Canyon, AZ. Many of these springs provide base flow to Colorado River tributaries, and support stands of native riparian vegetation. Development of the Redwall-Muav aquifer as a water supply began in 1989, with potential abstraction rates up to ~1.1 x 106 m3/yr. Regional groundwater flow models predict that groundwater pumping has the potential to result in diminished discharges at the South Rim Springs, which may result in negative impacts to the associated riparian ecosystems. Management of this regional spring-aquifer system requires an interdisciplinary understanding of the dynamics between the operating hydrologic, ecologic and cultural processes. To aid in this effort, we calibrated a coupled numerical surface-water and groundwater flow model for the riparian aquifer associated with one of the smaller of the South Rim springs, Cottonwood Springs. The model simulated the seasonal variability of surface-water and groundwater flow in the aquifer as observed between March 2003 and January 2004 at a 1-m grid spacing. Surface-water flux and groundwater flux data were extracted from the model at various transects through the riparian area to highlight temporal and spatial variations in water availability to the associated riparian communities. During the winter, the total flux of water was relatively constant throughout the model area and was ~60 m3/d. During the peak of the growing season, the total flux of water in the upstream portion of the model area was ~60 m3/d and decreased progressively down to ~35 m3/d in the downstream portion of the model. The downstream decrease in water availability is manifested in downstream changes in woody riparian vegetation structure and composition. Changes in cottonwood stand and individual tree metrics were examined quantitatively in relation to this moisture availability gradient. An analysis of stream gauging data (1994-2003) from two South Rim springs showed statistically significant decreasing discharge trends over the period of record. These trends, coupled with ongoing groundwater pumping, climatic predictions of continuing drought, and the observed sensitivity of the riparian vegetation to variations in water availability suggests there is a potential for alteration to the riparian ecosystem over relatively short timescales.

Kobor, J. S.; Springer, A. E.; Scott, M. L.; Shafroth, P.

2004-12-01

71

Pollination ecology of Tabebuia aurea (Manso Benth. & Hook. and T. ochracea (Cham. Standl. (Bignoniaceae in Central Brazil cerrado vegetation  

Directory of Open Access Journals (Sweden)

Full Text Available The pollination ecology and breeding systems of Tabebuia aurea (Manso Benth. & Hook., and T. ochracea (Cham. Standl. were investigated in an area of cerrado vegetation in the Federal District of Brazil. These species occur sympatrically, flower massively and synchronously for a month, during the dry season (July to September. Both have diurnal anthesis, with similar floral structures, a yellow tubular corolla and produce nectar. Fourteen species of bees visited both Tabebuia species, but, only three Centris species and Bombus morio, were considered potential pollinators, because of their high frequency on the flowers and their efficiency in carrying pollen. Tests on the breeding systems of T. aurea and T. ochracea demonstrated that boths species are self-incompatible, with late-acting self-incompatibility. The proportion of fruit set from cross pollination (T. aurea 17.2% and T. ochracea 12.3% in both species was low considering the great number of flowers displayed. This suggests a lack of maternal resources for fruit-set. The great amount of seeds per fruit (about 92 in T. aurea and 285 in T. ochracea may represent an investment of maternal resources allocated on higher quality of fertilized ovules.

BARROS MARILUZA GRANJA

2001-01-01

72

Effect of vegetative filter strips on herbicide runoff under various types of rainfall.  

Science.gov (United States)

Narrow vegetative filter strips proved to effectively reduce herbicide runoff from cultivated fields mainly due to the ability of vegetation to delay surface runoff, promote infiltration and adsorb herbicides. A field trial was conducted from 2007 to 2009 in north-east Italy in order to evaluate the effectiveness of various types of vegetative filter strips to reduce spring-summer runoff of the herbicides mesotrione, metolachlor and terbuthylazine, widely used in maize, and to evaluate the effect of the rainfall characteristics on the runoff volume and concentration. Results show that without vegetative filter strip the herbicide load that reaches the surface water is about 5-6 g ha(-1)year(-1) for metolachlor and terbuthylazine (i.e. 0.5-0.9% of the applied rate), confirming that runoff from flat fields as in the Po Valley can have a minor effect on the water quality, and that most of the risk is posed by a few, or even just one extreme rainfall event with a return period of about 25-27 years, causing runoff with a maximum concentration of 64-77 ?g L(-1). Mesotrione instead showed rapid soil disappearance and was observed at a concentration of 1.0-3.8 ?g L(-1) only after one extreme (artificial) rainfall. Vegetative filter strips of any type are generally effective and can reduce herbicide runoff by 80-88%. Their effectiveness is steady even under severe rainfall conditions, and this supports their implementation in an environmental regulatory scheme at a catchment or regional scale. PMID:22463948

Otto, Stefan; Cardinali, Alessandra; Marotta, Ester; Paradisi, Cristina; Zanin, Giuseppe

2012-06-01

73

Effect of non-crop vegetation types on conservation biological control of pests in olive groves  

Directory of Open Access Journals (Sweden)

Full Text Available Conservation biological control (CBC is an environmentally sound potential alternative to the use of chemical insecticides. It involves modifications of the environment to promote natural enemy activity on pests. Despite many CBC studies increasing abundance of natural enemies, there are far fewer demonstrations of reduced pest density and very little work has been conducted in olive crops. In this study we investigated the effects of four forms of non-crop vegetation on the abundance of two important pests: the olive psyllid (Euphyllura olivina and the olive moth (Prays oleae. Areas of herbaceous vegetation and areas of woody vegetation near olive crops, and smaller patches of woody vegetation within olive groves, decreased pest abundance in the crop. Inter-row ground covers that are known to increase the abundance of some predators and parasitoids had no effect on the pests, possibly as a result of lack of synchrony between pests and natural enemies, lack of specificity or intra-guild predation. This study identifies examples of the right types of diversity for use in conservation biological control in olive production systems.

Daniel Paredes

2013-07-01

74

Effect of non-crop vegetation types on conservation biological control of pests in olive groves.  

Science.gov (United States)

Conservation biological control (CBC) is an environmentally sound potential alternative to the use of chemical insecticides. It involves modifications of the environment to promote natural enemy activity on pests. Despite many CBC studies increasing abundance of natural enemies, there are far fewer demonstrations of reduced pest density and very little work has been conducted in olive crops. In this study we investigated the effects of four forms of non-crop vegetation on the abundance of two important pests: the olive psyllid (Euphyllura olivina) and the olive moth (Prays oleae). Areas of herbaceous vegetation and areas of woody vegetation near olive crops, and smaller patches of woody vegetation within olive groves, decreased pest abundance in the crop. Inter-row ground covers that are known to increase the abundance of some predators and parasitoids had no effect on the pests, possibly as a result of lack of synchrony between pests and natural enemies, lack of specificity or intra-guild predation. This study identifies examples of the right types of diversity for use in conservation biological control in olive production systems. PMID:23904994

Paredes, Daniel; Cayuela, Luis; Gurr, Geoff M; Campos, Mercedes

2013-01-01

75

Spatial variability models of soil respiration from some vegetation types in Maritime Antarctica  

Science.gov (United States)

Soil respiration is an important part of the terrestrial carbon cycling and is influenced by several aspects, such as type and distribution of vegetation. In this work we evaluated the spatial variability of the soil respiration (or soil CO2 emission) in three sites located in Maritime Antarctica at Admiralty Bay, King George Island under contrasting vegetation, representative of this region: (I) a mixed Deschampsia/Mosses field, (II) a moss carpet of Sanionia uncinata and (III) a grass field of Deschampsia Antarctica. Soil respiration was measured in a 60-point regularly spaced grid previously installed at each site. The grid size was 3 x 1.5 meter with a minimum distance of 0.5 m between grid points in March 2009 during the morning at site I and afternoon at sites II and III. The spatial variability was analyzed by using descriptive statistics and the adjustment of the semivariogram models to the soil respiration and soil temperature data. The model adjusted to the semivariogram was used in order to generate the so-called kriging map by interpolation techniques, estimating the studied property at non-sampled places. Higher mean emission was observed in the Deschampsia field (4.13 µmol m-2 s-1), but the highest variability was detected in the mixed vegetation site I. The overall results indicate that soil temperature is not directly related to the spatial pattern of the soil respiration in the studied sites. The degree of spatial dependence was moderate for emission in all studied sites. Temperature values presented degree of spatial dependence classified as strong for sites I and III and moderate in site II. CO2 emission ranges were 1.29, 2.23 and 2.79 m for sites I - II - III, respectively. Higher range values observed in site II and III suggest higher emission homogeneity. In mixed vegetation at site I, points under Deschampsia Antarctica had an overall higher mean respiration (1.49 µmol m-2 s-1) compared with remaining points under mosses tuffs (1.32 µmol m-2 s-1). Kriging maps of soil CO2 emission and soil temperature indicate a more continuity of isolines for emission maps from sites II and III. This can also be observed in soil temperature maps, suggesting that vegetation cover may also control the continuity or discontinuity of both properties in space. Therefore distribution of soil respiration and soil temperature did not appear to be related to soil type, but more associated to the vegetation type and distribution at each site.

La Scala, Newton, Jr.; Mendonça, Eduardo S.; Rodrigo Panosso, Alan; Dimas, Felipe N.; Schaefer, Carlos Eduardo G.

2010-05-01

76

[Soil microbial properties under different vegetation types in Loess hilly region].  

Science.gov (United States)

By using fumigation-extract (FE) method and Biolog Ecoplate, this paper investigated the microbial biomass and diversity in 0-20 cm soil layer under five vegetation types, including artificial woodland, shrubland, cropland, abandoned farmland, and natural grassland, in Dingxi of Gansu Province. In the meanwhile, the relationships between soil microbes and soil nutrients were studied by path analysis, and the five typical vegetation types were evaluated from the aspect of soil microbes. Relative to cropland, "grain for green" project played a key role in improving soil microbial resources. Microbial biomass carbon was the highest in ridge grassland, abandoned farmland, and pine woodland, followed by in Caragana korshinskii land, Medicago sativa land, restored land, and roadside land, and in wheat field and potato field. Microbial biomass nitrogen was the highest in ridge land, abandoned farmland, Pinus tabulaeformis woodland, Caragana korshinskii land, and Medicago sativa land, followed by in restored land and roadside land, and in wheat field and potato field. Caragana korshinskii land and Medicago sativa land, due to the existence of N-fixing rhizobium, had the highest ratio of soil microbial biomass nitrogen to soil total nitrogen. Owing to the continual biomass loss and rare feedback, cropland had the lowest quantity and activity of soil microbes. Through planting trees, shrubs and grasses or through fallowing, soil microbial biomass and activity were recovered, and the effect was increased with time. In 20-year old Caragana korshinskii land, the quantity and activity of soil microbes were similar to those in 50-year old Pinus tabulaeformis woodland, and the microbial community catabolic activity and soil nutrient use efficiency were higher. Considering the features of soil microbes under test vegetation types, Caragana korshinskii would be a good choice for local vegetation restoration. PMID:20387439

Zhang, Yan-Yan; Qu, Lai-Ye; Chen, Li-Ding; Wei, Wei

2010-01-01

77

Hotspots of human-induced biomass productivity decline and their social-ecological types toward supporting national policy and local studies on combating land degradation  

Science.gov (United States)

Identification and social-ecological characterization of areas that experience high levels of persistent productivity decline are essential for planning appropriate management measures. Although land degradation is mainly induced by human actions, the phenomenon is concurrently influenced by global climate changes that need to be taken into account in land degradation assessments. This study aims to delineate the geographic hotspots of human-induced land degradation in the country and classify the social-ecological characterizations of each specific degradation hotspot type. The research entailed a long-term time-series (1982-2006) of Normalized Difference Vegetation Index to specify the extents of areas with significant biomass decline or increase in Vietnam. Annual rainfall and temperature time-series were then used to separate areas of human-induced biomass productivity decline from those driven by climate dynamics. Next, spatial cluster analyses identified social-ecological types of degradation for guiding further investigations at regional and local scales. The results show that about 19% of the national land mass experienced persistent declines in biomass productivity over the last 25 years. Most of the degraded areas are found in the Southeast and Mekong River Delta (17,984 km2), Northwest Mountains (14,336 km2), and Central Highlands (13,504 km2). We identified six and five social-ecological types of degradation hotspots in agricultural and forested zones, respectively. Constraints in soil nutrient availability and nutrient retention capability are widely spreading in all degradation hotspot types. These hotspot types are different from each other in social and ecological conditions, suggesting that region-specific strategies are needed for the formulation of land degradation combating policy.

Vu, Quyet Manh; Le, Quang Bao; Vlek, Paul L. G.

2014-10-01

78

Holocene planform change in broad valleys in the Southern Rocky Mountains: the role of vegetation type and beaver in shaping long-term channel complexity  

Science.gov (United States)

Over the past decade, researchers have shown the importance of streambank vegetation in forming meandering channels. Recent work has also showed the importance of beaver in creating a more heterogeneous landscape, in terms of channel planform and complexity, sedimentation, and riparian vegetation. Streambank vegetation and beavers interact as ecosystem engineers to determine long-term channel planform, floodplain processes, and complexity. We use studies of Holocene beaver aggradation and effects on channel complexity, in addition to measurements of added bank strength by various riparian vegetation types, to predict Holocene planform change in broad (>200 m, disconnected from hillslopes), high-elevation (>2300 m) valleys of the Colorado Front Range in the Southern Rocky Mountains. Sediment core analyses and shallow subsurface geophysical measurements indicate that post-glacial beaver-related aggradation is significant. Additionally, historical and field evidence from the last century, when the beaver population steadily declined, shows that beaver contribute to the formation of a complex, multi-thread channel network. Streambank vegetation in the Colorado Front Range can be categorized based on its ability to provide added strength to the streambank, where riparian or rhizomatous shrubs and trees provide more strength than xeric trees or non-rhizomatous graminoids and herbs, depending on the bank texture and hydrologic conditions. Assuming a snowmelt-dominated flow regime in a gravel-bed channel system, four planform regimes are identified based on beaver populations and the abundance and presence of xeric or riparian vegetation. Following deglaciation, without beaver or bank-stabilizing vegetation, (1) a braided channel formed. The introduction of riparian vegetation and a more stable flow regime triggered a transition to (2) a meandering channel, which in turn provided habitat for beaver, allowing the formation of (3) a complex multi-thread channel system. The fourth planform regime occurs only after beaver that occupied a valley for a long period have been removed. With a stable beaver population, ponds trap large amounts of fine, cohesive sediment, which becomes incorporated into the floodplain sediment and streambanks after channel migration. A legacy effect from beaver removal, which is accompanied by higher gradient and thus stream power, and a lowered water table and thus more xeric vegetation, is (4) a narrow, incised channel. These planform regimes can be inferred over the range of Holocene climate conditions in the Colorado Front Range, and understanding of these biotic-physical interactions should be a crucial component of any management decisions for geomorphic or ecologic conditions.

Polvi-Pilgrim, L. E.; Wohl, E.

2012-04-01

79

The influence of distinct types of aquatic vegetation on the flow field  

Science.gov (United States)

The Sustainable management of fluvial systems dealing with flood prevention, erosion protection and restoration of rivers and estuaries requires implementation of soft/green-engineering methods. In-stream aquatic vegetation can be regarded as one of these as it plays an important role for both river ecology (function) and geomorphology (form). The goal of this research is to offer insight gained from pilot experimental studies on the effects of a number of different elements modeling instream, aquatic vegetation on the local flow field. It is hypothesized that elements of the same effective "blockage" area but of distinct characteristics (structure, porosity and flexibility), will affect both the mean and fluctuating levels of the turbulent flow to a different degree. The above hypothesis is investigated through a set of rigorous set of experimental runs which are appropriately designed to assess the variability between the interaction of aquatic elements and flow, both quantitatively and qualitatively. In this investigation three elements are employed to model aquatic vegetation, namely a rigid cylinder, a porous but rigid structure and a flexible live plant (Cupressus Macrocarpa). Firstly, the flow field downstream each of the mentioned elements was measured under steady uniform flow conditions employing acoustic Doppler velocimetry. Three-dimensional flow velocities downstream the vegetation element are acquired along a measurement grid extending about five-fold the element's diameter. These measurements are analyzed to develop mean velocity and turbulent intensity profiles for all velocity components. A detailed comparison between the obtained results is demonstrative of the validity of the above hypothesis as each of the employed elements affects in a different manner and degree the flow field. Then a flow visualization technique, during which fluorescent dye is injected upstream of the element and images are captured for further analysis and comparison, was employed to visualize the flow structures shed downstream the aquatic elements. This method allows to further observe qualitatively and visually identify the different characteristics of the eddies advected downstream, conclusively confirming the results of the aforementioned experimental campaign.

Valyrakis, Manousos; Barcroft, Stephen; Yagci, Oral

2014-05-01

80

Interactions between soil moisture and Atmospheric Boundary Layer at the Brazilian savana-type vegetation Cerrado  

Science.gov (United States)

Before the large people influx and development of the central part of Brazil in the sixties, due to new capital Brasília, Cerrado, a typical Brazilian savanna-type vegetation, used to occupy about 2 million km2, going all the way from the Amazon tropical forest, in the north of the country, to the edges of what used to be of the Atlantic forest in the southeast. Today, somewhat 50% of this area has given place to agriculture, pasture and managed forests. It is forecasted that, at the current rate of this vegetation displacement, Cerrado will be gone by 2030. Understanding how Cerrado interacts with the atmosphere and how this interaction will be modified with this land-use change is a crucial step towards improving predictions of future climate-change scenarios. Cerrado is a vegetation adapted to a climate characterized by two very distinct seasons, a wet season (Nov-Mar) and dry season (May-Ago), with April and October being transitions between seasons. Typically, based on measurements in a weather station located in Brasilia, 75% of precipitation happens in the wet-season months and only 5% during dry-season. Under these circumstances, it is clear that the vegetation will have to cope with long periods of water stress. In this work we studied using numerical simulations, the interactions between soil-moisture, responsible for the water stress, with the Atmospheric Boundary Layer (ABL). The numerical model comprises of a Soil-Vegetation-Atmosphere model where the biophysical processes are represented with a big-leaf approach. Soil water is estimated with a simple logistic model and with water-stress effects on stomatal conductance are parameterized from local measurements of simultaneous latent-heat fluxes and soil moisture. ABL evolution is calculate with a slab model that considers independently surface and entrainment fluxes of sensible- and latent- heat. Temperature tropospheric lapse-rate is taken from soundings at local airport. Simulations of 30-day dry down from saturation to complete water stress were performed and is analyzed as far how ABL respond to soil moisture changes. This provides informations about ABL behavior on the transition states. Future studies will look on how this behavior will change with the new vegetation covers.

Pinheiro, L. R.; Siqueira, M. B.

2013-05-01

 
 
 
 
81

Major vegetation types of the Soutpansberg Conservancy and the Blouberg Nature Reserve, South Africa  

Scientific Electronic Library Online (English)

Full Text Available SciELO South Africa | Language: English Abstract in english The Major Megetation Types (MVT) and plant communities of the Soutpansberg Centre of Endemism are described in detail, with special reference to the Soutpansberg Conservancy and the Blouberg Nature Reserve. Phytosociological data from 442 sample plots were ordinated using a DEtrended CORrespondence [...] ANAlysis (DECORANA) and classified using TWo-Way INdicator SPecies ANalysis (TWINSPAN). The resulting classification was further refined with table-sorting procedures based on the Braun-Blanquet floristic-sociological approach of vegetation classification using MEGATAB. Eight MVT's were identified and described as Eragrostis lehmanniana var. lehmanniana-Sclerocarya birrea subsp. caffra Blouberg Northern Plains Bushveld, Euclea divinorum-Acacia tortilis Blouberg Southern Plains Bushveld, Englerophytum magalismontanum-Combretum molle Blouberg Mountain Bushveld, Adansonia digitata-Acacia nigrescens Soutpansberg Arid Northern Bushveld, Catha edulis-Flueggia virosa Soutpansberg Moist Mountain Thickets, Diplorhynchus condylocarpon-Burkea africana Soutpansberg Leached Sandveld, Rhus rigida var. rigida-Rhus magalismontanum subsp. coddii Soutpansberg Mistbelt Vegetation and Xymalos monospora-Rhus chirendensis Soutpansberg Forest Vegetation.

Theo H.C., Mostert; George J., Bredenkamp; Hannes L., Klopper; Cornie, Verwey; Rachel E., Mostert; Norbert, Hahn.

82

Major Vegetation Types of the Soutpansberg Conservancy and the Blouberg Nature Reserve, South Africa  

Directory of Open Access Journals (Sweden)

Full Text Available The Major Megetation Types (MVT and plant communities of the Soutpansberg Centre of Endemism are described in detail, with special reference to the Soutpansberg Conservancy and the Blouberg Nature Reserve. Phytosociological data from 442 sample plots were ordinated using a DEtrended CORrespondence ANAlysis (DECORANA and classified using TWo-Way INdicator SPecies ANalysis (TWINSPAN. The resulting classification was further refined with table-sorting procedures based on the Braun–Blanquet floristic–sociological approach of vegetation classification using MEGATAB. Eight MVT’s were identified and described as Eragrostis lehmanniana var. lehmanniana–Sclerocarya birrea subsp. caffra Blouberg Northern Plains Bushveld, Euclea divinorum–Acacia tortilis Blouberg Southern Plains Bushveld, Englerophytum magalismontanum–Combretum molle Blouberg Mountain Bushveld, Adansonia digitata–Acacia nigrescens Soutpansberg Arid Northern Bushveld, Catha edulis–Flueggia virosa Soutpansberg Moist Mountain Thickets, Diplorhynchus condylocarpon–Burkea africana Soutpansberg Leached Sandveld, Rhus rigida var. rigida–Rhus magalismontanum subsp. coddii Soutpansberg Mistbelt Vegetation and Xymalos monospora–Rhus chirendensis Soutpansberg Forest Vegetation.

Rachel E. Mostert

2008-05-01

83

Variation in net greenhouse gas balance across high Arctic vegetation types  

Science.gov (United States)

Climate in high-latitude environments is predicted to undergo the most pronounced warming and increase in precipitation. In warmer and wetter soils, the net balance of greenhouse gases (GHGs) such as CO2, CH4 and N2O could be altered, Changes in GHG dynamics, however, may not be uniform across the arctic landscape, where different vegetation types are distributed along moisture gradients. To predict the future contribution of Arctic ecosystems to global climate, it is important to understand the interactions between vegetation type and net GHG balance. Little research, however, has explored spatial variability in net GHG emissions from high-Arctic landscapes, especially in polar barrens that dominate the region. Most studies concentrated either on CO2 fluxes, or were performed in low-Arctic ecosystems and polar oases. In 2008 and 2009, we measured CO2, CH4 and N2O fluxes using static chamber techniques at Cape Bounty, Melville Island, Nunavut, Canada. Measurements were performed using transparent static chambers (to measure NEP, or opaque static chambers (for CH4, N2O and ecosystem respiration) in three major plant community types across a moisture gradient: polar semi-desert (PD), mid-moisture tundra (MM) and wet sedge meadow (WS). CO2 fluxes were measured with a VAISALA infrared gas analyzer, while trace gas fluxes were measured in air samples collected over 40 minutes and stored in pre-evacuated glass vials. In 2008, only the WS community was a net CO2sink, whereas in 2009 all vegetation types were CO2 sources, with MM emitting almost ten-fold more carbon than the other two plant communities. WS released the most N2O and CH4, followed by MM communities, while PD soils were net CH4 sinks. There was little discernible influence of environmental factors on N2O fluxes. Emissions of CH4 and N2O, tended to be higher in the warmer year 2008. On a given land area, depending on the climate of a given season and on the relative cover of the different vegetation types, CH4 flux can result either in carbon efflux or uptake (4.12x10-3 g C m-2 season-1 in 2008 vs. -12.69x10-3 g C m-2 season-1 in 2009 for the entire Cape Bounty area). The CH4 effluxes are small compared to more southern ecosystems, but uptake values are significant, comparable even to tropical ecosystems. Given the vast expanses of polar deserts, and the more potent nature of CH4 as a GHG, changes in the spatial extent of the different vegetation types could have a significant impact on net climate forcing attributed to high-Arctic ecosystems.

Scott, N. A.; Wagner, I.; Neil, A.

2012-12-01

84

Evaluation of the shelf-life of vegetable-type soybean pods  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english The shelf-life of the vegetable-type soybean pods stored under different conditions was evaluated by chemical characteristics and color. The pods were harvested in the R6 stage and stored either at 30 or 7ºC for 9 d. After the storage period, the pods were blanched and threshed, and the immature gre [...] en grains were used for the analysis. The protein content decreased after 6 d of storage at 7ºC. There was no difference in the lipid content after the storage at 30 and 7ºC for 9 d. The starch and sucrose contents decreased after the first day of storage at 30ºC. There was no difference in trypsin inhibitor activity until 6 d of storage at 30 and 7ºC. The green color of the pods that was an indication of the quality that was maintained when stored at 7ºC during 3 d. To preserve the quality of vegetable-type soybean, pods should be stored at 30ºC and consumed within 24 h or stored at 7ºC for up to 3 d of storage.

Andréia Cristina, Santana; Mercedes Concórdia, Carrão-Panizzi; José Marcos Gontijo, Mandarino; Rodrigo Santos, Leite; Josemeyre Bonifácio da, Silva; Elza Iouko, Ida.

85

Species composition and temporal activity of Arctiinae (Lepidoptera: Erebidae) in two cerrado vegetation types  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english Arctiinae moths include nearly 11,000 species worldwide, of which approximately 700 species occur in the Brazilian Cerrado. The aim of this study was to describe the species composition of Arctiinae, as well as the variation in annual and nightly moth activity, in two Cerrado vegetation types. We sa [...] mpled moths one night per month from September 2008 to June 2009, in the gallery forest and in the cerrado sensu stricto in the Jardim Botânico de Brasília. We collected 395 tiger moths belonging to 65 morphospecies; 74% of the species belonged to the tribe Arctiini and 26% to Lithosiini. Thirty-one species (47.7%) occurred only in the gallery forest, 13 (20%) occurred only in the cerrado sensu stricto, and 21 (32.3%) occurred in both vegetation types. Additionally, we found the greatest species richness between 7:00 p.m. and 8:00 p.m., and these hours were associated with 21 and 22 species, respectively. Most species (51.8%) were active for up to three hours during the night. In general, the species composition differed between the dry and rainy seasons, and the similarity of the fauna also varied hourly. Based on our results, we suggest that rapid inventories of Arctiinae be performed in both rainy and dry seasons, and sampling should be carried out the entire night.

Scheila, Scherrer; Viviane G., Ferro; Marina N., Ramos; Ivone R., Diniz.

2013-04-01

86

Type of vegetable oils used in cooking and risk of metabolic syndrome among Asian Indians.  

Science.gov (United States)

There is little data on the type of vegetable oil used and the prevalence of metabolic syndrome (MS) in Asian Indians. Food frequency questionnaire was used to document the type of cooking oil in 1875 adults in Chennai city. MS was assessed by new harmonizing criteria. The prevalence of MS was higher among sunflower oil users (30.7%) than palmolein (23.2%) and traditional oil (17.1%, p < 0.001) users. The higher prevalence of MS in sunflower oil group persisted even when stratified according to body mass index, except in obese groups. The risk of MS was further compounded by quantity of refined cereals consumed. Higher LA%E and linoleic acid/alpha-linolenic acid ratio in sunflower oil probably contributes to increased risk of MS. PMID:23025245

Lakshmipriya, Nagarajan; Gayathri, Rajagopal; Praseena, Kallingal; Vijayalakshmi, Parthasarathy; Geetha, Gunasekaran; Sudha, Vasudevan; Krishnaswamy, Kamala; Anjana, Ranjit Mohan; Henry, Jeyakumar; Mohan, Viswanathan

2013-03-01

87

On the potential vegetation feedbacks that enhance phosphorus availability – insights from a process-based model linking geological and ecological timescales  

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We find that active P uptake is an essential mechanism for sustaining P availability on long timescales, whereas biotic de-occlusion might serve as a buffer on timescales shorter than 10 000 yr. Although active P uptake is essential for reducing P losses by leaching, humid lowland soils reach P limitation after around 100 000 yr of soil evolution. Given the generalized modelling framework, our model results compare reasonably with observed or independently estimated patterns and ranges of P concentrations in soils and vegetation. Furthermore, our simulations suggest that P limitation might be an important driver of biomass production efficiency (the fraction of the gross primary productivity used for biomass growth, and that vegetation on old soils has a smaller biomass production rate when P becomes limiting. With this study, we provide a theoretical basis for investigating the responses of terrestrial ecosystems to P availability linking geological and ecological timescales under different environmental settings.

C. Buendía

2014-07-01

88

An ecological study of the major vegetation communities of the Vaalbos National Park, Northern Cape. 2. The Graspan-Holpan section  

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Full Text Available Detailed classification, description and mapping of the Graspan-Holpan section of the Vaalbos National Park, Northern Cape, were initiated. This classification is intended to serve as a basis for the establishment of an efficient wildlife management programme as well as conservation policies for the Vaalbos National Park. Using a numerical classification technique (TWINSPAN as a first approximation, the classification was refined by applying Braun-Blanquet procedures. A hierarchical plant community clas- sification, description, ecological interpretation and a vegetation map are presented. In the phytosociological table nine major plant communities are recognised.

H. Bezuidenhout

1995-09-01

89

Ecological restoration and recovery in the wind-blown sand hazard areas of northern China: relationship between soil water and carrying capacity for vegetation in the Tengger Desert.  

Science.gov (United States)

The main prevention and control area for wind-blown sand hazards in northern China is about 320000 km(2) in size and includes sandlands to the east of the Helan Mountain and sandy deserts and desert-steppe transitional regions to the west of the Helan Mountain. Vegetation recovery and restoration is an important and effective approach for constraining wind-blown sand hazards in these areas. After more than 50 years of long-term ecological studies in the Shapotou region of the Tengger Desert, we found that revegetation changed the hydrological processes of the original sand dune system through the utilization and space-time redistribution of soil water. The spatiotemporal dynamics of soil water was significantly related to the dynamics of the replanted vegetation for a given regional precipitation condition. The long-term changes in hydrological processes in desert areas also drive replanted vegetation succession. The soil water carrying capacity of vegetation and the model for sand fixation by revegetation in aeolian desert areas where precipitation levels are less than 200 mm are also discussed. PMID:24699917

Li, XingRong; Zhang, ZhiShan; Tan, HuiJuan; Gao, YanHong; Liu, LiChao; Wang, XingPing

2014-05-01

90

Cavity types and microclimate: implications for ecological, evolutionary, and conservation studies.  

Science.gov (United States)

The abiotic conditions of the immediate environment of organisms are key factors for a better understanding of ecological and evolutionary processes. Yet, information in this regard is biased towards some habitat types, landscapes, and organisms. Here, we present a 2-year comparative study of the microclimatic properties (temperature, relative humidity, and their fluctuation) of three cavity types (nest boxes, cavities in bridges, and burrows in sandy cliffs) in an arid environment. We found marked and consistent months-long differences in microclimate among the three cavity types. Nest boxes were colder than the other cavity types, with temperature oscillations being an order of magnitude higher than in other cavity types. In contrast, microclimate was very stable in burrows and cavities in bridges, the former being generally warmer and drier than the latter. We also discuss the biological implications of microclimatic conditions and its variation in different cavity types by presenting two case studies, namely the temperature-humidity index and water vapor pressure during the hatching period of an endotherm and the chilling period during the diapause of an ectotherm ectoparasite. We stress the need for comparative studies of the same organisms subjected to different microclimates given the important ecological, evolutionary, and conservation implications. PMID:24573376

Amat-Valero, M; Calero-Torralbo, M A; Václav, R; Valera, F

2014-11-01

91

Wildfires alter rodent community structure across four vegetation types in southern California, USA  

Science.gov (United States)

We surveyed burned and unburned plots across four habitat reserves in San Diego County, California, USA, in 2005 and 2006, to assess the effects of the 2003 wildfires on the community structure and relative abundance of rodent species. The reserves each contained multiple vegetation types (coastal sage scrub, chaparral, woodland, and grassland) and spanned from 250 m to 1078 m in elevation. Multivariate analyses revealed a more simplified rodent community structure in all burned habitats in comparison to unburned habitats. Reduction in shrub and tree cover was highly predictive of changes in post-fire rodent community structure in the burned coastal sage scrub and chaparral habitats. Reduction in cover was not predictive for the less substantially burned woodlands and grasslands, for which we hypothesized that interspecific competition played a greater role in post-fire community structure. Across vegetation types, generalists and open habitat specialists typically increased in relative abundance, whereas closed habitat specialists decreased. We documented significant increases in relative abundance of the deer mouse (Peromyscus maniculatus Wagner) and Dulzura kangaroo rat (Dipodomys simulans Merriam). In contrast, we found significant decreases in relative abundance for the California mouse (Peromyscus californicus Gambel), San Diego pocket mouse (Chaetodipus fallax Merriam), desert woodrat (Neotoma lepida Thomas), and brush mouse (Peromyscus boylii Baird). Currently, our research program involves assessment of whether habitat conservation plans (HCPs) in southern California provide long-term protection to HCP covered species, as well as preserve ecosystem function. The scenario of increased wildfires needs to be incorporated into this assessment. We discuss our results in relation to management and conservation planning under a future scenario of larger and more frequent wildfires in southern California.

Brehme, Cheryl S.; Clark, Denise R.; Rochester, Carlton J.; Fisher, Robert N.

2011-01-01

92

The vegetation types and management units of Goedverwacht farm in the mixed bushveld of the Northern Province, South Africa  

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Full Text Available An analysis of the vegetation of Goedverwacht farm in the mixed bushveld of the Northern Province is presented. Releves were compiled in 33 stratified random sample plots. Eight distinct plant communities were identified by means ofBraun-Blanquet pro-cedures. Detrended correspondence analysis (DCA was applied to the floristic data set using the computer programme DECORANA (Detrended Correspondence Analysis to determine a probable environmental gradient and to facilitate in the identification of management units. The computer programme CANOCO (Canonical Correspondence Analysis was used to apply canonical correspondence analysis (CCA to the floristic data set. Two management units were determined by means of vegetation ordinations and soil data. A classification, description and ecological interpretation of the plant communities as well as a description of the management units are presented.

M. Deutschlander

1997-02-01

93

Some pathogenetic aspects of influence of ecological factors on the vegetative and haemodynamic status at children of Belarus  

International Nuclear Information System (INIS)

The paradoxal sympathic vegetative regulation of central haemodynamice and the fall of basal activity of sympathoadrenal system at children under the combination chronic radio-chemical influence were established

94

kurkku, a Phenotype of Acetabularia acetabulum That Is Arrested in Vegetative Growth, Can Be Rescued with Wild-Type Cytoplasm.  

Science.gov (United States)

We isolated several spontaneous phenotypes in the giant unicell Acetabularia acetabulum that have vegetative terminal morphologies. Because they arrest in vegetative development, these cell lines are effectively immortalized. However, they had to be rescued before they could be studied via classical genetics because no heterozygotes from the original self-crosses were found, that is, the wild-type siblings yielded only wild-type progeny. We attempted to rescue these phenotypes in three ways: by amputating the cell apex, by "piggybacking" the mutant nucleus through development in a binucleate heterokaryon, and by replacing the abnormal apex with a wild-type apex. We used one of our immortal cell lines, kurkku, which has a terminal phenotype consistent with arrest early in the juvenile phase of vegetative development, as a prototype for these rescue methods. The kurkku phenotype segregated 1:3 in the original self-cross in which it arose as if it were a single, recessive Mendelian trait. Although amputation failed to rescue kurkku, we succeeded in compensating for the defect both in binucleate heterokaryons and in apical grafts to wild-type cells. kurkku was always recovered in the progeny of the self-crosses of these grafts. These unique ways of analyzing vegetative mutants, combined with the ability to then perform classical genetics, may make A. acetabulum a powerful unicellular model system for the study of vegetative phase change in plants. PMID:12239386

Mandoli, D. F.; Hunt, B. E.

1996-02-01

95

Survey to determine the adequacy of existing conserved areas in relation to vegetation types. A preliminary report.  

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Full Text Available

The report is a broad survey of the conservation status of South African vegetation. Data and maps show the distribution and total areas of conserved lands by the various conservation agencies, the size structure of nature reserves, the areas and percentages of conserved areas in relation to the 70 veld types and seven main vegetation types into which South Africa was divided by Acocks (1953, and important conservation requirements in the Bantu Homelands. Major conservation deficiencies lie in the Karoo and Karroid Bushveld and Grassland Types of vegetation, where 42 veld types have none or virtually no conservation, and in the Tropical Bush and Savanna Types to which-belong nine of the 10 remaining veld types extremely lacking in conservation. Additional reserves are needed' to conserve certain important and local ecosystems and species in the remaining 18 veld types, especially the Sclerophyllous Bush (Macchia or Fynbos and Temperate and Transitional Forest and Scrub Types, and in certain Coastal Tropical Forest and Thornveld Types. Apart from minor deficiencies, the conservation status is outstanding for six of these 18 veld types (up to 47 per cent under conservation, and very good for another six veld types.

D. Edwards

1974-07-01

96

Effects of storage time and temperature on the characteristics of vegetable-type soybean grain minimally processed  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english The objective of this study was to evaluate the effects of storage time and temperature on the characteristics of vegetable-type soybean grain (cultivar BRS 267) minimally processed and to define the best conditions for its storage. The evaluation was performed by measurement of vitamin C levels, we [...] ight loss and color parameters (L*, a*, and b*). The time of storage of vegetable-type soybean grains minimally processed and storage in Styrofoam trays and wrapped with PVC film, caused a decreased in vitamin C levels and color parameters and increased weight loss. This process was intensified with higher temperature at 25 °C than 5°C. To maintain appropriate levels of vitamin C, weight and color of vegetable-type soybean grains minimally processed and storage in trays wrapped in plastic wrap, recommended storage for 3 days at 5°C.

Karina, Czaikoski; Mercedes Concórdia, Carrão-Panizzi; Josemeyre Bonifácio da, Silva; Elza Iouko, Ida.

97

Ecological transcriptomics of lake-type and riverine sockeye salmon (Oncorhynchus nerka  

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Full Text Available Abstract Background There are a growing number of genomes sequenced with tentative functions assigned to a large proportion of the individual genes. Model organisms in laboratory settings form the basis for the assignment of gene function, and the ecological context of gene function is lacking. This work addresses this shortcoming by investigating expressed genes of sockeye salmon (Oncorhynchus nerka muscle tissue. We compared morphology and gene expression in natural juvenile sockeye populations related to river and lake habitats. Based on previously documented divergent morphology, feeding strategy, and predation in association with these distinct environments, we expect that burst swimming is favored in riverine population and continuous swimming is favored in lake-type population. In turn we predict that morphology and expressed genes promote burst swimming in riverine sockeye and continuous swimming in lake-type sockeye. Results We found the riverine sockeye population had deep, robust bodies and lake-type had shallow, streamlined bodies. Gene expression patterns were measured using a 16 k microarray, discovering 141 genes with significant differential expression. Overall, the identity and function of these genes was consistent with our hypothesis. In addition, Gene Ontology (GO enrichment analyses with a larger set of differentially expressed genes found the "biosynthesis" category enriched for the riverine population and the "metabolism" category enriched for the lake-type population. Conclusions This study provides a framework for understanding sockeye life history from a transcriptomic perspective and a starting point for more extensive, targeted studies determining the ecological context of genes.

Pavey Scott A

2011-12-01

98

Type D personality and cardiovascular reactivity to an ecologically valid multitasking stressor.  

Science.gov (United States)

Previous research investigating the influence of Type D personality on cardiovascular reactivity to stress in healthy young adults is somewhat mixed. The present study sought to investigate this question using an ecologically valid laboratory stressor. Beat-to-beat blood pressure and heart rate were measured in 77 healthy young adults during exposure to multitasking stress. Mood and background stress were both associated with Type D personality when Type D was conceptualised as a dimensional construct, with less robust findings observed using the traditional dichotomous typological approach. However, the continuous Type D construct added limited predictive value of the self-report measures above that of its constituent components, negative affectivity (NA) and social inhibition (SI). Further, an inverse relationship between the continuous Type D construct and blood pressure reactivity to multitasking stress was observed. In summary, our findings suggest that Type D personality is predictive of blunted cardiovascular reactivity to stress in healthy individuals when Type D is considered as a dimensional construct and the independent influence of NA and SI is controlled for. Further, our findings suggest that Type D does not predict additional variance in mood and background stress above that of NA and SI when these constituent factors are considered independently. PMID:24754252

Kelly-Hughes, Denise H; Wetherell, Mark A; Smith, Michael A

2014-01-01

99

GIS-based analysis of relationships between ecological factors and forest vegetation in the Prealps (North-east Italy  

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Full Text Available The forest communities distribution in mountainous areas is strongly related to some primary ecological factors (e.g. water, temperature, geology and to some other factors derived from the soil morphology (e.g. slope, aspect and solar radiation. The aim of this study is to investigate and express quantitatively the relationships between ecological factors and forest communities through geospatial analysis in a GRASS GIS. There are significant statistical differences between forest communities according to environmental factors (Kruskal-Wallis test, T2 of Tamhane, PCA. Some ecological factors studied (e.g. solar potential radiation are useful to describe forest communities in indirect gradient analysis. The study area is located in the Eastern Prealps of Friuli Venezia Giulia (Italy and is characterized by a large environmental variability (climate, natural and human disturbances.

Bonfanti PL

2004-01-01

100

Seasonal variations in the biomass, quantity and quality of agar, from the reproductive and vegetative stages of Gracilaria (verrucosa type)  

Energy Technology Data Exchange (ETDEWEB)

Optimum growth of Gracilaria (verrucosa type) in British Columbia occurred between 5 and 6 meters below mean field level and correlated with solar radiation throughout the season. Vegetative populations declined with a consequent increase in reproductive forms to a maximum in July. Tetrasporophytes dominated the reproductive population and in July attained the greatest seasonal biomass of all forms of the alga. Maximum population and biomass were attained by carposporophytes in July and by male gametophytes one month earlier. An inverse relationship between biomass and yield of agar was apparent only for the vegetative and tetrasporic forms of the alga. Variations in yields, gel strengths, and gelation characteristics of the agars isolated, were demonstrated to be dependent on time of season and life stages of the alga. Ranked in the following decreasing order of merit as a source of agar were the cystocarpic, tetrasporic, vegetative and male gametophytic forms of Gracilaria (verrucosa type).

Whyte, J.N.C.; Englar, J.R.; Saunders, R.G.; Lindsay, J.C.

1981-09-01

 
 
 
 
101

Assessment of the transfer of {sup 137}Cs in three types of vegetables consumed in Hong Kong  

Energy Technology Data Exchange (ETDEWEB)

A dynamic food chain model has been built for the modeling of the transfer of {sup 137}Cs in three types of vegetables consumed in Hong Kong, namely, white flowering cabbage (Brassica chinensis), head lettuce (Lactuca sativa) and celery (Apium graveolens). Some parameters have been estimated from the experimental data obtained in this work. The experimental data include the transfer factors of {sup 137}Cs from soil to the different vegetable species which are determined through high resolution gamma spectrometry, maximum crop biomasses for the vegetable species, the dry-to-fresh ratios for the vegetable species, the bulk density of soil layers and the average concentration of {sup 137}Cs in air. The derived parameters include the deposition rate and the root uptake rate, information for tillage, the logistic growth model and radionuclide concentrations in vegetables. The dynamic food chain model is solved by the Birchall-James algorithm to give the {sup 137}Cs concentration in subsurface soil, from the 0.1-25 cm soil layer, and the {sup 137}Cs concentration in harvested and unwashed vegetables. As validation of the model and parameters, the concentrations obtained experimentally and from the model are compared and are found to be in good agreement.

Yu, K.N.; Mao, S.Y.; Young, E.C.M

1998-12-01

102

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)

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 SAVANNA included a land cover map, long-term weather data, soil maps, and a digital elevation model. Parameterization and calibration were conducted using field plots. Model predictions of herbaceous biomass production and weather were consistent with available data and spatial interpolations of snow were considered reasonable for this study. Dynamic outputs generated by SAVANNA were integrated with static variables, movement rules, and parameters developed for the individual-based model through the application of a habitat suitability index. Model validation indicated reasonable model fit when compared to an independent test set. The finished model was applied to 2 realistic management scenarios for the Jemez Mountains and management implications were discussed. Ongoing validation of the individual-based model presented in this dissertation provides an adaptive management tool that integrates interdisciplinary experience and scientific information, which allows users to make predictions about the impact of alternative management policies.

S.P. Rupp

2005-10-01

103

A new quantitative classification of ecological types in the bromeliad genus Tillandsia (Bromeliaceae based on trichomes  

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Full Text Available Using collection specimens, we measured the density and wing area of trichomes in 37 species of the bromeliad genus Tillandsia, specifically the abaxial proximal, abaxial distal, adaxial proximal and adaxial distal parts of the leaf. The product of the trichome "wing" area by the number of trichomes (means produced a pure number (T that was correlated to ecological features. The correlation was positive with respect to arid environments (xeric Tillands and negative with respect to humid environments (mesic Tillands. Bulbous, and particularly myrmecophytic species and species with tanks, represented particular categories. Other intermediate types were identified based on the T number, totalling five ecological types. In comparison with other systems of ecological typification for Tillands and other Bromeliaceae, the present system offers measurable data whose analysis is reproducible. Rev. Biol. Trop. 56 (1: 191-203. Epub 2008 March 31.Medimos el número por milímetro cuadrado y el área del "ala" (parte móvil de los tricomas en las partes adaxial próxima y distal, y adaxial próxima y distal, de la hoja de 37 especies de bromelias del género Tillandsia. El producto del área del ala para el número de los tricomas (promedio produjo un número puro (T. Hallamos que T se correlaciona con las características ecológicas de las tilandsias investigadas. La correlación es positiva con respecto a ambientes áridos (especies xéricas y negativa con respecto a los ambientes húmedos (especies mésicas. Las especies con bulbo, y particularmente las asociadas con hormigas y especies con de tanque representan categorías particulares. Identificamos otros tipos intermedios, agradando así cinco tipos ecológicos. En comparación con otros sistemas de tipificación ecológica, este sistema ofrece la ventaja de ser reproducible y cuantitativo.

