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Sample records for vol a-96-2 phenological

  1. The effects of nitrogen rates on phenology and yield components of ...

    African Journals Online (AJOL)

    The effects of nitrogen rates on phenology and yield components of early maturing maize cultivars. DT Gungula, AO Togun, JG Kling. Abstract. No Abstract. Global Journal of Pure and Applied Sciences Vol. 13 (3) 2007: pp.319-324. Full Text: EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD ...

  2. Phenology MMS: a program to simulate crop phenological responses to water stress

    Science.gov (United States)

    Crop phenology is fundamental for understanding crop growth and development, and increasingly influences many agricultural management practices. Water deficits are one environmental factor that can influence crop phenology through shortening or lengthening the developmental phase, yet the phenologic...

  3. Phenology and growth in four annual species grown in ambient and elevated CO2

    Energy Technology Data Exchange (ETDEWEB)

    Reekie, E.G. (Acadia Univ., Wolfville, NS (Canada)); Bazzaz, F.A. (Harvard Univ., Cambridge, MA (USA))

    1991-01-01

    The objectives of this study were to test the hypothesis that changes in phenology with CO{sub 2} are a function of the effect of CO{sub 2} upon growth and to determine if CO{sub 2}-induced changes in phenology can influence competitive outcome. The effect of 350, 525, and 700{mu}l/l CO{sub 2} on Guara brachycarpa, Gailardia pulchella, Oenothera laciniata, and Lupinus texenis was examined. Plants were grown as individuals in 150-, 500-, or 1000-ml pots and in competition in 1000-ml pots. Growth and development were monitored at twice-weekly intervals by recording the number of leaves and noting the presence or absence of stem elongation, branching, flower buds, and open flowers. Elevated CO{sub 2} affected both growth and phenology, but the direction and magnitude of effects varied with species and soil volume. Elevated CO{sub 2} did not appear to affect development through its effect on growth. Those treatments in which there were significant effects of CO{sub 2} did not appear to affect development through its effect on growth. Those treatments in which there were significant effects of CO{sub 2} on growth were generally different from those treatments in which CO{sub 2} affected phenology. Rather than affecting phenology by changing plant size, CO{sub 2} appeared to affect phenology by modifying the size at which plants switched from one stage to the next. The level of CO{sub 2} changed competitive outcome; the importance of Lupinus increased whereas that of Oenothera decreased with increased CO{sub 2}. These changes were more closely related to the effect of CO{sub 2} on growth than its effect on phenology. 19 refs., 2 figs., 4 tabs.

  4. The Plant Phenology Ontology: A New Informatics Resource for Large-Scale Integration of Plant Phenology Data.

    Science.gov (United States)

    Stucky, Brian J; Guralnick, Rob; Deck, John; Denny, Ellen G; Bolmgren, Kjell; Walls, Ramona

    2018-01-01

    Plant phenology - the timing of plant life-cycle events, such as flowering or leafing out - plays a fundamental role in the functioning of terrestrial ecosystems, including human agricultural systems. Because plant phenology is often linked with climatic variables, there is widespread interest in developing a deeper understanding of global plant phenology patterns and trends. Although phenology data from around the world are currently available, truly global analyses of plant phenology have so far been difficult because the organizations producing large-scale phenology data are using non-standardized terminologies and metrics during data collection and data processing. To address this problem, we have developed the Plant Phenology Ontology (PPO). The PPO provides the standardized vocabulary and semantic framework that is needed for large-scale integration of heterogeneous plant phenology data. Here, we describe the PPO, and we also report preliminary results of using the PPO and a new data processing pipeline to build a large dataset of phenology information from North America and Europe.

  5. e-phenology: monitoring leaf phenology and tracking climate changes in the tropics

    Science.gov (United States)

    Morellato, Patrícia; Alberton, Bruna; Almeida, Jurandy; Alex, Jefersson; Mariano, Greice; Torres, Ricardo

    2014-05-01

    The e-phenology is a multidisciplinary project combining research in Computer Science and Phenology. Its goal is to attack theoretical and practical problems involving the use of new technologies for remote phenological observation aiming to detect local environmental changes. It is geared towards three objectives: (a) the use of new technologies of environmental monitoring based on remote phenology monitoring systems; (b) creation of a protocol for a Brazilian long term phenology monitoring program and for the integration across disciplines, advancing our knowledge of seasonal responses within tropics to climate change; and (c) provide models, methods and algorithms to support management, integration and analysis of data of remote phenology systems. The research team is composed by computer scientists and biology researchers in Phenology. Our first results include: Phenology towers - We set up the first phenology tower in our core cerrado-savanna 1 study site at Itirapina, São Paulo, Brazil. The tower received a complete climatic station and a digital camera. The digital camera is set up to take daily sequence of images (five images per hour, from 6:00 to 18:00 h). We set up similar phenology towers with climatic station and cameras in five more sites: cerrado-savanna 2 (Pé de Gigante, SP), cerrado grassland 3 (Itirapina, SP), rupestrian fields 4 ( Serra do Cipo, MG), seasonal forest 5 (Angatuba, SP) and Atlantic raiforest 6 (Santa Virginia, SP). Phenology database - We finished modeling and validation of a phenology database that stores ground phenology and near-remote phenology, and we are carrying out the implementation with data ingestion. Remote phenology and image processing - We performed the first analyses of the cerrado sites 1 to 4 phenology derived from digital images. Analysis were conducted by extracting color information (RGB Red, Green and Blue color channels) from selected parts of the image named regions of interest (ROI). using the green color

  6. On the uncertainty of phenological responses to climate change, and implications for a terrestrial biosphere model

    Directory of Open Access Journals (Sweden)

    M. Migliavacca

    2012-06-01

    degree of warming varied between 2.2 days °C−1 and 5.2 days °C−1 depending on model structure.

    We quantified the impact of uncertainties in bud-burst forecasts on simulated photosynthetic CO2 uptake and evapotranspiration (ET using a process-based terrestrial biosphere model. Uncertainty in phenology model structure led to uncertainty in the description of forest seasonality, which accumulated to uncertainty in annual model estimates of gross primary productivity (GPP and ET of 9.6% and 2.9%, respectively. A sensitivity analysis shows that a variation of ±10 days in bud-burst dates led to a variation of ±5.0% for annual GPP and about ±2.0% for ET.

    For phenology models, differences among future climate scenarios (i.e. driver represent the largest source of uncertainty, followed by uncertainties related to model structure, and finally, related to model parameterization. The uncertainties we have quantified will affect the description of the seasonality of ecosystem processes and in particular the simulation of carbon uptake by forest ecosystems, with a larger impact of uncertainties related to phenology model structure, followed by uncertainties related to phenological model parameterization.

  7. 51. Meeting of the Chemical Societies: Almanac of Contributions, Vol. Program, 1, 2, 3, 4 Molecular Models (Workshop)

    International Nuclear Information System (INIS)

    Uher, M.; Benes, P.; Carsky, J.; Ctrnactova, H.; Fecenko, J.; Fellner, P.; Hodul, P.; Koprda, V.; Kratochvil, B.; Krkoska, P.; Kuruc, J.; Lehotay, J.; Matousek, J.; Milichovsky, P.; Omastova, M.; Petrus, L. jr.; Petrus, L. sr.; Schwendt, P.; Silny, P.; Sevcik, P.; Toma, S.; Uherova, R.; Zachar, P.

    1999-09-01

    The publication has been set up as a abstracts of the meeting dealing with different chemical problems. The book (Vol. 1) consists of the sections: All-plenary lectures (9 papers); (D) History of the chemistry (14); (K) Didactics of chemistry (32); The book (Vol. 2) consists of the sections: (A) Analytical chemistry (48); (B) Inorganic chemistry (75); (C) Physical chemistry (27); (F) Nuclear chemistry and radioecology (12); (L) Environmental chemistry and toxicology (33); (M) Agricultural chemistry (20). The book (Vol. 3) consists of the sections: (E) Wood, pulp, paper (15); (G) Macromolecular chemistry (42); (H) Organic chemistry, bio-organic chemistry and pharmaceutical chemistry (96); (I) Food chemistry and biochemistry (34); (J) Textile, fibres and foil materials (9). The book (Vol. 4) consists of the workshop Molecular models (3 papers)

  8. Investigating the impact of climate change on crop phenological events in Europe with a phenology model

    Science.gov (United States)

    Ma, Shaoxiu; Churkina, Galina; Trusilova, Kristina

    2012-07-01

    Predicting regional and global carbon and water dynamics requires a realistic representation of vegetation phenology. Vegetation models including cropland models exist (e.g. LPJmL, Daycent, SIBcrop, ORCHIDEE-STICS, PIXGRO) but they have various limitations in predicting cropland phenological events and their responses to climate change. Here, we investigate how leaf onset and offset days of major European croplands responded to changes in climate from 1971 to 2000 using a newly developed phenological model, which solely relies on climate data. Net ecosystem exchange (NEE) data measured with eddy covariance technique at seven sites in Europe were used to adjust model parameters for wheat, barley, and rapeseed. Observational data from the International Phenology Gardens were used to corroborate modeled phenological responses to changes in climate. Enhanced vegetation index (EVI) and a crop calendar were explored as alternative predictors of leaf onset and harvest days, respectively, over a large spatial scale. In each spatial model simulation, we assumed that all European croplands were covered by only one crop type. Given this assumption, the model estimated that the leaf onset days for wheat, barley, and rapeseed in Germany advanced by 1.6, 3.4, and 3.4 days per decade, respectively, during 1961-2000. The majority of European croplands (71.4%) had an advanced mean leaf onset day for wheat, barley, and rapeseed (7.0% significant), whereas 28.6% of European croplands had a delayed leaf onset day (0.9% significant) during 1971-2000. The trend of advanced onset days estimated by the model is similar to observations from the International Phenology Gardens in Europe. The developed phenological model can be integrated into a large-scale ecosystem model to simulate the dynamics of phenological events at different temporal and spatial scales. Crop calendars and enhanced vegetation index have substantial uncertainties in predicting phenological events of croplands. Caution

  9. PHENOALP: a new project on phenology in the Western Alps

    Science.gov (United States)

    Cremonese, E.

    2009-04-01

    PHENOALP is a new EU co-funded Interreg Project under the operational programme for cross-border cooperation "Italy-France (Alps-ALCOTRA)" 2007 - 2013, aiming to get a better understanding of phenological changes in the Alps. The major goals of the project are: 1- The implementation of an observation network in the involved territories (i.e. the Aosta Valley and the Savoies in the Western Alps); 2- The definition of a common observation strategy and common protocols; 3- The involvement of local community members (e.g. through schools) in the observation activities as a way to increase the awareness on the issue of the effects of climate change. Project leader is the Environmental Protection Agency of Aosta Valley (ARPA Valle d'Aosta - IT) and the partners are the Research Center on High Altitude Ecosystem (CREA - FR), Mont Avic Regional Parc (IT), Bauges Massif Regional Natural Parc (FR) and the Protected Area Service of Aosta Valley (IT). Project activities are: 1. Pheno-plantes: definition of common observation protocols (e.g. field observation and webcams) of different alpine species (trees and herbaceous) and implementation of the observation network; analysis of the relations between climate and phenological events; application and evaluation of phenological models. 2. Pheno-detection: remote sensing of European larch and high elevation pastures with MODIS data; multitemporal analysis (2000-2011) of phenological variations in the Western Alps. 3. Pheno-flux: analysis of the relation between the seasonal and interannual variability of plant phenology and productivity, assessed measuring CO2 fluxes (eddy-covariance technique), radiometric indexes and phenological events at specific (European larch stand and alpine pastures) monitoring site. 4. Pheno-zoo: definition of common observation protocols for the phenology of animal taxa (birds, mammals, amphibians and insects) along altitudinal gradients; implementation of the observation network. 5. Inter

  10. Toward a U.S. National Phenological Assessment

    Science.gov (United States)

    Henebry, Geoffrey M.; Betancourt, Julio L.

    2010-01-01

    Third USA National Phenology Network (USA-NPN) and Research Coordination Network (RCN) Annual Meeting; Milwaukee, Wisconsin, 5-9 October 2009; Directional climate change will have profound and lasting effects throughout society that are best understood through fundamental physical and biological processes. One such process is phenology: how the timing of recurring biological events is affected by biotic and abiotic forces. Phenology is an early and integrative indicator of climate change readily understood by nonspecialists. Phenology affects the planting, maturation, and harvesting of food and fiber; pollination; timing and magnitude of allergies and disease; recreation and tourism; water quantity and quality; and ecosystem function and resilience. Thus, phenology is the gateway to climatic effects on both managed and unmanaged ecosystems. Adaptation to climatic variability and change will require integration of phenological data and models with climatic forecasts at seasonal to decadal time scales. Changes in phenologies have already manifested myriad effects of directional climate change. As these changes continue, it is critical to establish a comprehensive suite of benchmarks that can be tracked and mapped at local to continental scales with observations and climate models.

  11. Flower power: tree flowering phenology as a settlement cue for migrating birds.

    Science.gov (United States)

    McGrath, Laura J; van Riper, Charles; Fontaine, Joseph J

    2009-01-01

    1. Neotropical migrant birds show a clear preference for stopover habitats with ample food supplies; yet, the proximate cues underlying these decisions remain unclear. 2. For insectivorous migrants, cues associated with vegetative phenology (e.g. flowering, leaf flush, and leaf loss) may reliably predict the availability of herbivorous arthropods. Here we examined whether migrants use the phenology of five tree species to choose stopover locations, and whether phenology accurately predicts food availability. 3. Using a combination of experimental and observational evidence, we show migrant populations closely track tree phenology, particularly the flowering phenology of honey mesquite (Prosopis glandulosa), and preferentially forage in trees with more flowers. Furthermore, the flowering phenology of honey mesquite reliably predicts overall arthropod abundance as well as the arthropods preferred by migrants for food. 4. Together, these results suggest that honey mesquite flowering phenology is an important cue used by migrants to assess food availability quickly and reliably, while in transit during spring migration.

  12. Vol 41 No 2

    African Journals Online (AJOL)

    Esem

    3 Centre for Primary Care Research. Medical Journal of Zambia, Vol. 41, No. 2: 59 - 64 (2014) ... pollutants by inhaling second-hand tobacco smoke are at risk of adverse health ..... To put the measured PM levels into perspective, a. 2.5. 5.

  13. The plant phenological online database (PPODB): an online database for long-term phenological data

    Science.gov (United States)

    Dierenbach, Jonas; Badeck, Franz-W.; Schaber, Jörg

    2013-09-01

    We present an online database that provides unrestricted and free access to over 16 million plant phenological observations from over 8,000 stations in Central Europe between the years 1880 and 2009. Unique features are (1) a flexible and unrestricted access to a full-fledged database, allowing for a wide range of individual queries and data retrieval, (2) historical data for Germany before 1951 ranging back to 1880, and (3) more than 480 curated long-term time series covering more than 100 years for individual phenological phases and plants combined over Natural Regions in Germany. Time series for single stations or Natural Regions can be accessed through a user-friendly graphical geo-referenced interface. The joint databases made available with the plant phenological database PPODB render accessible an important data source for further analyses of long-term changes in phenology. The database can be accessed via www.ppodb.de .

  14. Phenology Data Products to Support Assessment and Forecasting of Phenology on Multiple Spatiotemporal Scales

    Science.gov (United States)

    Gerst, K.; Enquist, C.; Rosemartin, A.; Denny, E. G.; Marsh, L.; Moore, D. J.; Weltzin, J. F.

    2014-12-01

    The USA National Phenology Network (USA-NPN; www.usanpn.org) serves science and society by promoting a broad understanding of plant and animal phenology and the relationships among phenological patterns and environmental change. The National Phenology Database maintained by USA-NPN now has over 3.7 million records for plants and animals for the period 1954-2014, with the majority of these observations collected since 2008 as part of a broad, national contributory science strategy. These data have been used in a number of science, conservation and resource management applications, including national assessments of historical and potential future trends in phenology, regional assessments of spatio-temporal variation in organismal activity, and local monitoring for invasive species detection. Customizable data downloads are freely available, and data are accompanied by FGDC-compliant metadata, data-use and data-attribution policies, vetted and documented methodologies and protocols, and version control. While users are free to develop custom algorithms for data cleaning, winnowing and summarization prior to analysis, the National Coordinating Office of USA-NPN is developing a suite of standard data products to facilitate use and application by a diverse set of data users. This presentation provides a progress report on data product development, including: (1) Quality controlled raw phenophase status data; (2) Derived phenometrics (e.g. onset, duration) at multiple scales; (3) Data visualization tools; (4) Tools to support assessment of species interactions and overlap; (5) Species responsiveness to environmental drivers; (6) Spatially gridded phenoclimatological products; and (7) Algorithms for modeling and forecasting future phenological responses. The prioritization of these data products is a direct response to stakeholder needs related to informing management and policy decisions. We anticipate that these products will contribute to broad understanding of plant

  15. Results of a first look into the Austrian animal phenological records

    Energy Technology Data Exchange (ETDEWEB)

    Scheifinger, H.; Koch, E. [Central Inst. for Meteorology and Geodynamics, Vienna (Austria); Winkler, H. [Konrad Lorenz Inst. for Ethology, Vienna (Austria)