Mosti Stefano

2008-03-01

104

Regular, high, and moderate intake of vegetables rich in antioxidants may reduce cataract risk in Central African type 2 diabetics  

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Full Text Available Moise Mvitu,1 Benjamin Longo-Mbenza,2 Dieudonné Tulomba,3 Augustin Nge31Department of Ophthalmology, University of Kinshasa, Democratic Republic of Congo; 2Faculty of Health Sciences, Walter Sisulu University, South Africa; 3Biostatistics Unit, Lomo Medical Center and Heart of Africa Center of Cardiology, Kinshasa, Democratic Republic of CongoBackground: Antioxidant nutrients found in popularly consumed vegetables, including red beans, are thought to prevent diabetic complications. In this study, we assessed the frequency and contributing factors of intake of fruits and vegetables rich in antioxidants, and we determined their impact on the prevention of diabetes-related cataract extraction.Methods: This was a cross-sectional study, run in Congo among 244 people with type 2 diabetes mellitus. An intake of ?three servings of vegetables rich in antioxidants/day, intake of red beans, consumption of fruit, and cataract extraction were considered as dependent variables.Results: No patient reported a fruit intake. Intake of red beans was reported by 64 patients (26.2%, while 77 patients (31.6% reported ?three servings of vegetables rich in antioxidants. High socioeconomic status (OR = 2.3; 95% CI: 1.1–12.5; P = 0.030 and moderate alcohol intake (OR = 4; 95% CI: 1.1–17.4; P = 0.049 were the independent determinants of eating ?three servings of vegetables rich in antioxidants. Red beans intake (OR = 0.282; 95% CI: 0.115–0.687; P > 0.01 and eating ?three servings of vegetables rich in antioxidants (OR = 0.256; 95% CI: 0.097–0.671; P = 0.006 were identified as independent and protective factors against the presence of cataracts (9.8% n = 24, whereas type 2 diabetes mellitus duration ?3 years was the independent risk factor for cataract extraction (OR = 6.3; 95% CI: 2.1–19.2; P > 0.001 in the model with red beans intake and OR = 7.1; 95% CI: 2.3–22.2; P > 0.001 in the model with ?three servings of vegetables rich in antioxidants.Conclusion: Red beans intake and adequate quantity of intake of vegetables rich in antioxidants were found to be associated with reduced risk of cataract in these Congolese with type 2 diabetes mellitus. Education on nutrition and health promotion programs are needed to encourage people to eat vegetables and fruit.Keywords: red beans, cataract extraction, socioeconomic status, public health implications

Mvitu M

2012-06-01

105

A comparative analysis of MODIS based spectral indices for drought monitoring over fire prone vegetation types  

Science.gov (United States)

Drought is a complex natural hazard with severe impacts on ecosystems. Several studies have highlighted links between drought spatio-temporal patterns and wildfire behaviour. Recent research showed drought can affect the development of catastrophic fires through influence on the spatial connectivity of dry fuel patches. Wildfires that are initiated at isolated ignition points (‘within patch scale’) can propagate non-linearly across landscapes (“among-patches”) if fuels are sufficiently dry and connected. Consequently, accurate mapping of drought at fine spatial resolution represents a priority to monitor “among-patches” continuity of flammable fuels in fire prone regions. Traditional methods of drought monitoring are based on meteorological indices (MI) calculated from weather stations data. The network of weather stations is often sparse and inadequate to produce fine spatial resolution surfaces of MI especially across remote forested areas. Spectral indices (SI) based on satellite data provide sound and cost-effective alternatives to MI, offering spatially dense information regularly recorded over large areas across a wide range of wavelengths. Since a considerable number of SI have been proposed as drought monitoring tool, the selection of the most appropriate index for a specific region represents an essential operation to ensure efficiency in drought mapping. In this study we propose a comprehensive analysis to evaluate the performance of a wide range of Vis, NIR and SWIR based SI towards drought condition monitoring over fire prone vegetation types, using the Sydney Basin bioregion (Australia) as case study. All spectral indices were derived from reflectance data sets obtained from MODIS Terra time series (2000-2009). The relationships between SI and drought conditions were analysed using a meteorological index (Standardized Precipitation Index, SPI) as rainfall deficiency indicator. The spatial and temporal co-variability between SPI and spectral indices was analysed and the sensitivity of MODIS indices to drought-related vegetation conditions was tested against a series of dry/wet years. Strong relationships between MODIS data and drought conditions were found. All spectral indices showed strong temporal and spatial correlations with SPI, with higher sensitivity to drought among SWIR based indices. The results revealed also that the spectral index routinely used by bushfire authorities in the Sydney Basin for drought monitoring is not the best indicator available, and there are potentials for the development of an enhanced MODIS-based monitoring tool. Our findings confirmed that extensive comparative analysis is necessary prior to implementation of SI in drought monitoring systems.

Caccamo, G.; Chisholm, L. A.; Bradstock, R.; Puotinen, M. L.

2010-12-01

106

Spatial and temporal patterns of greenness on the Yamal Peninsula, Russia: interactions of ecological and social factors affecting the Arctic normalized difference vegetation index  

Energy Technology Data Exchange (ETDEWEB)

The causes of a greening trend detected in the Arctic using the normalized difference vegetation index (NDVI) are still poorly understood. Changes in NDVI are a result of multiple ecological and social factors that affect tundra net primary productivity. Here we use a 25 year time series of AVHRR-derived NDVI data (AVHRR: advanced very high resolution radiometer), climate analysis, a global geographic information database and ground-based studies to examine the spatial and temporal patterns of vegetation greenness on the Yamal Peninsula, Russia. We assess the effects of climate change, gas-field development, reindeer grazing and permafrost degradation. In contrast to the case for Arctic North America, there has not been a significant trend in summer temperature or NDVI, and much of the pattern of NDVI in this region is due to disturbances. There has been a 37% change in early-summer coastal sea-ice concentration, a 4% increase in summer land temperatures and a 7% change in the average time-integrated NDVI over the length of the satellite observations. Gas-field infrastructure is not currently extensive enough to affect regional NDVI patterns. The effect of reindeer is difficult to quantitatively assess because of the lack of control areas where reindeer are excluded. Many of the greenest landscapes on the Yamal are associated with landslides and drainage networks that have resulted from ongoing rapid permafrost degradation. A warming climate and enhanced winter snow are likely to exacerbate positive feedbacks between climate and permafrost thawing. We present a diagram that summarizes the social and ecological factors that influence Arctic NDVI. The NDVI should be viewed as a powerful monitoring tool that integrates the cumulative effect of a multitude of factors affecting Arctic land-cover change.

Walker, D A; Bhatt, U S; Raynolds, M K; Romanovsky, V E [University of Alaska Fairbanks, Fairbanks, AK (United States); Leibman, M O; Gubarkov, A A; Khomutov, A V; Moskalenko, N G; Orekhov, P; Ukraientseva, N G [Earth Cryosphere Institute, Russian Academy of Science, Siberian Branch, Tyumen (Russian Federation); Epstein, H E; Yu, Q [University of Virginia, Charlottesville, VA (United States); Forbes, B C; Kaarlejaervi, E [Arctic Center, University of Lapland, Rovaniemi (Finland); Comiso, J C [NASA Goddard Space Flight Center, MD (United States); Jia, G J [Chinese Academy of Sciences, Institute for Atmospheric Physics, Beijing (China); Kaplan, J O [Swiss Federal Institute for Forest Snow and Landscape Research, Birmensdorf (Switzerland); Kumpula, T [University of Joensuu, Joensuu (Finland); Kuss, P [University of Berne, Berne (Switzerland); Matyshak, G [Moscow State University, Moscow (Russian Federation)

2009-10-15

107

Biodiesel classification by base stock type (vegetable oil) using near infrared spectroscopy data  

International Nuclear Information System (INIS)

The use of biofuels, such as bioethanol or biodiesel, has rapidly increased in the last few years. Near infrared (near-IR, NIR, or NIRS) spectroscopy (>4000 cm-1) has previously been reported as a cheap and fast alternative for biodiesel quality control when compared with infrared, Raman, or nuclear magnetic resonance (NMR) methods; in addition, NIR can easily be done in real time (on-line). In this proof-of-principle paper, we attempt to find a correlation between the near infrared spectrum of a biodiesel sample and its base stock. This correlation is used to classify fuel samples into 10 groups according to their origin (vegetable oil): sunflower, coconut, palm, soy/soya, cottonseed, castor, Jatropha, etc. Principal component analysis (PCA) is used for outlier detection and dimensionality reduction of the NIR spectral data. Four different multivariate data analysis techniques are used to solve the classification problem, including regularized discriminant analysis (RDA), partial least squares method/projection on latent structures (PLS-DA), K-nearest neighbors (KNN) technique, and support vector machines (SVMs). Classifying biodiesel by feedstock (base stock) type can be successfully solved with modern machine learning techniques and NIR spectroscopy data. KNN and SVM methods were found to be highly effective for biodiesel classification by feedstock oil type. A classification error (E) of less than 5% can be reached using an SVM-based approach. If computational time is an important consideration, the KNN technique (E = 6.2%) can be recommended for practical (industrial) implementation. Comparison with gasoline and motor oil data shows the relative simplicity of this methodology for biodiesel classification.

108

Biodiesel classification by base stock type (vegetable oil) using near infrared spectroscopy data  

Energy Technology Data Exchange (ETDEWEB)

The use of biofuels, such as bioethanol or biodiesel, has rapidly increased in the last few years. Near infrared (near-IR, NIR, or NIRS) spectroscopy (>4000 cm{sup -1}) has previously been reported as a cheap and fast alternative for biodiesel quality control when compared with infrared, Raman, or nuclear magnetic resonance (NMR) methods; in addition, NIR can easily be done in real time (on-line). In this proof-of-principle paper, we attempt to find a correlation between the near infrared spectrum of a biodiesel sample and its base stock. This correlation is used to classify fuel samples into 10 groups according to their origin (vegetable oil): sunflower, coconut, palm, soy/soya, cottonseed, castor, Jatropha, etc. Principal component analysis (PCA) is used for outlier detection and dimensionality reduction of the NIR spectral data. Four different multivariate data analysis techniques are used to solve the classification problem, including regularized discriminant analysis (RDA), partial least squares method/projection on latent structures (PLS-DA), K-nearest neighbors (KNN) technique, and support vector machines (SVMs). Classifying biodiesel by feedstock (base stock) type can be successfully solved with modern machine learning techniques and NIR spectroscopy data. KNN and SVM methods were found to be highly effective for biodiesel classification by feedstock oil type. A classification error (E) of less than 5% can be reached using an SVM-based approach. If computational time is an important consideration, the KNN technique (E = 6.2%) can be recommended for practical (industrial) implementation. Comparison with gasoline and motor oil data shows the relative simplicity of this methodology for biodiesel classification.

Balabin, Roman M., E-mail: balabin@org.chem.ethz.ch [Department of Chemistry and Applied Biosciences, ETH Zurich, 8093 Zurich (Switzerland); Safieva, Ravilya Z. [Gubkin Russian State University of Oil and Gas, 119991 Moscow (Russian Federation)

2011-03-18

109

Sebkhas as ecological archives and the vegetation and landscape history of southeastern Tunisia during the last two millennia  

Science.gov (United States)

Sebkhas are temporary lacustrine systems depending on the number and extension of floodings. They may create laminated sediments which can be exploited as ecological archives. Contrary to those of meromictic lakes they are seasonal but not annual. After each flooding a detritus layer and a plasmo-condensed layer of bacteria and algae are formed in the water body or film and during the subsequent dessication a third subaeric layer of evaporites is build up. These laminae show a quasi-textile fabric and they can trap and conserve any dust and fine grained material. A high resolution pollendiagram covering the last two millennia as well as geochemical analysis from a southeastern Tunisian sebkha demonstrate the potentials of these ecological archives.

Schulz, E.; Abichou, A.; Hachicha, T.; Pomel, S.; Salzmann, U.; Zouari, K.

2002-05-01

110

[Ecological effect of different types land consolidation in Hubei Province of China].  

Science.gov (United States)

A model for estimating the ecosystem services value under effects of land consolidation was built to quantitatively evaluate the ecological effects of three different types of land consolidation projects in Jianghan Plain, middle hilly region, and western mountainous area of Hubei Province. With the implementation of the projects, the total value of ecosystem services in Jianghan Plain was decreased by 0.3%, among which, the values of food production service and other three services increased but those of water conservation and other four services decreased. In hilly region, the total value of ecosystem services was decreased by 14.6%, with the value of food production service increased by 55.2% and those of other eight services all decreased. In mountainous area, the total value of ecosystem services was decreased by 19.9%, with the value of food production service increased by 24.9% while the values of other eight services all decreased. In the land consolidation in the middle hilly region and western mountainous area of Hubei Province, there was an obvious conversion process 'from ecology to production' in the ecosystem services value. PMID:23189708

Gu, Xiao-Kun

2012-08-01

111

Increasing children's consumption of fruit and vegetables: does the type of exposure matter?  

Science.gov (United States)

This study sought to determine how eight days of home exposure to information about healthful foods and eating behaviors in the form of children's books and a variety of fruit and vegetables interacted to affect 4- to 8-year-old children's (N=59) consumption of fruit and vegetables. Before and after the home exposure, children participated in a task in which their consumption of a variety of fruit and vegetables that ranged in familiarity was measured. Results indicated that exposure to food and books were both effective at increasing consumption of fruit, but not vegetables. Additionally, children who were exposed to books consumed more of an infrequently consumed fruit presented during the post-test, but only if they had not been exposed to food during the home exposure. Overall, children's fruit consumption increased more if their mothers did not pressure them to eat, and those who were less neophobic were more likely to try a novel fruit or vegetable during the post-test. These findings suggest that information and food variety both can be effective for increasing acceptance of fruit, and highlight the need for more research that investigates the efficacy of intervention strategies that promote vegetable consumption in young children. PMID:22266134

Osborne, Chelsea L; Forestell, Catherine A

2012-06-01

112

Grazing effects on species composition in different vegetation types (La Palma, Canary Islands)  

Science.gov (United States)

Grazing management is probably one of the most extensive land uses, but its effects on plant communities have in many cases been revealed to be contradictory. Some authors have related these contradictions to the stochastic character of grazing systems. Because of that, it is necessary to implement specific analyses of grazing effects on each community, especially in natural protected areas, in order to provide the best information to managers. We studied the effects of grazing on the species composition of the main vegetation types where it takes place (grasslands, shrublands and pine forests) on the island of La Palma, Canary Islands. We used the point-quadrat intersect method to study the species composition of grazed and ungrazed areas, which also were characterized by their altitude, distance to farms, distance to settlements, year of sampling, herbaceous aboveground biomass and soil organic matter. The variables organic matter, productivity and species richness were not significantly affected by grazing. The species composition of the analyzed plant communities was affected more by variables such as altitude or distance to farms than by extensive grazing that has been traditionally carried out on the island of La Palma involving certain practices such as continuous monitoring of animals by goat keepers, medium stocking rates adjusted to the availability of natural pastures, supplementation during the dry season using local forage shrubs or mown pastures and rotating animals within grazing areas Although some studies have shown a negative effect of grazing on endangered plant species, these results cannot be freely extrapolated to the traditional grazing systems that exert a low pressure on plant communities (as has been found in this study). We consider extensive grazing as a viable way of ensuring sustainable management of the studied ecosystems.

Arévalo, J. R.; de Nascimento, L.; Fernández-Lugo, S.; Mata, J.; Bermejo, L.

2011-05-01

113

Satellite-based analysis of clouds and radiation properties of different vegetation types in the Brazilian Amazon region  

Science.gov (United States)

Land-use changes impact the energy balance of the Earth system, and feedbacks in the Earth system can dampen or amplify this perturbation. We analyze here from satellite data the response of clouds and subsequently radiation to a change of land use for the example of deforestation in the Amazon Basin. In this region, the characteristics of different cloud types over two vegetation types (forest and crop-/grasslands) were calculated for a time period of five years by using satellite data from the instruments MODIS and CERES. The cloud types are defined according to height, optical thickness, and fraction of cloud cover. For calculating the radiative forcing caused by deforestation, the dependency of spatial and temporal averages for the reflected shortwave and outgoing longwave radiation of the top of the atmosphere on vegetation types were determined as well. The results show distinct differences in cloud cover and radiative forcing over crop-/grasslands and forests for the two vegetation regimes, implying a potentially significant positive cloud feedback to deforestation.

Schneider, Nadine; Quaas, Johannes; Claussen, Martin; Reick, Christian

2013-05-01

114

Differences in organotin accumulation among ecological migratory types of the Japanese eel Anguilla japonica  

Science.gov (United States)

In order to examine the ecological risks caused by organotin compounds (OTs) in diadromous fish migrating between sea and freshwater, tributyltin (TBT) and triphenyltin (TPT) compounds, and their breakdown products, were determined in the catadromous eel Anguilla japonica having sea, estuarine and river life histories, collected in Japanese sea, brackish and fresh waters. Ontogenic changes in otolith strontium (Sr) and calcium (Ca) concentrations were examined along life history transect to discriminate the migration type. There were generally three different patterns, which were categorized 'sea eels' (spent most of their life in the sea and did not enter freshwater), 'estuarine eels' (inhabited estuaries or switched between different habitats), and 'river eels' (entered and remained in freshwater river habitats after arrival in the estuary) according to the otolith Sr:Ca ratio. There were generally no significant correlations between TBT and TPT accumulation and various biological characteristics such as total length (TL), body weight (BW), age and sex in A. japonica. The concentrations of TBT and TPT in silver eels (mature eels) were significantly higher than those in yellow eels (immature eels), and the percentages of TBT and TPT were also higher in silver eels than in yellow eels. A positive correlation was found between TBT concentration and the gonad-somatic index (GSI). It is thus considered that silver eels have a higher risk of contamination by TBT than yellow eels. TBT and TPT concentrations in sea eels were significantly higher than those in river eels. In contrast, no significant differences were observed in TBT and TPT concentrations in estuarine eels compared to sea and river eels. These results suggest that sea eels have a higher ecological risk of OT contamination than river eels during their life history, and the risk of OTs in estuarine eels is considered to be intermediate between that of sea and river eels. Positive linear relationships were found between Sr:Ca ratios and the concentrations of TBT and TPT. Therefore, these results suggest that the ecological risk of OTs increase, as the sea residence period in the eel become longer. Even at the same maturation stage, TBT and TPT concentrations in sea eels were significantly higher than those in river eels. Thus, it is clear that migratory type is a more important factor for OT accumulation than maturation stage.

Ohji, Madoka; Harino, Hiroya; Arai, Takaomi

2006-08-01

115

Landscape scale vegetation-type conversion and fire hazard in the San Francisco bay area open spaces  

Science.gov (United States)

Successional pressures resulting from fire suppression and reduced grazing have resulted in vegetation-type conversion in the open spaces surrounding the urbanized areas of the San Francisco bay area. Coverage of various vegetation types were sampled on seven sites using a chronosequence of remote images in order to measure change over time. Results suggest a significant conversion of grassland to shrubland dominated by Baccharis pilularison five of the seven sites sampled. An increase in Pseudotsuga menziesii coverage was also measured on the sites where it was present. Increases fuel and fire hazard were determined through field sampling and use of the FARSITE fire area simulator. A significant increase in biomass resulting from succession of grass-dominated to shrub-dominated communities was evident. In addition, results from the FARSITE simulations indicated significantly higher fire-line intensity, and flame length associated with shrublands over all other vegetation types sampled. These results indicate that the replacement of grass dominated with shrub-dominated landscapes has increased the probability of high intensity fires. ?? 2003 Elsevier Science B.V. All rights reserved.

Russell, W. H.; McBride, J. R.

2003-01-01

116

Distribution of phytoplankton functional types in high-nitrate, low-chlorophyll waters in a new diagnostic ecological indicator model  

Science.gov (United States)

Modeling and monitoring plankton functional types (PFTs) is challenged by the insufficient amount of field measurements of ground truths in both plankton models and bio-optical algorithms. In this study, we combine remote sensing data and a dynamic plankton model to simulate an ecologically sound spatial and temporal distribution of phyto-PFTs. We apply an innovative ecological indicator approach to modeling PFTs and focus on resolving the question of diatom-coccolithophore coexistence in the subpolar high-nitrate and low-chlorophyll regions. We choose an artificial neural network as our modeling framework because it has the potential to interpret complex nonlinear interactions governing complex adaptive systems, of which marine ecosystems are a prime example. Using ecological indicators that fulfill the criteria of measurability, sensitivity and specificity, we demonstrate that our diagnostic model correctly interprets some basic ecological rules similar to ones emerging from dynamic models. Our time series highlight a dynamic phyto-PFT community composition in all high-latitude areas and indicate seasonal coexistence of diatoms and coccolithophores. This observation, though consistent with in situ and remote sensing measurements, has so far not been captured by state-of-the-art dynamic models, which struggle to resolve this "paradox of the plankton". We conclude that an ecological indicator approach is useful for ecological modeling of phytoplankton and potentially higher trophic levels. Finally, we speculate that it could serve as a powerful tool in advancing ecosystem-based management of marine resources.

Palacz, A. P.; St. John, M. A.; Brewin, R. J. W.; Hirata, T.; Gregg, W. W.

2013-11-01

117

Distribution of phytoplankton functional types in high-nitrate low-chlorophyll waters in a new diagnostic ecological indicator model  

DEFF Research Database (Denmark)

Modeling and monitoring plankton functional types (PFTs) is challenged by insufficient amount of field measurements to ground-truth both plankton models and bio-optical algorithms. In this study, we combine remote sensing data and a dynamic plankton model to simulate an ecologically-sound spatial and temporal distribution of phyto-PFTs. We apply an innovative ecological indicator approach to modeling PFTs, and focus on resolving the question of diatom-coccolithophore co-existence in the subpolar high-nitrate and low-chlorophyll regions. We choose an artificial neural network as our modeling framework because it has the potential to interpret complex nonlinear interactions governing complex adaptive systems, of which marine ecosystems are a prime example. Using ecological indicators that fulfill the criteria of measurability, sensitivity and specificity, we demonstrate that our diagnostic model correctly interprets some basic ecological rules similar to ones emerging from dynamic models. Our time series highlight a dynamic phyto-PFT community composition in all high latitude areas, and indicate seasonal co-existence of diatoms and coccolithophores. This observation, though consistent with in situ and remote sensing measurements, was so far not captured by state-of-the-art dynamic models which struggle to resolve this "paradox of the plankton". We conclude that an ecological indicator approach is useful for ecological modeling of phytoplankton and potentially higher trophic levels. Finally, we speculate that it could serve as a powerful tool in advancing ecosystem-based management of marine resources

Palacz, Artur; St. John, Michael

2013-01-01

118

Distribution of phytoplankton functional types in high-nitrate low-chlorophyll waters in a new diagnostic ecological indicator model  

Directory of Open Access Journals (Sweden)

Full Text Available Modeling and monitoring plankton functional types (PFTs is challenged by insufficient amount of field measurements to ground-truth both plankton models and bio-optical algorithms. In this study, we combine remote sensing data and a dynamic plankton model to simulate an ecologically-sound spatial and temporal distribution of phyto-PFTs. We apply an innovative ecological indicator approach to modeling PFTs, and focus on resolving the question of diatom-coccolithophore co-existence in the subpolar high-nitrate and low-chlorophyll regions. We choose an artificial neural network as our modeling framework because it has the potential to interpret complex nonlinear interactions governing complex adaptive systems, of which marine ecosystems are a prime example. Using ecological indicators that fulfill the criteria of measurability, sensitivity and specificity, we demonstrate that our diagnostic model correctly interprets some basic ecological rules similar to ones emerging from dynamic models. Our time series highlight a dynamic phyto-PFT community composition in all high latitude areas, and indicate seasonal co-existence of diatoms and coccolithophores. This observation, though consistent with in situ and remote sensing measurements, was so far not captured by state-of-the-art dynamic models which struggle to resolve this "paradox of the plankton". We conclude that an ecological indicator approach is useful for ecological modeling of phytoplankton and potentially higher trophic levels. Finally, we speculate that it could serve as a powerful tool in advancing ecosystem-based management of marine resources.

A. P. Palacz

2013-05-01

119

Floodplain restoration leads to wetter and more diverse soil water regimes and vegetation types: Insight from an integrated hydroecological model  

Science.gov (United States)

Soil moisture availability in the root zone is one of the most important factors affecting plant species composition by creating stress on vegetation both when it is lacking (water stress) and when it is excessive (oxygen stress). Plant species have individual tolerance ranges along a gradient of available soil moisture that can be described as a hydrological niche. Combining a hydrological model and a habitat niche model can provide spatially-extensive predictions of vegetation composition, which would be useful for land management decision-making under changing environmental conditions. Floodplain ecosystem restoration provides an example of the utility of such a predictive tool as a site is hydrologically altered to create a wetter environment. We developed an integrated hydroecological model that links a quasi-3D, variably-saturated, groundwater flow model that simulates soil moisture with several plant habitat niche models. The focus of this research is a floodplain in southwestern Wisconsin where post-settlement alluvium was removed with the expectation of increasing regionally-threatened wetland plant species. Hydrological niche models were created based on simultaneous observations of vegetation composition and surface effective saturation. These models were then used to predict probability of presence for two dominant plant species (Carex vulpinoidea and Elymus canadensis) and composite wetland indicator score based on simulated surface effective saturation across the study site. The model predicts the site to be more wetland-species dominant overall following restoration. However, the soil moisture regime and vegetation types are slightly drier following restoration in zones where a silt-clay confining layer is present that inhibits vertical groundwater flow from a basal gravel aquifer to the near-surface soil zone. This differential response to restoration leads to a mosaic of soil water regimes across the site, which is reflected in a wider distribution of vegetation types. Therefore, the management goal of increasing wetland plant species occurrence is shown to co-occur with an increase in the site-scale diversity of plant community types. This result reveals the unique ability of the presented modeling framework to predict vegetation composition and aid land managers that are faced with difficult management decisions in a complex and uncertain future.

Booth, E. G.; Loheide, S. P.

2011-12-01

120

Fruit and vegetable intake and type 2 diabetes : EPIC-InterAct prospective study and meta-analysis  

DEFF Research Database (Denmark)

Fruit and vegetable intake (FVI) may reduce the risk of type 2 diabetes (T2D), but the epidemiological evidence is inconclusive. The aim of this study is to examine the prospective association of FVI with T2D and conduct an updated meta-analysis. In the European Prospective Investigation into Cancer-InterAct (EPIC-InterAct) prospective case-cohort study nested within eight European countries, a representative sample of 16?154 participants and 12?403 incident cases of T2D were identified from 340?234 individuals with 3.99 million person-years of follow-up. For the meta-analysis we identified prospective studies on FVI and T2D risk by systematic searches of MEDLINE and EMBASE until April 2011. In EPIC-InterAct, estimated FVI by dietary questionnaires varied more than twofold between countries. In adjusted analyses the hazard ratio (95% confidence interval) comparing the highest with lowest quartile of reported intake was 0.90 (0.80-1.01) for FVI; 0.89 (0.76-1.04) for fruit and 0.94 (0.84-1.05) for vegetables. Among FV subtypes, only root vegetables were inversely associated with diabetes 0.87 (0.77-0.99). In meta-analysis using pooled data from five studies including EPIC-InterAct, comparing the highest with lowest category for FVI was associated with a lower relative risk of diabetes (0.93 (0.87-1.00)). Fruit or vegetables separately were not associated with diabetes. Among FV subtypes, only green leafy vegetable (GLV) intake (relative risk: 0.84 (0.74-0.94)) was inversely associated with diabetes. Subtypes of vegetables, such as root vegetables or GLVs may be beneficial for the prevention of diabetes, while total FVI may exert a weaker overall effect.European Journal of Clinical Nutrition advance online publication, 1 August 2012; doi:10.1038/ejcn.2012.85.

Cooper, A J; Forouhi, N G

2012-01-01

 
 
 
 
121

Protease Production In Dermatophytes During Sporulation And Vegetative Phase - Its Role In Pathogenesis And Mating Type Associated Virulence  

Directory of Open Access Journals (Sweden)

Full Text Available Different strains of common dermatophytes including different mating strain, collected from clinical, animal and soil sources as also some tester strains, were studied for their proteolytic enzyme activity during vegetative and sporulation phases. Sabouraus�s dextrose broth and Takashio broth were used to induce vegetative and sporulation phases respectively in these dermatophytes. All the strains of T. rubrum showed very low enzyme activity during sporulation when compared vegetative growth phase. In other species of dermatophytes. The enzyme activity was found to be almost similar during both the growth phases. High protease production in association with one mating type of A. vanbreuseghemii was observed. The enzme activity of clinical isolates of the non-anthropophilic species such T. simii, M. nanum and M. gypseum were relatively low when compared to T.mentagrophytes var. interdigitale and T. tonsurans. The severity of the lesion produced by these established the fact that protease in dermatophytes has a define role in pathogenesis. Protease production during sporulation in T. rubrum may be one of the selective advantages of this species. General protease production was found to be independent of mating type in most of the dermatophyte species.

Ranganathan S

2000-01-01

122

Wild fire effects on floristic diversity in three thermo-Mediterranean vegetation types in a small islet of eastern Aegean sea  

Science.gov (United States)

Sclerophyllus scrub formations, the main vegetation type in many islands of the Aegean area, are characterized by their high biodiversity. Dominant shrub species of sclerophyllus formations are well adapted to dry season conditions by various anatomical and physiological mechanisms. As a result, their biomass acts as very flammable fine fuel, and consequently wild fires are very common in these ecosystems. Wildfire effects on vegetation and biodiversity in the Mediterranean basin have been studied and the results are diverse depending mainly on vegetation type and frequency of fire. The aim of this study was to evaluate the effects of wildfire on floristic diversity and species composition in three thermo-Mediterranean vegetation types 1) Sacropoterium spinosum phrygana, 2) low formations of Cistus creticus and 3) low formations of Cistus creticus in abandoned terraces. The research was conducted in Enoussa islet, which is located northeastern of Chios Island, in May 2013 (one year after the fire). Vegetation sampling was performed along five transects placed in recently burned and in adjacent unburned sites of each vegetation type. The plant cover and the floristic composition were measured, while diversity, evenness and dominance indices were determined for the vegetation data. Vegetation cover and the floristic diversity were significant lower and higher respectively in burned areas in comparison to the unburned. The woody species followed by the annual grasses and the annual forbs dominated in both burned and unburned areas. However, the woody species were significantly decreased in the burned areas in all vegetation types, while the annual grasses only in the burned areas of Sacropoterium spinosum phrygana and Cistus creticus in abandoned terraces. Inversely, the annual forbs significantly increased in the burned sites of Cistus creticus formations. The highest value of Morisita-Horn Index of similarity between burned and unburned sites (beta diversity) was observed for the Sacropoterium spinosum phrygana (0.83) indicating limited effect of fire on the species composition of this vegetation type.

Abraham, Eleni; Kyriazopoulos, Apostolos; Korakis, George; Parissi, Zoi; Chouvardas, Dimitrios

2014-05-01

123

Morpho?ecological characterization of the peniche?baleal dune system (portuguese west coast  

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Full Text Available the Peniche?Baleal coastal dune system has a strategic importance on regional development, marked by considerable investment in tourism and recreational sectors. the increasing human impact on this coastal dune system caused by human trampling tends to modify its geomorphological and ecological degradation, namely sand dune vegetation reduction. the morpho?ecological characterization of the coastal dune system was accomplished by six morpho?ecological profiles as well as data from field surveys that allowed the (i haracterisation of foredune morphology and coastal dune system morphology; (ii identification of different morpho?ecological coastal dunes types; (iii identification of sand dune vegetation diversity and main spatial mosaics; (iv identification of sand dune species of the different morpho?ecological costal dunes types. as a result, sand dune vegetation shows high biodiversity and good conservation conditions especially landward. it is possible to identify two important Portuguese endemic sand dune species – Armeria welwitschii and Verbascum litigiosum – with legal protection status.

Raquel Paixão

2013-06-01

124

The Uptake of Heavy Metals by Fruit Type Vegetables Grown in Selected Agricultural Areas  

Directory of Open Access Journals (Sweden)

Full Text Available A study on the uptake of heavy metals by fruit vegetables from agricultural areas was conducted at Agrotek, Sepang and Bangi, Selangor. The objective of the study was to determine the uptake of heavy metals by chilies (Capsicum annum and long beans (Vigna sinensis from the soil. Heavy metals studied were Pb, Cd and Zn. Wet digestion method was used for heavy metals analysis in the vegetables. Heavy metals from soil samples were extracted by sequential extraction method, which extract heavy metals from easily and freely leachable fraction (EFLE, acid reduction (AR, organic oxidation (OO and resistant fraction (RR. The results of the study showed that the level of Zn content in long beans (Vigna sinensis was higher than in chilies (Capsicum annum. However the concentrations of heavy metals studied in these vegetables were still below the maximum level allowed by the Malaysian Food Act (1983 and Food Regulations (1985 for Pb (2.00 mg kg-1, Cd (1.00 mg kg-1 and Zn (30.00 mg kg-1.

J. Khairiah

2004-01-01

125

Ecological and socioeconomic correlates of fruit, juice, and vegetable consumption among African-American boys. — Measures of the Food Environment  

Science.gov (United States)

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126

Landscape Ecology of Large, Infrequent Fires in Yellowstone Park  

Science.gov (United States)

This Issue focuses on a research article by Turner et al. (2003) that was published in Frontiers in Ecology and the Environment. The article discusses the ecological causes and effects of intense, infrequent fires such as the large fire that occurred during 1988 in Yellowstone National Park. Turner et al. synthesize 15 years of research on vegetation and ecological processes at Yellowstone and discuss how factors such as fire intensity, patch size, plant species, and the type of forest factor in to a complex pattern of causes and effects. In this Issue, students explore some of those factors using two figures from the original research article and five figures from Ecological Monographs.

D'Avanzo, Charlene

2010-02-16

127

Variations in fresh fruit and vegetable quality by store type, urban-rural setting and neighbourhood deprivation in Scotland. — Measures of the Food Environment  

Science.gov (United States)

Cummins S, Smith DM, Taylor M, Dawson J, Marshall D, Sparks L, Anderson AS. Variations in fresh fruit and vegetable quality by store type, urban-rural setting and neighbourhood deprivation in Scotland.

128

Pollination ecology of Tabebuia aurea (Manso) Benth. & Hook. and T. ochracea (Cham.) Standl. (Bignoniaceae) in Central Brazil cerrado vegetation Ecologia da polinização de Tabebuia aurea (Manso) Benth. & Hook. e T. ochracea (Cham.) Standl. (Bignoniaceae) em cerrado do Brasil Central  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The pollination ecology and breeding systems of Tabebuia aurea (Manso) Benth. & Hook., and T. ochracea (Cham.) Standl. were investigated in an area of cerrado vegetation in the Federal District of Brazil. These species occur sympatrically, flower massively and synchronously for a month, during the dry season (July to September). Both have diurnal anthesis, with similar floral structures, a yellow tubular corolla and produce nectar. Fourteen species of bees visited both Tabebuia species, but, ...

MARILUZA GRANJA BARROS

2001-01-01

129

Effect of high intakes of fruit and vegetables on redox status in type 2 onset diabetes: a pilot study.  

Science.gov (United States)

Evidence has accumulated indicating that oxidative stress may play a key role in the etiology of diabetic complications and the protective effects of antioxidant nutrients are a topic of intense research. The purpose of this study was both to obtain preliminary data on the effect of a diet high in fruit and vegetables on metabolic control and the oxidative status of patients with type 2 onset diabetes, and to identify the most useful biochemical parameters for future research. At the beginning of the study all subjects were asked to follow their usual diet and keep a seven-day food diary. Diabetic patients then received a dietary treatment designed to ensure a daily intake of 700-1000 g of fruit and vegetables; no dietary advice was given to controls. Dietary antioxidants, redox status markers, and parameters of metabolic control were measured in plasma and erythrocytes before and after the diet. Before following the diet, diabetic patients had lower levels of ascorbic acid, beta-carotene, and alpha-tocopherol/cholesterol ratio than controls. After the diet these parameters increased and there was also a reduction in total antioxidant capacity, uric acid, and malondialdehyde and a rise in reduced glutathione accompanied by a reduction in body mass index and cholesterol. In conclusion, a high consumption of fruit and vegetables by diabetic patients not receiving pharmacological treatment, seems to produce an improvement in some redox status parameters. PMID:15628668

Giammarioli, Stefania; Filesi, Carmelina; Vitale, Barbara; Cantagallo, Anna; Dragoni, Francesco; Sanzini, Elisabetta

2004-09-01

130

Landscape object-based analysis of wetland plant functional types: the effects of spatial scale, vegetation classes and classifier methods  

Science.gov (United States)

Remote sensing-based vegetation classifications representing plant function such as photosynthesis and productivity are challenging in wetlands with complex cover and difficult field access. Recent advances in object-based image analysis (OBIA) and machine-learning algorithms offer new classification tools; however, few comparisons of different algorithms and spatial scales have been discussed to date. We applied OBIA to delineate wetland plant functional types (PFTs) for Poyang Lake, the largest freshwater lake in China and Ramsar wetland conservation site, from 30-m Landsat TM scene at the peak of spring growing season. We targeted major PFTs (C3 grasses, C3 forbs and different types of C4 grasses and aquatic vegetation) that are both key players in system's biogeochemical cycles and critical providers of waterbird habitat. Classification results were compared among: a) several object segmentation scales (with average object sizes 900-9000 m2); b) several families of statistical classifiers (including Bayesian, Logistic, Neural Network, Decision Trees and Support Vector Machines) and c) two hierarchical levels of vegetation classification, a generalized 3-class set and more detailed 6-class set. We found that classification benefited from object-based approach which allowed including object shape, texture and context descriptors in classification. While a number of classifiers achieved high accuracy at the finest pixel-equivalent segmentation scale, the highest accuracies and best agreement among algorithms occurred at coarser object scales. No single classifier was consistently superior across all scales, although selected algorithms of Neural Network, Logistic and K-Nearest Neighbors families frequently provided the best discrimination of classes at different scales. The choice of vegetation categories also affected classification accuracy. The 6-class set allowed for higher individual class accuracies but lower overall accuracies than the 3-class set because individual classes differed in scales at which they were best discriminated from others. Main classification challenges included a) presence of C3 grasses in C4-grass areas, particularly following harvesting of C4 reeds and b) mixtures of emergent, floating and submerged aquatic plants at sub-object and sub-pixel scales. We conclude that OBIA with advanced statistical classifiers offers useful instruments for landscape vegetation analyses, and that spatial scale considerations are critical in mapping PFTs, while multi-scale comparisons can be used to guide class selection. Future work will further apply fuzzy classification and field-collected spectral data for PFT analysis and compare results with MODIS PFT products.

Dronova, I.; Gong, P.; Wang, L.; Clinton, N.; Fu, W.; Qi, S.

2011-12-01

131

Forecasts of future terrain and vegetation types at Olkiluoto and implications for spatial and temporal aspects of biosphere modelling.  

Science.gov (United States)

In Finland, a nuclear repository site is situated on the western coast where the current land uplift rate is 6mm/yr. A set of tools has been developed for predicting the future terrain and vegetation types, and for producing estimates of the site-specific parameter values for use in simplified radionuclide transport models. Although the landscape will change considerably within the next millennia, the likely changes are relatively predictable. By comparing the results to the site data, the effect of human activities can be at least partially quantified. PMID:18515124

Ikonen, A T K; Aro, L; Leppänen, V

2008-11-01

132

Characterisation of pastures in a eastern Alpine area in relation to ecological and management parameters  

Directory of Open Access Journals (Sweden)

Full Text Available The present investigation was carried out in Val Visdende (north-eastern Italian Alps on a surface of 1108 ha, with the aim of identifying the most important pasture vegetation types. Based on the conditions observed in the area, main parameters concerning topographic, ecological and management conditions were evaluated and expressed using synthetic indexes. Cluster and principal component analyses were used for the interpretation of the distribution of pasture types in relation to ecological factors, allowing to formulate hypotheses on the evolution of pasture vegetation as a function of ecological and management parameters.

Sabatini S

2008-03-01

133

Does sleep aggravate tension-type headache?: An investigation using computerized ecological momentary assessment and actigraphy  

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Full Text Available Abstract Background Both insufficient sleep and oversleeping have been reported as precipitating and aggravating factors of tension-type headache (TTH. However, previous studies relied on recalled self-reports, and the relationship has not been confirmed prospectively and objectively in a daily life situation. Recently, ecological momentary assessment (EMA using electronic diaries, i.e., computerized EMA, is used to record subjective symptoms with the advantages of avoiding recall bias and faked compliance in daily settings. In addition, actigraphy has become an established method to assess sleep outside laboratories. Therefore, the aim of this study was to investigate the within-individual effect of sleep on the following momentary headache intensity in TTH patients during their daily lives utilizing EMA and actigraphy. Methods Twenty-seven patients with TTH wore watch-type computers as electronic diaries for seven consecutive days and recorded their momentary headache intensity using a visual analog scale of 0-100 approximately every six hours, on waking up, when going to bed, and at the time of headache exacerbations. They also recorded their self-report of sleep quality, hours of sleep and number of awakenings with the computers when they woke up. Physical activity was continuously recorded by an actigraph inside the watch-type computers. Activity data were analyzed by Cole's algorithm to obtain total sleep time, sleep efficiency, sleep latency, wake time after sleep onset and number of awakenings for each night. Multilevel modeling was used to test the effect of each subjective and objective sleep-related variable on momentary headache intensity on the following day. Results Objectively measured total sleep time was significantly positively associated with momentary headache intensity on the following day, while self-reported sleep quality was significantly negatively associated with momentary headache intensity on the following day. Conclusions Using computerized EMA and actigraphy, longer sleep and worse sleep quality were shown to be related to more intense headache intensity on within-individual basis and they may be precipitating or aggravating factors of TTH.

Komaki Gen

2011-08-01

134

Influência do tipo da cobertura vegetal sobre a erosão no semi-árido Paraibano Influence of the type of vegetal cover on sediment yield in the semiarid of Paraíba state  

Directory of Open Access Journals (Sweden)

Full Text Available O tipo de cobertura vegetal, presente numa área, tem grande influência sobre o escoamento superficial e a produção de sedimentos. O objetivo do presente trabalho é estabelecer uma relação entre o tipo da cobertura vegetal e a erosão do solo nu, mediante uma equação empírica da perda de solo. A equação proposta foi calibrada usando-se dados sintéticos gerados por um modelo físico hidrossedimentológico, cujos parâmetros de erosão foram determinados como valores representativos de uma área desmatada do semi-árido paraibano. Apresenta-se uma comparação entre os valores calculados pela equação e os dados observados em várias parcelas de erosão, as quais apresentavam condições de cobertura vegetal e declividade distintas, localizadas na Bacia Experimental de Sumé, PB. Esta comparação permitiu uma avaliação da influência do tipo de cobertura vegetal sobre a erosão do solo.The type of vegetation cover present in an area, greatly influences the surface runoff as well as the sediment yield. The objective of this paper is to establish a relationship between the type of vegetal cover and erosion by means of an empirical equation for soil loss. The proposed equation was calibrated using synthetic data obtained from a physically-based runoff-erosion model in which the erosion parameter values are representative of a cleared bare-land surface in the semiarid area of Paraíba State. A comparison between the values obtained from the equation and the observed data collected from several erosion plots in the Sumé Experimental Watershed with different conditions of vegetal cover and slope is presented as an evaluation of the influence of the vegetation cover on soil erosion.

Celso Augusto Guimarães Santos

2000-04-01

135

Influência do tipo da cobertura vegetal sobre a erosão no semi-árido Paraibano / Influence of the type of vegetal cover on sediment yield in the semiarid of Paraíba state  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese O tipo de cobertura vegetal, presente numa área, tem grande influência sobre o escoamento superficial e a produção de sedimentos. O objetivo do presente trabalho é estabelecer uma relação entre o tipo da cobertura vegetal e a erosão do solo nu, mediante uma equação empírica da perda de solo. A equaç [...] ão proposta foi calibrada usando-se dados sintéticos gerados por um modelo físico hidrossedimentológico, cujos parâmetros de erosão foram determinados como valores representativos de uma área desmatada do semi-árido paraibano. Apresenta-se uma comparação entre os valores calculados pela equação e os dados observados em várias parcelas de erosão, as quais apresentavam condições de cobertura vegetal e declividade distintas, localizadas na Bacia Experimental de Sumé, PB. Esta comparação permitiu uma avaliação da influência do tipo de cobertura vegetal sobre a erosão do solo. Abstract in english The type of vegetation cover present in an area, greatly influences the surface runoff as well as the sediment yield. The objective of this paper is to establish a relationship between the type of vegetal cover and erosion by means of an empirical equation for soil loss. The proposed equation was ca [...] librated using synthetic data obtained from a physically-based runoff-erosion model in which the erosion parameter values are representative of a cleared bare-land surface in the semiarid area of Paraíba State. A comparison between the values obtained from the equation and the observed data collected from several erosion plots in the Sumé Experimental Watershed with different conditions of vegetal cover and slope is presented as an evaluation of the influence of the vegetation cover on soil erosion.

Celso Augusto Guimarães, Santos; Koichi, Suzuki; Masahiro, Watanabe; Vajapeyam S., Srinivasan.

136

Scaling vegetation carbon uptake across a broad range of ecosystem types utilizing flux measurements and high resolution remote sensing.  

Science.gov (United States)

The accurate detection of vegetation carbon flux patterns across multiple ecosystem types and at continental scales is critical to the development and parameterization of ecosystem models. Existing production efficiency and DGVM style ecosystem models are typically driven by broad scale estimates of effective canopy FPAR and are not specifically sensitive to landscape level variability in canopy chemistry or vertical structure. While FPAR and LAI can be related to productivity across broad ecosystem gradients, recent evidence suggests that approaches using these broad scale effective indexes alone may mischaracterize fine scale variability in carbon assimilation for dense canopy temperate forests in which photosynthetic potential may be more tightly coupled to leaf level chemistry (specifically nitrogen and chlorophyll content). We present the results of a multi-year study focused on the refinement of broad scale remote sensing of vegetation carbon uptake by conducting a series of scaling and model exercises at a number of field sites across North America. The field sites are all part of the AmeriFlux network and were chosen to represent functional end members of dominant vegetation classes across the continent. Techniques for remote sensing of canopy nitrogen using high resolution remote sensing, utilization of these data in an ecosystem model and comparison of the scaled results to flux measurements, existing remote sensing approaches from MODIS and field inventories are discussed. Additionally, we explore the relative influence of canopy structural and chemical/optical properties on photosynthetic capacity between different ecosystem types and discuss the benefit for model parameterization of independent retrievals of these parameters.