    2005-04-01

    The year to year variability and trends of animal phenological phases (honey bee, cockchafer, 3 butterfly species, swallow and cuckoo) of the Austrian phenological observational network were related to each other and to mean monthly temperatures over the time period 1951-1998. Insect phases were well correlated with each other (r{sup 2} = 0.4 to 0.6) and with temperature (r{sup 2} = 0.25 to 0.55), whereas both bird phases were only well correlated with each other (r{sup 2} = 0.57), but showed low common variance values with temperature and with other animal phases. The slope of the temperature-pheno regression, also termed as temperature sensitivity of the phenological phase, was high in the case of the insect phases (-3 to -5 days/ C), but low in the cases of both bird phases (about -1 days/ C). All animal phenological time series showed a trend towards later occurrence dates. The trends of the bird phases were even significant (p<0.1). There was a marked discrepancy between the trends of all animal phenological and temperature time series, especially between the insects and temperature: the mean temperature time series of February, March and April with the highest common variance with the insect phases showed a strongly increasing trend (0.027 C/year), whereas the first appearance dates of the insects tended to occur later (0.06 to 0.15 days/year). Both bird phases correlated weakly with the mean April temperature (r{sup 2} about 0.1). The temperature trend of April was 0.0003 C/year, whereas the trend of the bird phases was 0.2 days/year for the cuckoo and 0.25 days/year for the swallow. From these observations we conclude that a strong temperature sensitivity of the phenological phase based on the year to year variability (in days/ C) does not necessarily result in corresponding trends of temperature and phenological phase. A strong trend of non-atmospheric factors such as population density influencing the animal phases is suspected. Factors other than local

  16. 51. Meeting of the Chemical Societies: Almanac of Contributions, Vol. Program, 1, 2, 3, 4 Molecular Models (Workshop); 51. Zjazd chemickych spolocnosti: Zbornik prispevkov, Diel: Program, 1, 2, 3, 4 Molekulove modely (Workshop)

    Energy Technology Data Exchange (ETDEWEB)

    Uher, M [ed.; Dept. of Org. Chem., Slovak Techn. Univ., Bratislava (Slovakia); Benes, P [ed.; Dept. Nucl. Chem., Czech Techn. Univ., Prague (Czech Republic); Carsky, J [ed.; Inst. of Med. Chem., Biochem. and Clin. Biochem., Comenius Univ., Bratislava (Slovakia); Ctrnactova, H [ed.; Dept. of Educat. and Didactics of Chem., Charles Univ., Prague (Czech Republic); Fecenko, J [ed.; Dept. of Agricult. Chem. and Susten. of Veget., Slovak Agricult. Univ., Nitra (Slovakia); Fellner, P [ed.; Dept. of Inorg. Chem., Slovak Techn. Univ., Bratislava (Slovakia); Hodul, P [ed.; Dept. of Fibres and Textile, Slovak Techn. Univ., Bratislava (Slovakia); Koprda, V [ed.; Dept. of Envir., Slovak Techn. Univ., Bratislava (Slovakia); Kratochvil, B [ed.; Inst. of. Solid State Chem., Chem. Univ., Prague (Czech Republic); Krkoska, P [ed.; Dept. of Chem. Technol. of Wood, Pulp and Paper, Slovak Techn. Univ., Bratislava (Slovakia); Kuruc, J [ed.; Dept. of Nucl. Chem., Comenius Univ., Bratislava (Slovakia); Lehotay, J [ed.; Dept. of Anal. Chem., Slovak Techn. Univ., Bratislava (Slovakia); Matousek, J [ed.; Inst. of Chem. and Technol. of the Envir., Techn. Univ, Brno (Czech Republic); Milichovsky, P [ed.; Dept. of Chem. Techn. of Wood, Pulp and Paper, Univ. Pardubice, Pardubice (Czech Republic); Omastova, M [ed.; Inst. of Polym., SAS, Bratislava (Slovakia); Petrus, L jr; Petrus, L sr [eds.; Inst. of Chem., SAS, Bratislava (Slovakia); Salisova, M [ed.; Dept. of Org. Chem., Comenius Univ., Bratislava (Slovakia); Schwendt, P [ed.; Dept. of Inorg. Chem., Comenius Univ., Bratislava (Slovakia); Silny, P; Sevcik, P; Toma, S [eds.; Comenius Univ., Bratislava (Slovakia); Uherova, R [ed.; Slovak Techn. Univ., Bratislava (Slovakia); Vanek, L [ed.; Charles Univ., Prague (Czech Republic); Zachar, P [ed.; Chem. Univ., Prague (Czech Republic)

    1999-09-01

    The publication has been set up as a abstracts of the meeting dealing with different chemical problems. The book (Vol. 1) consists of the sections: All-plenary lectures (9 papers); (D) History of the chemistry (14); (K) Didactics of chemistry (32); The book (Vol. 2) consists of the sections: (A) Analytical chemistry (48); (B) Inorganic chemistry (75); (C) Physical chemistry (27); (F) Nuclear chemistry and radioecology (12); (L) Environmental chemistry and toxicology (33); (M) Agricultural chemistry (20). The book (Vol. 3) consists of the sections: (E) Wood, pulp, paper (15); (G) Macromolecular chemistry (42); (H) Organic chemistry, bio-organic chemistry and pharmaceutical chemistry (96); (I) Food chemistry and biochemistry (34); (J) Textile, fibres and foil materials (9). The book (Vol. 4) consists of the workshop Molecular models (3 papers)

  17. Simulating crop phenological responses to water stress using the phenology mms software component

    Science.gov (United States)

    Crop phenology is fundamental for understanding crop growth and development, and increasingly influences many agricultural management practices. Water deficits are one environmental factor that can influence crop phenology through shortening or lengthening the developmental phase, yet the phenologic...

  18. Continental-scale patterns and climatic drivers of fruiting phenology: A quantitative Neotropical review

    Science.gov (United States)

    Mendoza, Irene; Peres, Carlos A.; Morellato, Leonor Patrícia C.

    2017-01-01

    Changes in the life cycle of organisms (i.e. phenology) are one of the most widely used early-warning indicators of climate change, yet this remains poorly understood throughout the tropics. We exhaustively reviewed any published and unpublished study on fruiting phenology carried out at the community level in the American tropics and subtropics (latitudinal range: 26°N-26°S) to (1) provide a comprehensive overview of the current status of fruiting phenology research throughout the Neotropics; (2) unravel the climatic factors that have been widely reported as drivers of fruiting phenology; and (3) provide a preliminary assessment of the potential phenological responses of plants under future climatic scenarios. Despite the large number of phenological datasets uncovered (218), our review shows that their geographic distribution is very uneven and insufficient for the large surface of the Neotropics ( 1 dataset per 78,000 km2). Phenological research is concentrated in few areas with many studies (state of São Paulo, Brazil, and Costa Rica), whereas vast regions elsewhere are entirely unstudied. Sampling effort in fruiting phenology studies was generally low: the majority of datasets targeted fewer than 100 plant species (71%), lasted 2 years or less (72%), and only 10.4% monitored > 15 individuals per species. We uncovered only 10 sites with ten or more years of phenological monitoring. The ratio of numbers of species sampled to overall estimates of plant species richness was wholly insufficient for highly diverse vegetation types such as tropical rainforest, seasonal forest and cerrado, and only slightly more robust for less diverse vegetation types, such as deserts, arid shrublands and open grassy savannas. Most plausible drivers of phenology extracted from these datasets were environmental (78.5%), whereas biotic drivers were rare (6%). Among climatic factors, rainfall was explicitly included in 73.4% of cases, followed by air temperature (19.3%). Other

  19. Can phenological models predict tree phenology accurately under climate change conditions?

    Science.gov (United States)

    Chuine, Isabelle; Bonhomme, Marc; Legave, Jean Michel; García de Cortázar-Atauri, Inaki; Charrier, Guillaume; Lacointe, André; Améglio, Thierry

    2014-05-01

    The onset of the growing season of trees has been globally earlier by 2.3 days/decade during the last 50 years because of global warming and this trend is predicted to continue according to climate forecast. The effect of temperature on plant phenology is however not linear because temperature has a dual effect on bud development. On one hand, low temperatures are necessary to break bud dormancy, and on the other hand higher temperatures are necessary to promote bud cells growth afterwards. Increasing phenological changes in temperate woody species have strong impacts on forest trees distribution and productivity, as well as crops cultivation areas. Accurate predictions of trees phenology are therefore a prerequisite to understand and foresee the impacts of climate change on forests and agrosystems. Different process-based models have been developed in the last two decades to predict the date of budburst or flowering of woody species. They are two main families: (1) one-phase models which consider only the ecodormancy phase and make the assumption that endodormancy is always broken before adequate climatic conditions for cell growth occur; and (2) two-phase models which consider both the endodormancy and ecodormancy phases and predict a date of dormancy break which varies from year to year. So far, one-phase models have been able to predict accurately tree bud break and flowering under historical climate. However, because they do not consider what happens prior to ecodormancy, and especially the possible negative effect of winter temperature warming on dormancy break, it seems unlikely that they can provide accurate predictions in future climate conditions. It is indeed well known that a lack of low temperature results in abnormal pattern of bud break and development in temperate fruit trees. An accurate modelling of the dormancy break date has thus become a major issue in phenology modelling. Two-phases phenological models predict that global warming should delay

  20. A global synthesis of animal phenological responses to climate change

    Science.gov (United States)

    Cohen, Jeremy M.; Lajeunesse, Marc J.; Rohr, Jason R.

    2018-03-01

    Shifts in phenology are already resulting in disruptions to the timing of migration and breeding, and asynchronies between interacting species1-5. Recent syntheses have concluded that trophic level1, latitude6 and how phenological responses are measured7 are key to determining the strength of phenological responses to climate change. However, researchers still lack a comprehensive framework that can predict responses to climate change globally and across diverse taxa. Here, we synthesize hundreds of published time series of animal phenology from across the planet to show that temperature primarily drives phenological responses at mid-latitudes, with precipitation becoming important at lower latitudes, probably reflecting factors that drive seasonality in each region. Phylogeny and body size are associated with the strength of phenological shifts, suggesting emerging asynchronies between interacting species that differ in body size, such as hosts and parasites and predators and prey. Finally, although there are many compelling biological explanations for spring phenological delays, some examples of delays are associated with short annual records that are prone to sampling error. Our findings arm biologists with predictions concerning which climatic variables and organismal traits drive phenological shifts.

  1. Building a Shared Understanding of Phenology

    Science.gov (United States)

    Rosemartin, A.; Posthumus, E.; Gerst, K.

    2017-12-01

    The USA National Phenology Network (USA-NPN) seeks to advance the science of phenology and support the use of phenology information in decision-making. We envision that natural resource, human health, recreation and land-use decisions, in the context of a variable and changing climate, will be supported by USA-NPN products and tools. To achieve this vision we developed a logic model, breaking down the necessary inputs (e.g., IT infrastructure), participants, activities and the short- to long-term goals (e.g., use of phenological information in adaptive management). Here we compare the ongoing activities and outcomes of three recent collaborations to our logic model, in order to improve the model and inform future collaborations. At Midway Atoll National Wildlife Refuge, resource managers use the USA-NPN's phenology monitoring program to pinpoint the minimum number of days between initial growth and seed set in an invasive species. The data output and calendar visualizations that USA-NPN provides are sufficient to identify the appropriate treatment window. In contrast to a direct relationship with a natural resource manager using USA-NPN tools and products, some collaborations require substantive iterative work between partners. USA-NPN and National Park Service staff, along with academic researchers, assessed advancement in the timing of spring, and delivered the work in a format appropriate for park managers. Lastly, collaborations with indigenous communities reveal a requirement to reconsider the relationship between Western science and indigenous knowledge systems, as well as address ethical considerations and develop trust, before Western science can be meaningfully incorporated into decision-making. While the USA-NPN is a boundary organization, working in between federal agencies, states and universities, and is mandated to support decision-making, we still face challenges in generating usable science. We share lessons learned based on our experience with

  2. Nature's Notebook Provides Phenology Observations for NASA Juniper Phenology and Pollen Transport Project

    Science.gov (United States)

    Luval, J. C.; Crimmins, T. M.; Sprigg, W. A.; Levetin, E.; Huete, A.; Nickovic, S.; Prasad, A.; Vukovic, A.; VandeWater, P. K.; Budge, A. M.; hide

    2014-01-01

    Phenology Network has been established to provide national wide observations of vegetation phenology. However, as the Network is still in the early phases of establishment and growth, the density of observers is not yet adequate to sufficiently document the phenology variability over large regions. Hence a combination of satellite data and ground observations can provide optimal information regarding juniperus spp. pollen phenology. MODIS data was to observe Juniperus supp. pollen phenology. The MODIS surface reflectance product provided information on the Juniper supp. cone formation and cone density. Ground based observational records of pollen release timing and quantities were used as verification. Approximately 10, 818 records of juniper phenology for male cone formation Juniperus ashei., J. monosperma, J. scopulorum, and J. pinchotti were reported by Nature's Notebook observers in 2013 These observations provided valuable information for the analysis of satellite images for developing the pollen concentration masks for input into the PREAM (Pollen REgional Atmospheric Model) pollen transport model. The combination of satellite data and ground observations allowed us to improve our confidence in predicting pollen release and spread, thereby improving asthma and allergy alerts.

  3. Phenological patterns of flowering across biogeographical regions of Europe

    Science.gov (United States)

    Templ, Barbara; Templ, Matthias; Filzmoser, Peter; Lehoczky, Annamária; Bakšienè, Eugenija; Fleck, Stefan; Gregow, Hilppa; Hodzic, Sabina; Kalvane, Gunta; Kubin, Eero; Palm, Vello; Romanovskaja, Danuta; Vucˇ´, Višnja; žust, Ana; Czúcz, Bálint

    2017-07-01

    Long-term changes of plant phenological phases determined by complex interactions of environmental factors are in the focus of recent climate impact research. There is a lack of studies on the comparison of biogeographical regions in Europe in terms of plant responses to climate. We examined the flowering phenology of plant species to identify the spatio-temporal patterns in their responses to environmental variables over the period 1970-2010. Data were collected from 12 countries along a 3000-km-long, North-South transect from northern to eastern Central Europe. Biogeographical regions of Europe were covered from Finland to Macedonia. Robust statistical methods were used to determine the most influential factors driving the changes of the beginning of flowering dates. Significant species-specific advancements in plant flowering onsets within the Continental (3 to 8.3 days), Alpine (2 to 3.8 days) and by highest magnitude in the Boreal biogeographical regions (2.2 to 9.6 days per decades) were found, while less pronounced responses were detected in the Pannonian and Mediterranean regions. While most of the other studies only use mean temperature in the models, we show that also the distribution of minimum and maximum temperatures are reasonable to consider as explanatory variable. Not just local (e.g. temperature) but large scale (e.g. North Atlantic Oscillation) climate factors, as well as altitude and latitude play significant role in the timing of flowering across biogeographical regions of Europe. Our analysis gave evidences that species show a delay in the timing of flowering with an increase in latitude (between the geographical coordinates of 40.9 and 67.9), and an advance with changing climate. The woody species (black locust and small-leaved lime) showed stronger advancements in their timing of flowering than the herbaceous species (dandelion, lily of the valley). In later decades (1991-2010), more pronounced phenological change was detected than during

  4. Phenological patterns of flowering across biogeographical regions of Europe.

    Science.gov (United States)

    Templ, Barbara; Templ, Matthias; Filzmoser, Peter; Lehoczky, Annamária; Bakšienè, Eugenija; Fleck, Stefan; Gregow, Hilppa; Hodzic, Sabina; Kalvane, Gunta; Kubin, Eero; Palm, Vello; Romanovskaja, Danuta; Vucˇetic, Višnja; Žust, Ana; Czúcz, Bálint

    2017-07-01

    Long-term changes of plant phenological phases determined by complex interactions of environmental factors are in the focus of recent climate impact research. There is a lack of studies on the comparison of biogeographical regions in Europe in terms of plant responses to climate. We examined the flowering phenology of plant species to identify the spatio-temporal patterns in their responses to environmental variables over the period 1970-2010. Data were collected from 12 countries along a 3000-km-long, North-South transect from northern to eastern Central Europe.Biogeographical regions of Europe were covered from Finland to Macedonia. Robust statistical methods were used to determine the most influential factors driving the changes of the beginning of flowering dates. Significant species-specific advancements in plant flowering onsets within the Continental (3 to 8.3 days), Alpine (2 to 3.8 days) and by highest magnitude in the Boreal biogeographical regions (2.2 to 9.6 days per decades) were found, while less pronounced responses were detected in the Pannonian and Mediterranean regions. While most of the other studies only use mean temperature in the models, we show that also the distribution of minimum and maximum temperatures are reasonable to consider as explanatory variable. Not just local (e.g. temperature) but large scale (e.g. North Atlantic Oscillation) climate factors, as well as altitude and latitude play significant role in the timing of flowering across biogeographical regions of Europe. Our analysis gave evidences that species show a delay in the timing of flowering with an increase in latitude (between the geographical coordinates of 40.9 and 67.9), and an advance with changing climate. The woody species (black locust and small-leaved lime) showed stronger advancements in their timing of flowering than the herbaceous species (dandelion, lily of the valley). In later decades (1991-2010), more pronounced phenological change was detected than during the

  5. Remote sensing of land surface phenology

    Science.gov (United States)

    Meier, G.A.; Brown, Jesslyn F.

    2014-01-01

    Remote sensing of land-surface phenology is an important method for studying the patterns of plant and animal growth cycles. Phenological events are sensitive to climate variation; therefore phenology data provide important baseline information documenting trends in ecology and detecting the impacts of climate change on multiple scales. The USGS Remote sensing of land surface phenology program produces annually, nine phenology indicator variables at 250 m and 1,000 m resolution for the contiguous U.S. The 12 year archive is available at http://phenology.cr.usgs.gov/index.php.

  6. Physics at LEP2. Vol. 2

    International Nuclear Information System (INIS)

    Altarelli, G.; Sjoestrand, T.; Zwirner, F.