Jenkins, J. P.; Ollinger, S. V.; Martin, M. E.; Richardson, A. D.; Plourde, L.; Smith, M.; Hollinger, D. Y.

2006-12-01

137

Série temporal de índice de vegetação sobre diferentes tipologias vegetais no Rio Grande do Sul / Time series of vegetation index for different vegetation types in Rio Grande do Sul  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Com este trabalho objetivou-se identificar a dinâmica fenológica das principais tipologias vegetais do Rio Grande do Sul, para o período de 2000 a 2010, utilizando-se dados de Enhanced Vegetation Index, através da transformada de ondaleta. A identificação da fenologia em ciclos ou padrões sazonais e [...] m séries temporais de índices de vegetação, obtidos por sensores orbitais, permite a observação de anomalias e os efeitos de mudanças climáticas ou ambientais. Um perfil temporal do Enhanced Vegetation Index foi construído para o Rio Grande do Sul e retiradas amostras para quatro tipologias vegetais: campo nativo, floresta ombrófila mista, cultivo de soja e de arroz. Essas amostras foram submetidas à transformada de ondaleta, que permitiu a decomposição da série e apresentação dos dados em relação ao tempo e frequência com que os eventos fenológicos ocorreram. Os dados apresentaram regularidade na dinâmica das tipologias vegetais testadas, com ciclos anuais de maior vigor e crescimento vegetal nas estações de primavera e verão e menor no outono e inverno. Abstract in english The objective of this study was the identification of the phenology dynamics of the main types of vegetation of Rio Grande do Sul state, for the period from 2000 to 2010, using Enhanced Vegetation Index data through the wavelet transform. The identification of cycles or seasonal patterns in time ser [...] ies of vegetation indices obtained by orbital sensors allows the observation of anomalies and effects of climate and environmental change. A temporal profile of Enhanced Vegetation Index was built for the Rio Grande do Sul region, where samples of the four main plant typologies were selected: native grassland, mixed ombrophilous forest, soybean and rice crop. These samples were submitted to the wavelet transform, which allowed the decomposition of the series and presentation of data in relation to time and frequency with which the phenological events have occurred. The data showed regularity in the dynamics of vegetation types tested, with annual cycles of plant growth and higher Enhanced Vegetation Index values in spring and summer and lower Enhanced Vegetation Index values in autumn and winter.

Tatiana M., Kuplich; Andreise, Moreira; Denise C., Fontana.

138

Vegetables and PUFA-rich plant oil reduce DNA strand breaks in individuals with type 2 diabetes  

DEFF Research Database (Denmark)

SCOPE: Type 2 diabetes is a multifactorial disease associated with increased oxidative stress, which may lead to increased DNA damage. The aim of this study was to investigate the effect of a healthy diet on DNA oxidation in diabetics and nondiabetics. METHODS AND RESULTS: Seventy-six diabetic and 21 nondiabetic individuals participated in this study. All subjects received information about the benefits of a healthy diet, while subjects randomly assigned to the intervention group received additionally 300 g of vegetables and 25 mL PUFA-rich plant oil per day. DNA damage in mononuclear cells (Comet Assay), urinary excretion of 8-oxo-7-hydro-2'-deoxyguanosine (8-oxodG) and 8-oxo-7,8-dihydroguanosine (8-oxoGuo) and glycated hemoglobin (HbA1c) were measured at baseline, after 4, 8 (end of intervention), and 16 weeks. The intervention with vegetables and PUFA-rich oil led to a significant increase in plasma antioxidant concentrations. Diabetic individuals of the intervention group showed a significant reduction inHbA1c and DNA strand breaks. Levels of HbA1c were also improved in diabetics of the information group, but oxidative damage to DNA was not altered. Urinary 8-oxodG and 8-oxoGuo excretion remained unchanged in both groups. CONCLUSIONS: This study provides evidence that a healthy diet rich in antioxidants reduces levels of DNA strand breaks in diabetic individuals.

Müllner, Elisabeth; Brath, Helmut

2013-01-01

139

Dung beetle assemblage structure in Tswalu Kalahari Reserve : responses to a mosaic of landscape types, vegetation communities, and dung types  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Tswalu Kalahari Reserve is a private game reserve covering 1,020 km2 in the Northern Cape, South Africa. It has been created from a number of reclaimed farms and restocked with large indigenous mammals. Two surveys were conducted to inventory the dung beetle fauna (Coleoptera: Scarabaeidae: Scarabaeinae) and determine their spatial patterns and food type associations. The spatial survey used pig dungÐbaited pitfall traps to examine dung beetle distribution across three main la...

Davis, Adrian L. V.; Scholtz, Clarke H.; Kryger, Ute; Deschodt, Christian M.; Strumpher, Werner P.

2010-01-01

140

On the evaluation of vegetation resilience in Southern Italy by using VEGETATION, MODIS, TM satellite time series  

Science.gov (United States)

Satellite technologies can be profitably used for investigating the dynamics of vegetation re-growth after disturbance at different temporal and spatial scales. Nevertheless, disturbance -induced dynamical processes are very difficult to study since they affect the complex soil-surface-atmosphere system, due to the existence of feedback mechanisms involving human activity, ecological patterns and different subsystems of climate. The remote sensing of vegetation has been traditionally carried out by using vegetation indices, which are quantitative measures, based on vegetation spectral properties, that attempt to measure biomass or vegetative vigor. The vegetation indices operate by contrasting intense chlorophyll pigment absorption in the red against the high reflectance of leaf mesophyll in the near infrared. The simplest form of vegetation index is simply a ratio between two digital values from these two spectral bands. The most widely used index is the well-known normalized difference vegetation index NDVI = [NIR-R]/ [NIR+R]. The normalization of the NDVI reduces the effects of variations caused by atmospheric contaminations. High values of the vegetation index identify pixels covered by substantial proportions of healthy vegetation. NDVI is indicative of plant photosynthetic activity and has been found to be related to the green leaf area index and the fraction of photosynthetically active radiation absorbed by vegetation. Variations in NDVI values become indicative of variations in vegetation composition and dynamics. In this study, we analyze the mutiscale satellite temporal series ( 2000 to 2008) of NDVI and other vegetation indices from SPOT VEGETATION, MODIS and Landsat TM data acquired for some significant test areas affetced and unaffected (Southern Italy) by different types of environmental diturbances (drought, salinity, pollution, etc). Our objective was to characterize quantitatively the resilient effect of vegetation cover at differen temporal and spatial scales.

Didonna, I.; Coluzzi, R.

2009-04-01

 
 
 
 
141

CONVERGING PATTERNS OF UPTAKE AND HYDRAULIC REDISTRIBUTION OF SOIL WATER IN CONTRASTING WOODY VEGETATION TYPES  

Science.gov (United States)

We used concurrent measurements of soil water content and soil water potential (Ysoil) to assess the effects of Ysoil on uptake and hydraulic redistribution (HR) of soil water by roots during seasonal drought cycles in six sites characterized by different types and amounts of woo...

142

Some Ecological Aspects of Little Honeybee (Apis florea F. and Type of Sugar Contents in Honey in Northeast Thailand  

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Full Text Available This research was carried out at Khon Kaen and Maha Sarakham Provinces in northeastern region of Thailand. The work designed to investigate ecological locations and types of sugar in honey of Little Honeybee (Apis florea F.. The results showed that there were four types of ecological locations found, i.e. cropland and degradation forest, orchard farm, villages, and housing area of government?s official. Five types of sugar contents in honey were found with majority of fructose followed by glucose, lactose, maltose, and least with sucrose. The highest amounts of sugar in honey were highest in June followed by February, December, January, March, September, April, October and November. All types of sugar had no effect on egg rate, worker, and drone cells except fructose where it had highly significant effect on number of queen cells. A range of 1-1.05 (g ml-1 of total sugar had highly significant effect on number of queen cells, but with higher range number of queen cells was declined

Ch. Onlamai

2004-01-01

143

Analysis of the riparian vegetation (Ia land type of the proposed Vhembe-Dongola National Park, Limpopo Province, South Africa  

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Full Text Available The establishment of the Vhembe-Dongola National Park has been an objective of several conservationists for many years. The ultimate objective is that this park would become a major component of a transfrontier park shared by Botswana, Zimbabwe and South Africa. The aim of this study was to identify, classify and describe the plant communities present in the Ia land type of the proposed area for the park. Sampling was done by means of the Braun-Blanquet method. A total of 70 stratified random relevés were sampled in the Ia land type. All relevé data was imported into the database TURBOVEG after which the numerical classification technique TWINSPAN was used as a first approximation. Subsequently Braun-Blanquet procedures were used to refine data and a phytosociological table was constructed, using the visual editor, MEGATAB. From the phytosociological table four plant communities were identified and described in the Ia land type. The ordination algorithm, DECORANA, was applied to the floristic data in order to illustrate floristic relationships between plant communities, to detect possible gradients in and between communities and to detect possible habitat gradients and/or disturbance gradients associated with vegetation gradients.

K. Kellner

2003-12-01

144

Variation in Protein Content and Amino Acids in the Leaves of Grain, Vegetable and Weedy Types of Amaranths  

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Full Text Available Malnutrition has affected almost 31% of pre-school children. This paper provides the information of nutritional values (leaf protein, 15 amino acids, biomass and leaf dry matter of grain, vegetable and weedy types of amaranths (n = 76 accessions; particularly those novel materials originated from the highland areas of Sumatra-Takengon. The highest values of leaf protein and total amino acids were found in many weedy species (A. viridis, A. blitum L. and A. dubius. The ranges of leaf protein and total amino acids in most of weedy types were 12–29 g 100 g?1 DM and 84–93 g 100 g?1 DW protein, respectively. The leaves of amaranths were found to be a good source for lysine which is the limiting essential amino acids in most of cereal plants. Their values were in the range of 6 g 100 g?1 DW protein which are close to that of good protein quality according to FAO/WHO’s standard. The leaves of underutilized weedy species of A. dubius, A. blitum, A. viridis and the dual purpose types of A. caudatus L., A. cruentus L. deserve to be further exploited as a low cost solution for solving malnutrition problems, especially in Indonesia.

Ryo Ohsawa

2013-05-01

145

Vegetation associated with the occurrence of the Brenton blue butterfly  

Scientific Electronic Library Online (English)

Full Text Available SciELO South Africa | Language: English Abstract in english The Brenton blue butterfly, Orachrysops niobe (Trimen), is critically endangered and known only from one site near Knysna in the Western Cape province of South Africa, now proclaimed as the Brenton Blue Butterfly Reserve (BBBR). We have explored associations between vegetation types and the presence [...] of O. niobe's only host plant, Indigofera erecta (Thunb.), using Braun-Blanquet vegetation classification and ordination techniques as part of a broader research project at the BBBR. Positive correlations are demonstrated between the occurrence of I. erecta and certain thicket vegetation types dominated by Pterocelastrus tricuspidatus (candlewood trees). Ordinations using soil analysis and slope data have not detected significant environmental gradients influencing vegetation types. The high degree of vegetation heterogeneity at the BBBR appears to be driven in part by various disturbance histories. Historical ecological events at the site such as fire and megaherbivore impacts, and their role in sustaining the ideal habitat for I. erecta and O. niobe, are discussed. Management techniques for the BBBR such as controlled fires or the cutting of paths through the vegetation are evaluated and an optimum future management strategy is recommended. This is the most comprehensive vegetation study ever carried out at the habitat of an endangered butterfly in South Africa, and breaks new ground by using vegetation analysis to develop a well-informed management plan for conservation of this species. It has significance for the management of small sites where many such endangered butterflies occur.

D.A., Edge; S.S., Cilliers; R.F., Terblanche.

146

Residuos de plaguicidas organoclorados en 4 tipos de aceites vegetales / Organochlorine pesticide residues in 4 types of vegetable oils.  

Scientific Electronic Library Online (English)

Full Text Available SciELO Venezuela | Language: Spanish Abstract in spanish Esta investigación tuvo como objetivos identificar y cuantificar residuos de los plaguicidas organoclorados (POC) hexaclorobenceno (HCB), lindano, cis-clordano, heptacloro, aldrín, dieldrín, endrín y o,p’-diclorodifeniltricloroetano (o,p’-DDT) en aceites de maíz, soya, girasol y mezclas de aceites, [...] que se expenden en la ciudad de Maracaibo, Venezuela. Se analizaron 30 muestras de 4 tipos de aceites de 10 marcas comerciales. La extracción de residuos de POC se realizó según la técnica de la AOAC. Para la identificación y cuantificación se utilizó un cromatógrafo de gases con detector de captura electrónica (GC-ECD), y para la confirmación, un cromatógrafo de gases acoplado a un espectrómetro de masas (GCMS). Todos los residuos de POC investigados fueron detectados en las muestras analizadas. Se detectaron en mayor concentración (mg/ g) aldrín (0,0088), lindano (0,0054) y o,p’-DDT (0,0035). El análisis estadístico demostró diferencias significativas (P Abstract in english The present study had as objectives to identify and to quantify organochlorine pesticide residues (OCP) hexachlorobenzene (HCB), lindane, cis-chlordane, heptachlor, aldrín, dieldrín, endrín and o,p’-DDT in vegetable oils of corn, soybean, sunflower and mixtures of oils, sold in the city of Maracaibo [...] , Venezuela. 30 samples of 4 types of vegetable oils of 10 commercial brands were analyzed. The extraction of OCP residues was done according to the Official Method of AOAC. A gas chromatograph with an electronic capture detector (GC-ECD) was used for identification and quantification of OCP residues and confirmation was done with a gas chromatograph coupled with a mass spectrometer (GC-MS). All the OCP residues investigated were detected in the analyzed samples. Aldrin (0.0088), lindane (0.0054) and o,p’-DDT (0.0035) were the OCP residues detected in higher concentrations (mg/g). The statistical analysis showed significant differences (P

María, Piñero González; Pedro, Izquierdo Córser; María, Allara Cagnasso; Aiza, García Urdaneta.

147

Residuos de plaguicidas organoclorados en 4 tipos de aceites vegetales / Organochlorine pesticide residues in 4 types of vegetable oils.  

Scientific Electronic Library Online (English)

Full Text Available SciELO Venezuela | Language: Spanish Abstract in spanish Esta investigación tuvo como objetivos identificar y cuantificar residuos de los plaguicidas organoclorados (POC) hexaclorobenceno (HCB), lindano, cis-clordano, heptacloro, aldrín, dieldrín, endrín y o,p’-diclorodifeniltricloroetano (o,p’-DDT) en aceites de maíz, soya, girasol y mezclas de aceites, [...] que se expenden en la ciudad de Maracaibo, Venezuela. Se analizaron 30 muestras de 4 tipos de aceites de 10 marcas comerciales. La extracción de residuos de POC se realizó según la técnica de la AOAC. Para la identificación y cuantificación se utilizó un cromatógrafo de gases con detector de captura electrónica (GC-ECD), y para la confirmación, un cromatógrafo de gases acoplado a un espectrómetro de masas (GCMS). Todos los residuos de POC investigados fueron detectados en las muestras analizadas. Se detectaron en mayor concentración (mg/ g) aldrín (0,0088), lindano (0,0054) y o,p’-DDT (0,0035). El análisis estadístico demostró diferencias significativas (P Abstract in english The present study had as objectives to identify and to quantify organochlorine pesticide residues (OCP) hexachlorobenzene (HCB), lindane, cis-chlordane, heptachlor, aldrín, dieldrín, endrín and o,p’-DDT in vegetable oils of corn, soybean, sunflower and mixtures of oils, sold in the city of Maracaibo [...] , Venezuela. 30 samples of 4 types of vegetable oils of 10 commercial brands were analyzed. The extraction of OCP residues was done according to the Official Method of AOAC. A gas chromatograph with an electronic capture detector (GC-ECD) was used for identification and quantification of OCP residues and confirmation was done with a gas chromatograph coupled with a mass spectrometer (GC-MS). All the OCP residues investigated were detected in the analyzed samples. Aldrin (0.0088), lindane (0.0054) and o,p’-DDT (0.0035) were the OCP residues detected in higher concentrations (mg/g). The statistical analysis showed significant differences (P

María, Piñero González; Pedro, Izquierdo Córser; María, Allara Cagnasso; Aiza, García Urdaneta.

2007-12-01

148

Variation of combined heat-irradiation effects on cell inactivation in different types of vegetative bacteria  

International Nuclear Information System (INIS)

Combined effects of irradiation and heating on cell inactivation were studied with E. coli K-12 derivatives of different DNA repair capacities and some thermophilic bacteria. With E. coli K-12 mutants log-phase cells of all four strains tested were sensitized to radiation by simultaneous heating. This means that the synergistic interaction between irradiation and heating is independent of pol, uvr and rec mutation. Simultaneous heating was more effective for radiosensitization than heating before or after irradiation. This combination effect was not or only weakly observed with stationary-phase cells. From recovery experiments and sedimentation analysis of DNA from E. coli cells the process of the synergistic interaction may involve the inhibition of the recovery from heat damage and the DNA repair, especially Type II repair. In respect of thermophilic bacteria, it was found that Streptococcus thermophilus becomes more sensitive to radiation under the combined treatment with heating, while other thermophilic strains do not, according to a comparison of the radiosensitivities in terms of the D10 value of the exponential slopes of the survival curves. The latter observation with thermophilic bacteria is in contrast to E. coli. The results of sedimentation analysis of DNA of thermophiles gave unique features. (author)

149

Variation of Combined Heat-Irradiation Effects on Cell Inactivation in Different Types of Vegetative Bacteria  

International Nuclear Information System (INIS)

Combined effects of irradiation and heating on cell inactivation were studied with E. coli K-12 derivatives of different DNA repair capacities and some thermophilic bacteria. With E. coli K-12 mutants log-phase cells of all four strains tested were sensitized to radiation by simultaneous heating. This means that the synergistic interaction between irradiation and heating is independent of pol, uvr and rec mutation. Simultaneous heating was more effective for radiosensitization than heating before or after irradiation. This combination effect was not or only weakly observed with stationary-phase cells. From recovery experiments and sedimentation analysis of DNA from E. coli cells the process of the synergistic interaction may involve the inhibition of the recovery from heat damage and the DNA repair, especially Type II repair. In respect of thermophilic bacteria, it was found that Streptococcus thermophilus becomes more sensitive to radiation under the combined treatment with heating, while other thermophilic strains do not, according to a comparison of the radiosensitivities in terms of the Dio value of the exponential slopes of the survival curves. The latter observation with thermophilic bacteria is in contrast to E. coli. The results of sedimentation analysis of DNA of thermophiles gave unique features. (author)

150

Soil respiration at mean annual temperature predicts annual total across vegetation types and biomes  

Directory of Open Access Journals (Sweden)

Full Text Available Soil respiration (SR constitutes the largest flux of CO2 from terrestrial ecosystems to the atmosphere. However, there still exist considerable uncertainties as to its actual magnitude, as well as its spatial and interannual variability. Based on a reanalysis and synthesis of 80 site-years for 57 forests, plantations, savannas, shrublands and grasslands from boreal to tropical climates we present evidence that total annual SR is closely related to SR at mean annual soil temperature (SRMAT, irrespective of the type of ecosystem and biome. This is theoretically expected for non water-limited ecosystems within most of the globally occurring range of annual temperature variability and sensitivity (Q10. We further show that for seasonally dry sites where annual precipitation (P is lower than potential evapotranspiration (PET, annual SR can be predicted from wet season SRMAT corrected for a factor related to P/PET. Our finding indicates that it can be sufficient to measure SRMAT for obtaining a well constrained estimate of its annual total. This should substantially increase our capacity for assessing the spatial distribution of soil CO2 emissions across ecosystems, landscapes and regions, and thereby contribute to improving the spatial resolution of a major component of the global carbon cycle.

M. Bahn

2010-07-01

151

Soil respiration at mean annual temperature predicts annual total across vegetation types and biomes  

Directory of Open Access Journals (Sweden)

Full Text Available Soil respiration (SR constitutes the largest flux of CO2 from terrestrial ecosystems to the atmosphere. There still exist considerable uncertainties as to its actual magnitude, as well as its spatial and interannual variability. Based on a reanalysis and synthesis of 72 site-years for 58 forests, plantations, savannas, shrublands and grasslands from boreal to tropical climates we present evidence that total annual SR is closely related to SR at mean annual soil temperature (SR MAT, irrespective of the type of ecosystem and biome. This convergence is to be theoretically expected for non water-limited ecosystems within most of the globally occurring range of annual temperature variability and sensitivity (Q10. We further show that for seasonally dry sites where annual precipitation (P is lower than potential evapotranspiration (PET, annual SR can be predicted from wet season SR MAT corrected for a factor related to P/PET. Our finding indicates that it is sufficient to measure SR MAT for obtaining a highly constrained estimate of its annual total. This should substantially increase our capacity for assessing the spatial distribution and interannual variation of soil CO2 emissions across ecosystems, landscapes and regions, and thereby contribute to improving the spatio-temporal resolution of a major component of the global carbon cycle.

M. Bahn

2009-12-01

152

On variability of evapotranspiration : the role of surface type and vegetation  

DEFF Research Database (Denmark)

This dissertation is part of the long-term catchment-scale hydrological observatory, HOBE, situated in the Skjern River catchment covering 2500 km2 on the western coast of Denmark. To gain a more detailed knowledge of how evapotranspiration is controlled by the local surface and weather patterns, eddy-covariance systems was installed over the tree dominant surface types in the catchment; an agricultural field, a spruce [Picea abies (L.) H. Karst] plantation and a meadow site. Measurements started in late 2008, and the full evaporation and energy balances for the years 2009-2011 forms the basis for this study. At the spruce plantation additional separate measurements of transpiration, interception evaporation and forest floor evaporation was performed. Transpiration was measured in the growing season of 2010 using Granier type TDP sap flux probes, interception was measured using net precipitation gauges for the years of 2010 and 2011 and forest floor evaporation was measured on a campaign basis by weighing cut out sections for forest floor. The cumulative measured evapotranspiration from the three surfaces showed large differences. 2009 was an unusually dry year with much lower than normal rates of precipitation in April, May and June, while 2010 and 2011 where normal years in terms of precipitation. The meadow site and agricultural site had the largest evapotranspiration in dry year of 2009 at 512 and 470 mm respectively, while the normal years 2010 and 2011 saw 446 and 455 mm for the meadow and 406 and 400 mm for the agricultural site. The spruce plantation showed the opposite pattern. In 2009 the ET was 494 mm while in 2010 and 2011 the sum was 545 and 544 mm respectively. In all years the agricultural site had less evapotranspiration than the natural surfaces. In the dry year 2009 the meadow had slightly more evapotranspiration than spruce plantation, while in the normal years 2010 and 2011 the forest had considerably more evapotranspiration than either the Meadows or the Farm. At the agricultural site, transpiration was the most important component of the evapotranspiration. The rate of evapotranspiration was controlled by crop development and by the available energy. At the meadow site soil evaporation and evaporation from free water surfaces was the most important parts of the evapotranspiration. The rate of evapotranspiration was controlled by the water level in the Skjern River which influenced the ground water level in the meadows and by the available energy. At the spruce plantation transpiration and terception evaporation were both important. The rate of transpiration was heavily influenced by stomatal control in response to high vapor pressure deficits. In addition soil moisture stress had a limiting effect during prolonged dry periods. Interception evaporation was controlled by the amount and duration of precipitation. During rain, advection was found to comprise about half the energy balance of the spruce plantation in summer and the majority the energy balance in winter. On average, 19% of the precipitation evaporated during rain in summer, and 12% of the precipitation evaporated during rain in winter. Canopy structure in the forest were found to affect both transpiration and interception evaporation. Young stands with an open canopy structure transpired at about 30% higher rate than mature stands with a close canopy structure; the young stands had an interception evaporation of 31% of the gross precipitation, while the mature stands had an interception evaporation of 34% of the gross precipitation. Within the mature stands there was an edge effect with trees next to access roads and aisles being responsible for a disproportionally large part of the stand transpiration.

Ringgaard, Rasmus

2012-01-01

153

Habitat types ecology of the drained Mouria lake : flora and vegetation study and ecological examination of the environmental parameters in a pilot-scale wetland rehabilitation program  

Digital Repository Infrastructure Vision for European Research (DRIVER)

? ??????? ??? ???????????? ?????? ??????? ????????? ??? ?. ?????? 5 ?m ?? ??? ????? ??? ?????? ????? ???? ??????? ??? ??????? ???????. ? ????? ????? ???????????? ??? ??????? 1967-69. ??????????? ??? ????????? ?????: ?) ? ?????? ??? ???????? ??? ???????? ??? ? ????????????? ?...

???????????, ??????????

2009-01-01

154

SOIL EMISSIONS OF N2O, NO AND CO2 IN BRAZILIAN SAVANNAS: EFFECTS OF VEGETATION TYPE, SEASONALITY, AND PRESCRIBED FIRES  

Science.gov (United States)

Using closed chamber techniques, soil fluxes of NO, N20 and C02 were measured from September 1999 through October 2000 in savanna areas in central Brazil (Cerrado) subjected to prescribed fires. Our studies focused on two vegetation types, cerrado stricto sensu (20-50% canopy cov...

155

The results from trial operation of the ecological display for monitoring of drum-separator status at RBMK-type NPP  

International Nuclear Information System (INIS)

The paper describes procedure and results of ecological interface for monitoring of drum-separator at RBMK-type NPP. Trial operation has been carried out during four months at the full scope simulator of the leningrad NPP with participation of the licensed control room operators. The results from the trial operation demonstrate that ecological interface considerably increases efficiency of operator activity and essentially reduces protection activation rate caused by errors or untimely actions of operator compared to conventional human-machine interface

156

Effects of Vegetation Type on Soil Carbon Dynamics Along the Kaidu River in the Yanqi Basin of Northwestern China  

Science.gov (United States)

The Kaidu River originates from the central southern slopes of the Tian Shan from where it flows through the Yulduz Basin and the Yanqi Basin into Lake Bosten. There has been intensive agricultural development along the Kaidu River in the Yanqi Basin. Corn and pepper are two of the main crops. Here, we present a study includes comparisons of soil organic carbon (SOC) between typical native vegtation types (e.g., Glycyrhiza uralensis Fisch, Achnatherum splendens and Sophora alopecuroides Linn) and agricultural crops (i.e., corn and pepper). Fourteen soil pits were sampled at five depths (0-5, 5-15, 15-30, 30-50 and 50-100 cm) in August 2010 (Figure 1). Soil organic matter are determined using the traditional Walkley and Black method and Loss-on-ignition at 375°C for 17 hours. As expected, agricultural soils contain higher SOC than non-agriculatural lands. Native vegetation has various effects on vertical distribution of SOC. We discuss how root system influences SOC dynamics along the Kaidu River in the central Xinjiang, China. Fig. 1. Map of sampling sites along the Kaidu River in northwestern China.

Wang, J.; Wang, X.; Wang, W.

2010-12-01

157

On the Suitability of MODIS Time Series Metrics to Map Vegetation Types in Dry Savanna Ecosystems: A Case Study in the Kalahari of NE Namibia  

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Full Text Available The characterization and evaluation of the recent status of biodiversity in Southern Africa’s Savannas is a major prerequisite for suitable and sustainable land management and conservation purposes. This paper presents an integrated concept for vegetation type mapping in a dry savanna ecosystem based on local scale in-situ botanical survey data with high resolution (Landsat and coarse resolution (MODIS satellite time series. In this context, a semi-automated training database generation procedure using object-oriented image segmentation techniques is introduced. A tree-based Random Forest classifier was used for mapping vegetation type associations in the Kalahari of NE Namibia based on inter-annual intensity- and phenology-related time series metrics. The utilization of long-term inter-annual temporal metrics delivered the best classification accuracies (Kappa = 0.93 compared with classifications based on seasonal feature sets. The relationship between annual classification accuracies and bi-annual precipitation sums was conducted using data from the Tropical Rainfall Measuring Mission (TRMM. Increased error rates occurred in years with high rainfall rates compared to dry rainy seasons. The variable importance was analyzed and showed high-rank positions for features of the Enhanced Vegetation Index (EVI and the blue and middle infrared bands, indicating that soil reflectance was crucial information for an accurate spectral discrimination of Kalahari vegetation types. Time series features related to reflectance intensity obtained increased rank-positions compared to phenology-related metrics.

Stefan Dech

2009-09-01

158

Trace metals in Japanese eel Anguilla japonica in relation to ecological migratory types and growth stages  

Science.gov (United States)

In order to understand the metal concentrations in Japanese eel Anguilla japonica, nine elements were analyzed in the livers of different migratory types of eels collected from Tokushima region (south Japan). Migratory types were defined by examining the Sr:Ca ratio in otoliths. The results showed that there were significant differences in V, Cr, Cd, and Pb concentrations among the migratory types. Mature-sea-eels show a higher risk of metal accumulation than other migratory types of eels, and the concentrations of Mn, Cu, and Zn in mature eels were significantly higher than those in immature eels. The study suggests that the eel liver is a valuable bioindicator for trace metals; however, when using the eel as a bioindicator to reveal the pollutants in aquatic systems, life history analysis should be carried out for accurate interpretation of the results.

Le, Dung Quang; Chino, Naoko; Shirai, Kotaro; Arai, Takaomi

2010-04-01

159

MODIS Vegetation Metrics as Indicators of Hydrological Response in Watersheds of California Mediterranean-type Climate Zones  

Science.gov (United States)

Vegetation characteristics of a watershed can be important in determining hydrological response variables (HRVs) such as streamflow (Q), evapotranspiration (ET), and river yield (Q/P). Quantifying the relationship between satellite-derived vegetation metrics and hydrological response to precipitation (P) has the potential to aid in the prediction of streamflow and evapotranspiration for ungauged watersheds. The utility of Moderate Resolution Imaging Spectroradiometer (MODIS) satellite data to estimate HRVs of watersheds at the regional scale (southern and central California) is tested in this study. An exhaustive statistical regression analysis was conducted, to quantify the relationship between MODIS vegetation metrics and HRVs. Both ordinary least squares and spatially varying parameter models were tested. Moderate linear relationships were found between several MODIS-derived vegetation metrics and both ET and Q. MODIS Leaf Area Index (LAI) regressed on ET exhibited the strongest relationship regression coefficients of 0.50 and 0.95 for the study period mean and strongest annual mean, respectively. Results indicate that the inclusion of spatial-varying parameters can improve the fit in the relationship between MODIS vegetation metrics and HRVs relative to that of the traditional fixed parameter model. The use of a relatively novel exhaustive statistical approach to testing multiple watersheds with varying land cover and climatic characteristics shows that drought conditions in the southern watersheds (2002 and 2004) yielded the strongest fits between MODIS vegetation metrics and HRVs. Alternatively, the relationship between MODIS vegetation metrics and HRVs was weaker when sampling watersheds from similar climatic zones (i.e. humid or semi-arid). Results suggest that direct region-wide estimates of annual streamflow and evapotranspiration for ungauged watersheds can be made reliably for drier years, and that MODIS-derived vegetation metrics may be useful for aiding identification of hydrologically similar watersheds for model-based regionalization purposes.

Stow, D. A.; Fitch, D. T.; Hope, A. S.; Rey, S.

2008-12-01

160

Diurnal variation of tension-type headache intensity and exacerbation: An investigation using computerized ecological momentary assessment  

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Full Text Available Abstract Backgrounds Tension-type headache is a common psychosomatic disease. However, diurnal variation of headache is yet to be clarified, perhaps due to the lack of an appropriate method to investigate it. Like other painful diseases, it would be helpful to know if there is diurnal variation in tension-type headaches, both for managing headaches and understanding their pathophysiology. The aim of this study was to determine if there is diurnal variation in the intensity and exacerbation of tension-type headache. Methods Patients (N?=?31 with tension-type headache recorded for one week their momentary headache intensity several times a day and their acute headache exacerbations using a watch-type computer as an electronic diary (computerized ecological momentary assessment. Multilevel modeling was used to test the effects of time of day on momentary headache intensity and on the occurrence of acute exacerbations. Results A significant diurnal variation in momentary headache intensity was shown (P?=?0.0005, with the weakest headaches in the morning and a peak in the late afternoon. A between-individual difference in the diurnal pattern was suggested. On-demand medication use was associated with a different diurnal pattern (P?=?0.025, suggesting that headache intensity decreases earlier in the evening in subjects who used on-demand medication, while headache subtype, prophylactic medication use, and sex were not associated with the difference. The occurrence of acute headache exacerbation also showed a significant diurnal variation, with a peak after noon (P?=?0.0015. Conclusions Tension-type headache was shown to have a significant diurnal variation. The relation to pathophysiology and psychosocial aspects needs to be further explored.

Kikuchi Hiroe

2012-09-01

 
 
 
 
161

Vegetation of Upper Coastal Plain depression wetlands: Environmental templates and wetland dynamics within a landscape framework.  

Energy Technology Data Exchange (ETDEWEB)

Reference wetlands play an important role in efforts to protect wetlands and assess wetland condition. Because wetland vegetation integrates the influence of many ecological factors, a useful reference system would identify natural vegetation types and include models relating vegetation to important regional geomorphic, hydrologic, and geochemical properties. Across the U.S. Atlantic Coastal Plain, depression wetlands are a major hydrogeomorphic class with diverse characteristics. For 57 functional depression wetlands in the Upper Coastal Plain of South Carolina, we characterized the principal vegetation types and used a landscape framework to assess how local (wetland-level) factors and regional landscape settings potentially influence vegetation composition and dynamics. Wetland sites were stratified across three Upper Coastal Plain landscape settings that differ in soils, surface geology, topography, and land use. We sampled plant composition, measured relevant local variables, and analyzed historical transitions in vegetative cover types. Cluster analysis identified six vegetation types, ranging from open-water ponds and emergent marshes to closed forests. Significant vegetation-environment relationships suggested environmental ''templates'' for plant community development. Of all local factors examined, wetland hydrologic regime was most strongly correlated with vegetation type, but depression size, soil textural type, and disturbance history were also significant. Because hydrogeologic settings influence wetland features, local factors important to vegetation were partly predictable from landscape setting, and thus wetland types were distributed non-randomly across landscape settings. Analysis of long-term vegetation change indicated relative stability in some wetlands and succession in others. We developed a landscape-contingent model for vegetation dynamics, with hydroperiod and fire as major driving variables. The wetland classification, environmental templates, and dynamics model provide a reference framework to guide conservation priorities and suggest possible outcomes of restoration or management.

De Steven, Diane; Toner, Maureen, M.

2004-03-01

162

Remote sensing for identification and classification of wetland vegetation  

Science.gov (United States)

Multispectral photography and ground truth were obtained on an area 12 miles (19.3 km) east of Bemidji, Minnesota, to identify and map wetlands less than 2 acres (0.8 hectare) in size, to map emergent vegetation in lakes, and to explore the feasibility of classifying vegetation from aerial photographs. Wetlands less than 2 acres in size were identified on photography taken in May 1971, and emergent vegetation was recorded on purposely overexposed infrared black and white photography from a flight in September 1971. Several vegetation types and species groups were recognizable with the aid of color, color infrared, and black and white infrared photography. Proper timing of flights, use of multispectral photography, and knowledge of the ecology of the area are considered essential for wetland mapping by remote sensing.

Cowardin, L. M.; Myers, V. I.

1974-01-01

163

Real vegetation - southern part of the Vychodoslovenska nizina Lowland  

International Nuclear Information System (INIS)

The Vychodoslovenska nizina Lowland is one of the first territories where the real vegetation was mapped on the whole area at scale 1 : 25 000. The mapped units (43) were prepared relying on the accessible knowledge of vegetation of this territory, the proper research and aerial images. They were selected in a manner allowing for reflection of site conditions and human impact on vegetation. They are mostly at the level of vegetation associations (a complex of associations). The mapped units possess their physiognomy and groups of indicating species. The aim of mapping was not the syntaxonomic characteristics of vegetation, but the properties of sites reflected by the vegetation: the water soil regime, properties of soil and substratum and the way of use by man. This source material became part of the analyses, syntheses, interpretations, and proposals used in preparation of the Ecological optimisation of use of the Vychodoslovenska nizina Lowland by the LANDEP Methodology in 1986. The fragment represents a territory where the limiting factors of distribution of certain vegetation types are: the non calcareous sand and sand dunes with xerophilous grass, locust forests and vineyards, dead river arms and inter-dune depressions with water and swamp vegetation. Heavy clayey soils with extreme water regime represent the site of flooded and withering semi-natural meadows rich in species, and pastures. The mesophile meadows and pastures are on tillable (often meliorated) soils. They are intensively used, often sowed and of little significance from the point of view of biodiversity. (author)

164

Effects of soil type and farm management on soil ecological functional genes and microbial activities  

Energy Technology Data Exchange (ETDEWEB)

Relationships between soil microbial diversity and soil function are the subject of much debate. Process-level analyses have shown that microbial function varies with soil type and responds to soil management. However, such measurements cannot determine the role of community structure and diversity in soil function. The goal of this study was to investigate the role of gene frequency and diversity, measured by microarray analysis, on soil processes. The study was conducted in an agro-ecosystem characterized by contrasting management practices and soil types. Eight pairs of adjacent commercial organic and conventional strawberry fields were matched for soil type, strawberry variety, and all other environmental conditions. Soil physical, chemical and biological analyses were conducted including functional gene microarrays (FGA). Soil physical and chemical characteristics were primarily determined by soil textural type (coarse vs fine-textured), but biological and FGA measures were more influenced by management (organic vs conventional). Organically managed soils consistently showed greater functional activity as well as FGA signal intensity (SI) and diversity. Overall FGA SI and diversity were correlated to total soil microbial biomass. Functional gene group SI and/or diversity were correlated to related soil chemical and biological measures such as microbial biomass, cellulose, dehydrogenase, ammonium and sulfur. Management was the dominant determinant of soil biology as measured by microbial gene frequency and diversity, which paralleled measured microbial processes.

Reeve, Jennifer [Washington State University; Schadt, Christopher Warren [ORNL; Carpenter-Boggs, Lynne [Washington State University; Kang, S. [University of Oklahoma; Zhou, Jizhong [University of Oklahoma, Norman; Reganold, John P. [Washington State University

2010-01-01

165

Effects of soil type and farm management on soil ecological functional genes and microbial activities.  

Science.gov (United States)

Relationships between soil microbial diversity and soil function are the subject of much debate. Process-level analyses have shown that microbial function varies with soil type and responds to soil management. However, such measurements cannot determine the role of community structure and diversity in soil function. The goal of this study was to investigate the role of gene frequency and diversity, measured by microarray analysis, on soil processes. The study was conducted in an agro-ecosystem characterized by contrasting management practices and soil types. Eight pairs of adjacent commercial organic and conventional strawberry fields were matched for soil type, strawberry variety, and all other environmental conditions. Soil physical, chemical and biological analyses were conducted including functional gene microarrays (FGA). Soil physical and chemical characteristics were primarily determined by soil textural type (coarse vs fine-textured), but biological and FGA measures were more influenced by management (organic vs conventional). Organically managed soils consistently showed greater functional activity as well as FGA signal intensity (SI) and diversity. Overall FGA SI and diversity were correlated to total soil microbial biomass. Functional gene group SI and/or diversity were correlated to related soil chemical and biological measures such as microbial biomass, cellulose, dehydrogenase, ammonium and sulfur. Management was the dominant determinant of soil biology as measured by microbial gene frequency and diversity, which paralleled measured microbial processes. PMID:20376100

Reeve, Jennifer R; Schadt, Christopher W; Carpenter-Boggs, Lynne; Kang, Sanghoon; Zhou, Jizhong; Reganold, John P

2010-09-01

166

THE GENESIS OF PHOTOSYNTHESIS TYPES AS THE BASIS OF ECOLOGICAL EXPANSION OF HALOPHYTIC PLANTS  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The C3, C4, and CAM photosynthesis types are considerably differed by CO2 absorption intensity, its biochemistry, saturation level, water productivity, biological productivity, and other different features, which secure the plants survival at stress and extreme conditions. The aim of current research was to discover the photosynthesis peculiarities at halophytic plants species (Salicornia europaea L., Halimione pedunculata, Artemisia santonica L., Plantago lanceolata L.) by salinity at model ...

Ye, Pyurko O.

2011-01-01

167

On the Suitability of MODIS Time Series Metrics to Map Vegetation Types in Dry Savanna Ecosystems: A Case Study in the Kalahari of NE Namibia  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The characterization and evaluation of the recent status of biodiversity in Southern Africa’s Savannas is a major prerequisite for suitable and sustainable land management and conservation purposes. This paper presents an integrated concept for vegetation type mapping in a dry savanna ecosystem based on local scale in-situ botanical survey data with high resolution (Landsat) and coarse resolution (MODIS) satellite time series. In this context, a semi-automated training database generation p...

Stefan Dech; Christian Hüttich; Strohbach, Ben J.; Manfred Keil; Michael Schmidt; Martin Herold; Ursula Gessner

2009-01-01

168

Trace gas exchange in a high-Arctic valley: 1. Variationsin CO2 and CH4 Flux between tundra vegetation types  

Science.gov (United States)

Ecosystem exchanges of CO2 and CH4 were studied by chamber techniques in five different vegetation types in a high arctic valley at Zackenberg, NE Greenland. The vegetation types were categorized as Cassiope heath, hummocky fen, continuous fen, grassland and Salix arctica snowbed. Integrated daytime fluxes for the different vegetation types of the valley showed that the fen areas and the grassland, were significant sources of CH4 with a mean efflux of 6.3 mg CH4 m-2 hr-1 and sinks for CO2, with almost -170 mg CO2 m-2 hr-1. The heath and snowbed areas had much lower carbon sequestration rates of about -25 mg CO2 m-2 hr-1 and were also sinks for CH4. Methane emissions from the valley dominated in the hummocky fens. Computation of area integrated mean daytime flux values across all vegetation types of the entire valley bottom revealed that it was a sink of CO2 in the order of -96 ± 33 mg CO2 m-2 hr-1 and a source of 1.9 ± 0.7 mg CH4 m-2 hr-1. These values were in accordance with eddy correlation measurements reported elsewhere in this issue and reflect a high-carbon exchange despite the high arctic location. In the fens, where the water table was at or above the soil surface, methane emissions increased with net ecosystem CO2 flux. In places with the water table below the soil surface, such as particularly in the hummocky parts of the fen, oxidation tended to become the dominant controlling factor on methane efflux.

Christensen, T. R.; Friborg, T.; Sommerkorn, M.; Kaplan, J.; Illeris, L.; Soegaard, H.; Nordstroem, C.; Jonasson, S.

2000-09-01

169

Does the endangered Knysna seahorse, Hippocampus capensis, have a preference for aquatic vegetation type, cover or height?  

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Full Text Available The Knysna seahorse,Hippocampus capensis, is an endangered teleost confined to three South African estuaries. Its abundance within these systems is low and distributions are patchy. Consequently, monitoring population sizes is labour-intensive. The aim of this study was to establish if Knynsa seahorses are associated with specific regions within the estuaries, on which conservation efforts could concentrate. The relationship of Knysna seahorses with aquatic vegetation was analysed in the Knysna Estuary (the largest of the three estuarine systems inhabited by H. capensis to determine whether this species shows a preference for a particular plant species, vegetation density or vegetation height. Seahorses were associated with five dominant aquatic plants: Zostera capensis, Caulerpa filiformis, Codium extricatum, Halophila ovalis and Ruppia cirrhosa. Together, these comprised 96% of the submerged objects with which seahorses were associated. The relative abundance of plant species changed along the estuary, but seahorses were present throughout the system, except at the estuary mouth, which was characterized by low plant densities and strong currents. No significant difference was found between the proportion of plant species present in a particular region of the estuary and the proportion of plants that seahorses used as holdfasts. However, when Z. capensis and C. filiformis were present at the same sites, adult seahorses preferred C. filiformis as holdfast. Adult seahorse density (individuals/m2 was significantly correlated with percentage vegetation cover and with holdfast length, but juvenile seahorse density was not. Nonetheless, significantly more adult and juvenile seahorses were found at sites characterized by high vegetation cover (>75% than at sites with lower cover. Our results indicate that although there is some evidence that Knynsa seahorses prefer certain plant species over others, they are likely to be encountered anywhere in the estuary where aquatic plants are present. Conservation efforts in the Knysna Estuary should thus concentrate on such vegetated areas, which comprise approximately 11% of the total submerged surface area.

Thomas Hecht

2011-10-01

170

Reconstructing Past Vegetation Types During the Late Holocene Using Stable Carbon Isotopes of Leporids from Archaeological Sites in the American Southwest  

Science.gov (United States)

Stable carbon isotopes (?13C) from bone collagen in leporids provide high-resolution vegetation reconstruction. Leporids [e.g., cottontails (Sylvilagus sp.), jackrabbits (Lepus sp.)] die young (ca. 2 years) and use small home ranges (plants that use both C3 and C4/CAM photosynthetic pathways. Leporids appear to focus on new growth as it becomes available throughout the year, perhaps as a function of water content. Their diet, and their bone collagen, provides a high-resolution view of the carbon isotopic values present in their local plant community. Here we provide an example of the use of leporid bone collagen for reconstruction of past vegetation types using data from several archaeological sites as well as modern collections. All samples are from a basin and range setting within the Chihuahuan Desert in far west Texas and southern New Mexico, USA. The sites span a period back to roughly 1350 BP. Isotopic patterns in leporid collagen show clear evidence of change in vegetation from around 775 BP to the modern period, with a dramatic shift of 4.2‰ in median ?13C values over this period in jackrabbit collagen and a 7.3‰ decrease in median carbon isotopic values in cottontail rabbits. These data suggest a significant increase in C3 plants in leporid diet, and by extension a relative increase in these plant types in the local environment sampled by leporids. This shift is consistent with historic accounts of more C3 mesquite, possibly because of historic land use and ranching practices in the 1800s. However, while this shift may have been accelerated by historic land use changes, our data suggest that the vegetation shift began several hundred years earlier during the prehistoric period. The prehistoric collagen isotopic record also shows increased sample variability through time in both species, suggesting that year-to-year variability in vegetation may have increased late in that sequence. Our results, then, clearly show the potential of leporids for high resolution tracking of vegetation shifts. As leporids are common in paleontological and archaeological sites throughout the temperate zones, their use as a vegetation and climate proxy has wide application.