    1995-01-01

    This is final report of the Workshop on Physics at LEP2, held at CERN during 1995. The first part of vol. 1 is devoted to aspects of machine physics of particular relevance to experiments, including the energy, luminosity and interaction regions, as well as the measurement of beam energy. The second part of vol. 1 is a relatively concise, but fairly complete, handbook on the physics of e + e - annihilation above the WW threshold and up to √s∼200 GeV. It contains discussions on WW cross-sections and distributions, W mass determination, Standard Model processes, QCD and gamma-gamma physics, as well as aspects of discovery physics, such as Higgs, new particle searches, triple gauge boson couplings and Z'. The second volume contains a review of the existing Monte Carlo generators for LEP2 physics. These include generators for WW physics, QCD and gamma-gamma processes, Bhabha scattering and discovery physics. A special effort was made to co-ordinate the different parts, with a view to achieving a systematic and balanced review of the subject, rather than just publishing a collection of separate contributions. (orig.)

  7. Physics at LEP2. Vol. 2

    Energy Technology Data Exchange (ETDEWEB)

    Altarelli, G [ed.; Sjoestrand, T [ed.; Zwirner, F [ed.

    1995-02-19

    This is final report of the Workshop on Physics at LEP2, held at CERN during 1995. The first part of vol. 1 is devoted to aspects of machine physics of particular relevance to experiments, including the energy, luminosity and interaction regions, as well as the measurement of beam energy. The second part of vol. 1 is a relatively concise, but fairly complete, handbook on the physics of e{sup +}e{sup -} annihilation above the WW threshold and up to {radical}s{approx}200 GeV. It contains discussions on WW cross-sections and distributions, W mass determination, Standard Model processes, QCD and gamma-gamma physics, as well as aspects of discovery physics, such as Higgs, new particle searches, triple gauge boson couplings and Z`. The second volume contains a review of the existing Monte Carlo generators for LEP2 physics. These include generators for WW physics, QCD and gamma-gamma processes, Bhabha scattering and discovery physics. A special effort was made to co-ordinate the different parts, with a view to achieving a systematic and balanced review of the subject, rather than just publishing a collection of separate contributions. (orig.).

  8. Phylogenetic Conservatism in Plant Phenology

    Science.gov (United States)

    Davies, T. Jonathan; Wolkovich, Elizabeth M.; Kraft, Nathan J. B.; Salamin, Nicolas; Allen, Jenica M.; Ault, Toby R.; Betancourt, Julio L.; Bolmgren, Kjell; Cleland, Elsa E.; Cook, Benjamin I.; hide

    2013-01-01

    Phenological events defined points in the life cycle of a plant or animal have been regarded as highly plastic traits, reflecting flexible responses to various environmental cues. The ability of a species to track, via shifts in phenological events, the abiotic environment through time might dictate its vulnerability to future climate change. Understanding the predictors and drivers of phenological change is therefore critical. Here, we evaluated evidence for phylogenetic conservatism the tendency for closely related species to share similar ecological and biological attributes in phenological traits across flowering plants. We aggregated published and unpublished data on timing of first flower and first leaf, encompassing 4000 species at 23 sites across the Northern Hemisphere. We reconstructed the phylogeny for the set of included species, first, using the software program Phylomatic, and second, from DNA data. We then quantified phylogenetic conservatism in plant phenology within and across sites. We show that more closely related species tend to flower and leaf at similar times. By contrasting mean flowering times within and across sites, however, we illustrate that it is not the time of year that is conserved, but rather the phenological responses to a common set of abiotic cues. Our findings suggest that species cannot be treated as statistically independent when modelling phenological responses.Closely related species tend to resemble each other in the timing of their life-history events, a likely product of evolutionarily conserved responses to environmental cues. The search for the underlying drivers of phenology must therefore account for species' shared evolutionary histories.

  9. a R-Shiny Based Phenology Analysis System and Case Study Using Digital Camera Dataset

    Science.gov (United States)

    Zhou, Y. K.

    2018-05-01

    Accurate extracting of the vegetation phenology information play an important role in exploring the effects of climate changes on vegetation. Repeated photos from digital camera is a useful and huge data source in phonological analysis. Data processing and mining on phenological data is still a big challenge. There is no single tool or a universal solution for big data processing and visualization in the field of phenology extraction. In this paper, we proposed a R-shiny based web application for vegetation phenological parameters extraction and analysis. Its main functions include phenological site distribution visualization, ROI (Region of Interest) selection, vegetation index calculation and visualization, data filtering, growth trajectory fitting, phenology parameters extraction, etc. the long-term observation photography data from Freemanwood site in 2013 is processed by this system as an example. The results show that: (1) this system is capable of analyzing large data using a distributed framework; (2) The combination of multiple parameter extraction and growth curve fitting methods could effectively extract the key phenology parameters. Moreover, there are discrepancies between different combination methods in unique study areas. Vegetation with single-growth peak is suitable for using the double logistic module to fit the growth trajectory, while vegetation with multi-growth peaks should better use spline method.

  10. How Resource Phenology Affects Consumer Population Dynamics.

    Science.gov (United States)

    Bewick, Sharon; Cantrell, R Stephen; Cosner, Chris; Fagan, William F

    2016-02-01

    Climate change drives uneven phenology shifts across taxa, and this can result in changes to the phenological match between interacting species. Shifts in the relative phenology of partner species are well documented, but few studies have addressed the effects of such changes on population dynamics. To explore this, we develop a phenologically explicit model describing consumer-resource interactions. Focusing on scenarios for univoltine insects, we show how changes in resource phenology can be reinterpreted as transformations in the year-to-year recursion relationships defining consumer population dynamics. This perspective provides a straightforward path for interpreting the long-term population consequences of phenology change. Specifically, by relating the outcome of phenological shifts to species traits governing recursion relationships (e.g., consumer fecundity or competitive scenario), we demonstrate how changes in relative phenology can force systems into different dynamical regimes, with major implications for resource management, conservation, and other areas of applied dynamics.

  11. Urban phenological studies – Past, present, future

    International Nuclear Information System (INIS)

    Jochner, Susanne; Menzel, Annette

    2015-01-01

    Phenology is believed to be a suitable bio-indicator to track climate change. Based on the strong statistical association between phenology and temperature phenological observations provide an inexpensive means for the temporal and spatial analysis of the urban heat island. However, other environmental factors might also weaken this relationship. In addition, the investigation of urban phenology allows an estimation of future phenology from current information since cities with their amplified temperatures may serve as a proxy for future conditions. Nevertheless, the design of spatial compared to long-term studies might be influenced by different factors which should be taken into consideration when interpreting results from a specific study. In general, plants located in urban areas tend to flush and bloom earlier than in the countryside. What are the consequences of these urban–rural differences? This review will document existing findings on urban phenology and will highlight areas in which further research is needed. - Highlights: • Urban phenology can be used for the estimation of the urban heat island effect. • Confounding factors weaken the phenology–temperature relationship. • Urban phenology is useful as a proxy for climate change impacts on phenology. • Differences in the study design hinder the generalisation of one specific method. • Urban–rural variations in phenology affect vegetation, meteorology, human health. - Studies on urban phenology can be used to detect urban heat islands and to assess climate change impacts but it still remains important to adequately link spatial and long-term data

  12. The USA-NPN Information Management System: A tool in support of phenological assessments

    Science.gov (United States)

    Rosemartin, A.; Vazquez, R.; Wilson, B. E.; Denny, E. G.

    2009-12-01

    The USA National Phenology Network (USA-NPN) serves science and society by promoting a broad understanding of plant and animal phenology and the relationships among phenological patterns and all aspects of environmental change. Data management and information sharing are central to the USA-NPN mission. The USA-NPN develops, implements, and maintains a comprehensive Information Management System (IMS) to serve the needs of the network, including the collection, storage and dissemination of phenology data, access to phenology-related information, tools for data interpretation, and communication among partners of the USA-NPN. The IMS includes components for data storage, such as the National Phenology Database (NPD), and several online user interfaces to accommodate data entry, data download, data visualization and catalog searches for phenology-related information. The IMS is governed by a set of standards to ensure security, privacy, data access, and data quality. The National Phenology Database is designed to efficiently accommodate large quantities of phenology data, to be flexible to the changing needs of the network, and to provide for quality control. The database stores phenology data from multiple sources (e.g., partner organizations, researchers and citizen observers), and provides for integration with legacy datasets. Several services will be created to provide access to the data, including reports, visualization interfaces, and web services. These services will provide integrated access to phenology and related information for scientists, decision-makers and general audiences. Phenological assessments at any scale will rely on secure and flexible information management systems for the organization and analysis of phenology data. The USA-NPN’s IMS can serve phenology assessments directly, through data management and indirectly as a model for large-scale integrated data management.

  13. CO2, Temperature, and Soil Moisture Interactions Affect NDVI and Reproductive Phenology in Old-Field Plant Communities

    Science.gov (United States)

    Engel, C.; Weltzin, J.; Norby, R.

    2004-12-01

    Plant community composition and ecosystem function may be altered by global atmospheric and climate change, including increased atmospheric [CO2], temperature, and varying precipitation regimes. We are conducting an experiment at Oak Ridge National Laboratory (ORNL) utilizing open-top chambers to administer experimental treatments of elevated CO2 (+300 ppm), warming (+ 3 degrees Celsius), and varying soil moisture availability to experimental plant communities constructed of seven common old-field species, including C3 and C4 grasses, forbs, and legumes. During 2004 we monitored plant community phenology (NDVI) and plant reproductive phenology. Early in the year, NDVI was greater in wet treatment plots, and was unaffected by main effects of temperature or CO2. This result suggests that early in the season warming is insufficient to affect early canopy development. Differences in soil moisture sustained throughout the winter and into early spring may constitute an important control on early canopy greenup. Elevated CO2 alleviated detrimental effects of warming on NDVI, but only early in the season. As ambient temperatures increased, elevated temperatures negatively impacted NDVI only in the dry plots. Wetter conditions ameliorate the effects of warming on canopy greenness during the warmer seasons of the year. Warming increased rates of bolting, number of inflorescences, and time to reproductive maturity for Andropogon virginicus (a C4 bunchgrass). Solidago Canadensis (a C3 late-season forb) also produced flowers earlier in elevated temperatures. Conversely, none of the C3 grasses and forbs that bolt or flower in late spring or early summer responded to temperature or CO2. Results indicate that warming and drought may impact plant community phenology, and plant species reproductive phenology. Clearly community phenology is driven by complex interactions among temperature, water, and CO2 that change throughout the season. Our data stresses the importance of

  14. Perspectivs and challenges of phenology research on South America

    Science.gov (United States)

    Patrícia Morellato, Leonor

    2017-04-01

    Detecting plant responses to environmental changes across the Southern Hemisphere is an important question in the global agenda, as there is still a shortage of studies addressing phenological trends related to global warming. Here I bring a fresh perspective on the current knowledge of South America's phenology, and discusss the challenges and future research agendas for one of the most diverse regions of the world. I will syntethize: (i) What is the current focus of contemporany phenological research in South America? (ii) Is phenology contributing to the detection of trends and shifts related to climate or antropogenic changes? (iii) How has phenology been integrated to conservation, restoration, and management of natural vegetation and endangered species? (iv) What would be the main challenges and new avenues for South American phenological research in the 21st century? (v) Can we move towards phenology monitoring networks, linked to citizen science and education? My perspective is based on recent reviews addressing the Southeastern Hemisphere, South America, and Neotropical phenology; and on reviews and essays on the contribution of phenological research to biodiversity conservation, management, and ecological restoration, emphasizing tropical, species-rich ecosystems. Phenological research has grown at an unprecedented rate in the last 20 years, surpassing 100 articles per year after 2010. There is still a predominance of short-term studies (2-3 years) describing patterns and drivers for reproduction and leaf exchange. Only 10 long-term studies were found, based on direct observations or plant traps, and this number did not add much to the previous surveys. Therefore, we remain in need of more long-term studies to enhance the contribution of phenology to climate change research in South America. It is also mandatory to bring conservation issues to phenology research. The effects of climatic and antropogenic changes on plant phenology have been addressed

  15. Ethiopian Journal of Health Sciences - Vol 28, No 2 (2018)

    African Journals Online (AJOL)

    Ethiopian Journal of Health Sciences - Vol 28, No 2 (2018). Journal Home > Archives > Vol 28, No 2 (2018). Log in or Register to get access to full text downloads. ... Prevalence of opportunistic intestinal parasites and associated factors among HIV patients while receiving ART at Arba Minch Hospital in southern Ethiopia: a ...

  16. Atmospheric circulation patterns and phenological anomalies of grapevine in Italy

    Science.gov (United States)

    Cola, Gabriele; Alilla, Roberta; Dal Monte, Giovanni; Epifani, Chiara; Mariani, Luigi; Parisi, Simone Gabriele

    2014-05-01

    Grapevine (Vitis vinifera L.) is a fundamental crop for Italian agriculture as testified by the first place of Italy in the world producers ranking. This justify the importance of quantitative analyses referred to this crucial crop and aimed to quantify meteorological resources and limitations to development and production. Phenological rhythms of grapevine are strongly affected by surface fields of air temperature which in their turn are affected by synoptic circulation. This evidence highlights the importance of an approach based on dynamic climatology in order to detect and explain phenological anomalies that can have relevant effects on quantity and quality of grapevine production. In this context, this research is aimed to study the existing relation among the 850 hPa circulation patterns over the Euro-Mediterranean area from NOAA Ncep dataset and grapevine phenological fields for Italy over the period 2006-2013, highlighting the main phenological anomalies and analyzing synoptic determinants. This work is based on phenological fields with a standard pixel of 2 km routinely produced from 2006 by the Iphen project (Italian Phenological network) on the base of phenological observations spatialized by means of a specific algorithm based on cumulated thermal resources expressed as Normal Heat Hours (NHH). Anomalies have been evaluated with reference to phenological normal fields defined for the Italian area on the base of phenological observations and Iphen model. Results show that relevant phenological anomalies observed over the reference period are primarily associated with long lasting blocking systems driving cold air masses (Arctic or Polar-Continental) or hot ones (Sub-Tropical) towards the Italian area. Specific cases are presented for some years like 2007 and 2011.

  17. Estimating and Analyzing Savannah Phenology with a Lagged Time Series Model

    DEFF Research Database (Denmark)

    Boke-Olen, Niklas; Lehsten, Veiko; Ardo, Jonas

    2016-01-01

    cycle due to their areal coverage and can have an effect on the food security in regions that depend on subsistence farming. In this study we investigate how soil moisture, mean annual precipitation, and day length control savannah phenology by developing a lagged time series model. The model uses...... climate data for 15 flux tower sites across four continents, and normalized difference vegetation index from satellite to optimize a statistical phenological model. We show that all three variables can be used to estimate savannah phenology on a global scale. However, it was not possible to create...... a simplified savannah model that works equally well for all sites on the global scale without inclusion of more site specific parameters. The simplified model showed no bias towards tree cover or between continents and resulted in a cross-validated r2 of 0.6 and root mean squared error of 0.1. We therefore...

  18. Phenological response to climate change in China: a meta-analysis.

    Science.gov (United States)

    Ge, Quansheng; Wang, Huanjiong; Rutishauser, This; Dai, Junhu

    2015-01-01

    The change in the phenology of plants or animals reflects the response of living systems to climate change. Numerous studies have reported a consistent earlier spring phenophases in many parts of middle and high latitudes reflecting increasing temperatures with the exception of China. A systematic analysis of Chinese phenological response could complement the assessment of climate change impact for the whole Northern Hemisphere. Here, we analyze 1263 phenological time series (1960-2011, with 20+ years data) of 112 species extracted from 48 studies across 145 sites in China. Taxonomic groups include trees, shrubs, herbs, birds, amphibians and insects. Results demonstrate that 90.8% of the spring/summer phenophases time series show earlier trends and 69.0% of the autumn phenophases records show later trends. For spring/summer phenophases, the mean advance across all the taxonomic groups was 2.75 days decade(-1) ranging between 2.11 and 6.11 days decade(-1) for insects and amphibians, respectively. Herbs and amphibians show significantly stronger advancement than trees, shrubs and insect. The response of phenophases of different taxonomic groups in autumn is more complex: trees, shrubs, herbs and insects show a delay between 1.93 and 4.84 days decade(-1), while other groups reveal an advancement ranging from 1.10 to 2.11 days decade(-1) . For woody plants (including trees and shrubs), the stronger shifts toward earlier spring/summer were detected from the data series starting from more recent decades (1980s-2000s). The geographic factors (latitude, longitude and altitude) could only explain 9% and 3% of the overall variance in spring/summer and autumn phenological trends, respectively. The rate of change in spring/summer phenophase of woody plants (1960s-2000s) generally matches measured local warming across 49 sites in China (R=-0.33, P<0.05). © 2014 John Wiley & Sons Ltd.

  19. Proceedings of the 1. Arabic conference on chemical applications (Chemia 2). Vol. 2

    International Nuclear Information System (INIS)

    1997-11-01

    The conference of chemical application was held on 1-5 Nov 1997 in Cairo, This vol.2 contains of chemical application on nuclear materials. Studies on these vol.This second volume covers papers presented on the subjects

  20. Evaluating Gridded Spring Indices Using the USA National Phenology Network's Observational Phenology Data

    Science.gov (United States)

    Crimmins, T. M.; Gerst, K.

    2017-12-01

    The USA National Phenology Network (USA-NPN; www.usanpn.org) produces and freely delivers daily and short-term forecast maps of spring onset dates at fine spatial scale for the conterminous United States and Alaska using the Spring Indices. These models, which represent the start of biological activity in the spring season, were developed using a long-term observational record of four species of lilacs and honeysuckles contributed by volunteer observers. Three of the four species continue to be tracked through the USA-NPN's phenology observation program, Nature's Notebook. The gridded Spring Index maps have utility for a wide range of natural resource planning and management applications, including scheduling invasive species and pest detection and control activities, anticipating allergy outbreaks and planning agricultural harvest dates. However, to date, there has not been a comprehensive assessment of how well the gridded Spring Index maps accurately reflect phenological activity in lilacs and honeysuckles or other species of plants. In this study, we used observational plant phenology data maintained by the USA-NPN to evaluate how well the gridded Spring Index maps match leaf and flowering onset dates in a) the lilac and honeysuckle species used to construct the models and b) in several species of deciduous trees. The Spring Index performed strongly at predicting the timing of leaf-out and flowering in lilacs and honeysuckles. The average error between predicted and observed date of onset ranged from 5.9 to 11.4 days. Flowering models performed slightly better than leaf-out models. The degree to which the Spring Indices predicted native deciduous tree leaf and flower phenology varied by year, species, and region. Generally, the models were better predictors of leaf and flowering onset dates in the Northeastern and Midwestern US. These results reveal when and where the Spring Indices are a meaningful proxy of phenological activity across the United States.