Mauldin, R. P.; Munoz, C.; Kemp, L.; Hard, R.

2012-12-01

171

Ecological separation in foraging schedule and food type between pollinators of the California wildflower, Clarkia xantiana ssp. xantiana  

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Full Text Available The co-occurrence of several dimensions of resource separation between coexisting consumers strengthens the hypothesis that the separation arose from and/or ameliorates interspecific competition. The two most common pollinators of the California endemic plant Clarkia xantiana ssp. xantiana (Onagraceae, the bees Hesperapis regularis (Mellitidae and Lasioglossum pullilabre (Halictidae, are known to partition flower resources by flower colour. Here we asked whether H. regularis and L. pullilabre also partition flower resources by diurnal foraging schedule and by food type (pollen versus nectar. We also quantified diurnal patterns of nectar availability, expected to be related to foraging schedules and forager responses to flower colour. The diurnal schedules of the two species differed distinctly and significantly. The majority of L. pullilabre foraging visits occurred before midday, while the majority of H. regularis visits occurred afterwards. The two species foraged for alternative food types at significantly different frequencies—nectar and pollen approximately equally frequently for H. regularis, pollen almost exclusively for L. pullilabre. Nectar standing crop declined with time of day, but it did not clearly reflect or explain previously identified colour-morph preferences. The major pollinators of C. xantiana ssp. xantiana exhibit multiple forms of ecological separation that likely reduce the intensity of competition for floral resources.

Vince Eckhart

2010-10-01

172

THE GENESIS OF PHOTOSYNTHESIS TYPES AS THE BASIS OF ECOLOGICAL EXPANSION OF HALOPHYTIC PLANTS  

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Full Text Available The C3, C4, and CAM photosynthesis types are considerably differed by CO2 absorption intensity, its biochemistry, saturation level, water productivity, biological productivity, and other different features, which secure the plants survival at stress and extreme conditions. The aim of current research was to discover the photosynthesis peculiarities at halophytic plants species (Salicornia europaea L., Halimione pedunculata, Artemisia santonica L., Plantago lanceolata L. by salinity at model and natural conditions, and to generalize data in historical aspect. It was constituted that S. europaea L. was characterized by C3 photosynthesis passage which was switched on CAM CO2 fixation under soil salinity conditions till 4-4,5 %, but glycophyte A.santonica was immanent C4assimilation way of aspartate type.Analysis of literature data and own research allows to find out that in majority the C3photosynthesis dependence from environmental factors described by determinate curve with matched mathematical expression. It was suggested to generalize the data by Lagrange polynomial. The obtained results proved that the pattern of photosynthesis evolution is: C3 ? C4 ? CAM with commute possibilities: C3 ? CAM; C4 ? CAM.

Pyurko O.Ye.

2011-12-01

173

Ecologia do forrageio por Cyphomyrmex morschi Emery (Hymenoptera, Formicidae) em vegetação de restinga no Sul do Brasil / Foraging ecology of Cyphomyrmex morschi Emery (Hymenoptera, Formicidae) in sand dune vegetation at Southern Brazil  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Foram amostrados 400 ninhos de Cyphomyrmex morschi Emery, 1887 entre 1997 e 1998, nas dunas da praia da Joaquina, Florianópolis, SC, para a verificação do material transportado ao ninho. Estas formigas utilizam material de origem vegetal ou animal (fezes de lagartas de Lepidoptera ou partes de corpo [...] s de besouros ou formigas) ou mesmo material não identificado que são introduzidos no ninho para o cultivo do fungo. Assim, do ponto de vista do papel ecológico desempenhado, pode-se considerar C. morschi como uma espécie detritófaga. Abstract in english A total of 400 nests of Cyphomyrmex morschi Emery, 1887 was evaluated between 1997 and 1998 at the dunes of the Joaquina Beach, Florianópolis, Santa Catarina, in order to verify the substrate brought back to the nests. These ants use vegetable or animal material (excrements of lepidopteran larvae or [...] carcasses of beetles or ants) or even not identified material that are used to culture the fungus. Thus, ecologically speaking, C. morschi can be considered a detritiphagous species.

Benedito Cortês, Lopes.

174

Ecologia do forrageio por Cyphomyrmex morschi Emery (Hymenoptera, Formicidae em vegetação de restinga no Sul do Brasil Foraging ecology of Cyphomyrmex morschi Emery (Hymenoptera, Formicidae in sand dune vegetation at Southern Brazil  

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Full Text Available Foram amostrados 400 ninhos de Cyphomyrmex morschi Emery, 1887 entre 1997 e 1998, nas dunas da praia da Joaquina, Florianópolis, SC, para a verificação do material transportado ao ninho. Estas formigas utilizam material de origem vegetal ou animal (fezes de lagartas de Lepidoptera ou partes de corpos de besouros ou formigas ou mesmo material não identificado que são introduzidos no ninho para o cultivo do fungo. Assim, do ponto de vista do papel ecológico desempenhado, pode-se considerar C. morschi como uma espécie detritófaga.A total of 400 nests of Cyphomyrmex morschi Emery, 1887 was evaluated between 1997 and 1998 at the dunes of the Joaquina Beach, Florianópolis, Santa Catarina, in order to verify the substrate brought back to the nests. These ants use vegetable or animal material (excrements of lepidopteran larvae or carcasses of beetles or ants or even not identified material that are used to culture the fungus. Thus, ecologically speaking, C. morschi can be considered a detritiphagous species.

Benedito Cortês Lopes

2007-03-01

175

Projected impacts of 21st century climate change on the distribution of potential habitat for vegetation, forest types and major conifer species across Russia.  

Science.gov (United States)

Global simulations have demonstrated the potential for profound effects of GCM-projected climate change on the distribution of terrestrial ecosystems and individual species at all hierarchical levels. We modeled progressions of potential vegetation cover, forest cover and forest types in Russia in the warming climate during the 21st century. We used large-scale bioclimatic models to predict zonal vegetation (RuBCliM), and forest cover (ForCliM) and forest types. A forest type was defined as a combination of a dominant tree conifer and a ground layer. Distributions of vegetation zones (zonobiomes), conifer species and forest types were simulated based on three bioclimatic indices (1) growing degree-days above 5oC ; (2) negative degree-days below 0oC; and (3) an annual moisture index (ratio of growing degree days to annual precipitation). Additionally, the presence/absence of continuous permafrost, identified by active layer depth of 2 m, was explicitly included in the models as limiting the forests and tree species distribution in Siberia. All simulations to predict vegetation change across Russia were run by coupling our bioclimatic models with bioclimatic indices and the permafrost distribution for the baseline period 1971-2000 and for the future decades of 2011-2020, 2041-2050 and 2091-2100. To provide a range of warming we used three global climate models (CGCM3.1, HadCM3 and IPSLCM4) and three climate change scenarios (A1B, A2 and B1). The CGCM model and the B1 scenario projected the smallest temperature increases, and the IPSL model and the A2 scenario projected the greatest temperature increases. We compared the modeled vegetation and the modeled tree species distributions in the contemporary climate to actual vegetation and forest maps using Kappa (K) statistics. RuBioCliM models of Russian zonal vegetation were fairly accurate (K= 0.40). Contemporary major conifer species (Pinus sibirica, Pinus sylvestris, Larix spp., Abies sibirica and Picea obovata) distributions also showed good match with the modeled ranges for the major conifer species from 41% to 78%. Those matches would be higher if only later seral stages were considered, because historically part of the primary conifer forests have been replaced by secondary birch and aspen forests after large disturbances (clearcuts and wildfire). With these projected climates, the zonobiomes would need to shift far to the north in order to reach equilibrium with the change in climate. Under the warmer and drier projected future climate climate, most of Russia would be suitable for the forest-steppe ecotone and grasslands rather than for forests. Water stress tolerant light-needled taiga (Pinus sylvestris and Larix spp.) would have an increased advantage over water-loving dark-needled taiga (Pinus sibica, Abies sibirica, Picea obovata) in a new climate. The permafrost-tolerant L. dahurica taiga would remain the dominant forest type in the many current permafrost areas. Accumulated surface fuel loads due to increased tree mortality from drought, insects and other factors, especially at the southern forest border and in interior Siberia (Yakutia), together with an increase in severe fire weather would also lead to increases in large, high-severity fires, which are expected to facilitate vegetation progression towards equilibrium with the climate.

Tchebakova, Nadezda; Parfenova, Elena; Cantin, Alan; Shvetsov, Eugene; Soja, Amber; Conard, Susane

2013-04-01

176

Composição da entomofauna da Floresta Nacional do Araripe em diferentes vegetações e estações do ano / Composition of entomofauna on the Araripe National Forest in different vegetation types and year seasons  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese A ocorrência de insetos tem grande significado ecológico e está relacionada com os fatores ambientais, disponibilidade de alimento e abrigo. Para avaliar a composição da entomofauna, em diferentes tipos de vegetação (Cerrado, Carrasco e Mata Úmida) e estações do ano na Floresta Nacional do Araripe, [...] Crato, Ceará, nordeste brasileiro, foram realizadas coletas semanais na estação seca (setembro a dezembro) e chuvosa (abril a julho), por meio de armadilhas McPhail, de solo e bandejas amarelas. Os insetos da ordem Coleoptera são numerosos, na estação seca, agindo como polinizadores, fitófagos e detritívoros, além de decompositores de matéria orgânica, na estação chuvosa. Os Diptera são numerosos na estação chuvosa, quando são encontradas moscas frugívoras, decompositoras de carcaças de animais, de matéria orgânica e predadoras; os da família Calliphoridae predominam no Cerrado; da família Tachinidae, no Carrasco, e da Tephritidae, na Mata Úmida. Os Orthoptera Gryllidae predominam na Mata Úmida e os Hymenoptera Formicidae, no Carrasco e Cerrado na estação seca. Portanto, cada grupo de insetos desempenha um papel ecológico sobre as vegetações, nas diferentes estações do ano. Abstract in english The occurrence of insects has great ecological significance and is related to environmental factors, food availability, and refuge. We assess the composition of the entomofauna in different vegetation types (cerrado, carrasco and humid forest), and seasons in the Araripe National Forest, Crato-CE, b [...] y weekly collections made in the dry season (September to December) and in the rainy season (April to July), through McPhail, pitfall and yellow tray traps. Many Coleoptera occur in the dry season, acting as pollinators, phytophagous, detritivore and decomposers of organic matter in the rainy season. Already, the Diptera is abundant in the rainy season, when fruit flies are found, decomposing animal carcasses, organic matter and predators. The Calliphoridae family predominate in the Cerrado, the Tachinidae in the Carrasco and Tephritidae in the Humid Forest. The Orthoptera Gryllidae predominate in the Humid Forest and the Hymenoptera Formicidae in the Carrasco and Cerrado in the dry season. Therefore, there is a satisfactory balance in the structure and functioning of the Araripe National Forest as each group plays an important ecological role on the vegetation, in the different seasons of the year.

Francisco Roberto de, Azevedo; Maria Andréia Rodrigues de, Moura; Maria Solidade Barbosa, Arrais; Daniel Rodrigues, Nere.

177

Composição da entomofauna da Floresta Nacional do Araripe em diferentes vegetações e estações do ano Composition of entomofauna on the Araripe National Forest in different vegetation types and year seasons  

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Full Text Available A ocorrência de insetos tem grande significado ecológico e está relacionada com os fatores ambientais, disponibilidade de alimento e abrigo. Para avaliar a composição da entomofauna, em diferentes tipos de vegetação (Cerrado, Carrasco e Mata Úmida e estações do ano na Floresta Nacional do Araripe, Crato, Ceará, nordeste brasileiro, foram realizadas coletas semanais na estação seca (setembro a dezembro e chuvosa (abril a julho, por meio de armadilhas McPhail, de solo e bandejas amarelas. Os insetos da ordem Coleoptera são numerosos, na estação seca, agindo como polinizadores, fitófagos e detritívoros, além de decompositores de matéria orgânica, na estação chuvosa. Os Diptera são numerosos na estação chuvosa, quando são encontradas moscas frugívoras, decompositoras de carcaças de animais, de matéria orgânica e predadoras; os da família Calliphoridae predominam no Cerrado; da família Tachinidae, no Carrasco, e da Tephritidae, na Mata Úmida. Os Orthoptera Gryllidae predominam na Mata Úmida e os Hymenoptera Formicidae, no Carrasco e Cerrado na estação seca. Portanto, cada grupo de insetos desempenha um papel ecológico sobre as vegetações, nas diferentes estações do ano.The occurrence of insects has great ecological significance and is related to environmental factors, food availability, and refuge. We assess the composition of the entomofauna in different vegetation types (cerrado, carrasco and humid forest, and seasons in the Araripe National Forest, Crato-CE, by weekly collections made in the dry season (September to December and in the rainy season (April to July, through McPhail, pitfall and yellow tray traps. Many Coleoptera occur in the dry season, acting as pollinators, phytophagous, detritivore and decomposers of organic matter in the rainy season. Already, the Diptera is abundant in the rainy season, when fruit flies are found, decomposing animal carcasses, organic matter and predators. The Calliphoridae family predominate in the Cerrado, the Tachinidae in the Carrasco and Tephritidae in the Humid Forest. The Orthoptera Gryllidae predominate in the Humid Forest and the Hymenoptera Formicidae in the Carrasco and Cerrado in the dry season. Therefore, there is a satisfactory balance in the structure and functioning of the Araripe National Forest as each group plays an important ecological role on the vegetation, in the different seasons of the year.

Francisco Roberto de Azevedo

2011-12-01

178

Composição da entomofauna da Floresta Nacional do Araripe em diferentes vegetações e estações do ano / Composition of entomofauna on the Araripe National Forest in different vegetation types and year seasons  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese A ocorrência de insetos tem grande significado ecológico e está relacionada com os fatores ambientais, disponibilidade de alimento e abrigo. Para avaliar a composição da entomofauna, em diferentes tipos de vegetação (Cerrado, Carrasco e Mata Úmida) e estações do ano na Floresta Nacional do Araripe, [...] Crato, Ceará, nordeste brasileiro, foram realizadas coletas semanais na estação seca (setembro a dezembro) e chuvosa (abril a julho), por meio de armadilhas McPhail, de solo e bandejas amarelas. Os insetos da ordem Coleoptera são numerosos, na estação seca, agindo como polinizadores, fitófagos e detritívoros, além de decompositores de matéria orgânica, na estação chuvosa. Os Diptera são numerosos na estação chuvosa, quando são encontradas moscas frugívoras, decompositoras de carcaças de animais, de matéria orgânica e predadoras; os da família Calliphoridae predominam no Cerrado; da família Tachinidae, no Carrasco, e da Tephritidae, na Mata Úmida. Os Orthoptera Gryllidae predominam na Mata Úmida e os Hymenoptera Formicidae, no Carrasco e Cerrado na estação seca. Portanto, cada grupo de insetos desempenha um papel ecológico sobre as vegetações, nas diferentes estações do ano. Abstract in english The occurrence of insects has great ecological significance and is related to environmental factors, food availability, and refuge. We assess the composition of the entomofauna in different vegetation types (cerrado, carrasco and humid forest), and seasons in the Araripe National Forest, Crato-CE, b [...] y weekly collections made in the dry season (September to December) and in the rainy season (April to July), through McPhail, pitfall and yellow tray traps. Many Coleoptera occur in the dry season, acting as pollinators, phytophagous, detritivore and decomposers of organic matter in the rainy season. Already, the Diptera is abundant in the rainy season, when fruit flies are found, decomposing animal carcasses, organic matter and predators. The Calliphoridae family predominate in the Cerrado, the Tachinidae in the Carrasco and Tephritidae in the Humid Forest. The Orthoptera Gryllidae predominate in the Humid Forest and the Hymenoptera Formicidae in the Carrasco and Cerrado in the dry season. Therefore, there is a satisfactory balance in the structure and functioning of the Araripe National Forest as each group plays an important ecological role on the vegetation, in the different seasons of the year.

Francisco Roberto de, Azevedo; Maria Andréia Rodrigues de, Moura; Maria Solidade Barbosa, Arrais; Daniel Rodrigues, Nere.

2011-12-01

179

Using NEON to Measure Adaptation of Vegetation to Changes in Environmental Forcing  

Science.gov (United States)

The National Ecological Observatory Network (NEON) is a national-scale research platform for documenting and analyzing the impacts of climate change, land-use change, and invasive species on ecology. NEON features sensor networks and experiments linked by cyberinfrastructure to record and archive ecological data for at least 30 years. NEON partitions the United States into 20 ecoclimatic domains. Each domain hosts one fully instrumented core site in a wildland area and two re-locatable sites, which aims to capture ecologically significant gradients (e.g. landuse). Using standardized protocols and an open data policy, NEON data will be gathered from the level of the gene and organism to populations and communities, with extrapolations to the continental scale. In conjunction with environmental data, NEON will conduct field observations and analyses of biological specimens to track biodiversity, population dynamics, productivity, phenology, infectious disease, biogeochemistry and ecohydrology. Here we present a few examples of the type of research NEON will enable using this data. The NEON network will measure and scale many environmental factors that affect vegetation, e.g. temperature, precipitation, and nutrient availability. Direct monitoring of vegetation will enable the study of acclimatory and adaptive changes in vegetation properties over different time scales. Such data will improve the representation of vegetation responses to environmental change in models. The vision behind NEON aims to advance our ability to quantitatively predict ecological change.

Martin, P. H.; Kao, R.; Gibson, C.

2009-12-01

180

Comparative analysis of two vegetation types and its ecotone, Miranda - MS Análise comparativa de duas formações vegetacionais e de seu ecótono, Miranda - MS  

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Full Text Available The Pantanal consists of different vegetation types, including the Paratudal, a monodominat floodable savanna, and Riparian vegetation. This study aimed to analyze diversity and similarity in samples ofthese two vegetations, and its ecotone. The study was developed in the region of Passo do Lontra, at the Miranda river margins. Five plots 10 x 10m, were allocated in each area, where all individuals above 1m height were counted and identified. Nine hundred and thirteen individuals were registered, distributed in 70 taxa, of which 60 were identified in species level. The Shannon diversity index (H’ was 2.715 with Pielou Eveness (J’ of 0.806 in Paratudal, 3.010 and 0.835 in Riparian vegetation, and 2.739 and 0.797 in ecotone, respectively. These results show highest diversity in the Riparian vegetation, as expected, since the Paratudal’s ambient conditions are more restrictive. The floristic similarity between the Paratudal and the Riparian vegetation, according to the Sorensen index, was of 0.2, what distinguish both environments. Therefore, this study evidences the distinction among Riparian vegetation andParatudal, as well the existence of an intermediary values with ecotone. O Pantanal é constituído por diferentes formações vegetacionais, entre elas o Paratudal e a Mata Ciliar. Este trabalho objetivou analisar comparativamente essas duas formações, e o ecótono entre elas, quanto à diversidade e similaridade. O estudo foi desenvolvido na região do Passo do Lontra, às margens do rio Miranda, MS. Foram estabelecidas cinco parcelas de 10 x 10m em cada área e nelas todos os indivíduos acima de 1m de altura foram contados e identificados. Foram registrados 913 indivíduos, distribuídos em 70 taxa, dos quais 60 foram identificados em nível de espécie. O índice de diversidade de Shannon (H’ foi 2,715 com equidade de Pielou (J’ de 0,806 no Paratudal; 3,010 e 0,835 na MataCiliar; e 2,739 e 0,797 no ecótono, respectivamente. Esses resultados demonstram maior diversidade na Mata Ciliar, como esperado, já que as condições do ambiente do Paratudal são mais seletivas. A similaridade florística entre o Paratudal e a Mata Ciliar, de acordo com o índice de Sorensen, foi de 0,2 o que distingue ambos os ambientes. Portanto, este trabalho evidencia a distinção entre Mata Ciliar e Paratudal, bem como os valores intermediários do ecótono.

Mariana Chaves Mota

2011-12-01

 
 
 
 
181

Ecological carrying capacity of current land use assessed according to types of abiotic complexes; 1 : 500 000  

International Nuclear Information System (INIS)

itional ecological development in some cases complemented by protective measures are marked in the map. The present use approximates the threshold of ecological carrying capacity. · Unsuitable (unsustainable) use (3rd level of CCP) - this category covers all areas where it is not possible to maintain the existing way of use either from the ecological or technological points of view. The map shows the areas with necessary changes of use accompanied by proposal of measures, as the present use exceeds ecological carrying capacity (above the threshold of ecological carrying capacity). The resulting proposal has been assessed on the basis of abiotic limits and it requires further modifications pursuing the biotic, abiotic and socio-economic limits. (authors

182

Cell type specificity of female lung cancer associated with sulfur dioxide from air pollutants in Taiwan: An ecological study  

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Full Text Available Abstract Background Many studies have examined the association between air pollutants (including sulfur dioxide [SO2], carbon monoxide [CO], nitrogen dioxide [NO2], nitric oxide [NO], ozone [O3], and particulate matter 10] and lung cancer. However, data from previous studies on pathological cell types were limited, especially for SO2 exposure. We aimed to explore the association between SO2 exposure from outdoor air pollutants and female lung cancer incidence by cell type specificity. Methods We conducted an ecological study and calculated annual average concentration of 6 air pollutants (SO2, CO, NO2, NO, O3, and PM10 using data from Taiwan Environmental Protection Administration air quality monitoring stations. The Poisson regression models were used to evaluate the association between SO2 and age-standardized incidence rate of female lung cancer by two major pathological types (adenocarcinoma [AC] and squamous cell carcinoma [SCC]. In order to understand whether there is a dose-response relationship between SO2 and two major pathological types, we analyzed 4 levels of exposure based on quartiles of concentration of SO2. Results The Poisson regression results showed that with the first quartile of SO2 concentration as the baseline, the relative risks for AC/SCC type cancer among females were 1.20 (95% confidence interval [CI], 1.04-1.37/1.39 (95% CI, 0.96-2.01 for the second, 1.22 (95% CI, 1.04-1.43/1.58 (95% CI, 1.06-2.37 for the third, and 1.27 (95% CI, 1.06-1.52/1.80 (95% CI, 1.15-2.84 for the fourth quartile of SO2 concentration. The tests for trend were statistically significant for both AC and SCC at P = 0.0272 and 0.0145, respectively. Conclusion The current study suggests that SO2 exposure as an air pollutant may increase female lung cancer incidence and the associations with female lung cancer is much stronger for SCC than for AC. The findings of this study warrant further investigation on the role of SO2 in the etiology of SCC.

Tseng Ching-Yu

2012-01-01

183

An ecological type nonlinear model for the removal of carbon dioxide from the atmosphere by introducing liquid species  

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Full Text Available The average temperature of our planet is increasing in past several decades due to emission of global warming gases such as CO2, CH4, etc. in the atmosphere leading to undesirable environmental consequences. Therefore, it is necessary to find a mechanism by which a global warming gas can be removed from the regional atmosphere. In this paper, therefore, we proposed an ecological type nonlinear mathematical model for the removal of a global warming gas CO2 from the regional atmosphere by externally introduced liquid species, which may react with this gas and removed it by gravity. The model consists of three dependent variables namely; the concentration of carbon dioxide, the concentration of externally introduced liquid species and the concentration of particulate matters (secondary species formed due to interaction of carbon dioxide with liquid species. The local and global stability conditions are discussed using Routh-Hurwitz criteria and suitable Lyapunove's function respectively. It is shown, analytically and numerically, that the concentration of carbon dioxide decreases as the rate of introduction of externally introduced liquid species increases.

Shyam Sundar

2013-06-01

184

Selective acquisition of novel mating type and vegetative incompatibility genes via interspecies gene transfer in the globally invading eukaryote Ophiostoma novo-ulmi.  

Science.gov (United States)

The Dutch elm disease fungus Ophiostoma novo-ulmi, which has destroyed billions of elm trees worldwide, originally invaded Europe as a series of clonal populations with a single mating type (MAT-2) and a single vegetative incompatibility (vic) type. The populations then rapidly became diverse with the appearance of the MAT-1 type and many vegetative incompatibility types. Here, we have investigated the mechanism using isolates from sites in Portugal at which the rapid evolution of O. novo-ulmi populations from clonality to heterogeneity was well established. We show by genetic mapping of vic and MAT loci with AFLP markers and by sequence analysis of MAT loci that this diversification was due to selective acquisition by O. novo-ulmi of the MAT-1 and vic loci from another species, Ophiostoma ulmi. A global survey showed that interspecies transfer of the MAT-1 locus occurred on many occasions as O. novo-ulmi spread across the world. We discuss the possibility that fixation of the MAT-1 and vic loci occurred in response to spread of deleterious viruses in the originally clonal populations. The process demonstrates the potential of interspecies gene transfer for facilitating rapid adaptation of invasive organisms to a new environment. PMID:16367844

Paoletti, Mathieu; Buck, Kenneth W; Brasier, Clive M

2006-01-01

185

Using Ecosystem Functional Types in land-surface modeling to characterize and monitor the spatial and inter-annual variability of vegetation dynamics  

Science.gov (United States)

Including the inter-annual variability of vegetation dynamics into land-surface models is necessary to account for land use/cover change effects on Global Climate Models. However, land-surface models use land-cover classifications dictated by structural attributes of vegetation that have little sensitivity to environmental change and are difficult to update and result in a delayed response. This rigid representation of vegetation reduces the ability of models to represent rapid changes including land-use shifts, fires, floods, droughts, and insect outbreaks. Functional attributes of vegetation describing its energy and matter exchange with the atmosphere, have a shorter response to environmental changes and are relatively easy to monitor with satellite data. We applied the concept of Ecosystem Functional Types (EFTs; patches of the land-surface with similar carbon gain dynamics) to characterize the spatial and inter-annual variability of vegetation dynamics across natural and agricultural systems in the La Plata Basin of South America. Three descriptors of carbon gain dynamics were derived from seasonal curves of Normalized Difference Vegetation Index (NDVI) and used to identify EFTs based on annual mean (surrogate of primary production), seasonal coefficient of variation (indicator of seasonality), and date of maximum NDVI (descriptor of phenology). Results from two NDVI datasets were compared (AVHRR-LTDR version 2, 1982-1999, 15-day and 5 km resolution; and MOD13A2 MODIS, 2000-2006, 16-day and 1 km resolution). Both datasets showed greater spatial and inter-annual variability of the EFT composition in agricultural areas compared to natural areas. During 1982-1999, the percentage of the La Plata Basin occupied by EFTs with low productivity, high seasonality, and spring and fall NDVI maxima tended to decrease, while EFTs with high productivity, low seasonality, and summer maxima tended to increase. We speculate that these trends may be due to a positive trend in precipitation. By contrast, during the period 2000-2006, the areas of EFTs with high productivity, low seasonality, and spring and fall maxima (mainly associated with natural forests) tended to reduce, while EFTs with low to medium productivity, high seasonality, and summer maxima (mainly associated with crops) tended to expand. The AVHRR-LTDRv3, covering 1981-2007, will help to assess whether the observed difference between the 1981-1999 and the 2000-2006 periods may be partially due to the change from AVHRR to MODIS datasets. Likewise, it will allow us to study how the yearly changes in the EFTs composition affect the performance of Climate Models during 1982-2007.

Alcaraz-Segura, D.; Paruelo, J.; Epstein, H. E.; Berbery, E. H.; Kalnay, E.; Cabello, J.; Jobbagy, E. G.

2009-12-01

186

Comparison of different types of coatings in headspace solid phase micro extraction for the analysis of pesticide residues in vegetables and fruits  

International Nuclear Information System (INIS)

Despite the continuing development of solid-phase micro extraction (SPME) fiber coatings, their selection presents some difficulties for analytes in choosing the appropriate fiber for a particular application. There are many types of SPME coatings available commercially. The most widely used for determination of pesticide residues in vegetable and fruits are polydimethylsiloxane (PDMS) and polyacrylate (PA). A headspace solid phase micro extraction (HS-SPME) procedure using these two commercialized fibers (PDMS and PA) is presented for the determination of selected groups of organo chlorine and organophosphorus pesticides. The extraction performances of these compounds were compared using these two fibers. The optimal experimental procedures for the adsorption and desorption of pesticides were determined. An explanation for the extraction differences is suggested based on the different thickness, polarity of the polymeric film of fibers and the different extracting matrices. In addition, the higher detector response of the pesticides after addition of aliquots of water and an organic solvent to the vegetable and fruit samples are also discussed. The SPME fibers were reusable until a maximum of 120 extractions. Finally, the optimized procedures were applied successfully for the determination of these compounds in vegetable and fruits samples. Mean recoveries for all pesticides were between 75.0-97 % with RSD below 7 %. (author)

187

Dinâmica espaço-temporal (1962-2006) das fitofisionomias em unidade de conservação do Cerrado no sudeste do Brasil / Spatial and temporal dynamics (1962-2006) of Cerrado vegetation types in a protected area, southeastern Brazil  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Estudos recentes indicam que em áreas de Cerrado protegidas das atividades antrópicas ocorre uma evolução estrutural de fitofisionomias abertas para outras mais fechadas, com tendência ao desaparecimento das primeiras. Analisou-se a dinâmica das fisionomias do Cerrado ao longo de 44 anos, na Estação [...] Ecológica de Assis, SP, uma das poucas unidades de conservação do bioma no sudeste do Brasil, com o objetivo de caracterizar e quantificar possíveis tranformações fisionômicas no tempo e no espaço. Protegida de pressões antrópicas por longo tempo, observações de campo têm indicado um adensamento da vegetação em toda a área, rumo a um clímax de estrutura florestal. Para realizar este estudo foram utilizadas aerofotos (1962, 1984 e 1994), imagens "QuickBird" (2006) e reconhecimento de campo. Durante o período compreendido por este estudo, a área ocupada pelas fisionomias campestres foi reduzida de 23% para menos de 1% da área estudada, enquanto, no outro extremo do gradiente fisionômico, a proporção correspondente ao cerradão aumentou de 53% para 91%. O ritmo de adensamento da vegetação não foi o mesmo em toda a área, estando, aparentemente, correlacionado com a posição topográfica e diferenças edáficas. Acreditamos que as fisionomias campestres e savânicas inicialmente existentes eram mantidas em decorrência de pressões antrópicas, que impediam a evolução rumo a um clímax edafo-climático de maior fitomassa. Confirmando o que tem sido observado em outros locais, a proteção contra o fogo e a suspensão de atividades agropastoris possibilitaram uma evolução gradativa das formações abertas (campo, campo cerrado e cerrado típico) para outras mais fechadas (cerrado denso e cerradão), tendendo as primeiras ao desaparecimento, caso não ocorram novos distúrbios. As conseqüências dessas transformações, relacionadas com estratégias de manejo, conservação da biodiversidade e fixação de carbono são discutidas. Abstract in english Recent studies indicate that after protection from human pressures (fire, cattle grazing and agriculture), structural changes occur in the cerrado vegetation, changing open physiognomies into more closed savannas. We analyzed the dynamics of vegetation types along 44 years, at Assis Ecological Stati [...] on, one of the rare conservation units protecting the cerrado biome in the southeastern São Paulo State, Brazil, with the aim of characterizing and quantifying those changes in space and time. Protected against human pressures since a long time, field observations have shown an upgrade of local cerrado physiognomies, through a successional process whose structural climax can be a forest physiognomy, with a continuous arboreal stratum. The dynamics of the vegetation types was analyzed by using aerial photographs (1962, 1984 and 1994), Quick Bird satellite images (2006) and field surveys. During this 44 years period, field physiognomies were reduced from 23% to less than 1% of the total area studied. In the other extreme, woodland savanna increased from 53% to 91% of the area. Changes did not happen at the same rhythm across the area, and that is apparently correlated to microclimate and edaphyc differences. We believe that field and savannic physiognomies initially existing were mostly maintained due to heavy human pressures, constraining the secondary succession towards an edapho-climatic climax of greater biomass. Confirming the observations of cerrado areas elsewhere, protection against fire, cattle grazing and agriculture allowed the evolution of open vegetation types into more closed ones, tending to be locally extinct the first if new disturbances do not occur. Consequences of these changes related to management strategies, biodiversity conservation and carbon sink are discussed.

Eduardo Da Silva, Pinheiro; Giselda, Durigan.

2009-09-01

188

Dinâmica espaço-temporal (1962-2006 das fitofisionomias em unidade de conservação do Cerrado no sudeste do Brasil Spatial and temporal dynamics (1962-2006 of Cerrado vegetation types in a protected area, southeastern Brazil  

Directory of Open Access Journals (Sweden)

Full Text Available Estudos recentes indicam que em áreas de Cerrado protegidas das atividades antrópicas ocorre uma evolução estrutural de fitofisionomias abertas para outras mais fechadas, com tendência ao desaparecimento das primeiras. Analisou-se a dinâmica das fisionomias do Cerrado ao longo de 44 anos, na Estação Ecológica de Assis, SP, uma das poucas unidades de conservação do bioma no sudeste do Brasil, com o objetivo de caracterizar e quantificar possíveis tranformações fisionômicas no tempo e no espaço. Protegida de pressões antrópicas por longo tempo, observações de campo têm indicado um adensamento da vegetação em toda a área, rumo a um clímax de estrutura florestal. Para realizar este estudo foram utilizadas aerofotos (1962, 1984 e 1994, imagens "QuickBird" (2006 e reconhecimento de campo. Durante o período compreendido por este estudo, a área ocupada pelas fisionomias campestres foi reduzida de 23% para menos de 1% da área estudada, enquanto, no outro extremo do gradiente fisionômico, a proporção correspondente ao cerradão aumentou de 53% para 91%. O ritmo de adensamento da vegetação não foi o mesmo em toda a área, estando, aparentemente, correlacionado com a posição topográfica e diferenças edáficas. Acreditamos que as fisionomias campestres e savânicas inicialmente existentes eram mantidas em decorrência de pressões antrópicas, que impediam a evolução rumo a um clímax edafo-climático de maior fitomassa. Confirmando o que tem sido observado em outros locais, a proteção contra o fogo e a suspensão de atividades agropastoris possibilitaram uma evolução gradativa das formações abertas (campo, campo cerrado e cerrado típico para outras mais fechadas (cerrado denso e cerradão, tendendo as primeiras ao desaparecimento, caso não ocorram novos distúrbios. As conseqüências dessas transformações, relacionadas com estratégias de manejo, conservação da biodiversidade e fixação de carbono são discutidas.Recent studies indicate that after protection from human pressures (fire, cattle grazing and agriculture, structural changes occur in the cerrado vegetation, changing open physiognomies into more closed savannas. We analyzed the dynamics of vegetation types along 44 years, at Assis Ecological Station, one of the rare conservation units protecting the cerrado biome in the southeastern São Paulo State, Brazil, with the aim of characterizing and quantifying those changes in space and time. Protected against human pressures since a long time, field observations have shown an upgrade of local cerrado physiognomies, through a successional process whose structural climax can be a forest physiognomy, with a continuous arboreal stratum. The dynamics of the vegetation types was analyzed by using aerial photographs (1962, 1984 and 1994, Quick Bird satellite images (2006 and field surveys. During this 44 years period, field physiognomies were reduced from 23% to less than 1% of the total area studied. In the other extreme, woodland savanna increased from 53% to 91% of the area. Changes did not happen at the same rhythm across the area, and that is apparently correlated to microclimate and edaphyc differences. We believe that field and savannic physiognomies initially existing were mostly maintained due to heavy human pressures, constraining the secondary succession towards an edapho-climatic climax of greater biomass. Confirming the observations of cerrado areas elsewhere, protection against fire, cattle grazing and agriculture allowed the evolution of open vegetation types into more closed ones, tending to be locally extinct the first if new disturbances do not occur. Consequences of these changes related to management strategies, biodiversity conservation and carbon sink are discussed.

Eduardo Da Silva Pinheiro

2009-09-01

189

Dinâmica espaço-temporal (1962-2006) das fitofisionomias em unidade de conservação do Cerrado no sudeste do Brasil / Spatial and temporal dynamics (1962-2006) of Cerrado vegetation types in a protected area, southeastern Brazil  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Estudos recentes indicam que em áreas de Cerrado protegidas das atividades antrópicas ocorre uma evolução estrutural de fitofisionomias abertas para outras mais fechadas, com tendência ao desaparecimento das primeiras. Analisou-se a dinâmica das fisionomias do Cerrado ao longo de 44 anos, na Estação [...] Ecológica de Assis, SP, uma das poucas unidades de conservação do bioma no sudeste do Brasil, com o objetivo de caracterizar e quantificar possíveis tranformações fisionômicas no tempo e no espaço. Protegida de pressões antrópicas por longo tempo, observações de campo têm indicado um adensamento da vegetação em toda a área, rumo a um clímax de estrutura florestal. Para realizar este estudo foram utilizadas aerofotos (1962, 1984 e 1994), imagens "QuickBird" (2006) e reconhecimento de campo. Durante o período compreendido por este estudo, a área ocupada pelas fisionomias campestres foi reduzida de 23% para menos de 1% da área estudada, enquanto, no outro extremo do gradiente fisionômico, a proporção correspondente ao cerradão aumentou de 53% para 91%. O ritmo de adensamento da vegetação não foi o mesmo em toda a área, estando, aparentemente, correlacionado com a posição topográfica e diferenças edáficas. Acreditamos que as fisionomias campestres e savânicas inicialmente existentes eram mantidas em decorrência de pressões antrópicas, que impediam a evolução rumo a um clímax edafo-climático de maior fitomassa. Confirmando o que tem sido observado em outros locais, a proteção contra o fogo e a suspensão de atividades agropastoris possibilitaram uma evolução gradativa das formações abertas (campo, campo cerrado e cerrado típico) para outras mais fechadas (cerrado denso e cerradão), tendendo as primeiras ao desaparecimento, caso não ocorram novos distúrbios. As conseqüências dessas transformações, relacionadas com estratégias de manejo, conservação da biodiversidade e fixação de carbono são discutidas. Abstract in english Recent studies indicate that after protection from human pressures (fire, cattle grazing and agriculture), structural changes occur in the cerrado vegetation, changing open physiognomies into more closed savannas. We analyzed the dynamics of vegetation types along 44 years, at Assis Ecological Stati [...] on, one of the rare conservation units protecting the cerrado biome in the southeastern São Paulo State, Brazil, with the aim of characterizing and quantifying those changes in space and time. Protected against human pressures since a long time, field observations have shown an upgrade of local cerrado physiognomies, through a successional process whose structural climax can be a forest physiognomy, with a continuous arboreal stratum. The dynamics of the vegetation types was analyzed by using aerial photographs (1962, 1984 and 1994), Quick Bird satellite images (2006) and field surveys. During this 44 years period, field physiognomies were reduced from 23% to less than 1% of the total area studied. In the other extreme, woodland savanna increased from 53% to 91% of the area. Changes did not happen at the same rhythm across the area, and that is apparently correlated to microclimate and edaphyc differences. We believe that field and savannic physiognomies initially existing were mostly maintained due to heavy human pressures, constraining the secondary succession towards an edapho-climatic climax of greater biomass. Confirming the observations of cerrado areas elsewhere, protection against fire, cattle grazing and agriculture allowed the evolution of open vegetation types into more closed ones, tending to be locally extinct the first if new disturbances do not occur. Consequences of these changes related to management strategies, biodiversity conservation and carbon sink are discussed.

Eduardo Da Silva, Pinheiro; Giselda, Durigan.

190

Modelling vegetated dune landscapes  

Science.gov (United States)

This letter presents a self-organising cellular automaton model capable of simulating the evolution of vegetated dunes with multiple types of plant response in the environment. It can successfully replicate hairpin, or long-walled, parabolic dunes with trailing ridges as well as nebkha dunes with distinctive deposition tails. Quantification of simulated landscapes with eco-geomorphic state variables and subsequent cluster analysis and PCA yields a phase diagram of different types of coastal dunes developing from blow-outs as a function of vegetation vitality. This diagram indicates the potential sensitivity of dormant dune fields to reactivation under declining vegetation vitality, e.g. due to climatic changes. Nebkha simulations with different grid resolutions demonstrate that the interaction between the (abiotic) geomorphic processes and the biological vegetation component (life) introduces a characteristic length scale on the resultant landforms that breaks the typical self-similar scaling of (un-vegetated) bare-sand dunes.

Baas, A. C. W.; Nield, J. M.

2007-03-01

191

Description and validation of an automated methodology for mapping mineralogy, vegetation, and hydrothermal alteration type from ASTER satellite imagery with examples from the San Juan Mountains, Colorado  

Science.gov (United States)

The efficacy of airborne spectroscopic, or "hyperspectral," remote sensing for geoenvironmental watershed evaluations and deposit-scale mapping of exposed mineral deposits has been demonstrated. However, the acquisition, processing, and analysis of such airborne data at regional and national scales can be time and cost prohibitive. The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) sensor carried by the NASA Earth Observing System Terra satellite was designed for mineral mapping and the acquired data can be efficiently used to generate uniform mineral maps over very large areas. Multispectral remote sensing data acquired by the ASTER sensor were analyzed to identify and map minerals, mineral groups, hydrothermal alteration types, and vegetation groups in the western San Juan Mountains, Colorado, including the Silverton and Lake City calderas. This mapping was performed in support of multidisciplinary studies involving the predictive modeling of surface water geochemistry at watershed and regional scales. Detailed maps of minerals, vegetation groups, and water were produced from an ASTER scene using spectroscopic, expert system-based analysis techniques which have been previously described. New methodologies are presented for the modeling of hydrothermal alteration type based on the Boolean combination of the detailed mineral maps, and for the entirely automated mapping of alteration types, mineral groups, and green vegetation. Results of these methodologies are compared with the more detailed maps and with previously published mineral mapping results derived from analysis of high-resolution spectroscopic data acquired by the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) sensor. Such comparisons are also presented for other mineralized and (or) altered areas including the Goldfield and Cuprite mining districts, Nevada and the central Marysvale volcanic field, Wah Wah Mountains, and San Francisco Mountains, Utah. The automated mineral group mapping products described in this study are ideal for application to mineral resource and mineral-environmental assessments at regional and national scales.

Rockwell, Barnaby W.

2012-01-01

192

Vegetation type and the presence of ash as factors in the evolution of soil water repellency after a forest fire  

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Full Text Available After wildfires, burning may induce the occurrence of soil water repellency. Soil water repellency may vary in space and time in function of vegetation, the presence of ash and soil moisture. This study analyzes the evolution of fire-induced soil water repellency in function of these factors, and proposes measures to promote the restoration of fire-affected soils. Burnt and unburnt (control soil plots under pine and shrub from a recently burned area (Gorga, Alicante, SE Spain were established. Three treatments were applied: in some of the plots, the original ash layer was kept on the ground; in a second group, the ash layer was removed for simulating the effects of erosion; finally, in a third group, percolating irrigation was conducted to simulate a possible good input of water into the soil profile after burning, that could occur if the first rains were with high quantity but low intensity. During the dry season, soil moisture content was significantly lower in burned plots due to fire-induced water repellency and reduced vegetation cover. During the wet season, soil moisture decreased in the control unburnt plots due to direct evaporation of water intercepted by vegetation and consumption by roots. Fire increased soil water repellency only in plots under pine. Water repellency decreased during the wet season, disappearing in January and reappearing after declining rainfalls. This baseline recovery of soil water repellency was lower where ash removal was simulated. In unburned plots, seasonal fluctuations were less important. In general, ash removal promotes a rapid reduction of water repellency, since it can induce washing of hydrophobic compounds. Irrigation performed immediately after the fire also contributed to decreased water repellency.

P. Jiménez-Pinilla

2013-05-01

193

On the potential of long wavelength imaging radars for mapping vegetation types and woody biomass in tropical rain forests  

Science.gov (United States)

In the tropical rain forests of Manu, in Peru, where forest biomass ranges from 4 kg/sq m in young forest succession up to 100 kg/sq m in old, undisturbed floodplain stands, the P-band polarimetric radar data gathered in June of 1993 by the AIRSAR (Airborne Synthetic Aperture Radar) instrument separate most major vegetation formations and also perform better than expected in estimating woody biomass. The worldwide need for large scale, updated biomass estimates, achieved with a uniformly applied method, as well as reliable maps of land cover, justifies a more in-depth exploration of long wavelength imaging radar applications for tropical forests inventories.

Rignot, Eric J.; Zimmermann, Reiner; Oren, Ram

1995-01-01

194

Uncertainty of establishment scheme in the Community Land Model-Dynamic Global Vegetation Model  

Science.gov (United States)

Dynamic global vegetation models are very important tools to simulate and predict the relationship between terrestrial ecosystem processes and climate change. They usually consist of several main sub-models, such as establishment, growth, mortality due to stress, competition, reproductive and so forth. In this study, we focus on the establishment sub-model. Establishment sub-model describes the processes of germination of tree seeds and establishment of seedlings. However, due to the complexity of the ecological process and the lack of observation data, current DGVMs use different parameterization schemes of establishment, and the uncertainties of these establishment scheme as well as their impacts on vegetation distribution remain largely unknown. Our work is to introduce several new different establishment schemes, each based on different physical and ecological considerations, into a modified Community Land Model - Dynamic Global Vegetation Model (CLM-DGVM). The sensitivities of the vegetation distribution to different establishment schemes and some essential parameters in the schemes are investigated in different vegetation zones. Our research indicates that establishment scheme has remarkable effects not only on the percent of coverage and population density of different plant functional types (PFTs) but also the community structure such as coexistence of PFTs and even the dominant vegetation. Such changes will alter the ecosystem functioning, and hence have further impacts on climate through the vegetation-atmosphere feedback.

Song, X.; Zeng, X.