  1. The European Phenology Network

    NARCIS (Netherlands)

    Vliet, van A.J.H.; Groot, de R.S.; Bellens, Y.; Braun, P.; Bruegger, R.; Bruns, E.; Clevers, J.G.P.W.; Estreguil, C.; Flechsig, M.; Jeanneret, F.; Maggi, M.; Martens, P.; Menne, B.; Menzel, A.; Sparks, T.

    2003-01-01

    The analysis of changes in the timing of life cycle-events of organisms (phenology) has been able to contribute significantly to the assessment of potential impacts of climate change on ecology. These phenological responses of species to changes in climate are likely to have significant relevance

  2. Improving carbon model phenology using data assimilation

    Science.gov (United States)

    Exrayat, Jean-François; Smallman, T. Luke; Bloom, A. Anthony; Williams, Mathew

    2015-04-01

    Carbon cycle dynamics is significantly impacted by ecosystem phenology, leading to substantial seasonal and inter-annual variation in the global carbon balance. Representing inter-annual variability is key for predicting the response of the terrestrial ecosystem to climate change and disturbance. Existing terrestrial ecosystem models (TEMs) often struggle to accurately simulate observed inter-annual variability. TEMs often use different phenological models based on plant functional type (PFT) assumptions. Moreover, due to a high level of computational overhead in TEMs they are unable to take advantage of globally available datasets to calibrate their models. Here we describe the novel CARbon DAta MOdel fraMework (CARDAMOM) for data assimilation. CARDAMOM is used to calibrate the Data Assimilation Linked Ecosystem Carbon version 2 (DALEC2) model using Bayes' Theorem within a Metropolis Hastings - Markov Chain Monte Carlo (MH-MCMC). CARDAMOM provides a framework which combines knowledge from observations, such as remotely sensed LAI, and heuristic information in the form of Ecological and Dynamical Constraints (EDCs). The EDCs are representative of real world processes and constrain parameter interdependencies and constrain carbon dynamics. We used CARDAMOM to bring together globally spanning datasets of LAI and the DALEC2 and DALEC2-GSI models. These analyses allow us to investigate the sensitivity ecosystem processes to the representation of phenology. DALEC2 uses an analytically solved model of phenology which is invariant between years. In contrast DALEC2-GSI uses a growing season index (GSI) calculated as a function of temperature, vapour pressure deficit (VPD) and photoperiod to calculate bud-burst and leaf senescence, allowing the model to simulate inter-annual variability in response to climate. Neither model makes any PFT assumptions about the phenological controls of a given ecosystem, allowing the data alone to determine the impact of the meteorological

  3. Phenological Indicators of Vegetation Recovery in Wetland Ecosystems

    Science.gov (United States)

    Taddeo, S.; Dronova, I.

    2017-12-01

    Landscape phenology is increasingly used to measure the impacts of climatic and environmental disturbances on plant communities. As plants show rapid phenological responses to environmental changes, variation in site phenology can help characterize vegetation recovery following restoration treatments and qualify their resistance to environmental fluctuations. By leveraging free remote sensing datasets, a phenology-based analysis of vegetation dynamics could offer a cost-effective assessment of restoration progress in wetland ecosystems. To fulfill this objective, we analyze 20 years of free remote sensing data from NASA's Landsat archive to offer a landscape-scale synthesis of wetland restoration efforts in the Sacramento-San Joaquin Delta of California, USA. Through an analysis of spatio-temporal changes in plant phenology and greenness, we assess how 25 restored wetlands across the Delta have responded to restoration treatments, time, and landscape context. We use a spline smoothing approach to generate both site-wide and pixel-specific phenological curves and identify key phenological events. Preliminary results reveal a greater variability in greenness and growing season length during the initial post-restoration years and a significant impact of landscape context in the time needed to reach phenological stability. Well-connected sites seem to benefit from an increased availability of propagules enabling them to reach peak greenness and maximum growing season length more rapidly. These results demonstrate the potential of phenological analyses to measure restoration progress and detect factors promoting wetland recovery. A thorough understanding of wetland phenology is key to the quantification of ecosystem processes including carbon sequestration and habitat provisioning.

  4. Phenology prediction component of GypsES

    Science.gov (United States)

    Jesse A. Logan; Lukas P. Schaub; F. William Ravlin

    1991-01-01

    Prediction of phenology is an important component of most pest management programs, and considerable research effort has been expended toward development of predictive tools for gypsy moth phenology. Although phenological prediction is potentially valuable for timing of spray applications (e.g. Bt, or Gypcheck) and other management activities (e.g. placement and...

  5. Vegetation phenology from Sentinel-2 and field cameras for a Dutch barrier island

    NARCIS (Netherlands)

    Vrieling, A.; Meroni, Michele; Darvishzadeh, R.; Skidmore, A.K.; Wang, Tiejun; Zurita-Milla, R.; Oosterbeek, Kees; O'Connor, Brian; Marc, Paganini

    Remote sensing studies of vegetation phenology increasingly benefit from freely available satellite imagery acquired with high temporal frequency at fine spatial resolution. Particularly for heterogeneous landscapes this is good news, given the drawback of medium-resolution sensors commonly used for

  6. The USA National Phenology Network: A national science and monitoring program for understanding climate change

    Science.gov (United States)

    Weltzin, J.

    2009-04-01

    Patterns of phenology for plants and animals control ecosystem processes, determine land surface properties, control biosphere-atmosphere interactions, and affect food production, health, conservation, and recreation. Although phenological data and models have applications related to scientific research, education and outreach, agriculture, tourism and recreation, human health, and natural resource conservation and management, until recently there was no coordinated effort to understand phenology at the national scale in the United States. The USA National Phenology Network (USA-NPN; www.usanpn.org), established in 2007, is an emerging and exciting partnership between federal agencies, the academic community, and the general public to establish a national science and monitoring initiative focused on phenology. The first year of operation of USA-NPN produced many new phenology products and venues for phenology research and citizen involvement. Products include a new web-site (www.usanpn.org) that went live in June 2008; the web-site includes a tool for on-line data entry, and serves as a clearinghouse for products and information to facilitate research and communication related to phenology. The new core Plant Phenology Program includes profiles for 200 vetted local, regional, and national plant species with descriptions and (BBCH-consistent) monitoring protocols, as well as templates for addition of new species. A partnership program describes how other monitoring networks can engage with USA-NPN to collect, manage or disseminate phenological information for science, health, education, management or predictive service applications. Project BudBurst, a USA-NPN field campaign for citizen scientists, went live in February 2008, and now includes over 3000 registered observers monitoring 4000 plants across the nation. For 2009 and beyond, we will initiate a new Wildlife Phenology Program, create an on-line clearing-house for phenology education and outreach, strengthen

  7. Response of vegetation phenology to urbanization in the conterminous United States

    Energy Technology Data Exchange (ETDEWEB)

    Li, Xuecao [Department of Geological and Atmospheric Sciences, Iowa State University, Ames IA 50011 USA; Zhou, Yuyu [Department of Geological and Atmospheric Sciences, Iowa State University, Ames IA 50011 USA; Asrar, Ghassem R. [Pacific Northwest National Laboratory, Joint Global Change Research Institute, College Park MD 20740 USA; Mao, Jiafu [Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge TN 37831 USA; Li, Xiaoma [Department of Geological and Atmospheric Sciences, Iowa State University, Ames IA 50011 USA; Li, Wenyu [Ministry of Education Key Laboratory for Earth System Modeling, Center for Earth System Science, Tsinghua University, Beijing 100084 China

    2016-12-18

    The influence of urbanization on vegetation phenology is gaining considerable attention due to its implications for human health, cycling of carbon and other nutrients in Earth system. In this study, we examined the relationship between change in vegetation phenology and urban size, an indicator of urbanization, for the conterminous United States. We studied more than 4500 urban clusters of varying size to determine the impact of urbanization on plant phenology, with the aids of remotely sensed observations since 2003–2012. We found that phenology cycle (changes in vegetation greenness) in rural areas starts earlier (start of season, SOS) and ends later (end of season, EOS), resulting in a longer growing season length (GSL), when compared to the respective surrounding urban areas. The average difference of GSL between urban and rural areas over all vegetation types, considered in this study, is about 9 days. Also, the extended GSL in urban area is consistent among different climate zones in the United States, whereas their magnitudes are varying across regions. We found that a tenfold increase in urban size could result in an earlier SOS of about 1.3 days and a later EOS of around 2.4 days. As a result, the GSL could be extended by approximately 3.6 days with a range of 1.6–6.5 days for 25th ~ 75th quantiles, with a median value of about 2.1 days. For different vegetation types, the phenology response to urbanization, as defined by GSL, ranges from 1 to 4 days. The quantitative relationship between phenology and urbanization is of great use for developing improved models of vegetation phenology dynamics under future urbanization, and for developing change indicators to assess the impacts of urbanization on vegetation phenology.