2010-12-01

195

A change detection strategy for monitoring vegetative and land-use cover types using remotely-sensed, satellite-based data  

International Nuclear Information System (INIS)

Changes to the environment are of critical concern in the world today; consequently, monitoring such changes and assessing their impacts are tasks demanding considerably higher priority. The ecological impacts of the natural global cycles of gases and particulates in the earth's atmosphere are highly influenced by the extent of changes to vegetative canopy characteristics which dictates the need for capability to detect and assess the magnitude of such changes. The primary emphasis of this paper is on the determination of the size and configuration of the sampling unit that maximizes the probability of its intersection with a 'change' area. Assessment of the significance of the 'change' in a given locality is also addressed and relies on a statistical approach that compares the number of elemental units exceeding a reflectance threshold when compared to a previous point in time. Consideration is also given to a technical framework that supports quantifying the magnitude of the 'change' over large areas (i.e., the estimated area changing from forest to agricultural land-use). The latter entails a multistage approach which utilizes satellite-based and other related data sources

196

Approaches to vegetation mapping and ecophysiological hypothesis testing using combined information from TIMS, AVIRIS, and AIRSAR  

Science.gov (United States)

The Tropical Rainforest Ecology Experiment (TREE) had two primary objectives: (1) to design a method for mapping vegetation in tropical regions using remote sensing and determine whether the result improves on available vegetation maps; and (2) to test a specific hypothesis on plant/water relations. Both objectives were thought achievable with the combined information from the Thermal Infrared Multispectral Scanner (TIMS), Airborne Visible/Infrared Imaging Spectrometer (AVIRIS), and Airborne Synthetic Aperture Radar (AIRSAR). Implicitly, two additional objectives were: (1) to ascertain that the range within each variable potentially measurable with the three instruments is large enough in the site, relative to the sensitivity of the instruments, so that differences between ecological groups may be detectable; and (2) to determine the ability of the three systems to quantify different variables and sensitivities. We found that the ranges in values of foliar nitrogen concentration, water availability, stand structure and species composition, and plant/water relations were large, even within the upland broadleaf vegetation type. The range was larger when other vegetation types were considered. Unfortunately, cloud cover and navigation errors compromised the utility of the TIMS and AVIRIS data. Nevertheless, the AIRSAR data alone appear to have improved on the available vegetation map for the study area. An example from an area converted to a farm is given to demonstrate how the combined information from AIRSAR, TIMS, and AVIRIS can uniquely identify distinct classes of land use. The example alludes to the potential utility of the three instruments for identifying vegetation at an ecological scale finer than vegetation types.

Oren, R.; Vane, G.; Zimmermann, R.; Carrere, V.; Realmuto, V.; Zebker, Howard A.; Schoeneberger, P.; Schoeneberger, M.

1991-01-01

197

Influence of the Vegetation Type on CH2O and NO2 Tropospheric Emissions during Biomass Burning: Synergistic use of Satellite Observations  

Science.gov (United States)

Satellite observations are a helpful tool for the identification of the sources for tropospheric emissions by providing global observations of the different trace gases. We present case studies for the combined observations of CH2O and NO2 derived from observations made by the Global Ozone Monitoring Experiment (GOME). Launched on the ERS-2 satellite in April, 1995, GOME has already performed continuous operations over 8 years. The satellite CH2O observations provide information concerning the localization of biomass burning (intense source of CH2O). The principal biomass burning areas can be observed in the amazonian forest and in central Africa. Other high CH2O emissions can be correlated with climatic events like El Nino in 1997, which induced dry conditions in Indonesia causing many forest fires. Tree isoprene emissions contribute also for high CH2O concentrations especially in southwest United States. Biomass burning are also an important tropospheric source for NO2 emissions and can be compared with the CH2O emissions to discriminate the influence of the vegetation type on the tropospheric emissions of both trace gases during biomass burning: the change in the vegetation type can be followed with the change in the intensity of CH2O and NO2 emissions.

Marbach, T.; Beirle, S.; Hollwedel, J.; Khokhar, F.; Platt, U.; Wagner, T.

198

Soil, Vegetation, and Seed Bank of a Sonoran Desert Ecosystem Along an Exotic Plant ( Pennisetum ciliare) Treatment Gradient  

Science.gov (United States)

Ecological conditions following removal of exotic plants are a key part of comprehensive environmental management strategies to combat exotic plant invasions. We examined ecological conditions following removal of the management-priority buffelgrass ( Pennisetum ciliare) in Saguaro National Park of the North American Sonoran Desert. We assessed soil, vegetation, and soil seed banks on seven buffelgrass site types: five different frequencies of buffelgrass herbicide plus hand removal treatments (ranging from 5 years of annual treatment to a single year of treatment), untreated sites, and non-invaded sites, with three replicates for each of the seven site types. The 22 measured soil properties (e.g., pH) differed little among sites. Regarding vegetation, buffelgrass cover was low (?1 % median cover), or absent, across all treated sites but was high (10-70 %) in untreated sites. Native vegetation cover, diversity, and composition were indistinguishable across site types. Species composition was dominated by native species (>93 % relative cover) across all sites except untreated buffelgrass sites. Most (38 species, 93 %) of the 41 species detected in soil seed banks were native, and native seed density did not differ significantly across sites. Results suggest that: (1) buffelgrass cover was minimal across treated sites; (2) aside from high buffelgrass cover in untreated sites, ecological conditions were largely indistinguishable across sites; (3) soil seed banks harbored ?12 species that were frequent in the aboveground vegetation; and (4) native species dominated post-treatment vegetation composition, and removing buffelgrass did not result in replacement by other exotic species.

Abella, Scott R.; Chiquoine, Lindsay P.; Backer, Dana M.

2013-10-01

199

Effects of fertilization on the vascular ground vegetation of European beech (Fagus sylvatica L.) and sessile oak (Quercus petraea (Matt.) Lieb.) stands  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The objective of this study was to assess the effects of base cation (Ca, Mg, K) and phosphorous (P) fertilization on the vascular ground vegetation in mature European beech and sessile oak stands located on acid brown soils. Two types of treatment were applied next to control plots (dolomite lime, dolomite lime + natural phosphate + potassium sulphate). Specific richness, total cover (% ), equitability coefficient as well as the Ecological Group of the ground vegetation were studied. Four ye...

Misson, Laurent; Gaëtan du Bus de Warnaffe,; Jonard, Mathieu

2001-01-01

200

Decreased surface albedo driven by denser vegetation on the Tibetan Plateau  

Science.gov (United States)

The Tibetan Plateau (TP) has fundamental ecological and environmental significance to China and Asia through its influence on regional and continental climates. In recent years, climate warming has caused unprecedented changes to land surface processes on the TP, which would unavoidably undermine the ecological and environmental functions of the TP. Among the numerous land surface processes potentially impacted by climate warming, the effect of vegetation greenness on surface energy balance is one of the most critical, but has been long ignored. In this study, we investigated the spatial and temporal patterns of land surface albedo (LSA) on the TP and evaluated the vegetation greenness in relation to patterns of LSA. We found that LSA has been decreasing in most of the vegetated grasslands on the TP from 2000 to 2013, as compared to a flat trend for desert area. The regions where LSA has been decreasing were spatially correlated to areas of increased vegetation greenness. Along rising altitude, LSA decreasing rate exhibited an overall decreasing trend. Across the TP, elevated vegetation greenness in grasslands acted as a primary factor pulling down LSA. The driving effects of vegetation greenness on LSA vary with grassland types, as revealed by a more significant relationship between vegetation greenness and LSA for the sparsely vegetated zone (i.e. steppe) than the more densely vegetated zone (i.e. meadow). Furthermore, the driving effect of vegetation greenness on LSA exhibited an obvious dependence on altitude as effects with rising altitude were relatively strong up to 3000 m, then weakened from 3500 m to 5000 m, and then the effects again increased from 5000 to 6000 m. The growing season LSA trend revealed in this study emphasizes the need to give greater attention to the growing season LSA flux in future surface energy balance studies.

Tian, Li; Zhang, Yangjian; Zhu, Juntao

2014-10-01

 
 
 
 
201

COMMENT ON: APPLYING SPECIES-SENSITIVITY DISTRIBUTIONS IN ECOLOGICAL RISK ASSESSMENT: ASSUMPTION OF DISTRIBUTION TYPE AND SUFFICIENT NUMBER OF SPECIES  

Science.gov (United States)

Newman et al. (2000) addressed some important issues regarding the characterization of species-sensitivity distributions (SSDs) used in ecological risk assessments. A common assumption is that SSDs are log-normal, and this allows data sets to be analyzed by standard parametric me...

202

Administrative Ecology  

Science.gov (United States)

This article discusses how all four facets of administrative ecology help dispel the claims about the "impossibility" of the superintendency. These are personal ecology, professional ecology, organizational ecology, and community ecology. Using today's superintendency as an administrative platform, current literature describes a preponderance of…

McGarity, Augustus C., III; Maulding, Wanda

2007-01-01

203

Transgenes sustain epigeal insect biodiversity in diversified vegetable farm systems.  

Science.gov (United States)

Many ecological studies have focused on the effects of transgenes in field crops, but few have considered multiple transgenes in diversified vegetable systems. We compared the epigeal, or soil surface-dwelling, communities of Coleoptera and Formicidae between transgenic and isoline vegetable systems consisting of sweet corn, potato, and acorn squash, with transgenic cultivars expressing Cry1(A)b, Cry3, or viral coat proteins. Vegetables were grown in replicated split plots over 2 yr with integrated pest management (IPM) standards defining insecticide use patterns. More than 77.6% of 11,925 insects from 1,512 pitfall traps were identified to species, and activity density was used to compare dominance distribution, species richness, and community composition. Measures of epigeal biodiversity were always equal in transgenic vegetables, which required fewer insecticide applications than their near isolines. There were no differences in species richness between transgenic and isoline treatments at the farm system and individual crop level. Dominance distributions were also similar between transgenic and isoline farming systems. Crop type, and not genotype, had a significant influence on Carabidae and Staphylinidae community composition in the first year, but there were no treatment effects in the second year, possibly because of homogenizing effects of crop rotations. Communities were more influenced by crop type, and possibly crop rotation, than by genotype. The heterogeneity of crops and rotations in diversified vegetable farms seems to aid in preserving epigeal biodiversity, which may be supplemented by reductions in insecticide use associated with transgenic cultivars. PMID:17349138

Leslie, T W; Hoheisel, G A; Biddinger, D J; Rohr, J R; Fleischer, S J

2007-02-01

204

Response of Coprophagus Beetles (Coleoptera: Scarabaeidae on changes of vegetation structure in various habitat types at Lore Lindu National Park, Central Sulawesi  

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Full Text Available This study analysed the response of dung beetles ? a group of beetles which play a major role in decomposition of dung and animal carcasses ? to changes of vegetation structure due to forest conversion to different human-made habitat types at the margin of Lore Lindu National Park. Therefore, dung beetles were sampled at natural forest, cacao agroforestry systems and open area. A total of 28 species of coprophagus beetle species were recorded from the sampled sites. Species richness and abundance of dung beetles, particularly of large species, decreased from forest towards agroforestry systems and open areas. However, more than 80 % of the species recorded in natural forest were found in cacao agroforestry systems Of the measured habitat parameters, particularly the number of tree species, air temperature, and canopy cover had a significant power for explaining changes in dung beetle ensembles along the gradient of land-use intensity.

CHRISTIAN H. SCHULZE

2007-01-01

205

Diversidad de reptiles en tres tipos de vegetación del estado de Hidalgo, México / Diversity of reptiles in three vegetation types of the Hidalgo state, México  

Scientific Electronic Library Online (English)

Full Text Available SciELO Mexico | Language: Spanish Abstract in spanish La zona sureste del estado de Hidalgo presenta diversos tipos de vegetación, como el bosque mesófilo de montaña, bosque de pino-encino y bosque de pino, con alta riqueza de reptiles. En este estudio, se analizó la diversidad alfa y beta de los reptiles en los 3 tipos de vegetación presentes en la zo [...] na sureste. Durante el periodo de recolección, de junio 2008 a agosto del 2009, se realizaron 12 salidas, 1 por mes, con duración de 3 días cada una. La diversidad de reptiles está compuesta por 25 especies, incluyendo un registro nuevo para el estado, la culebra Thamnophis scaliger. El bosque mesófilo de montaña (BMM) presentó la mayor riqueza, con 15 especies, seguido del bosque de pino (BP), con 13, y el bosque de pino-encino (BPE), con 12. Las asociaciones realizadas entre el BMM-BP y BMM-BPE presentaron la más alta disimilitud en especies, y el menor valor fue para el BPE-BP. Este estudio muestra la riqueza y distribución de las especies de los reptiles en los diferentes tipos de vegetación del sureste del estado y presenta nuevos registros de especies para la entidad. El conocimiento de la riqueza de especies por tipos de vegetación de este estudio sienta las bases sobre la biodiversidad, lo que ayuda a plantear estudios dirigidos a la conservación de este grupo. Abstract in english The southeast of Hidalgo in Mexico includes various vegetation types, such as cloud forest, pine-oak forest and pine forest, all harbouring a high species richness of reptiles. In this study we analyzed the alpha and beta diversity of reptiles in 3 vegetation types in the southeast of the state. The [...] field work period was from June 2008 to August 2009, comprising 12 sampling periods of 3 days, 1 per month. The diversity of reptiles is composed of 25 species, reporting the snake Thamnophis scaliger as a new record for the state. The cloud forest (CF) has the highest richness, with 15 species, followed by pine forest (PF), with 13, and finally, the pine-oak forest (POF), with 12 species. The associations between the CF-PF and CF-POF showed the highest dissimilarity in species, and the lowest the POF-PF. This study shows the richness and distribution species of the reptiles in the different vegetation types from southeast of the state, presents new records of species from the state and provides the basis for future studies on the biology of some species of reptiles in the area. The knowledge of species richness by vegetation types from this study provides the basis on the biodiversity that help to raise studies directed to the conservation of this group.

Raciel, Cruz-Elizalde; Aurelio, Ramírez-Bautista.

206

Extraction of Urban Vegetation in Highly Dense Urban Environment with Application to Measure Inhabitants’ Satisfaction of Urban Green Space  

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Full Text Available Urban environment has functioned not only for ecological reason but also for socioeconomic function, due to this reason extraction of urban vegetation in highly dense urban environment becomes more important to understand the inhabitants’ satisfaction of urban green space. With a medium resolution of satellite imagery, the precision is very low. We used high resolution of WorldView-2 satellite to raise the accuracy. We chose Depok City in West Java as a case study area, analyse four multispectral bands, and apply TCT algorithm for getting vegetation density. The relationship between vegetation density and inhabitants’ satisfaction was calculated by Geo-statistical technique based on administrative boundary. We extracted three types of urban vegetation density: good, mid and low. The final result shows that the inhabitants are mostly satisfied with good density of urban vegetation in the city forest inside Campus University of Indonesia.

Fatwa Ramdani

2013-04-01

207

Relating variation in the annual catchment water budget to vegetation dynamics  

Science.gov (United States)

It is widely recognized that the hydrologic system is a nonlinear one and that significant variation exists in the partitioning of annual precipitation input to catchments. This variation is a product of feedbacks between climate fluctuation and vegetation, soil moisture and soil nutrient dynamics. The complex relationship between these four factors requires an ecohydrological approach toward understanding water budget variability so that anticipated changes in any one factor may be used to predict streamflow response. Of these, vegetation stands out as the factor which both directly influences, and is influenced by, the other three and can be viewed as the major integrator of ecosystem conditions. We hypothesize that vegetation dynamics can provide significant insight into interannual variability in catchment hydrologic partitioning. Hydrological and ecological data has been analyzed across catchments within the Long Term Ecological Research (LTER) network of varied ecosystem type and disturbance history over multiples spatial scales. Remotely sensed measures of vegetative characteristics were compared with annual water budget data. Results indicate that distinct threshold behavior may exist in the vegetation-hydrologic partitioning relationship with respect to catchment climate and disturbance severity. Further, the vegetation-partitioning relationship observed at the biome scale differs from that observed within and between catchments of individual LTER sites.

Somor, A. J.; Troch, P. A.; Brooks, P. D.

2009-12-01

208

The importance of evolutionary history in studies of plant physiological ecology: examples from cerrados and forests of central Brazil / A importância da história evolutiva em estudos de ecofisiologia vegetal: exemplos dos cerrados e florestas do Brasil Central  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese Estudos que comparam a fisiologia, anatomia e ecologia das espécies têm oferecido algumas das melhores apreciações sobre as limitações adaptativas e evolucionárias em plantas. Como resultado, a abordagem comparativa tem sido cada vez mais utilizada em estudos de ecofisiologia vegetal. A alta diversi [...] dade de espécies dos biomas brasileiros fornece excelentes oportunidades para estudos de ecofisiologia vegetal comparada, uma abordagem que poderia ser melhor explorada em pesquisas que visam a compreensão da evolução da forma e função em plantas. Neste artigo nós enfatizarmos a importância de considerar a informação filogenética no desenho e analises de estudos comparativos, utilizando como exemplos espécies lenhosas do cerrado e de mata de galeria (mata ripária). O uso de pares congenéricos, cada par contendo uma espécie do cerrado e uma espécie de floresta do mesmo gênero, aumenta o poder estatístico das análises, enquanto assegura concomitantemente a independência filogenética, uma condição essencial para inferência em estudos comparativos. Por exemplo, em um estudo comparativo de nove espécies do cerrado e nove de mata, não seria possível concluir que as espécies de cerrado e de mata diferem na razão de área foliar (LAR), área foliar especifica (SLA) e altura da plântula, se as relações filogenéticas forem ignoradas. Entretanto, se utilizarmos agrupamentos genéricos para contabilizar os efeitos filogenéticos, nós vamos encontrar que as plântulas de espécies de cerrado tem menores valores de LAR, SLA e altura da plântula. Muito da inércia filogenética observada para estes atributos em plântulas parece estar relacionada ao fato de que estas características se correlacionam fortemente com a massa da semente, que estudos anteriores demonstraram ser um atributo fortemente conservado em termos filogenéticos. Estes exemplos ressaltam a importância da informação filogenética em estudos comparativos. Abstract in english Studies that compare physiology, anatomy, and ecology across species have offered some of the best insight into adaptation and evolutionary constraints in plants. As a result, the comparative approach has become increasingly used in studies of plant physiological ecology. The high species diversity [...] of Brazilian biomes provides many excellent opportunities for comparative plant ecophysiology, and could be better exploited for understanding the evolution of plant form and function. In this paper we emphasize the importance of considering phylogenetic information for the design and analysis of comparative studies, relying on examples from comparisons of woody plants from cerrado and gallery (riparian) forests. The use of congeneric species pairs, each containing one cerrado species and one forest species of the same genus, greatly improves statistical power while assuring phylogenetic independence, an essential condition for inference in comparative studies. For example, in a study of seedlings of nine cerrado species and nine forest species, when we ignore phylogenetic relationships, it is not be possible to conclude that cerrado and forest species differ with regard to leaf area ratio (LAR), specific leaf area (SLA), or seedling height. If, however, we use the generic groupings to account for phylogenetic effects, then we find that seedlings of savanna species have lower LAR, SLA, and seedling height. Much of the phylogenetic inertia observed for these traits appears related to the fact that these traits are all strongly correlated with seed mass, which has been previously shown to be strongly conserved phylogenetically. These examples emphasize the importance of phylogenetic information in comparative studies.

William A., Hoffmann; Augusto C., Franco.

2008-09-01

209

Exposure of trees to drought-induced die-off is defined by a common climatic threshold across different vegetation types.  

Science.gov (United States)

Increases in drought and temperature stress in forest and woodland ecosystems are thought to be responsible for the rise in episodic mortality events observed globally. However, key climatic drivers common to mortality events and the impacts of future extreme droughts on tree survival have not been evaluated. Here, we characterize climatic drivers associated with documented tree die-off events across Australia using standardized climatic indices to represent the key dimensions of drought stress for a range of vegetation types. We identify a common probabilistic threshold associated with an increased risk of die-off across all the sites that we examined. We show that observed die-off events occur when water deficits and maximum temperatures are high and exist outside 98% of the observed range in drought intensity; this threshold was evident at all sites regardless of vegetation type and climate. The observed die-off events also coincided with at least one heat wave (three consecutive days above the 90th percentile for maximum temperature), emphasizing a pivotal role of heat stress in amplifying tree die-off and mortality processes. The joint drought intensity and maximum temperature distributions were modeled for each site to describe the co-occurrence of both hot and dry conditions and evaluate future shifts in climatic thresholds associated with the die-off events. Under a relatively dry and moderate warming scenario, the frequency of droughts capable of inducing significant tree die-off across Australia could increase from 1 in 24 years to 1 in 15 years by 2050, accompanied by a doubling in the occurrence of associated heat waves. By defining commonalities in drought conditions capable of inducing tree die-off, we show a strong interactive effect of water and high temperature stress and provide a consistent approach for assessing changes in the exposure of ecosystems to extreme drought events. PMID:24772285

Mitchell, Patrick J; O'Grady, Anthony P; Hayes, Keith R; Pinkard, Elizabeth A

2014-04-01

210

Plant traits demonstrate that temperate and tropical giant eucalypt forests are ecologically convergent with rainforest not savanna.  

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Ecological theory differentiates rainforest and open vegetation in many regions as functionally divergent alternative stable states with transitional (ecotonal) vegetation between the two forming transient unstable states. This transitional vegetation is of considerable significance, not only as a test case for theories of vegetation dynamics, but also because this type of vegetation is of major economic importance, and is home to a suite of species of conservation significance, including the world's tallest flowering plants. We therefore created predictions of patterns in plant functional traits that would test the alternative stable states model of these systems. We measured functional traits of 128 trees and shrubs across tropical and temperate rainforest - open vegetation transitions in Australia, with giant eucalypt forests situated between these vegetation types. We analysed a set of functional traits: leaf carbon isotopes, leaf area, leaf mass per area, leaf slenderness, wood density, maximum height and bark thickness, using univariate and multivariate methods. For most traits, giant eucalypt forest was similar to rainforest, while rainforest, particularly tropical rainforest, was significantly different from the open vegetation. In multivariate analyses, tropical and temperate rainforest diverged functionally, and both segregated from open vegetation. Furthermore, the giant eucalypt forests overlapped in function with their respective rainforests. The two types of giant eucalypt forests also exhibited greater overall functional similarity to each other than to any of the open vegetation types. We conclude that tropical and temperate giant eucalypt forests are ecologically and functionally convergent. The lack of clear functional differentiation from rainforest suggests that giant eucalypt forests are unstable states within the basin of attraction of rainforest. Our results have important implications for giant eucalypt forest management. PMID:24358359

Tng, David Y P; Jordan, Greg J; Bowman, David M J S

2013-01-01

211

Seasonal variation and controlling factors of soil carbon effluxes in six vegetation types in southeast of Sweden  

Energy Technology Data Exchange (ETDEWEB)

Soil carbon effluxes of a pine stand, a spruce stand, a lichen rock, two oak stands and a meadow in the Laxemar investigation area in south-eastern Sweden (57 deg 5 N, 16 deg 7 E) have been measured with the closed chamber technique at 14 occasions between 23 of March 2004 and 10th of March 2005. Soil temperature at 10 cm depth, air temperature, soil moisture and photosynthetically active radiation (PAR) were also measured. Exponential regressions with soil respiration against air and soil temperature were used to estimate soil respiration between 15th of March 2004 and 14th of March 2005. A light response curve with Gross Primary Production (GPP) against PAR and a cubic regression with GPP against air temperature were used for modelling GPP in meadow for the growing season, 15th of March to 31st of October 2004. The exponential regressions with soil respiration against air and soil temperature explained on average 30.6% and 47.6% of the variation, respectively. Soil moisture had a linear limiting effect on soil respiration for all ecosystems but spruce, where soil moisture was the limiting factor above a threshold value of about 50%vol. In the forest ecosystems, GPP of the ground vegetation were not reducing soil carbon effluxes, while in meadow it was. In meadow, the light response curve with GPP against PAR explained 32.7% of the variation in GPP while the cubic regression against air temperature explained 33.9%. No significant effect of soil moisture on GPP was detected. The exponential regression equations with air and soil temperature against soil respiration could be used to temporally extrapolate the occasional field measurements. The light response curve with GPP against PAR and the cubic regression with GPP against air temperature could also be used for temporal extrapolation. From the modelled soil respiration, annual soil respiration for the ecosystems in Laxemar, during 15th of March 2004 to 14th of March 2005, were estimated to be between 0.56 and 1.18 kg C/m2/y. Annual GPP of meadow was estimated to be between 0.49 and 0.54 kg C/m2/y, which gives a net ecosystem exchange for the meadow of between 0.38 and 0.66 kg C/m2/y, i.e. a significant loss of carbon to the atmosphere

Tagesson, Torbern (Dept. of Physical Geography and Ecosystem Analysis, Lund Univ., Lund (SE))

2007-11-15

212

Preliminary Ecological Survey of Microflora Inhabitant Different Types of Hydrophytes in Fresh Water Systems at Middle Egypt Belt with Reference to Physico-chemical Parameters and Phytochemistry  

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Full Text Available Fungal as well as algal flora inhabiting different types of hydrophytes (floating, submerged and emerged in case of healthy and unhealthy ones and from different habitats represent different aquatic ecotypes in middle Egypt area (River Nile, channels, drains and pools were studied. The relations between fungal and algal flora were studied. Some in vivo experiments were done to analyze and confirm the in vitro observations. In addition to complete analysis of ecological parameters which may affect the abilities of microflora to colonize and inhabitant these hydrophytes, e.g. complete physical and chemical analysis of water of investigated sites, also phytochemical investigations of studied hydrophytes were conducted.

A.H. Abo El-lil

2003-01-01

213

Alpine vegetation type affects composition of nutritionally important C18 fatty acids in tissues of lambs from different breeds  

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A total of 110 lambs of the breeds Engadine Sheep and Valaisian Black Nose Sheep were fattened on one lowland and three different alpine pasture types. The experiment was conducted in two consecutive years and lasted for 9 weeks of grazing in each year. Immediately afterwards, the lambs were slaughtered. Perirenal adipose tissue and the Longissimus dorsi muscle were analysed for fatty acid composition. The lambs on the lowland pasture had the lowest proportions of linoleic and ?-linolenic...

Willems, H.; Kreuzer, M.; Leiber, F.

2013-01-01

214

VEGETAL ASSOCIATIONS EDIFIED BY PINUS SYLVESTRIS L. IN NEAGRA BRO?TENILOR HYDROGRAPHIC BASIN  

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Full Text Available The diversity of the natural habitats specific to Neagra Bro?teni hydrographical basin have favoured installation of two different types of pine phytocoenoses. Although both of these plants communities are characteristic to acid substrata, one is specific to oligotrophic peat - bogs (Oxycocco – Sphagnetea and the other to mountain versants presenting acidophilous soils and accentuated slopes (Vaccinio – Piceetea. These vegetal associations are presented in phytosociological tables and analysed in this paper from the bioforms, floristic elements and ecological requests perspectives.

MARDARI CONSTANTIN

2008-11-01

215

Coevolution of hydraulic, soil and vegetation processes in estuarine wetlands  

Science.gov (United States)

Estuarine wetlands of south eastern Australia, typically display a vegetation zonation with a sequence mudflats - mangrove forest - saltmarsh plains from the seaward margin and up the topographic gradient. Estuarine wetlands are among the most productive ecosystems in the world, providing unique habitats for fish and many terrestrial species. They also have a carbon sequestration capacity that surpasess terrestrial forest. Estuarine wetlands respond to sea-level rise by vertical accretion and horizontal landward migration, in order to maintain their position in the tidal frame. In situations in which buffer areas for landward migration are not available, saltmarsh can be lost due to mangrove encroachment. As a result of mangrove invasion associated in part with raising estuary water levels and urbanisation, coastal saltmarsh in parts of south-eastern Australia has been declared an endangered ecological community. Predicting estuarine wetlands response to sea-level rise requires modelling the coevolving dynamics of water flow, soil and vegetation. This paper presents preliminary results of our recently developed numerical model for wetland dynamics in wetlands of the Hunter estuary of NSW. The model simulates continuous tidal inflow into the wetland, and accounts for the effect of varying vegetation types on flow resistance. Coevolution effects appear as vegetation types are updated based on their preference to prevailing hydrodynamic conditions. The model also considers that accretion values vary with vegetation type. Simulations are driven using local information collected over several years, which includes estuary water levels, accretion rates, soil carbon content, flow resistance and vegetation preference to hydraulic conditions. Model results predict further saltmarsh loss under current conditions of moderate increase of estuary water levels.

Trivisonno, Franco; Rodriguez, Jose F.; Riccardi, Gerardo; Saco, Patricia; Stenta, Hernan

2014-05-01

216

Ecological bioavailability of permethrin and p,p'-DDT: toxicity depends on type of organic matter resource.  

Science.gov (United States)

Hydrophobic organic contaminants readily partition from aqueous to organic phases in aquatic systems with past research largely focusing on sediment. However, within many aquatic systems, matrices such as leaf material and detritus are abundant and ecologically important, as they may represent a primary exposure route for aquatic invertebrates. The objectives of the present study were to examine partitioning and toxicity to Hyalella azteca among permethrin and p,p'-DDT contaminated sediment, leaf, and a sediment-leaf mixture. Log organic carbon-water partitioning coefficients ranged from 4.21 to 5.82 for both insecticides, and were greatest within sediment and lowest in coarse leaf material. H. azteca lethal concentrations for 50% of the population (LC50s) ranged from 0.5 to 111?gg(-1) organic carbon, and were dependent on the matrix composition. The variation in sorption and toxicity among matrices common within stream ecosystems suggests that the ecological niche of aquatic organisms may be important for estimating risk of hydrophobic pesticides. PMID:23948608

de Perre, Chloé; Trimble, Andrew J; Maul, Jonathan D; Lydy, Michael J

2014-02-01

217

Canadian vegetation response to climate and projected climatic change  

Energy Technology Data Exchange (ETDEWEB)

The response of Canadian vegetation to climate and climatic change was modeled at three organizational levels of the vegetation mosaic. Snowpack, degree-days, minimum temperature, soil moisture deficit, and actual evapotranspiration are components of climate that physiologically constrain distribution of dominant plant life-forms and species. The rule-based Canadian Climate-Vegetation Model (CCVM) predicts the response of vegetation formations to climate. The CCVM simulation for current climatic conditions is more accurate and detailed than those of other equilibrium models. Ecological response surfaces predict the probability of dominance for eight boreal tree species in Canada with success. Variation in the probability of dominance is related to the species' individualistic response to climatic constraints within different airmass regions. A boreal forest-type classification shows a high degree of geographic correspondence with observed forest-types. Under two doubled-CO[sub 2] climatic scenarios, CCVM predicts a reduction in arctic tundra and subarctic woodland, a northward shift in the distribution of boreal evergreen forest, and an expansion of temperate forest, boreal summergreen woodland, and two prairie formations. The response surfaces predict significant changes in species dominance under both climatic scenarios. Species exhibit an individualistic responses to climatic change. Most of the boreal forest-types derived from future probabilities of dominance are analogous to extant forest-types, but fewer types are distinguished. Geographic correspondence in the simulated boreal forest regions under both the current and projected climates provides a link between the results of the two modelling approaches. Even with constraints, the realism of the vegetation scenarios in this study are arguably the most reliable and comprehensive predictions for Canada.

Lenihan, J.M.

1992-01-01

218

THE STUDY OF VEGETATION FOR A DIAGNOSTICAL EVALUATION OF AGRICULTURAL LANDSCAPES. SOME EXAMPLES FROM LOMBARDY  

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Full Text Available Considering that a landscape is much more than a set of spatial characters, I tried to focus its ecological elements and processes, proposing (a new concepts (e.g. ecocenotope, ecotissue, (b new functions (e.g. biological and territorial aspects of vegetation (c new applications (e.g. evaluation of vegetation, etc.. To verify these applications, a study on the landscape agricultural units of the hinterland of Milan (about 45° 26’N - 09° 17E, 100 m osl is in process in these years. The characters of some forested tesserae along a transect between the Adda river and the Ticino river (East to West, passing through Milan have been expressed, using the biological integrated method of vegetation survey proposed by Ingegnoli (2002. An example of how to use the ecological characters of all the different types of vegetation existing within a landscape unit is given by the study of corridors and crop fields. A comparison among 3 landscape units has been done, to demonstrate the diagnostic evaluation method, after a parametric analysis based on landscape ecological indexes.

V. INGEGNOLI

2006-01-01

219

Wetland vegetation establishment in L-Lake  

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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.

Kroeger, S.R.

1990-07-01

220

Wetland vegetation establishment in L-Lake  

International Nuclear Information System (INIS)

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

 
 
 
 
221

The behavior of sheep and goats co-grazing on pasture with different types of vegetation in the karst region.  

Science.gov (United States)

The Slovenian karst region and similar types of land are difficult to cultivate and often exposed to the process of being abandoned and overgrown with shrubs, trees, and brushwood. Co-grazing in a mixed group may be a way to optimize the management of sheep and goat flocks in such areas. To obtain more knowledge of the natural behavior of small ruminants, the experiment was designed on pasture in the mountain karst region. The experimental area was divided in 6 paddocks, of which 3 paddocks were covered with grass, herbs, and legumes (i.e., grassy paddock [GP]). In the other 3 paddocks the area was additionally overgrown with hazel, beech trees, and bushes (i.e., woody paddock [WP]). In a mixed flock of 40 Slovenian local sheep breed (Istrian Pramenka) and 10 crossbreed goats (Saanen × Alpine goat), 10 animals per species were focally observed during daylight (0500-2100 h). The natural behavior was scored on 12 d, 2 consecutive days in each of the paddocks. Animals were rotated between 6 paddocks according to the balanced schedule. They stayed at each paddock for 5 or 6 d. Observations started on the third day after moving the animals into a specific paddock, following 2 d of adaptation. The results indicated that botanically diverse paddock together with climate conditions affected the behavior. Goats were grazing more (P Goats drank (P goats grazed less (P goats drank more (P goats less autogrooming when temperature was lower (both P goats (P goats suggests different foraging strategies and adaptation between the species, which may be taken into account for management decisions under specific environmental conditions in the mountain karst region. PMID:24778331

Bojkovski, D; Štuhec, I; Kompan, D; Zupan, M

2014-06-01

222

Fruit and vegetable intake, as reflected by serum carotenoid concentrations, predicts reduced probability of polychlorinated biphenyl-associated risk for type 2 diabetes: National Health and Nutrition Examination Survey 2003-2004.  

Science.gov (United States)

Type 2 diabetes has been shown to occur in response to environmental and genetic influences, among them nutrition; food intake patterns; sedentary lifestyle; body mass index; and exposure to persistent organic pollutants, such as polychlorinated biphenyls (PCBs). Nutrition is essential in the prevention and management of type 2 diabetes and has been shown to modulate the toxicity of PCBs. Serum carotenoid concentrations, considered a reliable biomarker of fruit and vegetable intake, are associated with the reduced probability of chronic diseases, such as type 2 diabetes and cardiovascular disease. Our hypothesis is that fruit and vegetable intake, reflected by serum carotenoid concentrations, is associated with the reduced probability of developing type 2 diabetes in US adults with elevated serum concentrations of PCBs 118, 126, and 153. This cross-sectional study used the Center for Disease Control and Prevention database, National Health and Nutrition Examination Survey 2003-2004, in logistic regression analyses. Overall prevalence of type 2 diabetes was approximately 11.6% depending on the specific PCB. All 3 PCBs were positively associated with the probability of type 2 diabetes. For participants at higher PCB percentiles (eg, 75th and 90th) for PCB 118 and 126, increasing serum carotenoid concentrations were associated with a smaller probability of type 2 diabetes. Fruit and vegetable intake, as reflected by serum carotenoid concentrations, predicted notably reduced probability of dioxin-like PCB-associated risk for type 2 diabetes. PMID:24774064

Hofe, Carolyn R; Feng, Limin; Zephyr, Dominique; Stromberg, Arnold J; Hennig, Bernhard; Gaetke, Lisa M

2014-04-01

223

Effect of the first generation of spruce on ground vegetation  

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Full Text Available Nowadays, the changes in tree species composition represent a great threat for productive forests of Slovakia. The change of edificator species is coupled with the change of ground vegetation, which can be used as a phytoindicator of site conditions in forest stands. Our goal was to compare two communities with different tree species composition. In the first case, tree species composition resembled the natural composition, i.e. the mixture of spruce, fir, and beech. In the second case, tree species composition was changed to favour spruce. Both communities belonged to Abieto-Fagetum group of forest types. In both communities, 15 plant relevés were collected and subsequently evaluated using an ecological analysis according to Ellenberg (1992. The results of the analysis were presented in graphs to visualise the changes. Statistical test and ecological analysis did not detect any differences between ground vegetation communities in the stands with natural and changed tree-species composition. Therefore, we conclude that the first generation of spruce in the altered forest stands has not significantly affected species composition of ground vegetation communities yet.

Juraj Ni?

2011-12-01

224

Ecological land classification and terrestrial environment effects assessment for the Port Hope and Port Granby projects  

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The Ecological Land Classification system was developed to provide a standardized methodology for describing plant communities and wildlife habitat in southern Ontario. The method employs a hierarchical classification system. It can be applied at different levels of accuracy, i.e., at regional, sub-regional, and local scales with an increasing differentiation of vegetation communities. The standardization of the approach permits a comparison of vegetation communities from different sites and an evaluation of the rarity of these communities within the province. Further, the approach facilitates the monitoring of changes in terrestrial communities with time. These characteristics make Ecological Land Classification mapping a useful tool for environmental assessment such as the ones undertaken for the Port Hope and Port Granby Long-Term Waste Management Projects, which were conducted pursuant to the Canadian Environmental Assessment Act 1992. In the context of the Environmental Assessment for the Port Hope and Port Granby Projects, an Ecological Land Classification study was undertaken to characterize the terrestrial environment at regional, local and site levels. Vegetation patches (polygons) were delineated on the basis of air photo interpretation. The individual polygons were then visited for detailed inventory and classified to the most detailed level; that is to the vegetation type. Plant communities were then compared with those listed in the Ontario Natural Heritage Information Centre database to determine their rarity and to determine where they rank as Valued Ecosystem Components. Ecological Land Classification mapping results were used in the assessment of effects to Valued Ecosystem Components. A spatial analysis of the digitized vegetation maps showed the geographic extent of habitat losses and impairments due to various project works and activities. Landscape rehabilitation strategies and concepts were subsequently developed based on Ecological Land Classification inventory data and predicted effects. (author)

Taylor, M.; Wittkugel, U. [Amec Earth and Environmental, Mississauga, Ontario (Canada)]. E-mail: mark.e.taylor@amec.com; uwe.wittkugel@amec.com; Kleb, H. [Atomic Energy of Canada Limited, Ottawa, Ontario (Canada)]. E-mail: klebh@aecl.ca

2006-07-01

225

MAP OF ECOLOGICAL UNITS IN ROMANIA  

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Full Text Available The ecological units were delineated based on the ensemble of life conditions whose variety is defined by the specific association of various conditions of climate, relief and lithology, hydrology, vegetable formations and soils, including also the anthropic influence. In the Romania territory 20 ecoregions were delineated, hierarchically grouped in 10 ecological domains and 4 ecological subzones belonging to 2 ecological zones (cold temperate and temperate. Each ecological regions (ecoregions is shortly characterized from following point of views: climatic, topographical, lithological, pedological and land use.

N. Florea

2005-10-01

226

Ecological Species Groups of Hornbeam Forest Ecosystems in Southern Caspian (North of Iran  

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Full Text Available Ecological species group were developed for hornbeam forest ecosystems in North of Iran that had been moderately disturbed. Species groups were determined from field observations and sample plot data arranged and analyzed in association tables. The groups were defined on the basis of species patterns of presence, absence and coverage values. Vegetation was sampled with randomized-systematic method. Vegetation data including density and cover percentage were estimated quantitatively within each quadrate and using the two-way indicator species analysis (TWINSPAN. The objectives of the study were to develop ecological species groups for lowland ecosystems types dominated by hornbeam in north of Iran, describe the site indicator values of species groups and increase our understanding of site-species relationships in moderately disturbed landscape in Khanikan lowland forests of Mazandaran province. Five vegetation groups were identified after the application of TWINSPAN programs. They are named after the characterizing species as follows: Menta aquatica (I, Oplismenus undulatifolius (II, Carex grioletia (III, Viola odarata (IV and Rubus caesius (V. Result have showed that II, III vegetation groups and I, II vegetation groups had the most (65.5% and the least (30% of Sorenson similarity coefficient, respectively. Apparently, similarity coefficient of differentiated vegetation groups was high.

H. Jalilvand

2007-01-01

227

Ecological aspects of the use of fuels and lubricants from plant and animal sources  

International Nuclear Information System (INIS)

In attacking the problems involved in preventing or mitigating the growing ecological crisis and its consequences, the leading place is occupied by the search for an alternative ecologically clean raw material for the production of various types of energy and the manufacture of chemical products. Fuels and lubricants, whether of petroleum or synthetic origin, pose a significant threat to the environment. Here, the authors are generally speaking of ecologically dangerous products, but in many cases even toxic products. They pollute the air, soil, and water with automotive exhaust, spills of used oils, and the incineration and burial of wastes. Vegetable and animal fats do not have any of the shortcomings that are enumerated above. They are biodegradable, nontoxic, and do not form xenobiotics. The use of fats and oils as base stocks or components of fuels and lubricants may well facilitate and accelerate the solution of certain ecological problems. 26 refs., 1 fig., 3 tabs

228

Monitoring vegetation responses to drought -- linking Remotely-sensed Drought Indices with Meteorological drought indices  

Science.gov (United States)

Abstract: Effectively monitoring vegetation drought is of great significance in ecological conservation and agriculture irrigation at the regional scale. Combining meteorological drought indices with remotely sensed drought indices can improve tracking vegetation dynamic under the threat of drought. This study analyzes the dynamics of spatially-defined Temperature Vegetation Dryness Index (TVDI) and temporally-defined Vegetation Health Index (VHI) from remotely sensed NDVI and LST datasets in the dry spells in Southwest China. We analyzed the correlation between remotely sensed drought indices and meteorological drought index of different time scales. The results show that TVDI was limited by the spatial variations of LST and NDVI, while VHI was limited by the temporal variations of LST and NDVI. Station-based buffering analysis indicates that the extracted remotely sensed drought indices and Standard Precipitation Index (SPI) could reach stable correlation with buffering radius larger than 35 km. Three factors affect the spatiotemporal relationship between remotely sensed drought indices and SPI: i) different vegetation types; ii) the timescale of SPI; and iii) remote sensing data noise. Vegetation responds differently to meteorological drought at various time scales. The correlation between SPI6 and VHI is more significant than that between SPI6 and TVDI. Spatial consistency between VHI and TVDI varies with drought aggravation. In early drought period from October to December, VHI and TVDI show limited consistency due to the low quality of remotely sensed images. The study helps to improve monitoring vegetation drought using both meteorological drought indices and remotely sensed drought indices.

Wang, H.; Lin, H.; Liu, D.

2013-12-01

229

Mapping ecological states in a complex environment  

Science.gov (United States)

The vegetation of northern Chihuahuan Desert rangelands is sparse, heterogeneous and for most of the year, consists of a large proportion of non-photosynthetic material. The soils in this area are spectrally bright and variable in their reflectance properties. Both factors provide challenges to the application of remote sensing for estimating canopy variables (e.g., leaf area index, biomass, percentage canopy cover, primary production). Additionally, with reference to current paradigms of rangeland health assessment, remotely-sensed estimates of canopy variables have limited practical use to the rangeland manager if they are not placed in the context of ecological site and ecological state. To address these challenges, we created a multifactor classification system based on the USDA-NRCS ecological site schema and associated state-and-transition models to map ecological states on desert rangelands in southern New Mexico. Applying this system using per-pixel image processing techniques and multispectral, remotely sensed imagery raised other challenges. Per-pixel image classification relies upon the spectral information in each pixel alone, there is no reference to the spatial context of the pixel and its relationship with its neighbors. Ecological state classes may have direct relevance to managers but the non-unique spectral properties of different ecological state classes in our study area means that per-pixel classification of multispectral data performs poorly in discriminating between different ecological states. We found that image interpreters who are familiar with the landscape and its associated ecological site descriptions perform better than per-pixel classification techniques in assigning ecological states. However, two important issues affect manual classification methods: subjectivity of interpretation and reproducibility of results. An alternative to per-pixel classification and manual interpretation is object-based image analysis. Object-based image analysis provides a platform for classification that more closely resembles human recognition of objects within a remotely sensed image. The analysis presented here compares multiple thematic maps created for test locations on the USDA-ARS Jornada Experimental Range ranch. Three study sites in different pastures, each 300 ha in size, were selected for comparison on the basis of their ecological site type (';Clayey', ';Sandy' and a combination of both) and the degree of complexity of vegetation cover. Thematic maps were produced for each study site using (i) manual interpretation of digital aerial photography (by five independent interpreters); (ii) object-oriented, decision-tree classification of fine and moderate spatial resolution imagery (Quickbird; Landsat Thematic Mapper) and (iii) ground survey. To identify areas of uncertainty, we compared agreement in location, areal extent and class assignation between 5 independently produced, manually-digitized ecological state maps and with the map created from ground survey. Location, areal extent and class assignation of the map produced by object-oriented classification was also assessed with reference to the ground survey map.

Steele, C. M.; Bestelmeyer, B.; Burkett, L. M.; Ayers, E.; Romig, K.; Slaughter, A.

2013-12-01

230

Desempenho de um trator operando em solo com diferentes tipos de cobertura vegetal Tractor performance in soil with different types of plants covering  

Directory of Open Access Journals (Sweden)

Full Text Available A eficiência de um trator para desenvolver esforço tratório depende da interação entre o rodado e o solo, envolvendo um complexo conjunto de fatores: característica do rodado, patinagem, transferência de peso do trator, tipo de solo, umidade, estado de compactação, tipo de cobertura do solo, entre outros, que proporcionam diferentes condições de trabalho e interferem no desempenho do trator. Assim, conduziu-se o presente trabalho com o propósito de avaliar alguns desses fatores no desempenho de um trator agrícola, em área coberta com diferentes tipos de cobertura vegetal (aveia, ervilhaca, nabo, aveia e nabo e sem cobertura. O trator foi submetido a cargas por meio do acoplamento a um escarificador de arrasto e instrumentado para a obtenção da força de tração, velocidade de deslocamento, patinagem e consumo de combustível sendo os dados armazenados por meio de um sistema de aquisição de dados. A patinagem foi maior onde a massa de matéria seca era maior, porém não influenciou na potência requerida na barra de tração. A melhor eficiência de tração foi obtida nas parcelas sem cobertura. O coeficiente de tração foi maior nos tratamentos com cobertura de aveia, ervilhaca e nabo comparados com a área sem cobertura. Conclui-se que a cobertura do solo interfere na capacidade do trator em desenvolver esforço para tracionar máquinas e implementos e que o tipo de cobertura pode causar mudanças na patinagem e na eficiência tratória.The efficiency of a tractor to draft development depends on the interaction among the wheeled and the soil where it moves and it involves a complex group of factors, such as: characteristic of the tire, slip, the tractor weight transfer, soil type, water texture and soil compactation, type of soil covering, among others. The aim of this work was to evaluate the acting of an agricultural tractor in an area covered with different types of plants. It was used five types of soil covering (oat, Vicia sativa, turnip, oat and V. sativa together and without cover. A load cell, pulse sensor, flow meters and a system of data acquisition, was used. The slip was larger where the mass of dry matter was larger, even so it didn't influence in the potency requested in the drawbar and in the consumption of fuel. The best traction efficiency was obtained in the portions without covering. The traction coefficient was larger in the treatments with covering of oat, Vicia sativa and turnip, when compared with the area without covering. It is ended that the covering of the soil interferes in the capacity of the tractor in developing effort for pull machines and the covering type can intervene in the slip and tractor efficiency.

Antonio Gabriel Filho

2004-12-01

231

Past and future scenarios of the effect of carbon dioxide on plant growth and transpiration for three vegetation types of southwestern France  

Directory of Open Access Journals (Sweden)

Full Text Available The sensitivity of an operational CO2-responsive land surface model (the ISBA-A-gs model of Météo-France to the atmospheric CO2 concentration, (CO2, is investigated for 3 vegetation types (winter wheat, irrigated maize, coniferous forest. Past (1960 and future (2050 scenarios of (CO2 corresponding to 320 ppm and 550 ppm, respectively, are explored. The sensitivity study is performed for 4 annual cycles presenting contrasting conditions of precipitation regime and air temperature, based on continuous measurements performed on the SMOSREX site near Toulouse, in southwestern France. A significant CO2-driven reduction of canopy conductance is simulated for the irrigated maize and the coniferous forest. The reduction is particularly large for maize, from 2000 to 2050 (?18%, and triggers a drop in optimum irrigation (?30 mm y?1. In the case of wheat, the response is more complex, with an equal occurrence of enhanced or reduced canopy conductance.

J.-C. Calvet

2008-01-01

232

Quantifying soil carbon and nitrogen under different types of vegetation cover using near infrared-spectroscopy: a case study from India  

Science.gov (United States)

Near Infrared Reflectance Spectroscopy (NIRS) is becoming a promising technique in soil analyses. Several studies have demonstrated the ability of NIRS, for rapid and non-destructive technique for the quantification of soil carbon and nitrogen in different ecosystems. We have used this technique for measuring the soil carbon and nitrogen concentrations in soils from different climatic zones (semi arid, dry sub humid and mist sub humid) under different types of vegetation cover. The effects of different soil moisture contents on predicting equations were developed for the quantification of soil carbon and nitrogen. Soil carbon and nitrogen was successfully predicted (R2= 0.90 for carbon and R2= 0.85 for nitrogen) by the equations developed. The standard error of prediction (SEP), standard error of prediction corrected for bias SEP (C) and bias for predicting equations of carbon and nitrogen were 0.73, 0.73, 0.04 and 0.07, 0.07, 0.005, respectively. Our results of soil moisture experiments showed that the equations developed by the NIRS predicted most accurately for carbon and nitrogen in dried soil samples than soils with moisture content. The results of this study showed that NIRS can be used as a rapid and non destructive analytical technique to measure the soil carbon and nitrogen. Key words: Soil carbon, soil nitrogen, NIRS, India, chemometric analysis.

Jesudoss, Dinakaran; Rao, Ks

2014-05-01

233

SFRSF: Landscape Synthesis and Ecological Modeling  

Science.gov (United States)

This South Florida Restoration Science Forum (SFRSF) site explores how to understand, describe, and predict ecological changes at the landscape and regional levels. Issues discussed include the effects of landscape hydrology on specific animal populations, predicting ecological responses to landscape management, understanding changes in the landscape by studying vegetation patterns, and the Cape Sable Seaside Sparrow's importance to understanding ecological changes. Links are provided for further information.

234

[Tourism function zoning of Jinyintan Grassland Scenic Area in Qinghai Province based on ecological sensitivity analysis].  

Science.gov (United States)

Based on the statistical data of natural ecology and social economy in Jinyintan Grassland Scenic Area in Qinghai Province in 2008, an evaluation index system for the ecological sensitivity of this area was established from the aspects of protected area rank, vegetation type, slope, and land use type. The ecological sensitivity of the sub-areas with higher tourism value and ecological function in the area was evaluated, and the tourism function zoning of these sub-areas was made by the technology of GIS and according to the analysis of eco-environmental characteristics and ecological sensitivity of each sensitive sub-area. It was suggested that the Jinyintan Grassland Scenic Area could be divided into three ecological sensitivity sub-areas (high, moderate, and low), three tourism functional sub-areas (restricted development ecotourism, moderate development ecotourism, and mass tourism), and six tourism functional sub-areas (wetland protection, primitive ecological sightseeing, agriculture and pasture tourism, grassland tourism, town tourism, and rural tourism). PMID:20879542

Zhong, Lin-sheng; Tang, Cheng-cai; Guo, Hua

2010-07-01

235

Behavior of the vegetable crops section in three types of food retail stores in Campo Grande, Brazil / Desempenho da seção de hortaliças em equipamentos varejistas de alimentos  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese Neste estudo foi avaliado, sob o ponto de vista do consumidor, o desempenho da seção de hortaliças em três equipamentos varejistas de alimentos em Campo Grande(MS): uma mercearia (quitanda), um supermercado e uma feira-livre. Foi realizada uma pesquisa quantitativo-descritiva com 120 indivíduos, res [...] ponsáveis pelas compras de hortaliças para suas residências. Para tanto, foram investigadas doze variáveis adaptadas das dimensões do modelo SERVQUAL, onde se destacam os atributos do equipamento varejista como higiene e limpeza da loja e exposição dos produtos; capacitação dos funcionários como atendimento e cortesia; e atributos do produto como qualidade, variedade e preço. Os resultados mostram que as compras de hortaliças são realizadas semanalmente, sendo que 80% dos consumidores as realizam em supermercados e 94% em feiras-livres. A feira livre apresentou o melhor desempenho nos atributos em que foi avaliada quando comparada com a quitanda e o supermercado. Esse estudo, também revela que, quanto maior a idade do consumidor, maior sua freqüência de compra. Abstract in english The behavior of the fresh fruits and vegetable produce section was evaluated, under the point of view of the consumer, in three types of food retail stores in Campo Grande, Brazilian southeast: a grocery store ("quitanda"), a supermarket, and an open-air market. A quantitative-descriptive survey was [...] conducted with 120 individuals, responsible for purchasing fresh fruit and vegetable produce for their homes. To accomplish that, twelve variables were investigated and adapted from the parameters used in the SERVQUAL model, in which the attributes of the retail outlet are pointed out, such as store hygiene and cleanliness and manner by which produce is displayed; employee training traits, such as courtesy and helpfulness; and quality, price range, and variety of the produce for sale. The results reveal that shopping for grocery is done weekly; 80% of the shoppers interviewed do their shopping in supermarkets and 94% do theirs in open-air markets. The open-air market had the best results in the attributes for which they were evaluated when compared with the grocery store and the supermarket. The study also points out that the older the shopper the more often he/she does grocery shopping.

Dario de O, Lima-Filho; Anderson S, Hokama; Caroline P, Spanhol.

2009-03-01

236

Behavior of the vegetable crops section in three types of food retail stores in Campo Grande, Brazil Desempenho da seção de hortaliças em equipamentos varejistas de alimentos  

Directory of Open Access Journals (Sweden)

Full Text Available The behavior of the fresh fruits and vegetable produce section was evaluated, under the point of view of the consumer, in three types of food retail stores in Campo Grande, Brazilian southeast: a grocery store ("quitanda", a supermarket, and an open-air market. A quantitative-descriptive survey was conducted with 120 individuals, responsible for purchasing fresh fruit and vegetable produce for their homes. To accomplish that, twelve variables were investigated and adapted from the parameters used in the SERVQUAL model, in which the attributes of the retail outlet are pointed out, such as store hygiene and cleanliness and manner by which produce is displayed; employee training traits, such as courtesy and helpfulness; and quality, price range, and variety of the produce for sale. The results reveal that shopping for grocery is done weekly; 80% of the shoppers interviewed do their shopping in supermarkets and 94% do theirs in open-air markets. The open-air market had the best results in the attributes for which they were evaluated when compared with the grocery store and the supermarket. The study also points out that the older the shopper the more often he/she does grocery shopping.Neste estudo foi avaliado, sob o ponto de vista do consumidor, o desempenho da seção de hortaliças em três equipamentos varejistas de alimentos em Campo Grande(MS: uma mercearia (quitanda, um supermercado e uma feira-livre. Foi realizada uma pesquisa quantitativo-descritiva com 120 indivíduos, responsáveis pelas compras de hortaliças para suas residências. Para tanto, foram investigadas doze variáveis adaptadas das dimensões do modelo SERVQUAL, onde se destacam os atributos do equipamento varejista como higiene e limpeza da loja e exposição dos produtos; capacitação dos funcionários como atendimento e cortesia; e atributos do produto como qualidade, variedade e preço. Os resultados mostram que as compras de hortaliças são realizadas semanalmente, sendo que 80% dos consumidores as realizam em supermercados e 94% em feiras-livres. A feira livre apresentou o melhor desempenho nos atributos em que foi avaliada quando comparada com a quitanda e o supermercado. Esse estudo, também revela que, quanto maior a idade do consumidor, maior sua freqüência de compra.

Dario de O Lima-Filho

2009-03-01

237

Behavior of the vegetable crops section in three types of food retail stores in Campo Grande, Brazil / Desempenho da seção de hortaliças em equipamentos varejistas de alimentos  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese Neste estudo foi avaliado, sob o ponto de vista do consumidor, o desempenho da seção de hortaliças em três equipamentos varejistas de alimentos em Campo Grande(MS): uma mercearia (quitanda), um supermercado e uma feira-livre. Foi realizada uma pesquisa quantitativo-descritiva com 120 indivíduos, res [...] ponsáveis pelas compras de hortaliças para suas residências. Para tanto, foram investigadas doze variáveis adaptadas das dimensões do modelo SERVQUAL, onde se destacam os atributos do equipamento varejista como higiene e limpeza da loja e exposição dos produtos; capacitação dos funcionários como atendimento e cortesia; e atributos do produto como qualidade, variedade e preço. Os resultados mostram que as compras de hortaliças são realizadas semanalmente, sendo que 80% dos consumidores as realizam em supermercados e 94% em feiras-livres. A feira livre apresentou o melhor desempenho nos atributos em que foi avaliada quando comparada com a quitanda e o supermercado. Esse estudo, também revela que, quanto maior a idade do consumidor, maior sua freqüência de compra. Abstract in english The behavior of the fresh fruits and vegetable produce section was evaluated, under the point of view of the consumer, in three types of food retail stores in Campo Grande, Brazilian southeast: a grocery store ("quitanda"), a supermarket, and an open-air market. A quantitative-descriptive survey was [...] conducted with 120 individuals, responsible for purchasing fresh fruit and vegetable produce for their homes. To accomplish that, twelve variables were investigated and adapted from the parameters used in the SERVQUAL model, in which the attributes of the retail outlet are pointed out, such as store hygiene and cleanliness and manner by which produce is displayed; employee training traits, such as courtesy and helpfulness; and quality, price range, and variety of the produce for sale. The results reveal that shopping for grocery is done weekly; 80% of the shoppers interviewed do their shopping in supermarkets and 94% do theirs in open-air markets. The open-air market had the best results in the attributes for which they were evaluated when compared with the grocery store and the supermarket. The study also points out that the older the shopper the more often he/she does grocery shopping.

Dario de O, Lima-Filho; Anderson S, Hokama; Caroline P, Spanhol.

238

Vegetated foreshores as coastal protection strategy: Coping with uncertainties and implementation  

Science.gov (United States)

Promising Building with Nature solutions for flood protection, such as vegetated foreshores, inherently have a dynamic nature. Therefore there is a relatively large degree of uncertainty with respect to their contribution to flood protection. This hampers innovation and the implementation of vegetated foreshores in flood risk management worldwide. We aim to develop new methods to assess how, and how much vegetated foreshores can contribute to flood risk reduction. The project will lead to a better understanding of (uncertainties in) the functioning and stability of these ecosystems and the development of novel governance arrangements. This requires integration of knowledge from ecology, biogeomorphology, hydraulic engineering, and governance. By field observations on several sites and flume measurements we will analyse fundamental ecological and physical processes for various types of wetland vegetations. The knowledge obtained will be applied in one implementation case study for a location in the Netherlands where dike reinforcement is needed in the future. This case study integrates fundamental knowledge from all the disciplines. It is used to design governance and implementation arrangements, and to demonstrate how vegetated foreshores can contribute to flood risk reduction. The project will provide the knowledge, methods and tools (e.g. a maptable) required for the design and implementation of vegetated foreshores as a safe, ecologically desirable, and cost effective alternative in flood management. Strong cooperation with end-users from the private sector, government and non-governmental organizations is embedded in the project to enhance the implementation of our findings in practice. In the full-paper, we present a multidisciplinary research agenda how to address the uncertainties hampering application, how to develop probabilistic tools to derive failure chance in legally imposed terms and how to derive at suitable governance arrangements.

Borsje, Bas; Bouma, Tjeerd; De Vries, Mindert; Timmermans, Jos; Vuik, Vincent; Hermans, Leon; Hulscher, Suzanne; Jonkman, Bas

2014-05-01

239

Ecological Footprint  

Science.gov (United States)

Students explore their own Ecological Footprint in the context of how many Earths it would take if everyone used the same amount of resources they did. They compare this to the Ecological Footprint of individuals in other parts of the world and to the Ecological footprint of a family member when they were the student's age.

Education, Connecticut E.

240

Comparison of deep soil moisture in two re-vegetation watersheds in semi-arid regions  

Science.gov (United States)

Soil moisture stored below rainfall infiltration depth is a reliable water resource for plant growth in semi-arid ecosystems. Along with the large-scale ecological restoration in Chinese Loess Plateau, identifying the ecohydrological response to human-introduced vegetation restoration has become an important issue in current research. In this study, soil moisture data in depth of 0-5 m was obtained by field observation and geostatistical method in two neighboring re-vegetation watersheds. Profile characteristics and spatial pattern of soil moisture was compared between different land use types, transects, and watersheds. The results showed that: (1) Introduced vegetation drastically decreased deep soil moisture when compared with farmland and native grassland. No significant differences in deep soil moisture were found between different introduced vegetation types. (2) An analysis of differences in soil moisture for different land use patterns indicated that land use had significant influence on deep soil moisture spatial variability. Land use structure determined the soil moisture condition and its spatial variation. (3) Vegetation restoration with introduced plants diminished the spatial heterogeneity of deep soil moisture on watershed scale. The improvement of land use management was suggested to improve the water management and maintain the sustainability of vegetation restoration.

Yang, Lei; Chen, Liding; Wei, Wei; Yu, Yang; Zhang, Handan

2014-05-01

 
 
 
 
241

Potential natural vegetation; 1 : 500 000  

International Nuclear Information System (INIS)

Potential natural vegetation is the reflection of the present ecological landscape potential. It presents the natural vegetation, which could be formed in the territory of Slovakia in future, if man stopped to influence the vegetation cover. In the territory of Slovakia it is, with minor exceptions, mainly the forest vegetation. The alpine zone of high mountains, steep exposed rocks in lower positions, and the areas of open water tables represent the mentioned exceptions. The prevailing part of the mapped units consists of willow poplar, alder, elm, oak, oakhornbeam, beech, fir-beech, spruce and dwarf pine forests. The presented map is a follow-up to the map Potential natural vegetation at scale 1 : 500 000 (Atlas Slovenskej socialistickej republiky, SAV, SUGK, Bratislava, 1980) and Karte der natuerlichen Vegetation Europas at scale 1 : 2 500 000 (Bundesamt fuer Naturschutz - ed., Bonn, 2000). (author)

242

Historical and Contemporary Geographic Data Reveal Complex Spatial and Temporal Responses of Vegetation to Climate and Land Stewardship  

Directory of Open Access Journals (Sweden)

Full Text Available Vegetation and land-cover changes are not always directional but follow complex trajectories over space and time, driven by changing anthropogenic and abiotic conditions. We present a multi-observational approach to land-change analysis that addresses the complex geographic and temporal variability of vegetation changes related to climate and land use. Using land-ownership data as a proxy for land-use practices, multitemporal land-cover maps, and repeat photography dating to the late 19th century, we examine changing spatial and temporal distributions of two vegetation types with high conservation value in the southwestern United States: grasslands and riparian vegetation. In contrast to many reported vegetation changes, notably shrub encroachment in desert grasslands, we found an overall increase in grassland area and decline of xeroriparian and riparian vegetation. These observed change patterns were neither temporally directional nor spatially uniform over the landscape. Historical data suggest that long-term vegetation changes coincide with broad climate fluctuations while fine-scale patterns are determined by land-management practices. In some cases, restoration and active management appear to weaken the effects of climate on vegetation; therefore, if land managers in this region act in accord with on-going directional changes, the current drought and associated ecological reorganization may provide an opportunity to achieve desired restoration endpoints.

Miguel L. Villarreal

2013-05-01

243

Bacterial Ecology  

DEFF Research Database (Denmark)

Bacterial ecology is concerned with the interactions between bacteria and their biological and nonbiological environments and with the role of bacteria in biogeochemical element cycling. Many fundamental properties of bacteria are consequences of their small size. Thus, they can efficiently exploit very dilute solutions of organic matter and their potential growth rates are very high. Bacteria do not have a cytoskeleton and they are covered by a rigid cells wall. Therefore they can only take up dissolved low-molecular-weight compounds from their surroundings; when bacteria exploit polymeric compounds these must first be undergo extracellular hydrolysis. Bacteria have a great diversity with respect to types of metabolism that far exceeds the metabolic repertoire of eukaryotic organisms. Bacteria play a fundamental role in the biosphere and certain key processes such as, for example, the production and oxidation of methane, nitrate reduction and fixation of atmospheric nitrogen are exclusively carried out by different groups of bacteria. Some bacterial species – ‘extremophiles’ – thrive in extreme environments in which no eukaryotic organisms can survive with respect to temperature, salinity or pH. Key Concepts:Key Concepts: * Fundamental properties of bacteria are related to their small size and lack of cytoskeleton. * Bacteria display a great diversity in types of metabolism. * Bacteria play a key role in the biosphere in terms of transfer of matter and energy. * A number of fundamental biogeochemical processes are carried exclusively by bacteria. * Bacteria play an important role in all types of habitats including some that cannot support eukaryotic life.

Fenchel, Tom

2011-01-01

244

Ecological restoration and soil improvement performance of the seabuckthorn flexible dam in the Pisha Sandstone area of Northwestern China  

Science.gov (United States)

Soil erosion of the Pisha Sandstone area of Loess Plateau is extremely severe in China. The Pisha Sandstone is very hard when it is dry, while it is very frail when wet. The seabuckthorn flexible dam (SFD), a type of ecological engineering, was proposed to control soil erosion and meliorate soil within the Pisha Sandstone area. To assess its effectiveness and the ecological restoration and soil improvement performance, a field experiment was conducted in this area. We found the strong sediment retention capacity of the SFD is the basis of using it to restore the ecosystem. We compared some certain ecological factors and soil quality between a gully with the SFD and a gully without the SFD, including soil moisture, soil organic matter (SOM), soil nutrients (including Ammonia Nitrogen, available phosphorus and Potassium), vegetation coverage and biodiversity. The results showed that the SFD exhibits excellent performance for ecological restoration and soil improvement of this area. The results are as follows: (i) by the sediment retention action, the deposition commonly occurred in the SFD gully, and the deposition patterns are obviously different from upper to lower gully, (ii) more surprisingly, unlike trees or other shrubs, the seabuckthorn has good horizontal extending capacity by its root system, (iii) soil moisture, SOM, soil nutrients, vegetation coverage and biodiversity in the vegetated gully with the SFD are all markedly increased. The results showed the SFD is both effective and novel biological measure for ecological restoration and soil improvement within the Pisha Sandstone area.

Yang, F. S.; Cao, M. M.; Li, H. E.; Wang, X. H.; Bi, C. F.

2014-09-01

245

Efectos del cambio climático en la diversidad vegetal del corredor de conservación comunitaria Reserva Ecológica El Ángel- Bosque Protector Golondrinas en el norte del Ecuador / The effects of climate change on vegetative diversity in the El Angel Ecological Reserve-Golondrinas Protected Forest community conservation corridor in northern Ecuador  

Scientific Electronic Library Online (English)

Full Text Available SciELO Peru | Language: Spanish Abstract in spanish Para estimar el impacto del cambio climático en el corredor de conservación comunitaria Reserva Ecológica El Ángel - Bosque Protector Golondrinas en el norte del Ecuador se utilizó modelos de distribución potencial generados con MARS de 413 especies vegetales, usando 19 variables bioclimáticas de Wo [...] rldclim con el clima actual y para el 2080 estas mismas variables fueron estimadas de acuerdo al modelo HadCM3-A2. En base a esta información se generaron mapas de riqueza tanto para el presente como para el 2080. Para el área del corredor se han identificado zonas donde se estima que haya cambios de riqueza y donde potencialmente las especies podrían colonizar nuevas áreas o donde se extinguirán. Esto permite determinar el grado de perturbación que sufrirán los ecosistemas por efecto del cambio climático. La tendencia general de las especies estudiadas muestra que colonizarán altitudes más elevadas, cambiando la estructura de los ecosistemas naturales actuales. Toda esta información muestra que para afrontar potenciales impactos en la flora de los ecosistemas de montaña es necesario formar corredores que conecten altitudinalmente áreas naturales protegidas, que permitan la migración de especies y por ende la conservación de la biodiversidad. Abstract in english In order to estimate the impact of climate change on the El Angel Ecological Reserve - Golondrinas Protected Forest community conservation corridor, potential distribution models generated using MARS of 413 vegetative species were applied using 19 Worldclim bioclimatic variables for current climate, [...] and for the year 2080, these same variables were estimated according to the HadCM3-A2 general circulation model. Based on this information, richness maps were developed for the present and for 2080. In the area of the corridor, zones were identified where changes in richness were predicted, where species could potentially colonize, or where species could become extinct. This allows the determination of the level of disturbance that the ecosystems will suffer with climate change. The general tendency of the species studied shows that they will colonize higher altitudes thus changing the structures of current natural ecosystems. All of this information demonstrates that to deal with potential impacts on the flora of mountain ecosystems it will be necessary to create corridors that will connect protected areas located at differing altitudes and thus permit species migration that will in turn conserve biodiversity.

Tania, Delgado; David, Suárez-Duque.

2009-12-01

246

Cell type specificity of female lung cancer associated with sulfur dioxide from air pollutants in Taiwan: An ecological study  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Abstract Background Many studies have examined the association between air pollutants (including sulfur dioxide [SO2], carbon monoxide [CO], nitrogen dioxide [NO2], nitric oxide [NO], ozone [O3], and particulate matter 10]) and lung cancer. However, data from previous studies on pathological cell types were limited, especially for SO2 exposure. We aimed to explore the association between SO2 exposur...

Tseng Ching-Yu; Huang Yi-Chia; Su Shih-Yung; Huang Jing-Yang; Lai Cheng-Hsiu; Lung Chia-Chi; Ho Chien-Chang; Liaw Yung-Po

2012-01-01

247

Farm riparian land use and management: driving factors and tensions between technical and ecological functions.  

Science.gov (United States)

Because of their specific role in the fate of natural resources of landscapes, riparian lands are considered as landscape management units. Yet, they are part of many farms: In what way does this influence their land use and sustainability? In this article, farm riparian land was defined as the set of riparian fields of a given farm. Our aim was to evaluate farm riparian lands as farm management units and the balance between technical and ecological functions associated with farm riparian land-use types. Technical functions designated the role of land use in elaborating farm production and maintaining farm territory. Ecological functions corresponded to farm riparian land-use intensity and ratio of permanent vegetation. The analysis was carried on 102 farms from 5 study sites representative of dairy agriculture and landscapes in a region straddling Brittany and Normandy (France). Farm riparian land-use types were identified using statistical clustering. Technical and ecological functions associated with land-use types were expressed in the light of agronomy and landscape ecology expertise. Descriptors of farm holdings and farm riparian land were tested as explanatory factors of farm riparian land-use types. The use of farm riparian lands was diverse but well defined; they proved to be farm management units. Compatibilities or antagonisms between technical and ecological functions were underscored according to farm riparian land-use type. We argued that decision support could gain in combining perspectives on riparian lands as landscape management units and farm management units. PMID:16206022

Thenail, Claudine; Baudry, Jacques

2005-11-01

248

The role of plant type and salinity in the selection for the denitrifying community structure in the rhizosphere of wetland vegetation.  

Science.gov (United States)

Coastal wetlands, as transient links from terrestrial to marine environments, are important for nitrogen removal by denitrification. Denitrification strongly depends on both the presence of emergent plants and the denitrifier communities selected by different plant species. In this study, the effects of vegetation and habitat heterogeneity on the community of denitrifying bacteria were investigated in nine coastal wetlands in two preserved areas of Spain. Sampling locations were selected to cover a range of salinity (0.81 to 31.3 mS/cm) and nitrate concentrations (0.1 to 303 ?M NO3-), allowing the evaluation of environmental variables that select for denitrifier communities in the rhizosphere of Phragmites sp., Ruppia sp., and Paspalum sp. Potential nitrate reduction rates were found to be dependent on the sampling time and plant species and related to the denitrifier community structure, which was assessed by terminal restriction fragment length polymorphism analysis of the functional genes nirS, nirK and nosZ. The results showed that denitrifier community structure was also governed by plant species and salinity, with significant influences of other variables, such as sampling time and location. Ruppia sp. and Phragmites sp. selected for certain communities, whereas this was not the case for Paspalum sp. The plant species effect was strongest on nirK-type denitrifiers, whereas water carbon content was a significant factor defining the structure of the nosZ-harboring community. The differences recognized using the three functional gene markers indicated that different drivers act on denitrifying populations capable of complete denitrification, compared to the overall denitrifier community. This finding may have implications for emissions of the greenhouse gas nitrous oxide. PMID:22847270

Bañeras, Luís; Ruiz-Rueda, Olaya; López-Flores, Rocío; Quintana, Xavier D; Hallin, Sara

2012-06-01

249

Final vegetative cover for closed waste sites  

International Nuclear Information System (INIS)

Low-level, hazardous, and mixed waste disposal sites normally require some form of plant material to prevent erosion of the final closure cap. Waste disposal sites are closed and capped in a complex scientific manner to minimize water infiltration and percolation into and through the waste material. Turf type grasses are currently being used as an interim vegetative cover for most sites. This coverage allows for required monitoring of the closure cap for settlement and maintenance activities. The purpose of this five year study was to evaluate plant materials for use on wastes sites after the post-closure care period that are quickly and easily established and economically maintained, retard water infiltration, provide maximum year-round evapotranspiration, are ecologically acceptable and do not harm the closure cap. The results of the study suggest that two species of bamboo (Phyllostachys (P.) bissetii and P. rubromarginata) can be utilized to provide long lived, low maintenance, climax vegetation for the waste sites after surveillance and maintenance requirements have ceased

250

Canopy reflectance modelling of semiarid vegetation  

Science.gov (United States)

Three different types of remote sensing algorithms for estimating vegetation amount and other land surface biophysical parameters were tested for semiarid environments. These included statistical linear models, the Li-Strahler geometric-optical canopy model, and linear spectral mixture analysis. The two study areas were the National Science Foundation's Jornada Long Term Ecological Research site near Las Cruces, NM, in the northern Chihuahuan desert, and the HAPEX-Sahel site near Niamey, Niger, in West Africa, comprising semiarid rangeland and subtropical crop land. The statistical approach (simple and multiple regression) resulted in high correlations between SPOT satellite spectral reflectance and shrub and grass cover, although these correlations varied with the spatial scale of aggregation of the measurements. The Li-Strahler model produced estimated of shrub size and density for both study sites with large standard errors. In the Jornada, the estimates were accurate enough to be useful for characterizing structural differences among three shrub strata. In Niger, the range of shrub cover and size in short-fallow shrublands is so low that the necessity of spatially distributed estimation of shrub size and density is questionable. Spectral mixture analysis of multiscale, multitemporal, multispectral radiometer data and imagery for Niger showed a positive relationship between fractions of spectral endmembers and surface parameters of interest including soil cover, vegetation cover, and leaf area index.

Franklin, Janet

1994-01-01

251

Metabolic ecology.  

Science.gov (United States)

Ecological theory that is grounded in metabolic currencies and constraints offers the potential to link ecological outcomes to biophysical processes across multiple scales of organization. The metabolic theory of ecology (MTE) has emphasized the potential for metabolism to serve as a unified theory of ecology, while focusing primarily on the size and temperature dependence of whole-organism metabolic rates. Generalizing metabolic ecology requires extending beyond prediction and application of standardized metabolic rates to theory focused on how energy moves through ecological systems. A bibliometric and network analysis of recent metabolic ecology literature reveals a research network characterized by major clusters focused on MTE, foraging theory, bioenergetics, trophic status, and generalized patterns and predictions. This generalized research network, which we refer to as metabolic ecology, can be considered to include the scaling, temperature and stoichiometric models forming the core of MTE, as well as bioenergetic equations, foraging theory, life-history allocation models, consumer-resource equations, food web theory and energy-based macroecology models that are frequently employed in ecological literature. We conclude with six points we believe to be important to the advancement and integration of metabolic ecology, including nomination of a second fundamental equation, complementary to the first fundamental equation offered by the MTE. PMID:24028511

Humphries, Murray M; McCann, Kevin S

2014-01-01

252

cubierta vegetal  

Directory of Open Access Journals (Sweden)

Full Text Available Se realizó trabajo de campo para conocer el nivel de bienestar que la cubierta vegetal proporciona a la población en la región de Coatepec, Veracruz, México. Se aplicó una combinación de técnicas de valoración contingente y antropológicas, para obtener el valor e importancia que para los entrevistados tiene la cubierta vegetal, así como la importancia y disposición a pagar (DAP por calidad ambiental. Los resultados muestran que la población considera que los niveles de bienestar ambiental actuales son buenos y su DAP por la calidad ambiental es positiva en 51% de la muestra. Dentro del grupo con disposición positiva a pagar, la mayor proporción correspondió a los varones con altos niveles de educación formal e ingresos.

Ana Lid del \\u00C1ngel P\\u00E9rez

2006-01-01

253

Desempenho de um trator operando em solo com diferentes tipos de cobertura vegetal / Tractor performance in soil with different types of plants covering  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese A eficiência de um trator para desenvolver esforço tratório depende da interação entre o rodado e o solo, envolvendo um complexo conjunto de fatores: característica do rodado, patinagem, transferência de peso do trator, tipo de solo, umidade, estado de compactação, tipo de cobertura do solo, entre o [...] utros, que proporcionam diferentes condições de trabalho e interferem no desempenho do trator. Assim, conduziu-se o presente trabalho com o propósito de avaliar alguns desses fatores no desempenho de um trator agrícola, em área coberta com diferentes tipos de cobertura vegetal (aveia, ervilhaca, nabo, aveia e nabo e sem cobertura). O trator foi submetido a cargas por meio do acoplamento a um escarificador de arrasto e instrumentado para a obtenção da força de tração, velocidade de deslocamento, patinagem e consumo de combustível sendo os dados armazenados por meio de um sistema de aquisição de dados. A patinagem foi maior onde a massa de matéria seca era maior, porém não influenciou na potência requerida na barra de tração. A melhor eficiência de tração foi obtida nas parcelas sem cobertura. O coeficiente de tração foi maior nos tratamentos com cobertura de aveia, ervilhaca e nabo comparados com a área sem cobertura. Conclui-se que a cobertura do solo interfere na capacidade do trator em desenvolver esforço para tracionar máquinas e implementos e que o tipo de cobertura pode causar mudanças na patinagem e na eficiência tratória. Abstract in english The efficiency of a tractor to draft development depends on the interaction among the wheeled and the soil where it moves and it involves a complex group of factors, such as: characteristic of the tire, slip, the tractor weight transfer, soil type, water texture and soil compactation, type of soil c [...] overing, among others. The aim of this work was to evaluate the acting of an agricultural tractor in an area covered with different types of plants. It was used five types of soil covering (oat, Vicia sativa, turnip, oat and V. sativa together and without cover). A load cell, pulse sensor, flow meters and a system of data acquisition, was used. The slip was larger where the mass of dry matter was larger, even so it didn't influence in the potency requested in the drawbar and in the consumption of fuel. The best traction efficiency was obtained in the portions without covering. The traction coefficient was larger in the treatments with covering of oat, Vicia sativa and turnip, when compared with the area without covering. It is ended that the covering of the soil interferes in the capacity of the tractor in developing effort for pull machines and the covering type can intervene in the slip and tractor efficiency.

Antonio, Gabriel Filho; Suedêmio de L., Silva; Alcir J., Modolo; João C. M. da, Silveira.

2004-12-01

254

Desempenho de um trator operando em solo com diferentes tipos de cobertura vegetal / Tractor performance in soil with different types of plants covering  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese A eficiência de um trator para desenvolver esforço tratório depende da interação entre o rodado e o solo, envolvendo um complexo conjunto de fatores: característica do rodado, patinagem, transferência de peso do trator, tipo de solo, umidade, estado de compactação, tipo de cobertura do solo, entre o [...] utros, que proporcionam diferentes condições de trabalho e interferem no desempenho do trator. Assim, conduziu-se o presente trabalho com o propósito de avaliar alguns desses fatores no desempenho de um trator agrícola, em área coberta com diferentes tipos de cobertura vegetal (aveia, ervilhaca, nabo, aveia e nabo e sem cobertura). O trator foi submetido a cargas por meio do acoplamento a um escarificador de arrasto e instrumentado para a obtenção da força de tração, velocidade de deslocamento, patinagem e consumo de combustível sendo os dados armazenados por meio de um sistema de aquisição de dados. A patinagem foi maior onde a massa de matéria seca era maior, porém não influenciou na potência requerida na barra de tração. A melhor eficiência de tração foi obtida nas parcelas sem cobertura. O coeficiente de tração foi maior nos tratamentos com cobertura de aveia, ervilhaca e nabo comparados com a área sem cobertura. Conclui-se que a cobertura do solo interfere na capacidade do trator em desenvolver esforço para tracionar máquinas e implementos e que o tipo de cobertura pode causar mudanças na patinagem e na eficiência tratória. Abstract in english The efficiency of a tractor to draft development depends on the interaction among the wheeled and the soil where it moves and it involves a complex group of factors, such as: characteristic of the tire, slip, the tractor weight transfer, soil type, water texture and soil compactation, type of soil c [...] overing, among others. The aim of this work was to evaluate the acting of an agricultural tractor in an area covered with different types of plants. It was used five types of soil covering (oat, Vicia sativa, turnip, oat and V. sativa together and without cover). A load cell, pulse sensor, flow meters and a system of data acquisition, was used. The slip was larger where the mass of dry matter was larger, even so it didn't influence in the potency requested in the drawbar and in the consumption of fuel. The best traction efficiency was obtained in the portions without covering. The traction coefficient was larger in the treatments with covering of oat, Vicia sativa and turnip, when compared with the area without covering. It is ended that the covering of the soil interferes in the capacity of the tractor in developing effort for pull machines and the covering type can intervene in the slip and tractor efficiency.

Antonio, Gabriel Filho; Suedêmio de L., Silva; Alcir J., Modolo; João C. M. da, Silveira.

255

Tipos de estacas e substratos na propagação vegetativa da menta (Mentha arvensis L.) / Types of cuttings and substrates in the vegetative propagation of mint (Mentha arvensis L.)  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese O trabalho teve como objetivo avaliar a propagação vegetativa da menta utilizando diferentes tipos de estacas e substratos. O experimento foi conduzido no Horto de Plantas Medicinais da Unimontes, campus Janaúba - MG. O delineamento experimental utilizado foi o inteiramente casualizado, em esquema f [...] atorial 2 x 4 (dois tipos de estacas e quatro diferentes substratos) com quatro repetições, sendo cada parcela representada por seis estacas. Foram analisadas as variáveis comprimento de parte aérea e de raízes, massa seca de parte aérea e de raízes e número total de brotações formadas por planta. Os dados foram submetidos à análise de variância e as médias comparadas pelo teste de Scott-Knott a 5% de probabilidade. A interação entre os fatores estacas e substratos não foi significativa para as variáveis estudadas, passando-se a estudar o efeito isolado de cada fator. A propagação de Mentha arvensis L. pode ser realizada tanto por estacas apicais como medianas, utilizando o substrato solo + areia + esterco bovino (2:1:1) para a produção de mudas de qualidade. Abstract in english The purpose of the study was to evaluate the vegetative propagation using different types of mint cuttings and substrates. The experiment was conducted in the Garden of Medicinal Plants of Unimontes, in Janaúba - MG. The experimental design was completely randomized (CRD) in 2 x 4 factorial schemes [...] (two types of poles and four different substrates) with four replications and each plot was represented by six cuttings. The variables analyzed were the length of the shoots and roots, the dry matter of the shoots and roots and the total number of shoots per plant. The data were subject to ANOVA and the means were compared by Scott-Knott's test at 5% of probability. The interaction among stem cuttings and substrates was not significant for the variables studied, thus, the isolated effect of each factor was studied. The propagation of Mentha arvensis L. can be performed either by apical cuttings as medians, using the substrate soil + sand + manure bovine (2:1:1) for the production of quality seedlings.

H.T.R, Amaro; J.R, Silveira; A.M.S de S, David; M.A.V de, Resende; J.A.S., Andrade.

256

The influence of different environmental and climatic conditions on vegetated aeolian dune landscape development and response  

Science.gov (United States)

Aeolian dune field development in coastal and semi-arid environments is a function of complex ecogeomorphic interactions which are sensitive to fluctuations in climatic and environmental conditions. We explore the relationships between ecological and geomorphic processes in the development of these landscape patterns and speculate on their response to variations in vegetation vitality and sediment transport capacity, indicating possible consequences of climate and land use change, using the Discrete ECogeomorphic Aeolian Landscape (DECAL) cellular automaton algorithm. This algorithm models dune field behaviour that reflects long-term trends prevalent in palaeo-records, but also elucidates possible evolutionary progressions, relaxation period sequences and threshold sensitivities. The landscape response is sensitive both to the perturbation itself and the state of the system when the disturbance occurs. Response amplitude decreases in simulated systems with reduced mobility unless an external disturbance mimicking fire or land clearance is applied concurrently with a reduction in growth vigour triggering a threshold type response when sufficient vegetation is removed. The model demonstrates that the relative response characteristics of the multiple vegetation types and their mutual feedback with geomorphic processes impart a significant influence on landscape equilibrium or attractor states. Fast growing vegetation enables the formation of hairpin (long-walled) parabolic dune systems, which eventually become sediment starved and stabilise, whereas inhospitable conditions inhibiting vegetation growth contribute to the development of active transgressive transverse dune fields. This simple vegetated dune model illustrates the power and versatility of a cellular automaton approach for exploring thresholds, sensitivities and possible evolutionary trajectories associated with the interactions between ecology, geomorphology and climatic conditions in complex earth surface systems.

Nield, Joanna M.; Baas, Andreas C. W.

2008-11-01

257

Ecological Distribution of Indicator Species and Effective Edaphical Factors on the Northern Iran Lowland Forests  

Directory of Open Access Journals (Sweden)

Full Text Available The objectives of this research were to identify the ecological species groups and study the relationship between topographic and edaphic factors with plant species to determine the main factors affecting the separation of vegetation types in Khanikan lowland forests of Mazandaran province (North of Iran. Vegetation was sampled with randomized-systematic method. Vegetation data including density and cover percentage were estimated quantitatively within each quadrate and using the two-way indicator species analysis (TWINSPAN. Vegetation was classified into different groups. The topographic conditions were recorded in quadrate locations. Soil samples were taken from organic horizon (litter layer and mineral layers (0-10, 10-20 and 20-30 cm. Soil acidity, bulk density, saturation moisture, electrical conductivity, organic carbon, total nitrogen, cation exchangeable capacity, available phosphorous, soil texture, lime, biomass of earthworms, litter carbon and litter nitrogen were measured. Multivariate techniques were used to analyze the collected data. The results indicated that the vegetation distribution patters were mainly related to soil characteristics such as pH, bulk density, texture, phosphorous, organic carbon, nitrogen and CEC. Totally, considering the habitat conditions and ecological needs, each plant species has a significant relation with soil properties.

Y. Kooch

2007-01-01

258

Respostas fisiológicas da laranjeira 'Pêra' aos sistemas de manejo de cobertura permanente do solo nas entrelinhas Physiological responses of orange trees to permanent groundcover vegetation types  

Directory of Open Access Journals (Sweden)

Full Text Available A presença de plantas de cobertura permanente nas entrelinhas dos pomares pode comprometer a absorção de água e a fisiologia das laranjeiras. O objetivo deste estudo foi caracterizar as relações entre as variáveis fisiológicas das folhas das laranjeiras e o teor de água de um Argissolo Vermelho distrófico latossólico textura arenosa/média em sistemas de cobertura permanente do solo na entrelinha com gramínea "grama mato-grosso" ou "batatais" (Paspalum notatum, leguminosa amendoim forrageiro (Arachis pintoi e vegetação espontânea. O estudo foi realizado em um experimento de laranjeira 'Pêra', instalado em 1993, em Alto Paraná, no noroeste do Paraná. Entre 1999 a 2002, foram realizadas determinações do teor de água em camadas de solo estratificadas em 10 e 20 cm até 1 m de profundidade no centro da entrelinha e no limite da projeção da copa das laranjeiras, complementadas com medidas da taxa de fotossíntese, da condutância estomática e do potencial da água das folhas das laranjeiras. As respostas fisiológicas das folhas da laranjeira 'Pêra' apresentaram dependência específica aos teores de água das camadas de solo e dos sistemas de manejo da cobertura permanente nas entrelinhas. A condutância estomática das folhas da laranjeira dependeu dos teores de água da camada subsuperficial de textura média manejada com a leguminosa no centro da entrelinha. O potencial da água nas folhas da laranjeira mostrou-se dependente dos teores de água do solo na camada superficial arenosa sob o manejo da gramínea no centro da entrelinha e no limite da projeção da copa das laranjeiras. A manutenção das entrelinhas vegetadas com a gramínea no horizonte superficial arenoso aumentou a disponibilidade de água para as laranjeiras.The presence of a groundcover in-between tree rows in orange orchards can affect the water uptake and physiology of the orange trees. The objective of this study was to characterize the relationships between the physiological variables of orange leaf and soil water content in a Paleudults in groundcover management systems with bahiagrass (Paspalum notatum, leguminous perennial peanut (Arachis pintoi and spontaneous vegetation. The study was performed in in an experimental "Pêra" orange orchard established in 1993 in Alto Paraná, northwestern Paraná state, Brazil. From 1999 to 2002, the soil water content was determined in stratified soil layers up to the 1.00 m depth in-between the tree rows and within the canopy projection. The photosynthesis rate, stomatal conductance and leaf water potential of Pêra orange trees were also measured. The physiological response of the leaves of the orange trees depended specifically on the content of soil water and type of permanent groundcover vegetation in-between rows. With perennial peanut planted in-between the rows, the stomatal conductance of the orange leaves depended on the water content of the subsurface sandy clay loam soil layer. Under bahiagrass groundcover, the leaf water potential depended on the content of soil water in the sandy surface horizon in-between the rows and within the canopy projection. Bahiagrass groundcover on the sandy surface horizon increased water availability for the orange trees.

Jonez Fidalski

2008-06-01

259

General Ecology  

Science.gov (United States)

This tutorial explains how environmental conditions and organism interactions determine animal and tree distribution and abundance. There are definitions of important ecological terms such as ecology, interactions, and abundance; descriptions of the environmental conditions needed for rainforests and how they provide habitat for many species; and an explanation of the spawning process. The tutorial also introduces food chain concepts and the unique ecology of riparian habitats. A quiz is also available.

260

Ecological economics  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Ecological economics is a recently developed field, which sees the economy as a subsystem of a larger finite global ecosystem. Ecological economists question the sustainability of the economy because of its environmental impacts and its material and energy requirements, and also because of the growth of population. Attempts at assigning money values to environmental services and losses, and attempts at correcting macroeconomic accounting, are part of ecological economics, but its main thrust ...

Marti?nez Alier, Joan

2001-01-01

 
 
 
 
261

Post-fire vegetation dynamics in Portugal  

Science.gov (United States)

The number of fires and the extent of the burned surface in Mediterranean Europe have increased significantly during the last three decades. This may be due either to modifications in land-use (e.g. land abandonment and fuel accumulation) or to climatic changes (e.g. reduction of fuel humidity), both factors leading to an increase of fire risk and fire spread. As in the Mediterranean ecosystems, fires in Portugal have an intricate effect on vegetation regeneration due to the complexity of landscape structures as well as to the different responses of vegetation to the variety of fire regimes. A thorough evaluation of vegetation recovery after fire events becomes therefore crucial in land management. In the above mentioned context remote sensing plays an important role because of its ability to monitor and characterise post-fire vegetation dynamics. A number of fire recovery studies, based on remote sensing, have been conducted in regions characterised by Mediterranean climates and the use of NDVI to monitor plant regeneration after fire events was successfully tested (Díaz-Delgado et al., 1998). In particular, several studies have shown that rapid regeneration occurs within the first 2 years after the fire occurrences, with distinct recovery rates according to the geographical facing of the slopes (Pausas and Vallejo, 1999). In 2003 Portugal was hit by the most devastating sequence of large fires, responsible by a total burnt area of 450 000 ha (including 280 000 ha of forest), representing about 5% of the Portuguese mainland (Trigo et al., 2006). The aim of the present work is to assess and monitor the vegetation behaviour over Portugal following the 2003 fire episodes. For this purpose we have used the regional fields of the Normalized Difference Vegetation Index (NDVI) as obtained from the VEGETATION-SPOT5 instrument, from 1999 to 2008. We developed a methodology to identify large burnt scars in Portugal for the 2003 fire season. The vegetation dynamics was then analysed for some selected areas and a regression model of post-fire recovery was fitted to the recorded values of NDVI. The model allowed characterising the dynamics of the regeneration process. It was found that recovery rates depend on geographical location, fire intensity/severity and type of vegetation cover. Díaz-Delgado, R., Salvador, R. and Pons, X., 1998: Monitoring of plant community regeneration after fire by remote sensing. In L. Traboud (Ed.), Fire management and landscape ecology (pp. 315-324). International Association of Wildland Fire, Fairfield, WA. Pausas, G.J. and Vallejo, V.R., 1999: The role of fire in European Mediterranean Ecosystems. In: E. Chuvieco (Ed.), Remote sensing of large wildfires in the European Mediterranean basin (pp. 3-16). Springer-Verlag. Trigo R.M., Pereira J.M.C., Pereira M.G., Mota B., Calado M.T., DaCamara C.C., Santo F.E., 2006: Atmospheric conditions associated with the exceptional fire season of 2003 in Portugal. International Journal of Climatology 26 (13): 1741-1757 NOV 15 2006.

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

2009-04-01

262

Spatial modelling of Bacillus anthracis ecological niche in Zimbabwe.  

Science.gov (United States)

Anthrax continues to cause significant mortalities in livestock, wildlife and humans worldwide. In Zimbabwe, anthrax outbreaks have been reported almost annually over the past four decades. In this study we tested whether anthrax outbreak data and a set of environmental variables can be used to predict the ecological niche for Bacillus anthracis using maximum entropy modelling for species geographical distribution (Maxent). Confirmed geo-referenced anthrax outbreaks data for the period 1995-2010 were used as presence locations and a set of environmental parameters; precipitation, temperature, vegetation biomass, soil type and terrain as predictor variables. Results showed that the environmental variables can adequately predict the ecological niche of B. anthracis (AUC for test data=0.717, pmodel we tested may be used by animal health authorities in devising better control strategies for anthrax. PMID:23726015

Chikerema, S M; Murwira, A; Matope, G; Pfukenyi, D M

2013-08-01

263

Possible incipient sympatric ecological speciation in blind mole rats (Spalax).  

Science.gov (United States)

Sympatric speciation has been controversial since it was first proposed as a mode of speciation. Subterranean blind mole rats (Spalacidae) are considered to speciate allopatrically or peripatrically. Here, we report a possible incipient sympatric adaptive ecological speciation in Spalax galili (2n = 52). The study microsite (0.04 km(2)) is sharply subdivided geologically, edaphically, and ecologically into abutting barrier-free ecologies divergent in rock, soil, and vegetation types. The Pleistocene Alma basalt abuts the Cretaceous Senonian Kerem Ben Zimra chalk. Only 28% of 112 plant species were shared between the soils. We examined mitochondrial DNA in the control region and ATP6 in 28 mole rats from basalt and in 14 from chalk habitats. We also sequenced the complete mtDNA (16,423 bp) of four animals, two from each soil type. Remarkably, the frequency of all major haplotype clusters (HC) was highly soil-biased. HCI and HCII are chalk biased. HC-III was abundant in basalt (36%) but absent in chalk; HC-IV was prevalent in basalt (46.5%) but was low (20%) in chalk. Up to 40% of the mtDNA diversity was edaphically dependent, suggesting constrained gene flow. We identified a homologous recombinant mtDNA in the basalt/chalk studied area. Phenotypically significant divergences differentiate the two populations, inhabiting different soils, in adaptive oxygen consumption and in the amount of outside-nest activity. This identification of a possible incipient sympatric adaptive ecological speciation caused by natural selection indirectly refutes the allopatric alternative. Sympatric ecological speciation may be more prevalent in nature because of abundant and sharply abutting divergent ecologies. PMID:23359700

Hadid, Yarin; Tzur, Shay; Pavlícek, Tomáš; Šumbera, Radim; Šklíba, Jan; Lövy, Mat?j; Fragman-Sapir, Ori; Beiles, Avigdor; Arieli, Ran; Raz, Shmuel; Nevo, Eviatar

2013-02-12

264

Mollusc and plant assemblages controlled by different ecological gradients at Eastern European fens  

Science.gov (United States)

Ecological patterns of mollusc assemblages and vegetation in relation to water chemistry, water regime, nutrient availability and climate were studied in eastern Polish lowland fens. Our goal was to examine if major compositional changes differ for molluscs and vegetation under the joint influence of multiple ecological gradients. Altogether 32 fen sites were investigated in 2010-2011, and analyzed using metric multidimensional scaling, cluster analysis and generalized additive models. Two major gradients driving the differences in mollusc species composition were revealed. The main direction of compositional changes was associated with the water table gradient, governing a species turnover from inundated and strongly water-logged sites occupied mostly by aquatic mollusc species, to moderately wet sites with the predominance of fen and meadow species. The second most important gradient for molluscs was that of mineral richness. For vegetation, three major gradients explained the changes in species composition. The highest importance was assigned to the nitrogen-to-phosphorus availability gradient (defined as a shift from N-limited to P-limited vegetation), followed by the water table gradient, and the mineral richness gradient. Our results demonstrate that the impact of mineral richness gradient, which has been often reported as the major determinant of compositional changes of fen molluscs and vegetation, can be exceeded by other ecological gradients of comparable variation. We also document for the first time that the main species turnover of fen vegetation is not accompanied by the analogous change in species composition of mollusc assemblages, due to a different sensitivity of these taxa to particular environmental factors (i.e. water level dynamics and type of nutrient limitation).

Schenková, Veronika; Horsák, Michal; Hájek, Michal; Plesková, Zuzana; Dít?, Daniel; Pawlikowski, Pawe?

2014-04-01

265

Ecological Consultancy  

Science.gov (United States)

This is the first of a new regular feature on careers, designed to provide those who teach biology with some inspiration when advising their students. In this issue, two consultant ecologists explain how their career paths developed. It is a misconception that there are few jobs in ecology. Over the past 20 or 30 years ecological consultancy has…

Wilson, Scott McG.; Tattersfield, Peter

2004-01-01

266

Studying the effect of elevation and edaphic variables on vegetation composition in Khezrabad rangelands using principal component analysis (PCA  

Directory of Open Access Journals (Sweden)

Full Text Available A major scientific challenge in plant ecology is to identify and quantify the strength of environmental factors that are responsible for the distribution and abundance of plant species within and among ecosystems. Hence, this study is focused on relation between plant communities and environmental variables in Khezrabad region of Iran. Based on field surveys, eight vegetation types including Artemisia sieberi-Acantholimon erinaceum, Artemisia sieberi-Hertia angustifolia, Artemisia sieberi-Launea acanthodes, Artemisia sieberi-Salsola tomentosa, Artemisia sieberi-Zygophyllum atriplicoides, Artemisia aucheri-Astrgalus albispinus, Artemisia sieberi-Fortuynia bungei, Haloxylon aphyllum were identified. With respecting to the present variance between vegetation and environmental factors, four samples were established in each vegetation type in 0–30 cm depth. The studied soil variables affecting plant communities were texture, EC, pH, Na+, k+, Cl-, Ca2+, Mg2+, SP, O.M, CaCO3, HCO3 - and CEC. Among the topographic conditions, elevation was recorded in sampling regions as well. Data matrix of environmental factors and vegetation type was made using the windows (ver. 4.17 of PC-ORD. Results according to PCA showed that in the study area, among different environmental factors, the distribution of vegetation types was most strongly correlated with some agents such as soil texture, salinity and sodicity. In fact, soil texture controls distribution of plant species by affecting moisture availability, ventilation and distribution of plant roots. Beside, soil salinity and sodicity because of habitat condition, plant ecological needs and tolerance range can have negative affect on plant diversity. In addition, results indicated that increasing of elevation had negative effect on plant distribution. However, soil characteristics have more influence on vegetation separation than to the elevation in this study.

Ruhollah TAGHIZADEH MEHRJARDI

2009-11-01

267

SRS ecology: Environmental information document  

International Nuclear Information System (INIS)

The purpose of this Document is to provide a source of ecological information based on the exiting knowledge gained from research conducted at the Savannah River Site. This document provides a summary and synthesis of ecological research in the three main ecosystem types found at SRS and information on the threatened and endangered species residing there

268

SRS ecology: Environmental information document  

Energy Technology Data Exchange (ETDEWEB)

The purpose of this Document is to provide a source of ecological information based on the exiting knowledge gained from research conducted at the Savannah River Site. This document provides a summary and synthesis of ecological research in the three main ecosystem types found at SRS and information on the threatened and endangered species residing there.

Wike, L.D.; Shipley, R.W.; Bowers, J.A. [and others

1993-09-01

269

The decision of ecological products consumers  

Directory of Open Access Journals (Sweden)

Full Text Available In Romania the ecological agriculture registered an annual growth rate over 20%, in present time there are 26.736 operators in the ecological agriculture system. Due to the fact that the ecological products are requested mainly on the external markets there was a study concerning the way the ecological products are perceived by the consumers and which are their information sources. The geographical area of the research was Timisoara city, the survey being realized in crowded places (markets, supermarkets, universities. The questionnaire was filled in by 150 persons. From the researches we noticed that among the ecological products constantly purchased there are fruits and vegetables and on the second place in the consumers preferences are the ecological eggs purchased from the supermarkets.

Corina Constanta Ru?e?

2013-05-01

270

Ecological Footprints  

Science.gov (United States)

Ever wondered what sort of impact your everyday existence has on the planet? The University of Texas at Austin offers this information as part of their training in Natural Resource Management. An ecological footprint is defined here as "the area on the surface of Earth that each person appropriates in order to live," including many kinds of ecological services -- from food, air, water, and living space, to the recycling of wastes. This site offers an introduction to the concept of Ecological Footprints, including links to spreadsheets for calculation, national footprints, and related scientific articles.

271

Transfer factors of 40K, 226Ra, 232Th from soil to different types of local vegetables, radiation hazard indices and their annual doses  

International Nuclear Information System (INIS)

This work aims to determine the transfer factors (TFs) of 40K, 226Ra and 232Th from soil to vegetables, because there are few surveys of them in Iraq. The samples were taken from three important agricultural areas supplying the vegetable products needed by the Iraqi population. Using NaI(Tl) technique, the average values of TFs of the above radioactive isotopes were found to be 0.60, 0.41, 0.59 and 0.05, 0.03, 0.05 from soil to dry and fresh samples, respectively. The radiation hazard indices and the total annual dose were found to be within the range of the world values. (author)

272

Economic and ecological outcomes of flexible biodiversity offset systems.  

Science.gov (United States)

The commonly expressed goal of biodiversity offsets is to achieve no net loss of specific biological features affected by development. However, strict equivalency requirements may complicate trading of offset credits, increase costs due to restricted offset placement options, and force offset activities to focus on features that may not represent regional conservation priorities. Using the oil sands industry of Alberta, Canada, as a case study, we evaluated the economic and ecological performance of alternative offset systems targeting either ecologically equivalent areas (vegetation types) or regional conservation priorities (caribou and the Dry Mixedwood natural subregion). Exchanging dissimilar biodiversity elements requires assessment via a generalized metric; we used an empirically derived index of biodiversity intactness to link offsets with losses incurred by development. We considered 2 offset activities: land protection, with costs estimated as the net present value of profits of petroleum and timber resources to be paid as compensation to resource tenure holders, and restoration of anthropogenic footprint, with costs estimated from existing restoration projects. We used the spatial optimization tool MARXAN to develop hypothetical offset networks that met either the equivalent-vegetation or conservation-priority targets. Networks that required offsetting equivalent vegetation cost 2-17 times more than priority-focused networks. This finding calls into question the prudence of equivalency-based systems, particularly in relatively undeveloped jurisdictions, where conservation focuses on limiting and directing future losses. Priority-focused offsets may offer benefits to industry and environmental stakeholders by allowing for lower-cost conservation of valued ecological features and may invite discussion on what land-use trade-offs are acceptable when trading biodiversity via offsets. Resultados Económicos y Ecológicos de Sistemas de Compensación de Biodiversidad Flexible Habib et al. PMID:23869724

Habib, Thomas J; Farr, Daniel R; Schneider, Richard R; Boutin, Stan

2013-12-01

273

The Role of plant type and salinity in the selection for the denitrifying community structure in the rhizosphere of wetland vegetation  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Coastal wetlands, as transient links from terrestrial to marine environments, are important for nitrogen removal by denitrification. Denitrification strongly depends on both the presence of emergent plants and the denitrifier communities selected by different plant species. In this study, the effects of vegetation and habitat heterogeneity on the community of denitrifying bacteria were investigated in nine coastal wetlands in two preserved areas of Spain. Sampling locations were selected to c...

Ban?eras Vives, Llui?s; Ruiz Rueda, Olaya; Lo?pez I Flores, Roci?o; Quintana Pou, Xavier; Hallin, Sara

2012-01-01

274

Biomass, composition and size structure of invertebrate communities associated to different types of aquatic vegetation during summer in Lago di Candia (Italy  

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Full Text Available We compared the biomass, taxonomic composition, and size distribution of invertebrates associated to emergent (Schoenoplectus lacustris, submerged (Myriophyllum spicatum, and floating leaved (Trapa natans vegetation at two depths (surface and water column during summer in Lago di Candia, Italy. Invertebrate biomass was positively related to epiphyton biomass (Chl-a. M. spicatum supported higher invertebrate biomass per unit of plant weight than S. lacustris whereas T. natans was somewhat intermediate. Depth did not affect invertebrate biomass significatively. Surface sections of M. spicatum and T. natans supported invertebrate communities with similar taxonomic composition dominated by oligochaetes and ostracods. Large hirudineans and gastropods characterized the communities on the water column sections of M. spicatum. S. lacustris and the water column sections of T. natans (composed of stems and aquatic roots were supporting invertebrate communities dominated by copepod nauplii and lacking large organisms. Changes in aquatic vegetation in Lago di Candia following harvesting of T. natans and removal of submerged vegetation by the invasion of the rodent coypu (Miocastor coypus may affect the invertebrate biomass of its littoral zone.

Giuseppe MORABITO

2004-08-01

275

Ecological investigation of three geophytes in the Deltaic Mediterranean coast of Egypt.  

Science.gov (United States)

This study was conducted to investigate the ecological features of three geophytes namely Asparagus stipularis, Cyperus capitatus and Stipagrostis lanata which grow naturally in the Nile Delta coast of Egypt. C. capitatus and S. lanata are growing in non-saline sandy soils and can tolerate drought stress while, A. stipularis is growing in saline and non-saline sandy and calcareous clay soils and can tolerate drought and salt stress. Multivariate analysis of the vegetation of 100 sampled stands supporting growth of the three geophytic species in the study area led to the recognition of four vegetation groups namely, (A) Alhagi graecorum, (B) Cyperus capitatus, (C) Lycium schweinfurthii var. schweinfurthii-Asparagus stipularis and (D) Juncus acutus subsp. acutus. Vegetationally, the vegetation groups associated with the three species can be distinguished into two community types. The first one is psammophytic community comprising vegetation groups A and B that may represent the non-saline sand formations (flats, hummocks and dunes). The second one is halophytic community including vegetation groups C and D that may represent the saline sand flats and salt marsh habitat types, respectively. Sodium adsorption ratio, electrical conductivity, sodium cation, chlorides, silt and sand fractions, pH value, moisture content, bicarbonates and available phosphorus were the most effective soil factors that controlling the abundance and distribution of the plant communities associated with the investigated geophytes. This study showed the ecological features of the selected geophytes in terms of their habitats, associated plant communities and the most edaphic factors controlling their richness and distribution in the study area. PMID:24506033

Maswada, Hanafey F; Elzaawely, Abdelnaser A

2013-12-01

276

Ecological Investigation of Three Geophytes in the Deltaic Mediterranean Coast of Egypt  

Directory of Open Access Journals (Sweden)

Full Text Available This study was conducted to investigate the ecological features of three geophytes namely Asparagus stipularis, Cyperus capitatus and Stipagrostis lanata which grow naturally in the Nile Delta coast of Egypt. C. capitatus and S. lanata are growing in non-saline sandy soils and can tolerate drought stress while, A. stipularis is growing in saline and non-saline sandy and calcareous clay soils and can tolerate drought and salt stress. Multivariate analysis of the vegetation of 100 sampled stands supporting growth of the three geophytic species in the study area led to the recognition of four vegetation groups namely, (A Alhagi graecorum, (B Cyperus capitatus, (C Lycium schweinfurthii var. schweinfurthii-Asparagus stipularis and (D Juncus acutus subsp. acutus. Vegetationally, the vegetation groups associated with the three species can be distinguished into two community types. The first one is psammophytic community comprising vegetation groups A and B that may represent the non-saline sand formations (flats, hummocks and dunes. The second one is halophytic community including vegetation groups C and D that may represent the saline sand flats and salt marsh habitat types, respectively. Sodium adsorption ratio, electrical conductivity, sodium cation, chlorides, silt and sand fractions, pH value, moisture content, bicarbonates and available phosphorus were the most effective soil factors that controlling the abundance and distribution of the plant communities associated with the investigated geophytes. This study showed the ecological features of the selected geophytes in terms of their habitats, associated plant communities and the most edaphic factors controlling their richness and distribution in the study area.

Abdelnaser A. Elzaawely

2013-01-01

277

Ecological Footprint Calculators  

Science.gov (United States)

This website contains interactive calculators for determining various environmental impacts. The site includes more than 15 different calculators to determine greenhouse gas emissions, ecological footprints, electricity pollution, air travel pollution, commuting costs, appliance costs, pollution prevention and more. These calculators can be used for computer-based classroom activities or to enable students to see which types of activities have the greatest environmental impact.

Ecobusinesslinks

278

Phytoplankton Ecology  

Science.gov (United States)

This site describes phytoplankton ecology research by marine ecologists at Mote Marine Laboratory (MML), an independent, nonprofit research organization based in Sarasota, Florida. The emphasis of MML's phytoplankton ecology research is the photophysiology of marine algae -- with recent emphasis on the ability to predict and possibly mitigate blooms of the toxic marine dinoflagellate, Gymnodinium breve. The no-frills phytoplankton ecology homepage describes research and offers data (maps, figures, tables) from 1998 and 1999 projects on Red Tide transects, Nutrient and chlorophyll concentrations, and Ecology and Oceanography of Harmful Algal Blooms (ECOHAB) transect data, among several others. The site also offers general information on Red Tides, Red Tide conditions in Southwest Florida, a chronology of historic Red Tide events, and links to related resources.

279

Vegetation communities associated with the 100-Area and 200-Area facilities on the Hanford Site  

Energy Technology Data Exchange (ETDEWEB)

The Hanford Site, Benton County, Washington, lies within the broad semi-arid shrub-steppe vegetation zone of the Columbia Basin. Thirteen different habitat types on the Hanford Site have been mapped in Habitat Types on the Hanford Site: Wildlife and Plant Species of Concern (Downs et al. 1993). In a broad sense, this classification is correct. On a smaller scale, however, finer delineations are possible. This study was conducted to determine the plant communities and estimate vegetation cover in and directly adjacent to the 100 and 200 Areas, primarily in relation to waste sites, as part of a comprehensive ecological study for the Compensation Environmental Response, Compensation, and Liability Act (CERCLA) characterization of the 100 and 200 Areas. During the summer of 1993, field surveys were conducted and a map of vegetation communities in each area, including dominant species associations, was produced. The field surveys consisted of qualitative community delineations. The community delineations described were made by field reconnaissance and are qualitative in nature. The delineations were made by visually determining the dominant plant species or vegetation types and were based on the species most apparent at the time of inspection. Additionally, 38 transects were run in these plant communities to try to obtain a more accurate representation of the community. Because habitat disturbances from construction/operations activities continue to occur in these areas, users of this information should be cautious in applying these maps without a current ground survey. This work will complement large-scale habitat maps of the Hanford Site.

Stegen, J.A.

1994-01-17

280

Campus Ecology  

Science.gov (United States)

This website from the National Wildlife Federation showcases environmental conservation projects that have been successfully undertaken by various universities. The site features example projects and resources for doing your own campus project. Topics include building design, energy, environmental literacy, habitat restoration, water, transportation and waste reduction. Links to the online Campus Ecology Yearbook and the Campus Ecology Research Station and other resources are also included.

Federation, National W.

 
 
 
 
281

Fire Ecology  

Science.gov (United States)

Forest fires have become a regular summertime occurrence in North America, sparking debate about the proper role of fire on the land. The following websites examine fires and fire ecology in different ecosystems, regions, and time periods. The first site (1), from the USGS-Western Ecological Research Center shares information about fire ecology research in the California shrublands, Sierra Nevada forests, and Mohave and Sonoran deserts. The second site (2) features the Fire Ecology Center at Texas Tech University. The Fire Ecology Center focuses on the role of fire in grassland ecosystems and their website contains information on current research, publications, managing pastures, managing problem plants, and more. The third site (3), from the USGS-Northern Prairie Wildlife Research Center contains "an annotated bibliography on fire in North American wetland ecosystems and a subject index of all fire-related literature that has appeared in Wildlife Review." Hosted by Yellowstone National Park, the fourth site (4) addresses wildland fires in Yellowstone. The Park website presents brief sections on Fire Ecology, Fire Monitoring, Prescribed Fire, and Fire Effects -- to name a few. The fifth (5) site, from the Canadian Forest Service, provides information about forest fires in Canada including weekly fire statistics, fire research, daily fire maps, a fire database, and more. Part of a great site on the land use history of the Colorado Plateau from Northern Arizona University, the sixth site (6) offers a brief overview of wildfire history and ecology on the Plateau with links to information about ponderosa pine fire ecology, reintroduction of fire to forest ecosystems, and fire ecology research studies. The seventh site (7), from DiscoverySchool.com, contains a lesson plan on forest fire ecology for grade levels 9-12. The lesson spans two class periods and the site provides objectives, materials needed, discussion questions, academic standards, and more. The final (8) website, from the Why Files, "examines the role of fire in natural systems, and the role of science in understanding wildfires." The eleven-page website follows a kid-friendly narrative format and includes a bibliography and glossary.

282

Comparing heavy metals accumulation potential in natural vegetation and soil adjoining wastewater canal  

International Nuclear Information System (INIS)

Heavy metal (HM) pollution of waters, soils and vegetation is a major ecological problem that needs to be investigated. The present study involved the collection of soil samples and natural vegetations (Tribilas terristris, Lepia nodiflora, Amaranthus viridis, Heliotropium euoropeum, Coronopis didymus, Cynodon ductylon, Chenopodium murale and Eclipta alba) from the vicinity of wastewater canal and subsequent analysis for their HM concentrations. Results showed that HM concentrations varied within the species of vegetation and type of metal analyzed. The order of vegetation for metal concentrations was A. viridis > E. alba > H. euoropeum > L. nodiflora > C. murale > C. didymus > C. ductylon > T. terristris. Metals prevailed in plants in the decreasing order of Fe > Mn > Zn > Pb > Cr > Cu > Cd, irrespective of the vegetation. Metal prevalence in soils was in the order of Fe > Mn > Cd > Cr > Pb > Zn > Cu. Samples near canal were found with higher level of Mn, Pb and Zn as compared to soil away from canal water. Distant sampling gave higher accumulation of Cd, Cr, Cu and Fe as compared to the soil nearby wastewater. The analyzed species of HM in the soils and plants may indicate the variability of their composition in wastewater. (author)

283

Terrestrial Laser Scanning for Vegetation Sampling  

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Full Text Available We developed new vegetation indices utilizing terrestrial laser scanning (TLS to quantify the three-dimensional spatial configuration of plant communities. These indices leverage the novelty of TLS data and rely on the spatially biased arrangement of a TLS point cloud. We calculated these indices from TLS data acquired within an existing long term manipulation of forest structure in Central Oregon, USA, and used these data to test for differences in vegetation structure. Results provided quantitative evidence of a significant difference in vegetation density due to thinning and burning, and a marginally significant difference in vegetation patchiness due to grazing. A comparison to traditional field sampling highlighted the novelty of the TLS based method. By creating a linkage between traditional field sampling and landscape ecology, these indices enable field investigations of fine-scale spatial patterns. Applications include experimental assessment, long-term monitoring, and habitat characterization.

Jeffrey J Richardson

2014-10-01

284

Terrestrial laser scanning for vegetation sampling.  

Science.gov (United States)

We developed new vegetation indices utilizing terrestrial laser scanning (TLS) to quantify the three-dimensional spatial configuration of plant communities. These indices leverage the novelty of TLS data and rely on the spatially biased arrangement of a TLS point cloud. We calculated these indices from TLS data acquired within an existing long term manipulation of forest structure in Central Oregon, USA, and used these data to test for differences in vegetation structure. Results provided quantitative evidence of a significant difference in vegetation density due to thinning and burning, and a marginally significant difference in vegetation patchiness due to grazing. A comparison to traditional field sampling highlighted the novelty of the TLS based method. By creating a linkage between traditional field sampling and landscape ecology, these indices enable field investigations of fine-scale spatial patterns. Applications include experimental assessment, long-term monitoring, and habitat characterization. PMID:25353981

Richardson, Jeffrey J; Moskal, L Monika; Bakker, Jonathan D

2014-01-01

285

The South African National Vegetation Database: history, development, applications, problems and future  

Scientific Electronic Library Online (English)

Full Text Available SciELO South Africa | Language: English Abstract in english Southern Africa has been recognised as one of the most interesting and important areas of the world from an ecological and evolutionary point of view. The establishment and development of the National Vegetation Database (NVD) of South Africa enabled South Africa to contribute to environmental plann [...] ing and conservation management in this floristically unique region. In this paper, we aim to provide an update on the development of the NVD since it was last described, near its inception, more than a decade ago. The NVD was developed using the Turboveg software environment, and currently comprises 46 697 vegetation plots (relevés) sharing 11 690 plant taxa and containing 968 943 species occurrence records. The NVD was primarily founded to serve vegetation classification and mapping goals but soon became recognised as an important tool in conservation assessment and target setting. The NVD has directly helped produce the National Vegetation Map, National Forest Type Classification, South African National Biodiversity Assessment and Forest Type Conservation Assessment. With further development of the NVD and more consistent handling of the legacy data (old data sets), the current limitations regarding certain types of application of the data should be significantly reduced. However, the use of the current NVD in multidisciplinary research has certainly not been fully explored. With the availability of new pools of well-trained vegetation surveyors, the NVD will continue to be purpose driven and serve the needs of biological survey in pursuit of sustainable use of the vegetation and flora resources of the southern African subcontinent.

Michael C., Rutherford; Ladislav, Mucina; Leslie W., Powrie.

286

Mathematical modeling riparian vegetation zonation in semiarid conditions based on a transpiration index.  

Science.gov (United States)

Initially riparian vegetation modeling was focused on the study of ecological patches without taking into account the interactive effects of structures and processes in between them (Tabacchi et al., 1998). One of the greatest challenges, when carrying out a riparian ecosystem restoration, is to understand the physical and ecological processes of a system and the interaction and feedback within these processes. Jorde (2002) pointed out the importance of addressing complex linkages between processes and biotic interactions in research and in the development of restoration projects over larger spatial and temporal scales in the future. According to Tabacchi et al. (2000), the water cycle in riparian zones depends on three important relations: the water absorption by the plants, water storage and atmospherical return by evaporation. During recent years a variety of ecological models have taken into account the changes in the plant species as consequence of changes in the environmental variables and hydrological alterations (Baptist, 2005; Braatne et al., 2002; Glenz, 2005; Hooke et al., 2005; Murphy et al., 2006). Most of these models are based on functional relationships between river hydrology and vegetation species or communities. In semiarid regions we make the hypothesis transpiration will be one of the key factors determining the riparian vegetation presence and therefore, we will not consider in our model other factors as recruitment, flood damages, etc. The objectives of this work are: firstly to develop a model capable of simulating several riparian vegetation types which can be applied in a wide range of conditions across Mediterranean environments; and secondly to calibrate and to validate the model in several Mediterranean river stretches of the Iberian Peninsula, both in undisturbed and disturbed flow regimes. To achieve these objectives the following methodology has been applied. The model has been conceptualized as a static tank flow model based on the actual evapotranspiration of the riparian plants. This tank represents a portion of soil of the superficial root layer. The lower capacity limit of this tank is the permanent wilting moisture of the soil sample. On the other hand the upper capacity limit is the field capacity moisture. The tank's input flows are the precipitation, the root water rise and the capillary water rise. In contrast output flows are the actual evapotranspiration and the excess water of the tank. The most relevant model parameters are the soil retention curves, vegetation functional type parameters (specially related to root depths and the transpiration efficiency factors) and the daily hidro-meteorological data, which are water table elevation, precipitation and potential evapotranspiration. The model runs for a limited amount of vegetation functional types. In our simulations the following four functional types were used: Riparian Herbs; Riparian Juveniles and Small Scrubs, Riparian Trees and Big Shrubs; and Terrestrial Vegetation. The general model output variable is an evapotranspiration index based in the quotient between the current and the potential evapotranspiration. This index is used to determine the suitability of the simulated vegetation functional types to certain environmental conditions. Secondly, a sensitivity analysis was made for determining the most relevant model parameters. Finally the model has been calibrated and validated using as objective function a confusion matrix which compares the observed and the simulated riparian vegetation zonation. The calibration/validation processes have been carried out in seven study sites of the Jucar River Basin District. Four of those sites have a natural flow regime and three of them a regulated flow regime due to the presence of dams. Results have shown that the model is capable of providing effective simulations in compared to the observed riparian vegetation.

Real, Joaquin; Morales, Marco; Garcia, Alicia; Garofano, Virginia; Martinez-Capel, Francisco; Frances, Felix

2010-05-01

287

Founding RGB ecology: The ecology of synthesis  

Directory of Open Access Journals (Sweden)

Full Text Available There is an arising need to interpret an amount of ecological information that is more and more available. It is not only the pursuit of an easy handling of a large amount of data, but above all the quest for a deep and multivariate interpretation of many sources of ecological info. To this aim, I introduce here RGB ecology as a new branch of ecology devoted to the cartographic synthesis of ecological information. RGB ecology has the following properties: (1 it can not be separated from GIS cartography; (2 it can compact ecological information along space and time; (3 it can create a decision space for management decisions; (4 it can go beyond the third dimension by using compressive statistical techniques. RGB ecology can also be an effective flanker of several branches of ecology, such as landscape ecology, conservation ecology, urban ecology, forest ecology and so forth.

Alessandro Ferrarini

2012-06-01

288

HIERARCHY OF ECOLOGICAL DIVERSITY OF INDUSTRIAL SOIL PLANTS  

Directory of Open Access Journals (Sweden)

Full Text Available Article presented the conception that for the quantitative characteristic of ecological diversity of vegetation the relation of distinction/similarity between species can be estimated by means ecomorphic features of plants or their phytoindicator properties. It is shown, that the network organization of ecological mutual relations can be presented in the form of hierarchical dendrogram in order to apply Warwick-Clarke taxonomic diversity indexes to a quantitative estimation of an ecological diversity. The idea to expand Whittaker concept of ?, ? and ?-diversity on ecological (hierarchical, organizational diversity was discussed that has allowed to introduce concepts of ?, ?, and ?-components of ecological diversity of plant community.

Zhukov A. V.

2013-12-01

289

Ecological Biology (Program Description)  

Science.gov (United States)

... Environmental Biology Ecological Biology Description The Ecological Biology Cluster supports ... findings into new paradigms. The Ecological Biology Cluster funds research in the following areas ...

290

The classification, mapping and description of the vegetation of the Rooipoort Nature Reserve, Northern Cape, South Africa  

Directory of Open Access Journals (Sweden)

Full Text Available The need for a scientifically-based wildlife management plan and for more knowledge on vegetation led to an investigation into the plant ecology of the Rooipoort Nature Reserve. The main aim of this study was therefore to classify, describe and map the vegetation of the reserve. The floristic data were analysed according to the Braun-Blanquet procedure using the BBPC suite. The data analysis resulted in the identification of 15 communities that can be grouped into ten major community types. This resulted in five ecology-based management units, which could assist with the compilation of an ecologically sound management plan for the reserve in order to achieve sustainable utilisation of the natural resources. The Rooipoort Nature Reserve is one of the oldest and largest private nature reserves in South Africa and as such deserves to be conserved and protected. The riverine and pan vegetation communities are considered to be endangered and are in need of special conservation and protection.

Conservation implication: The results suggest five management units, which will assist in the compilation of an ecologically sound management plan for the RNR, in order to allow sustainable utilization of natural resources.

How to cite this article: Bezuidenhout, H., 2009, ‘The classification, mapping and description of the vegetation of the Rooipoort Nature Reserve, Northern Cape, South Africa’, Koedoe 51(1, Art. #695, 11 pages. DOI: 10.4102/koedoe.v51i1.695

Hugo Bezuidenhout

2009-01-01

291

The peculiarities of accumulation and distribution of the natural isotopes of uranium in vegetative parts of Pinus sylvestris L. in the main types of pine woods of Minsk hills  

International Nuclear Information System (INIS)

The article contains experimental data regarding the accumulation and distribution of natural isotopes of uranium in vegetative parts of Pinus sylvestris L.; growing in various ecological conditions. The concentration of uranium in plants of pine is from 1.3·10-5 and up to 67.5·10-3% (in ash of plants). In parts of Pinus sylvestris L. the distribution of uranium is extremely irregular - the greatest amount of uranium is accumulated in the wood and bark, i. e. in the parts which do not have any processes of vital activity or have processes of activity which are badly manifested; the least concentrations of uranium are observed in pine needles which have the most active metabolism processes were shown. According to the concentration of uranium parts of Pinus sylvestris L. can be arranged in the following way: wood > bark > roots > branches > needles. The same parts of pine in different edaphic and phytocenosical conditions don't accumulate equal amount of uranium was founded. (authors)

292

Biodiversity analysis of vegetation on the Nevada Test Site  

International Nuclear Information System (INIS)

The Nevada Test Site (NTS), located in south-central Nevada, encompasses approximately 3,500 square kilometers and straddles two major North American deserts, Mojave and Great Basin. Transitional areas between the two desert types have been created by gradients in elevation, precipitation, temperature, and soils. From 1996 to 1998, more than 1,500 ecological landform units were sampled at the NTS for numerous biotic and abiotic parameters. The data provide a basis for spatial evaluations of biodiversity over landscape scales at the NTS. Biodiversity maps (species richness vs. species abundance) have been produced. Differences in biodiversity among ecoregions and vegetation alliances are presented. Spatial distribution maps of species' presence and abundance provide evidence of where transition zones occur and the resulting impact on biodiversity. The influences of abiotic factors, such as elevation, soil, and precipitation, on biodiversity are assessed

293

Computational Ecology: an emerging ecological science  

Directory of Open Access Journals (Sweden)

Full Text Available Computational ecology is an emerging science to integrate and synthesize computation intensive areas in ecology. It was clearly defined and described in an earlier study. Aims and scope of computational ecology are further refined in present discussion.

WenJun Zhang

2011-04-01

294

ECOLOGICAL FEATURES OF ALGAE COMMUNITIES IN FOREST FLOOR OF PINE PLANTATIONS OF DIFFERENT TYPES OF LANDSCAPES IN STEPPE AREA OF UKRAINE  

Directory of Open Access Journals (Sweden)

Full Text Available The steppe zone of Ukraine features a large variety of types of natural landscapes that together significantly differ in microclimatic, soil, hydrological and geobotanic conditions. Such a diversity of forest conditions affects not only the trees, but also on all biotic components of forest ecosystems including algae. Purpose of the study was establish systematic position of species, dominant and subdominant, leading families of algae for plantings in forest floor of pine plantations of the valley-terrace and inundable-terrace landscapes in steppe area of Ukraine. In general, in the forest floor of Samara pine forest marked 34 species of algae with 4 divisions, most of which related to green: Chlorophyta – 22 (65%, Xanthophyta – 8 (23%, Bacillariophyta – 2 (6% and Eustigmatophyta – 2 (6%. Among the leading families of the greatest number of species belonged to: Pleurochloridaceae (7 species, Chlorococcaceae (5, Chlamydomonadaceae (4. During all studied seasons in base of algae communities were species resistant to extreme values of all climatic conditions. Total in forest floor of pine forest in Altagir forest marked 42 species of algae with 5 divisions: Chlorophyta - 23 (55 %, Xanthophyta - 9 (21 %, Cyanophyta - 5 (12 %, Bacillariophyta - 3 (7% and Eustigmatophyta – 2 (5%. Systematic structure of list species determine three family, which have the number of species in excess of the average number (2: Pleurochloridaceae, Chlamydomonadaceae and Myrmeciaceae. The base of algae community are moisture-loving and shade-tolerant species, which may be the result of favorable moisture regime. In the forest floor of pine plantings in forest floor of pine plantations of the valley-terrace (Samara pine forest and inundable-terrace (Altagir forest landscapes found 64 species of algae with 5 divisions, which are dominated by green algae - 37 species (58%, that exceed xanthophytes - 15 (23%, blue-green 5 (8 %, eustigmatofites 4 (6% and diatoms 3 (5%. From an ecological point of view algal flora forest floor of studied plantings characterized by a predominance of species of soil-inhabiting algae from X-life forms.

Maltsev Yevhen

2013-12-01

295

Vegetation modulated landscape evolution: Effects of vegetation on landscape processes, drainage density and topography  

Science.gov (United States)

Topography acts as a template for numerous landscape processes that includes hydrologic, ecologic and biologic phenomena. These processes not only interact with each other but also contribute to shaping the landscape as they influence geomorphic processes. We have investigated the effects of vegetation on known geomorphic relations, thresholds for channel initiation and landform evolution, using both analytical and numerical approaches. Vegetation is assumed to form a uniform ground cover. Runoff erosion is modeled based on power function of excess shear stress, in which shear stress efficiency is inversely proportional to vegetation cover. Plant effect on slope stability is represented by additional cohesion provided by plant roots. Vegetation cover is assumed to reduce sediment transport rates due to physical creep processes (rainsplash, dry ravel, and expansion and contraction of sediments) according to a negative exponential relationship. Vegetation grows as a function of both available cover and unoccupied space by plants, and is killed by geomorphic disturbances (runoff erosion and landsliding), and wildfires. Analytical results suggest that, in an equilibrium basin with a fixed vegetation cover, plants may cause a transition in the dominant erosion process at the channel head. A runoff erosion dominated landscape, under none or loose vegetation cover, may become landslide dominated under a denser vegetation cover. The sign of the predicted relationship between drainage density and vegetation cover depends on the relative influence of vegetation on different erosion phenomena. With model parameter values representative of the Oregon Coast Range (OCR), numerical experiments conducted using the CHILD model. Numerical experiments reveal the importance of vegetation disturbances on the landscape structure. Simulated landscapes resemble real-world catchments in the OCR when vegetation disturbances are considered.

Bras, R. L.; Istanbulluoglu, E.

2004-12-01

296

Vegetation-modulated landscape evolution: Effects of vegetation on landscape processes, drainage density, and topography  

Science.gov (United States)

Topography acts as a template for numerous landscape processes that include hydrologic, ecologic, and biologic phenomena. These processes not only interact with each other but also contribute to shaping the landscape as they influence geomorphic processes. We have investigated the effects of vegetation on thresholds for channel initiation and landform evolution using both analytical and numerical approaches. Vegetation is assumed to form a uniform ground cover. Runoff erosion is modeled based on a power function of excess shear stress, in which shear stress efficiency is inversely proportional to vegetation cover. This approach is validated using data. Plant effect on slope stability is represented by additional cohesion provided by plant roots. Vegetation cover is assumed to reduce sediment transport rates due to physical creep processes (rainsplash, dry ravel, and expansion and contraction of sediments) according to a negative exponential relationship. Vegetation grows as a function of both available cover and unoccupied space by plants and is killed by geomorphic disturbances (runoff erosion and landsliding) and wildfires. Analytical results suggest that in an equilibrium basin with a fixed vegetation cover, plants may cause a transition in the dominant erosion process at the channel head. A runoff erosion-dominated landscape, under none or poor vegetation cover, may become landslide dominated under a denser vegetation cover. The sign of the predicted relationship between drainage density and vegetation cover depends on the relative influence of vegetation on different erosion phenomena. With model parameter values representative of the Oregon Coast Range (OCR), numerical experiments conducted using the Channel Hillslope Integrated Landscape Development (CHILD) model confirm the findings based on the analytical theory. A highly dissected fluvial landscape emerges when surface is assumed bare. When vegetation cover is modeled, landscape relief increases, resulting in hollow erosion dominated by landsliding. Interestingly, our simulations underscore the importance of vegetation disturbances by geomorphic events and wildfires on the landscape structure. Simulated landscapes resemble real-world catchments in the OCR when such disturbances are considered.

Istanbulluoglu, Erkan; Bras, Rafael L.

2005-06-01

297

Trash Ecology  

Science.gov (United States)

A hands on activity involving density, frequency and biomass using transects, quadrats and a local good deed by cleaning up the neighborhood while practicing important techniques in ecology is detailed. The activity is designed for KCC-STEP, whose primary goal is to expand the scientific knowledge and research experiences of their students, who…

Lind, Georgia J.

2004-01-01

298

Ecological concepts  

International Nuclear Information System (INIS)

This volume contains three critical contributions on the application of modern technology from the ethical point of view. The peaceful use of nuclear power is rejected as a technical error, which is overwhelming humanity. Ethical bases of a preventive technological policy and ecological aims are developed for the 21st century, in economy, technology, politics, and consciousness. (HSCH)

299

Representation of Ecological Systems within the Protected Areas Network of the Continental United States  

Digital Repository Infrastructure Vision for European Research (DRIVER)

If conservation of biodiversity is the goal, then the protected areas network of the continental US may be one of our best conservation tools for safeguarding ecological systems (i.e., vegetation communities). We evaluated representation of ecological systems in the current protected areas network and found insufficient representation at three vegetation community levels within lower elevations and moderate to high productivity soils. We used national-level data for ecological systems and a p...

Aycrigg, Jocelyn L.; Davidson, Anne; Svancara, Leona K.; Gergely, Kevin J.; Mckerrow, Alexa; Scott, J. Michael

2013-01-01

300

Use of a wetland index to evaluate changes in riparian vegetation after livestock exclusion  

Science.gov (United States)

A method was developed to characterize ecological integrity of riparian sites based on the abundance of hydric species. This wetland index can be calculated with species data, or with community type data as performed here. Classified riparian community types were used to describe vegetation at 14 livestock exclosures and adjacent grazed areas. Community type wetland index values were generated and used to calculate site wetland index values. It was hypothesized that removal of livestock would result in higher wetland index values because of release from herbivory and decreased physical disturbance of vegetation, streambanks, and soil. The wetland index for exclosures was about 12% higher than grazed sites; differences were statistically significant (p exclusion may have contributed to the greater bank stability (p = 0.002) and smaller width-to-depth ratio (p = 0.005) in exclosures. Challenges were encountered in using community types to describe and compare site vegetation, which could be avoided with species data collection. The wetland index can be a tool to monitor sites over time, compare sites with similar environments, or compare sites for which environmental differences can be accounted. ?? 2007 American Water Resources Association.

Coles-Ritchie, M. C.; Roberts, D.W.; Kershner, J.L.; Henderson, R.C.

2007-01-01

 
 
 
 
301

Aspectos florísticos e ecológicos da vegetação campestre do Morro da Polícia, Porto Alegre, RS, Brasil / Floristics and ecological aspects of a grassland vegetation on Morro da Polícia, Porto Alegre, RS, Brazil  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Estudou-se a variação da composição florística da vegetação campestre e suas relações com altitude e exposição no Morro da Polícia, de origem granítica, em Porto Alegre, Rio Grande do Sul, a 30ºS e 51 ºW. O levantamento foi realizado de novembro de 1992 a novembro de 1994. A presença e freqüência de [...] espécies foi avaliada usando o método de pontos sobre transecções em 19 unidades de vegetação, as quais foram delimitadas com base na exposição da encosta (N, S, L, O) e altitude (160 a 280m). Os dados foram submetidos a análise multivariada de agrupamentos e ordenação. Nas transecções foram observadas 189 espécies, sendo Poaceae, Asteraceae e Apiaceae as famílias mais freqüentes e Trachypogon montufari e Schizachyrium tenerum as espécies dominantes. A análise de agrupamentos e de ordenação revelou conexões entre variação da vegetação e fatores altitude e exposição solar. Aristida laevis e Sorghastrum albescens são características de comunidades mais expostas à radiação solar, enquanto Agenium villosum e Eryngium eriophorum o são de comunidades menos expostas. Vernonia nudiflora e Axonopus suffultus caracterizam as áreas mais elevadas do morro, enquanto Eupatoriitm ligulifolium e Sorghastrum albescens as mais baixas. Abstract in english We studied floristic composition variation and its conections to elevation and exposure in the grassland vegetation of Morro da Polícia, a hill of granitic origin in the city of Porto Alegre, Rio Grande do Sul, 30ºS e 51 ºW. The survey took place from November 1992 to November 1994. Species presence [...] and frequency were assessed by using the point method on transects in 19 vegetation units, which were delimited by slope exposure and elevation (160 to 280m). Data were subjected to cluster analysis and ordination. Based on data from transects we detected 189 species, mainly from the Poaceae, Asteraceae and Apiaceae families, with Trachypogon montufari and Schizachyrium tenerum as dominant species. Cluster analysis and ordination revealed conections of vegetation variation with elevation and exposure. Aristida laevis and Sorghastrum albescens are characteristic of more exposed comunities (N and NE slopes), while Agenium villosum and Eryngium eriophorum are from less exposed communities (on S and SW slopes). Vernonia nudiflora and Axonopus suffultus are characteristic of higher elevation areas on the hill, while Eupatorium ligulifolium and Sorghastrum albescens are characteristic of lower elevation areas.

Ilsi Iob, Boldrini; Silvia T. S, Miotto; Hilda M, Longhi-Wagner; Valério De P, Pillar; Katia, Marzall.

302

[Comparison of GIMMS and MODIS normalized vegetation index composite data for Qing-Hai-Tibet Plateau].  

Science.gov (United States)

Consistent NDVI time series are basic and prerequisite in long-term monitoring of land surface properties. Advanced very high resolution radiometer (AVHRR) measurements provide the longest records of continuous global satellite measurements sensitive to live green vegetation, and moderate resolution imaging spectroradiometer (MODIS) is more recent typical with high spatial and temporal resolution. Understanding the relationship between the AVHRR-derived NDVI and MODIS NDVI is critical to continued long-term monitoring of ecological resources. NDVI time series acquired by the global inventory modeling and mapping studies (GIMMS) and Terra MODIS were compared over the same time periods from 2000 to 2006 at four scales of Qinghai-Tibet Plateau (whole region, sub-region, biome and pixel) to assess the level of agreement in terms of absolute values and dynamic change by independently assessing the performance of GIMMS and MODIS NDVI and using 495 Landsat samples of 20 km x20 km covering major land cover type. High correlations existed between the two datasets at the four scales, indicating their mostly equal capability of capturing seasonal and monthly phenological variations (mostly at 0. 001 significance level). Simi- larities of the two datasets differed significantly among different vegetation types. The relative low correlation coefficients and large difference of NDVI value between the two datasets were found among dense vegetation types including broadleaf forest and needleleaf forest, yet the correlations were strong and the deviations were small in more homogeneous vegetation types, such as meadow, steppe and crop. 82% of study area was characterized by strong consistency between GIMMS and MODIS NDVI at pixel scale. In the Landsat NDVI vs. GIMMS and MODIS NDVI comparison of absolute values, the MODIS NDVI performed slightly better than GIMMS NDVI, whereas in the comparison of temporal change values, the GIMMS data set performed best. Similar with comparison results of GIMMS and MODIS NDVI, the consistency across the three datasets was clearly different among various vegetation types. In dynamic changes, differences between Landsat and MODIS NDVI were smaller than Landsat NDVI vs. GIMMS NDVI for forest, but Landsat and GIMMS NDVI agreed better for grass and crop. The results suggested that spatial patterns and dynamic trends of GIMMS NDVI were found to be in overall acceptable agreement with MODIS NDVI. It might be feasible to successfully integrate historical GIMMS and more recent MODIS NDVI to provide continuity of NDVI products. The accuracy of merging AVHRR historical data recorded with more modern MODIS NDVI data strongly depends on vegetation type, season and phenological period, and spatial scale. The integration of the two datasets for needleleaf forest, broadleaf forest, and for all vegetation types in the phenological transition periods in spring and autumn should be treated with caution. PMID:24830255

Du, Jia-Qiang; Shu, Jian-Min; Wang, Yue-Hui; Li, Ying-Chang; Zhang, Lin-Bo; Guo, Yang

2014-02-01

303

Spatial pattern formation of coastal vegetation in response to external gradients and positive feedbacks affecting soil porewater salinity: A model study  

Science.gov (United States)

Coastal vegetation of South Florida typically comprises salinity-tolerant mangroves bordering salinity-intolerant hardwood hammocks and fresh water marshes. Two primary ecological factors appear to influence the maintenance of mangrove/hammock ecotones against changes that might occur due to disturbances. One of these is a gradient in one or more environmental factors. The other is the action of positive feedback mechanisms, in which each vegetation community influences its local environment to favor itself, reinforcing the boundary between communities. The relative contributions of these two factors, however, can be hard to discern. A spatially explicit individual-based model of vegetation, coupled with a model of soil hydrology and salinity dynamics is presented here to simulate mangrove/hammock ecotones in the coastal margin habitats of South Florida. The model simulation results indicate that an environmental gradient of salinity, caused by tidal flux, is the key factor separating vegetation communities, while positive feedback involving the different interaction of each vegetation type with the vadose zone salinity increases the sharpness of boundaries, and maintains the ecological resilience of mangrove/hammock ecotones against small disturbances. Investigation of effects of precipitation on positive feedback indicates that the dry season, with its low precipitation, is the period of strongest positive feedback. ?? 2011 Springer Science+Business Media B.V. (outside the USA).

Jiang, J.; DeAngelis, D.L.; Smith, T. J., III; Teh, S.Y.; Koh, H.-L.

2012-01-01

304

Cuantificación del carbono almacenado en formaciones vegetales amazónicas en "CICRA", Madre de Dios (Perú) / Quantification of the carbon storage in amazon vegetation types at "CICRA", Madre de Dios (Peru)  

Scientific Electronic Library Online (English)

Full Text Available SciELO Peru | Language: Spanish Abstract in spanish La llanura amazónica peruana se caracteriza por la presencia de múltiples formaciones vegetales. Éstas cada vez reciben mayor impacto por actividades antropogénicas tales como la minería y tala. Todo esto, sumado al cambio climático global, genera desconcierto sobre el futuro de los bosques. La iden [...] tificación de los niveles de almacenamiento de carbono en áreas boscosas, y específicamente en cada formación vegetal, permitiría un mejor manejo de las zonas de conservación, así como identificar las áreas potenciales que servirían para el financiamiento de la absorción de carbono y otros servicios ambientales. El presente estudio fue desarrollado en la estación Biológica del Centro de Investigación y Capacitación Río Los Amigos (CICRA). En el CICRA se identificaron tres formaciones vegetales principales, el bosque de terraza, el bosque inundable y el aguajal. Siendo los bosques de terraza los de mayor extensión y mayor cantidad de carbono acumulado. Como resultado se valorizó la vegetación presente en el CICRA, en alrededor de 11 millones de dólares americanos. El ingreso a la oferta de los bonos de carbono promovería la conservación de los bosques. Abstract in english The Peruvian Amazon Basin is characterized by the presence of multiple vegetation types. They are being given great impact by human activities such as mining and, logging. All this, coupled with global climate change, creates confusion about the future of our forests. The identification of levels of [...] carbon storage in forested areas, and specifically in each vegetation type, would allow better management of conservation areas, and then identify potential areas that could serve to finance carbon sequestration and other environmental services. This study was conducted at the Biological Station for Research and Training Center Rio Los Amigos (CICRA, Spanish acronym). At the station three main formations were identified, alluvial terrace forests, flood terrace forests and Mauritia swamps. The alluvial terrace forest presents the most extensive area and the highest amount of carbon stored. As result, CICRA vegetations were valued at approx. 11 millions U.S. dollars. Admission to the supply of carbon credits could promote Amazon forest conservation.

Carlos, Martel; Lianka, Cairampoma.

305

Cuantificación del carbono almacenado en formaciones vegetales amazónicas en "CICRA", Madre de Dios (Perú) / Quantification of the carbon storage in amazon vegetation types at "CICRA", Madre de Dios (Peru)  

Scientific Electronic Library Online (English)

Full Text Available SciELO Peru | Language: Spanish Abstract in spanish La llanura amazónica peruana se caracteriza por la presencia de múltiples formaciones vegetales. Éstas cada vez reciben mayor impacto por actividades antropogénicas tales como la minería y tala. Todo esto, sumado al cambio climático global, genera desconcierto sobre el futuro de los bosques. La iden [...] tificación de los niveles de almacenamiento de carbono en áreas boscosas, y específicamente en cada formación vegetal, permitiría un mejor manejo de las zonas de conservación, así como identificar las áreas potenciales que servirían para el financiamiento de la absorción de carbono y otros servicios ambientales. El presente estudio fue desarrollado en la estación Biológica del Centro de Investigación y Capacitación Río Los Amigos (CICRA). En el CICRA se identificaron tres formaciones vegetales principales, el bosque de terraza, el bosque inundable y el aguajal. Siendo los bosques de terraza los de mayor extensión y mayor cantidad de carbono acumulado. Como resultado se valorizó la vegetación presente en el CICRA, en alrededor de 11 millones de dólares americanos. El ingreso a la oferta de los bonos de carbono promovería la conservación de los bosques. Abstract in english The Peruvian Amazon Basin is characterized by the presence of multiple vegetation types. They are being given great impact by human activities such as mining and, logging. All this, coupled with global climate change, creates confusion about the future of our forests. The identification of levels of [...] carbon storage in forested areas, and specifically in each vegetation type, would allow better management of conservation areas, and then identify potential areas that could serve to finance carbon sequestration and other environmental services. This study was conducted at the Biological Station for Research and Training Center Rio Los Amigos (CICRA, Spanish acronym). At the station three main formations were identified, alluvial terrace forests, flood terrace forests and Mauritia swamps. The alluvial terrace forest presents the most extensive area and the highest amount of carbon stored. As result, CICRA vegetations were valued at approx. 11 millions U.S. dollars. Admission to the supply of carbon credits could promote Amazon forest conservation.

Carlos, Martel; Lianka, Cairampoma.

2012-08-01

306

Distinguishing land use types using surface albedo and normalized difference vegetation index derived from the SEBAL model for the Atankwidi and Afram sub-catchments in Ghana  

Directory of Open Access Journals (Sweden)

Full Text Available Distinguishing land use types is mostly done through field surveys which does not easily capture the spatial changes in the land use/cover types. In this study, the Surface Energy Balance Algorithm for Land (SEBAL model was used to estimate surface albedo and NDVI, for different land use/cover types for two sub-catchments (i.e., Atankwidi and Afram in the Volta Basin of Ghana. The mean coefficient of variation (CV for individual land use/cover types compared to the mean CV for a given site was then used to distinguish among the land use/cover types. It was found that these parameters derived from the SEBAL model can be used to distinguish among different land use/cover types in the two sub-catchments. SEBAL estimates for surface albedo and NDVI across the different land use/cover types varied from 0.05 to 0.22 and -0.41 to 0.38, respectively. The range of CVs for surface albedo and NDVI, were 5-22% and 7-175%, respectively across the different land use/cover types for the two catchments. The results of this study demonstrate that SEBAL’s derived surface albedo and NDVI can be used to distinguish land use/cover types in catchments similar to those of the study areas with few ground measurements.

Tayari Salifu

2012-01-01

307

Sensitivity of vegetation indices to different burn and vegetation ratios using LANDSAT-5 satellite data  

Science.gov (United States)

The application of vegetation indices is a very common approach in remote sensing of burned areas to either map the fire scar or estimate burn severity since they minimize the effect of exogenous factors and enhance the correlation with the internal parameters of vegetation. In a recent study we found that the original spectral channels, based on which these indices are estimated, are sensitive to external parameters of the vegetation as for example the spectral reflectance of the background soil. In such cases, the influence of the soil in the reflectance values is different in the various spectral regions depending on its type. These problems are further enhanced by the non-homogeneous pixels, as created from fractions of different types of land cover. Parnitha (Greece), where a wildfire occurred on July 2007, was established as test site. The purpose of this work is to explore the sensitivity of vegetation indices when used to estimate and map different fractions of fire-scorched (burned) and non fire-scorched (vegetated) areas. IKONOS, a very high resolution satellite imagery, was used to create a three-class thematic map to extract the percentages of vegetation, burned surfaces, and bare soil. Using an overlaid fishnet we extracted samples of completely "burned", completely "vegetated" pixels and proportions with different burn/vegetation ratios (45%-55% burned - 45%-55% vegetation, 20%-30% burned - 70%- 80% vegetation, 70%-80% burned - 20%-30% vegetation). Vegetation indices were calculated (NDVI, IPVI, SAVI) and their values were extracted to characterize the mentioned classes. The main findings of our recent research were that vegetation indices are less sensitive to external parameters of the vegetation by minimizing external effects. Thus, the semi-burned classes were spectrally more consistent to their different fractions of scorched and non-scorched vegetation, than the original spectral channels based on which these indices are estimated.

Pleniou, M.; Koutsias, N.

2013-08-01

308

Satellite Ecology (SATECO)-linking ecology, remote sensing and micrometeorology, from plot to regional scale, for the study of ecosystem structure and function.  

Science.gov (United States)

There is a growing requirement for ecosystem science to help inform a deeper understanding of the effects of global climate change and land use change on terrestrial ecosystem structure and function, from small area (plot) to landscape, regional and global scales. To meet these requirements, ecologists have investigated plant growth and carbon cycling processes at plot scale, using biometric methods to measure plant carbon accumulation, and gas exchange (chamber) methods to measure soil respiration. Also at the plot scale, micrometeorologists have attempted to measure canopy- or ecosystem-scale CO(2) flux by the eddy covariance technique, which reveals diurnal, seasonal and annual cycles. Mathematical models play an important role in integrating ecological and micrometeorological processes into ecosystem scales, which are further useful in interpreting time-accumulated information derived from biometric methods by comparing with CO(2) flux measurements. For a spatial scaling of such plot-level understanding, remote sensing via satellite is used to measure land use/vegetation type distribution and temporal changes in ecosystem structures such as leaf area index. However, to better utilise such data, there is still a need for investigations that consider the structure and function of ecosystems and their processes, especially in mountainous areas characterized by complex terrain and a mosaic distribution of vegetation. For this purpose, we have established a new interdisciplinary approach named 'Satellite Ecology', which aims to link ecology, remote sensing and micrometeorology to facilitate the study of ecosystem function, at the plot, landscape, and regional scale. PMID:18958540

Muraoka, Hiroyuki; Koizumi, Hiroshi

2009-01-01

309

Ecological baseline studies in Los Alamos and Guaje Canyons County of Los Alamos, New Mexico. A two-year study  

Energy Technology Data Exchange (ETDEWEB)

During the summers of 1993 and 1994, the Biological Resource Evaluations Team (BRET) of the Environmental Protection Group (ESH-8) conducted baseline studies within two canyon systems, Los Alamos and Guaje Canyons. Biological data was collected within each canyon to provide background and baseline information for Ecological Risk models. Baseline studies included establishment of permanent vegetation plots within each canyon along the elevational gradient. Then, in association with the various vegetation types, surveys were conducted for ground dwelling insects, birds, and small mammals. The stream channels associated with the permanent vegetation plots were characterized and aquatic macroinvertebrates collected within the stream monthly throughout a six-month period. The Geographic Position System (GPS) in combination with ARC INFO was used to map the study areas. Considerable data was collected during these surveys and are summarized in individual chapters.

Foxx, T.S. [comp.

1995-11-01

310

Physiology and proteome responses of two contrasting rice mutants and their wild type parent under salt stress conditions at the vegetative stage.  

Science.gov (United States)

Salinity is one of the major environmental limiting factors that affects growth and productivity of rice (Oryza sativa L.) worldwide. Rice is among the most sensitive crops to salinity, especially at early vegetative stages. In order to get a better understanding of molecular pathways affected in rice mutants showing contrasting responses to salinity, we exploited the power of 2-DE based proteomics to explore the proteome changes associated with salt stress response. Our physiological observations showed that standard evaluation system (SES) scores, Na+ and K+ concentrations in shoots and Na+/K+ ratio were significantly different in contrasting mutants under salt stress condition. Proteomics analysis showed that, out of 854 protein spots which were reproducibly detected, 67 protein spots showed significant responses to salt stress. The tandem mass spectrometry analysis of these significantly differentially accumulated proteins resulted in identification of 34 unique proteins. These proteins are involved in various molecular processes including defense to oxidative stresses, metabolisms, photosynthesis, protein synthesis and processing, signal transduction. Several of the identified proteins were emerged as key participants in salt stress tolerance. The possible implication of salt responsive proteins in plant adaptation to salt stress is discussed. PMID:24094368

Ghaffari, Akram; Gharechahi, Javad; Nakhoda, Babak; Salekdeh, Ghasem Hosseini

2014-01-01

311

The movement ecology of seagrasses.  

Science.gov (United States)

A movement ecology framework is applied to enhance our understanding of the causes, mechanisms and consequences of movement in seagrasses: marine, clonal, flowering plants. Four life-history stages of seagrasses can move: pollen, sexual propagules, vegetative fragments and the spread of individuals through clonal growth. Movement occurs on the water surface, in the water column, on or in the sediment, via animal vectors and through spreading clones. A capacity for long-distance dispersal and demographic connectivity over multiple timeframes is the novel feature of the movement ecology of seagrasses with significant evolutionary and ecological consequences. The space-time movement footprint of different life-history stages varies. For example, the distance moved by reproductive propagules and vegetative expansion via clonal growth is similar, but the timescales range exponentially, from hours to months or centuries to millennia, respectively. Consequently, environmental factors and key traits that interact to influence movement also operate on vastly different spatial and temporal scales. Six key future research areas have been identified. PMID:25297859

McMahon, Kathryn; van Dijk, Kor-Jent; Ruiz-Montoya, Leonardo; Kendrick, Gary A; Krauss, Siegfried L; Waycott, Michelle; Verduin, Jennifer; Lowe, Ryan; Statton, John; Brown, Eloise; Duarte, Carlos

2014-11-22

312

Relationship between fire regime and vegetation symphenological timing in Sardinia  

Directory of Open Access Journals (Sweden)

Full Text Available Fire is a basic ecological factor that contributes to determine vegetation biodiversity and dynamics in time and space. Fuel characteristics play an essential role in fire ignition and propagation; for instance fuel availability and flammability are closely related to the coarse-scale vegetation phenological trends that directly affect wildfire distribution in time and space. In this perspective, the annual NDVI profiles derived from high temporal resolution satellite images like SPOT Vegetation represent an effective tool for monitoring plant seasonal dynamics at the landscape scale. The objective of this study consists in relating the wildfire regime in Sardinia during 2000-2004 with the remotely sensed phenological parameters of the vegetation, segmented according to potential natural vegetation characteristics. The results of our study highlight a good correspondence between the NDVI temporal dynamics of the potential natural vegetation of Sardinia and the corresponding fires regime characteristics.

Carlo Ricotta

2008-01-01

313

Marine ecology  

International Nuclear Information System (INIS)

Studies on marine ecology included marine pollution; distribution patterns of Pu and Am in the marine waters, sediments, and organisms of Bikini Atoll and the influence of physical, chemical, and biological factors on their movements through marine biogeochemical systems; transfer and dispersion of organic pollutants from an oil refinery through coastal waters; transfer of particulate pollutants, including sediments dispersed during construction of offshore power plants; and raft culture of the mangrove oysters

314

Composição de espécies de Arctiidae (Lepidoptera) no sul do Brasil: relação entre tipos de vegetação e entre a configuração espacial do hábitat / Composition of the Arctiidae species (Lepidoptera) in southern Brazil: relationship among vegetation types and among habitat spatial configuration  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Este trabalho descreve o padrão de diversidade beta das mariposas Arctiidae no Estado do Rio Grande do Sul (RS) e avalia se esse padrão é relacionado com o tipo de vegetação ou com a distância geográfica entre as áreas. A partir da observação de 9420 espécimes depositados em 13 coleções científicas [...] e de duas listas publicadas na literatura, obteve-se registro de 329 espécies de arctiídeos em 55 localidades do RS. Essa riqueza corresponde a 5,6% da fauna Neotropical e 16,5% da fauna estimada para o Brasil. Cinqüenta e duas espécies (15,8%) foram registradas pela primeira vez no Estado. Não houve relação entre a diversidade beta (distância de Sorensen) e a distância geográfica entre as localidades, sugerindo que a configuração espacial do ambiente não influencia de forma significativa a locomoção das mariposas Arctiidae entre as paisagens. As análises multivariadas indicaram que a fauna de Arctiidae apresenta uma composição diferente em cada tipo de vegetação. A composição da fauna de áreas de Floresta Ombrófila Mista (Mata de Araucária) difere da fauna dos demais tipos de vegetação. Além disso, verificou-se uma maior riqueza de espécies em ambientes florestais do que em campestres. Abstract in english We describe the beta-diversity pattern of the Arctiidae in Rio Grande do Sul State (RS) and assess whether this pattern is related to similarities in vegetation type or geographic distance among areas. We analysed 9420 specimens in 13 scientific collections, as well as two published checklists. Thre [...] e hundred twenty nine arctiid species were recorded for 55 localities. This richness corresponded to 5.6% of the Neotropical fauna, and 16.5% of the estimated Brazilian fauna. Fifty two species (15.8%) were recorded for the first time in the state. There was no relationship between beta-diversity (Sorensen distance) and geographic distance among the localities, suggesting that the spatial configuration of the habitat did not influence significantly the locomotion of the Arctiidae moths among landscapes. The multivariate analysis suggested that the Arctiidae fauna differ among vegetation types. The composition of the fauna at the Floresta Ombrófila Mista (Araucaria forest) is very distinct from other vegetation type faunas. Species richness was higher on forest habitats than in open habitats.

Viviane Gianluppi, Ferro; José Augusto, Teston.

315

Contributions to multiple element speciation in vegetable plants: Studies on the type of bonding of numerous elements, particularly zinc and cadmium  

International Nuclear Information System (INIS)

In the first part of the study, the total contents and the solubility characteristics of Zn, Cd, Fe, Mn, Cu, Ca, Sr, K and Rb in 26 different vegetable plants, the majority of them commercially available, are reported, obtained by post-decomposition analyses. The data are given for avocados, bananas, cauliflower, chicory, Chinese cabbage, dill, ice lettuce (two specimens), endive, field salad, cucumbers, kohlrabi, lettuce, chard beet, carrots, peppers, leek, radish, red cabbage, loose leaved lettuce, celery (two specimens), spinach, topinambur, white cabbage, and parsley. Cell decomposition was done by treatment of the plant material with an electric dispersing apparatus (Ultra-Turrax) in buffer solution (liquid shearing). The homogenates were separated into supernatants (cytosoles)and pellets by means of centrifugation. Cell decomposition of the plants by crushing with quartz sand after lyophilization (solid shearing) required much more technical effort and for some elements created problems with the blind values. At least 50% on the average of the elements Zn, Cd, Rb, and K could be transferred to the solutions by the dispersing treatment with Ultra-Turrax. In many cases, the cytosole-borne detectable contents of these 5 elements were above 70%. The solubility of Zn and Cd was more strongly dependent on the plant species than that of Cu, Rb, and K. All five elements thus can be analysed by conventional methods for further enhanced speciation. Mn, Ca, and especially hanced speciation. Mn, Ca, and especially Fe and Sr for the most part were found to be bonded to solid cell constituents. However, the solubility characteristics of Ca and Mn and Sr in particular was very homogeneous. In some plants, the contents of Mn and Sr in the cytosoles was approx. 90%, so that comprehensive speciation of these elements is possible. (orig./AJ)

316

Mutation breeding in vegetable crops  

International Nuclear Information System (INIS)

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.)

317

Application of LiDAR and discriminant analysis to determine landscape characteristics for different types of slope failures in heavily vegetated, steep terrain: Horseshoe Run watershed, West Virginia  

Science.gov (United States)

A landslide inventory map was created for Horseshoe Run watershed, West Virginia, using high-resolution topographic data obtained from airborne LiDAR. A total of 152 landslides were remotely mapped and classified as planar slides, rotational slumps, debris flows, debris fans, debris slides, and active slopes based on morphologic characteristics interpreted from LiDAR-derived shaded relief maps, with field verification at several locations. Seven landscape variables were calculated for the watershed from the high-resolution (0.5-m) topographic data: elevation, slope angle, slope aspect, distance from roads, distance from streams, plan curvature, and profile curvature. Statistical analyses were conducted to determine the mean and standard deviations for each variable and corresponding slope failure type. Discriminant analyses were conducted on the different types of failed slopes, with a maximum 86% accuracy level, to determine which landscape characteristics contribute to each type of landslide. Results from the discriminant analyses indicate that statistically significant differences exist between the failure classes mapped within the watershed and that slope angle, slope aspect, and landscape curvature are important variables influencing the type of process. The results from this study have important implications for predicting where certain types of slope failures may occur based on landscape characteristics.

Konsoer, Kory M.; Kite, J. Steven

2014-11-01

318

NATURAL VEGETATION OF BIHAR  

Directory of Open Access Journals (Sweden)

Full Text Available Naturally growing vegetation in any specified region is called natural vegetation which refers to the ground cover provided by plants to a particular taxis, life forms, structure, special extent or any other specific botanical or geographical characteristics.

R.N. Pandey

2014-04-01

319

Fungos micorrízicos arbusculares em fitofisionomias do Pantanal da Nhecolândia, Mato Grosso do Sul / Arbuscular mycorrhizal fungi in vegetation types in the Pantanal of Nhecolândia, Mato Grosso do Sul, Brazil  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese O bioma Pantanal é reconhecido como uma das maiores extensões úmidas contínua do planeta, com fauna e flora de rara beleza e abundância. Estudos para acessar a diversidade de fungos micorrízicos arbusculares (FMA) nesse ambiente são inexistentes. O objetivo deste trabalho foi avaliar a ocorrência de [...] FMA nas diferentes fitofisionomias do Pantanal da Nhecolândia, Mato Grosso do Sul. Foram coletadas amostras de solo no período seco e chuvoso em um Neossolo Quartzarênico, em fitofisionomias sujeitas a distintos regimes de inundação: livres de inundação - Floresta Semidecídua (FS) e Cerradão (CE); sujeitos à inundação ocasional - Campo limpo, predominando Elyonorus muticus (CLE) e Cerrado (CC); e sujeitos à inundação sazonal - Campo limpo, predominando Andropogon spp. (CLA), borda de baias (BB) e vazante/baixadas (VB). Culturas armadilhas foram estabelecidas com Brachiaria brizantha para recuperar espécies crípticas de FMA. De cada amostra de solo, foram realizadas a caracterização química do solo e extração dos esporos de FMA para determinar abundância, riqueza e identificação das espécies. Um total de 37 espécies de FMA, pertencentes a 10 gêneros e seis famílias foram detectadas nas duas estações de coleta. O número de esporos variou significativamente entre as fitofisionomias, e os maiores valores foram encontrados em CE e CLA. A maior riqueza específica foi detectada em CC (25 espécies) seguida de VB e CE com 22 e 21 espécies, respectivamente. Os resultados deste estudo sugeriram que a diversidade dos FMA está relacionada com a heterogeneidade existente entre as fitofisionomias, e que características químicas do solo têm influência na estruturação das comunidades desses fungos. Considerando que o bioma Pantanal é um dos ecossistemas mais conservado do planeta, o levantamento de ocorrência de FMA realizado neste trabalho forneceu informações importantes para melhor conhecimento da biodiversidade das fitofisionomias do Pantanal da Nhecolândia. Abstract in english The Pantanal (tropical wetland) biome is recognized as one of the largest continuous areas of natural wetlands, harboring a flora and fauna of rare beauty and abundance. Studies to assess the diversity of arbuscular mycorrhizal fungi (AMF) are nonexistent for this environment. The goal of this study [...] was to evaluate the occurrence of AMF in different vegetation types of the Pantanal of Nhecolândia, Brazil. Soil samples were collected during the dry and wet season in a Neossolo Quartzarênico (Entisol) in vegetation types subject to different flooding regimes: flood-free - semi-deciduous forest (FS) and "Cerradão" (CE); subject to occasional flooding - grassland dominated by Elyonurus muticus (CLE) and "Cerrado" (CC); and subject to seasonal flooding - grasslands dominated by Andropogon spp. (CLA), the edge of bays (BB), and areas exposed at low water/lowlands (VB). Trap crops were established with Brachiaria brizantha to recover cryptic AMF species. Chemical analyses and spore extraction were carried for each soil sample to identify AMF species and determine their abundance and richness. A total of 37 AMF species, belonging to 10 genera and six families, were detected for both seasons. Spore numbers varied significantly among vegetation types, and the highest values were found in CE and CLA. The greatest richness of species was detected in CC (25 species), followed by VB, with 22 species, and CE, with 21 species. This is the first report on AMF diversity from the Pantanal biome. Results of this study suggest that AMF diversity is related to the heterogeneity among vegetation types and that soil chemical characteristics influence the structure of these fungi communities. Considering that the Pantanal is one of the most conserved biomes in the world, the survey of the occurrence of AMF in this study provides important information for better understanding the biodiversity of the phytophysiognomies of this biome.

Plínio Henrique Oliveira, Gomide; Marx Leandro Naves, Silva; Cláudio Roberto Fonsêca Sousa, Soares; Evaldo Luis, Cardoso; Fernanda de, Carvalho; Patrícia Lopes, Leal; Rodrigo Magalhães, Marques; Sidney Luiz, Stürmer.

1114-11-01

320

Caracterização fitofisionômica e levantamento florístico preliminar no Pantanal dos Rios Mortes-Araguaia, Cocalinho, Mato Grosso, Brasil Vegetation types and preliminary floristic survey in the Mortes-Araguaia Pantanal, Cocalinho, Mato Grosso, Brazil  

Directory of Open Access Journals (Sweden)

Full Text Available O presente estudo realizou-se no Pantanal dos Rios Mortes-Araguaia, extensa planície inundável localizada no municípo de Cocalinho, nordeste de Mato Grosso, Brasil. Efetuou-se uma caracterização fitofisionômica e um levantamento florístico preliminar da região. Foram selecionados três Sítios, com fitofisionomias representativas: proximidades do Rio das Mortes (12° 37'S; 50° 55'W, foz do Rio das Mortes com o Araguaia (11° 54'S; 50° 48'W e porção mediana do Rio Cristalino (12° 52'S; 50° 49'W. O método de amostragem adotado foi o de levantamentos rápidos. Foram identificadas oito fitofisionomias: Mata Inundável, Caapão, Babaçual, Cerradão, Cerrado stricto sensu, Campo de Murunduns, Campo de Byrsonima orbignyana e Campo Cerrado de Vochysia rufa. Foram levantadas 248 espécies de árvores, arbustos, sub-arbustos e lianas, distribuídas em 158 gêneros e 62 famílias. As fitofisionomias apresentaram um padrão heterogêneo, sendo que nenhuma das espécies ocorreu em todas elas. Porém, Alibertia edulis (L. Rich. A. Rich., Andira cuyabensis Benth., Maprounea guianensis (Aubl. M. Arg., entre outras, ocorreram em seis das oito fitofisionomias. As famílias com maior riqueza foram: Caesalpiniaceae, Annonaceae e Myrtaceae. Ocorreram algumas semelhanças florísticas com o Pantanal do Rio Paraguai, porém, são necessários estudos mais aprofundados para confirmar. Os padrões de heterogeneidade fitofisionômica indicam que a área estudada necessita de medidas conservacionistas.This study was carried out in the Pantanal of the Mortes and Araguaia rivers, a flooded plain located in Cocalinho, northeastern Mato Grosso, Brazil. The objectives of this study were to conduct a preliminary survey of the flora and to characterize the vegetation types. Three representative sites were selected: one near Rio das Mortes (12° 37'S; 50° 55'W, one at the mouth of Araguaia and Mortes rivers (11° 54'S; 50° 48'W and one in the middle portion of the Cristalino river (12° 52'S; 50° 49'W. Sampling was by the Rapid Survey method. Eight vegetation types were identified: Mata Inundável (swamp forest, Caapão (also swamp forest, Babaçual (Attalea speciosa forest, Cerradão, Cerrado stricto sensu (savanna types, closed canopy woodland and savanna grassland, respectively, Campo de Murunduns (grassland with scattered mounds bearing termites, Campo de Byrsonima orbignyana (grassland dominated by B. orbignyana and Campo Cerrado de Vochysia rufa (grassland with scattered trees of V. rufa. A total of 248 species of trees, shrubs and lianas were recorded, distributed in 158 genera and 62 families. The vegetation types were heterogeneous; none of the species occurred at all sites, but Alibertia edulis (L. Rich. A. Rich., Andira cuyabensis Benth., Maprounea guianensis (Aubl. M. Arg., and others, were found at six sites. The families richest in species were Caesalpiniaceae, Annonaceae and Myrtaceae. The flora apparently was similar to that of the Pantanal of Paraguai river, however, further studies are needed to confirm. This Heterogeneous vegetation patterns in the study area indicate the need to protect the Pantanal of the Mortes and Araguaia rivers.

Beatriz Schwantes Marimon

2001-08-01

 
 
 
 
321

Caracterização fitofisionômica e levantamento florístico preliminar no Pantanal dos Rios Mortes-Araguaia, Cocalinho, Mato Grosso, Brasil / Vegetation types and preliminary floristic survey in the Mortes-Araguaia Pantanal, Cocalinho, Mato Grosso, Brazil  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese O presente estudo realizou-se no Pantanal dos Rios Mortes-Araguaia, extensa planície inundável localizada no municípo de Cocalinho, nordeste de Mato Grosso, Brasil. Efetuou-se uma caracterização fitofisionômica e um levantamento florístico preliminar da região. Foram selecionados três Sítios, com fi [...] tofisionomias representativas: proximidades do Rio das Mortes (12° 37'S; 50° 55'W), foz do Rio das Mortes com o Araguaia (11° 54'S; 50° 48'W) e porção mediana do Rio Cristalino (12° 52'S; 50° 49'W). O método de amostragem adotado foi o de levantamentos rápidos. Foram identificadas oito fitofisionomias: Mata Inundável, Caapão, Babaçual, Cerradão, Cerrado stricto sensu, Campo de Murunduns, Campo de Byrsonima orbignyana e Campo Cerrado de Vochysia rufa. Foram levantadas 248 espécies de árvores, arbustos, sub-arbustos e lianas, distribuídas em 158 gêneros e 62 famílias. As fitofisionomias apresentaram um padrão heterogêneo, sendo que nenhuma das espécies ocorreu em todas elas. Porém, Alibertia edulis (L. Rich.) A. Rich., Andira cuyabensis Benth., Maprounea guianensis (Aubl.) M. Arg., entre outras, ocorreram em seis das oito fitofisionomias. As famílias com maior riqueza foram: Caesalpiniaceae, Annonaceae e Myrtaceae. Ocorreram algumas semelhanças florísticas com o Pantanal do Rio Paraguai, porém, são necessários estudos mais aprofundados para confirmar. Os padrões de heterogeneidade fitofisionômica indicam que a área estudada necessita de medidas conservacionistas. Abstract in english This study was carried out in the Pantanal of the Mortes and Araguaia rivers, a flooded plain located in Cocalinho, northeastern Mato Grosso, Brazil. The objectives of this study were to conduct a preliminary survey of the flora and to characterize the vegetation types. Three representative sites we [...] re selected: one near Rio das Mortes (12° 37'S; 50° 55'W), one at the mouth of Araguaia and Mortes rivers (11° 54'S; 50° 48'W) and one in the middle portion of the Cristalino river (12° 52'S; 50° 49'W). Sampling was by the Rapid Survey method. Eight vegetation types were identified: Mata Inundável (swamp forest), Caapão (also swamp forest), Babaçual (Attalea speciosa forest), Cerradão, Cerrado stricto sensu (savanna types, closed canopy woodland and savanna grassland, respectively), Campo de Murunduns (grassland with scattered mounds bearing termites), Campo de Byrsonima orbignyana (grassland dominated by B. orbignyana) and Campo Cerrado de Vochysia rufa (grassland with scattered trees of V. rufa). A total of 248 species of trees, shrubs and lianas were recorded, distributed in 158 genera and 62 families. The vegetation types were heterogeneous; none of the species occurred at all sites, but Alibertia edulis (L. Rich.) A. Rich., Andira cuyabensis Benth., Maprounea guianensis (Aubl.) M. Arg., and others, were found at six sites. The families richest in species were Caesalpiniaceae, Annonaceae and Myrtaceae. The flora apparently was similar to that of the Pantanal of Paraguai river, however, further studies are needed to confirm. This Heterogeneous vegetation patterns in the study area indicate the need to protect the Pantanal of the Mortes and Araguaia rivers.

Beatriz Schwantes, Marimon; Edson de Souza, Lima.

322

Fungos micorrízicos arbusculares em fitofisionomias do Pantanal da Nhecolândia, Mato Grosso do Sul / Arbuscular mycorrhizal fungi in vegetation types in the Pantanal of Nhecolândia, Mato Grosso do Sul, Brazil  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese O bioma Pantanal é reconhecido como uma das maiores extensões úmidas contínua do planeta, com fauna e flora de rara beleza e abundância. Estudos para acessar a diversidade de fungos micorrízicos arbusculares (FMA) nesse ambiente são inexistentes. O objetivo deste trabalho foi avaliar a ocorrência de [...] FMA nas diferentes fitofisionomias do Pantanal da Nhecolândia, Mato Grosso do Sul. Foram coletadas amostras de solo no período seco e chuvoso em um Neossolo Quartzarênico, em fitofisionomias sujeitas a distintos regimes de inundação: livres de inundação - Floresta Semidecídua (FS) e Cerradão (CE); sujeitos à inundação ocasional - Campo limpo, predominando Elyonorus muticus (CLE) e Cerrado (CC); e sujeitos à inundação sazonal - Campo limpo, predominando Andropogon spp. (CLA), borda de baias (BB) e vazante/baixadas (VB). Culturas armadilhas foram estabelecidas com Brachiaria brizantha para recuperar espécies crípticas de FMA. De cada amostra de solo, foram realizadas a caracterização química do solo e extração dos esporos de FMA para determinar abundância, riqueza e identificação das espécies. Um total de 37 espécies de FMA, pertencentes a 10 gêneros e seis famílias foram detectadas nas duas estações de coleta. O número de esporos variou significativamente entre as fitofisionomias, e os maiores valores foram encontrados em CE e CLA. A maior riqueza específica foi detectada em CC (25 espécies) seguida de VB e CE com 22 e 21 espécies, respectivamente. Os resultados deste estudo sugeriram que a diversidade dos FMA está relacionada com a heterogeneidade existente entre as fitofisionomias, e que características químicas do solo têm influência na estruturação das comunidades desses fungos. Considerando que o bioma Pantanal é um dos ecossistemas mais conservado do planeta, o levantamento de ocorrência de FMA realizado neste trabalho forneceu informações importantes para melhor conhecimento da biodiversidade das fitofisionomias do Pantanal da Nhecolândia. Abstract in english The Pantanal (tropical wetland) biome is recognized as one of the largest continuous areas of natural wetlands, harboring a flora and fauna of rare beauty and abundance. Studies to assess the diversity of arbuscular mycorrhizal fungi (AMF) are nonexistent for this environment. The goal of this study [...] was to evaluate the occurrence of AMF in different vegetation types of the Pantanal of Nhecolândia, Brazil. Soil samples were collected during the dry and wet season in a Neossolo Quartzarênico (Entisol) in vegetation types subject to different flooding regimes: flood-free - semi-deciduous forest (FS) and "Cerradão" (CE); subject to occasional flooding - grassland dominated by Elyonurus muticus (CLE) and "Cerrado" (CC); and subject to seasonal flooding - grasslands dominated by Andropogon spp. (CLA), the edge of bays (BB), and areas exposed at low water/lowlands (VB). Trap crops were established with Brachiaria brizantha to recover cryptic AMF species. Chemical analyses and spore extraction were carried for each soil sample to identify AMF species and determine their abundance and richness. A total of 37 AMF species, belonging to 10 genera and six families, were detected for both seasons. Spore numbers varied significantly among vegetation types, and the highest values were found in CE and CLA. The greatest richness of species was detected in CC (25 species), followed by VB, with 22 species, and CE, with 21 species. This is the first report on AMF diversity from the Pantanal biome. Results of this study suggest that AMF diversity is related to the heterogeneity among vegetation types and that soil chemical characteristics influence the structure of these fungi communities. Considering that the Pantanal is one of the most conserved biomes in the world, the survey of the occurrence of AMF in this study provides important information for better understanding the biodiversity of the phytophysiognomies of this biome.

Plínio Henrique Oliveira, Gomide; Marx Leandro Naves, Silva; Cláudio Roberto Fonsêca Sousa, Soares; Evaldo Luis, Cardoso; Fernanda de, Carvalho; Patrícia Lopes, Leal; Rodrigo Magalhães, Marques; Sidney Luiz, Stürmer.

323

Comparative analysis of remotely-sensed data products via ecological niche modeling of avian influenza case occurrences in Middle Eastern poultry  

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Full Text Available Abstract Background Ecological niche modeling integrates known sites of occurrence of species or phenomena with data on environmental variation across landscapes to infer environmental spaces potentially inhabited (i.e., the ecological niche to generate predictive maps of potential distributions in geographic space. Key inputs to this process include raster data layers characterizing spatial variation in environmental parameters, such as vegetation indices from remotely sensed satellite imagery. The extent to which ecological niche models reflect real-world distributions depends on a number of factors, but an obvious concern is the quality and content of the environmental data layers. Methods We assessed ecological niche model predictions of H5N1 avian flu presence quantitatively within and among four geographic regions, based on models incorporating two means of summarizing three vegetation indices derived from the MODIS satellite. We evaluated our models for predictive ability using partial ROC analysis and GLM ANOVA to compare performance among indices and regions. Results We found correlations between vegetation indices to be high, such that they contain information that overlaps broadly. Neither the type of vegetation index used nor method of summary affected model performance significantly. However, the degree to which model predictions had to be transferred (i.e., projected onto landscapes and conditions not represented on the landscape of training impacted predictive strength greatly (within-region model predictions far out-performed models projected among regions. Conclusion Our results provide the first quantitative tests of most appropriate uses of different remotely sensed data sets in ecological niche modeling applications. While our testing did not result in a decisive "best" index product or means of summarizing indices, it emphasizes the need for careful evaluation of products used in modeling (e.g. matching temporal dimensions and spatial resolution for optimum performance, instead of simple reliance on large numbers of data layers.

Xiao Xiangming

2011-03-01

324

Survey of ecological resources at selected US Department of Energy sites  

Energy Technology Data Exchange (ETDEWEB)

The U.S. Department of Energy (DOE) owns and manages a wide range of ecological resources. During the next 30 years, DOE Headquarters and Field Offices will make land-use planning decisions and conduct environmental remediation and restoration activities in response to federal and state statutes. This document fulfills, in part, DOE`s need to know what types of ecological resources it currently owns and manages by synthesizing information on the types and locations of ecological resources at 10 DOE sites: Hanford Site, Idaho National Engineering Laboratory, Lawrence Livermore National Laboratory, Sandia National Laboratory, Rocky Flats Plant, Los Alamos National Laboratory, savannah River Site, Oak Ridge National Laboratory, Argonne National Laboratory, and Fernald Environmental Management Project. This report summarizes information on ecosystems, habitats, and federally listed threatened, endangered, and candidate species that could be stressed by contaminants or physical activity during the restoration process, or by the natural or anthropogenic transport of contaminants from presently contaminated areas into presently uncontaminated areas. This report also provides summary information on the ecosystems, habitats, and threatened and endangered species that exist on each of the 10 sites. Each site chapter contains a general description of the site, including information on size, location, history, geology, hydrology, and climate. Descriptions of the major vegetation and animal communities and of aquatic resources are also provided, with discussions of the treatened or endangered plant or animal species present. Site-specific ecological issues are also discussed in each site chapter. 106 refs., 11 figs., 1 tab.

McAllister, C.; Beckert, H.; Abrams, C. [and others

1996-09-01

325

Survey of ecological resources at selected US Department of Energy sites  

International Nuclear Information System (INIS)

The U.S. Department of Energy (DOE) owns and manages a wide range of ecological resources. During the next 30 years, DOE Headquarters and Field Offices will make land-use planning decisions and conduct environmental remediation and restoration activities in response to federal and state statutes. This document fulfills, in part, DOE's need to know what types of ecological resources it currently owns and manages by synthesizing information on the types and locations of ecological resources at 10 DOE sites: Hanford Site, Idaho National Engineering Laboratory, Lawrence Livermore National Laboratory, Sandia National Laboratory, Rocky Flats Plant, Los Alamos National Laboratory, savannah River Site, Oak Ridge National Laboratory, Argonne National Laboratory, and Fernald Environmental Management Project. This report summarizes information on ecosystems, habitats, and federally listed threatened, endangered, and candidate species that could be stressed by contaminants or physical activity during the restoration process, or by the natural or anthropogenic transport of contaminants from presently contaminated areas into presently uncontaminated areas. This report also provides summary information on the ecosystems, habitats, and threatened and endangered species that exist on each of the 10 sites. Each site chapter contains a general description of the site, including information on size, location, history, geology, hydrology, and climate. Descriptions of the major vegetation and animal communities and of aquatic resources are also provided, with discussions of the treatened or endangered plant or animal species present. Site-specific ecological issues are also discussed in each site chapter. 106 refs., 11 figs., 1 tab

326

Integrating field sampling, geostatistics and remote sensing to map wetland vegetation in the Pantanal, Brazil  

Directory of Open Access Journals (Sweden)

Full Text Available Development of efficient methodologies for mapping wetland vegetation is of key importance to wetland conservation. Here we propose the integration of a number of statistical techniques, in particular cluster analysis, universal kriging and error propagation modelling, to integrate observations from remote sensing and field sampling for mapping vegetation communities and estimating uncertainty. The approach results in seven vegetation communities with a known floral composition that can be mapped over large areas using remotely sensed data. The relationship between remotely sensed data and vegetation patterns, captured in four factorial axes, were described using multiple linear regression models. There were then used in a universal kriging procedure to reduce the mapping uncertainty. Cross-validation procedures and Monte Carlo simulations were used to quantify the uncertainty in the resulting map. Cross-validation showed that accuracy in classification varies according with the community type, as a result of sampling density and configuration. A map of uncertainty derived from Monte Carlo simulations revealed significant spatial variation in classification, but this had little impact on the proportion and arrangement of the communities observed. These results suggested that mapping improvement could be achieved by increasing the number of field observations of those communities with a scattered and small patch size distribution; or by including a larger number of digital images as explanatory variables in the model. Comparison of the resulting plant community map with a flood duration map, revealed that flooding duration is an important driver of vegetation zonation. This mapping approach is able to integrate field point data and high-resolution remote-sensing images, providing a new basis to map wetland vegetation and allow its future application in habitat management, conservation assessment and long-term ecological monitoring in wetland landscapes.

J. Arieira

2011-03-01

327

Natural Plant Communities in View of Response Variables and Ecological Indices from Lalsuhanra Biosphere Reserve, Pakistan  

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Full Text Available The present study aimed to investigate the ecology of vegetation and to see if the heterogeneity of soil is the main determining factor for the diversity of natural vegetation. Therophytes were the most prominent proportion of life-form spectrum. On the basis of highest IVI three plant communities, Ochthochloa-Cymbopogon- Community, Launaea-Aerva- Community and Lasiurus scindicus-Community were recognized at the three selected habitats. Measurements for ecological indices showed that Launaea-Aerva- Community was more diverse with regard to species