  8. USA National Phenology Network observational data documentation

    Science.gov (United States)

    Rosemartin, Alyssa H.; Denny, Ellen G.; Gerst, Katharine L.; Marsh, R. Lee; Posthumus, Erin E.; Crimmins, Theresa M.; Weltzin, Jake F.

    2018-04-25

    The goals of the USA National Phenology Network (USA-NPN, www.usanpn.org) are to advance science, inform decisions, and communicate and connect with the public regarding phenology and species’ responses to environmental variation and climate change. The USA-NPN seeks to advance the science of phenology and facilitate ecosystem stewardship by providing phenological information freely and openly. To accomplish these goals, the USA-NPN National Coordinating Office (NCO) delivers observational data on plant and animal phenology in several formats, including minimally processed status and intensity datasets and derived phenometrics for individual plants, sites, and regions. This document describes the suite of observational data products delivered by the USA National Phenology Network, covering the period 2009–present for the United States and accessible via the Phenology Observation Portal (http://dx.doi.org/10.5066/F78S4N1V) and via an Application Programming Interface. The data described here have been used in diverse research and management applications, including over 30 publications in fields such as remote sensing, plant evolution, and resource management.

  9. Herbarium records are reliable sources of phenological change driven by climate and provide novel insights into species' phenological cueing mechanisms.

    Science.gov (United States)

    Davis, Charles C; Willis, Charles G; Connolly, Bryan; Kelly, Courtland; Ellison, Aaron M

    2015-10-01

    Climate change has resulted in major changes in the phenology of some species but not others. Long-term field observational records provide the best assessment of these changes, but geographic and taxonomic biases limit their utility. Plant specimens in herbaria have been hypothesized to provide a wealth of additional data for studying phenological responses to climatic change. However, no study to our knowledge has comprehensively addressed whether herbarium data are accurate measures of phenological response and thus applicable to addressing such questions. We compared flowering phenology determined from field observations (years 1852-1858, 1875, 1878-1908, 2003-2006, 2011-2013) and herbarium records (1852-2013) of 20 species from New England, United States. Earliest flowering date estimated from herbarium records faithfully reflected field observations of first flowering date and substantially increased the sampling range across climatic conditions. Additionally, although most species demonstrated a response to interannual temperature variation, long-term temporal changes in phenological response were not detectable. Our findings support the use of herbarium records for understanding plant phenological responses to changes in temperature, and also importantly establish a new use of herbarium collections: inferring primary phenological cueing mechanisms of individual species (e.g., temperature, winter chilling, photoperiod). These latter data are lacking from most investigations of phenological change, but are vital for understanding differential responses of individual species to ongoing climate change. © 2015 Botanical Society of America.

  10. PEP725 Pan European Phenological Database

    Science.gov (United States)

    Koch, E.; Adler, S.; Lipa, W.; Ungersböck, M.; Zach-Hermann, S.

    2010-09-01

    Europe is in the fortunate situation that it has a long tradition in phenological networking: the history of collecting phenological data and using them in climatology has its starting point in 1751 when Carl von Linné outlined in his work Philosophia Botanica methods for compiling annual plant calendars of leaf opening, flowering, fruiting and leaf fall together with climatological observations "so as to show how areas differ". Recently in most European countries, phenological observations have been carried out routinely for more than 50 years by different governmental and non governmental organisations and following different observation guidelines, the data stored at different places in different formats. This has been really hampering pan European studies as one has to address many network operators to get access to the data before one can start to bring them in a uniform style. From 2004 to 2009 the COST-action 725 established a European wide data set of phenological observations. But the deliverables of this COST action was not only the common phenological database and common observation guidelines - COST725 helped to trigger a revival of some old networks and to establish new ones as for instance in Sweden. At the end of 2009 the COST action the database comprised about 8 million data in total from 15 European countries plus the data from the International Phenological Gardens IPG. In January 2010 PEP725 began its work as follow up project with funding from EUMETNET the network of European meteorological services and of ZAMG the Austrian national meteorological service. PEP725 not only will take over the part of maintaining, updating the COST725 database, but also to bring in phenological data from the time before 1951, developing better quality checking procedures and ensuring an open access to the database. An attractive webpage will make phenology and climate impacts on vegetation more visible in the public enabling a monitoring of vegetation development.

  11. Proceedings of the Seventh Conference of Nuclear Sciences and Applications. Vol.1,2,3

    International Nuclear Information System (INIS)

    Aly, H.F.

    2000-01-01

    The publication has been set up as a textbook for nuclear sciences and applications vol.1: (1) radiochemistry; (2) radiation chemistry; (3) isotope production; (4) waste management; vol.2: (1) nuclear and reactor; (2) physics; (3) plasma physics; (4) instrumentation and devices; (5) trace and ultra trace analysis; (6) environmental; vol.3: (1) radiation protection; (2) radiation health hazards; (3) nuclear safety; (4) biology; (5) agriculture

  12. Proceedings of the Seventh Conference of Nuclear Sciences and Applications. Vol.1,2,3

    Energy Technology Data Exchange (ETDEWEB)

    Aly, H F [ed.

    2000-07-01

    The publication has been set up as a textbook for nuclear sciences and applications vol.1: (1) radiochemistry; (2) radiation chemistry; (3) isotope production; (4) waste management; vol.2: (1) nuclear and reactor; (2) physics; (3) plasma physics; (4) instrumentation and devices; (5) trace and ultra trace analysis; (6) environmental; vol.3: (1) radiation protection; (2) radiation health hazards; (3) nuclear safety; (4) biology; (5) agriculture.

  13. Large hadron collider workshop. Proceedings. Vol. 2

    International Nuclear Information System (INIS)

    Jarlskog, G.; Rein, D.

    1990-01-01

    The aim of the LHC workshop at Aachen was to discuss the 'discovery potential' of a high-luminosity hadron collider (the Large Hadron Collider) and to define the requirements of the detectors. Of central interest was whether a Higgs particle with mass below 1 TeV could be seen using detectors potentially available within a few years from now. Other topics included supersymmetry, heavy quarks, excited gauge bosons, and exotica in proton-proton collisions, as well as physics to be observed in electron-proton and heavy-ion collisions. A large part of the workshop was devoted to the discussion of instrumental and detector concepts, including simulation, signal processing, data acquisition, tracking, calorimetry, lepton identification and radiation hardness. The workshop began with parallel sessions of working groups on physics and instrumentation and continued, in the second half, with plenary talks giving overviews of the LHC project and the SSC, RHIC, and HERA programmes, summaries of the working groups, presentations from industry, and conclusions. Vol.1 of these proceedings contains the papers presented at the plenary sessions, Vol.2 the individual contributions to the physics sessions, and Vol.3 those to the instrumentation sessions. (orig.)

  14. The role of spring and autumn phenological switches on spatiotemporal variation in temperate and boreal forest C balance: A FLUXNET synthesis

    Science.gov (United States)

    Richardson, A. D.; Reichstein, M.; Piao, S.; Ciais, P.; Luyssaert, S.; Stockli, R.; Friedl, M.; Gobron, N.; Fluxnet Site Pis, 21

    2009-04-01

    In temperate and boreal ecosystems, phenological transitions (particularly the timing of spring onset and autumn senescence) are thought to represent a major control on spatial and temporal variation in forest carbon sequestration. To investigate these patterns, we analyzed 153 site-years of data from the FLUXNET ‘La Thuile' database. Eddy covariance measurements of surface-atmosphere exchanges of carbon and water from 21 research sites at latitudes from 36°N to 67°N were used in the synthesis. We defined a range of phenological indicators based on the first (spring) and last (autumn) dates of (1) C source/sink transitions (‘carbon uptake period'); (2) measurable photosynthetic uptake (‘physiologically active period'); (3) relative thresholds for latent heat (evapotranspiration) flux; (4) phenological thresholds derived from a range of remote sensing products (JRC fAPAR, MOD12Q2, and the PROGNOSTIC model with MODIS data assimilation); and (5) a climatological metric based on the date where soil temperature equals mean annual air temperature. We then tested whether site-level flux anomalies were significantly correlated with phenological anomalies across these metrics, and whether the slopes of these relationships (representing the sensitivity to phenological variation) differed between deciduous broadleaf (DBF) and evergreen needleleaf (ENF) forests. Within sites, interannual variation in most phenological metrics was about 5-10 d, compared to 10-30 d across sites. Both spatial and temporal phenological variation were consistently larger at ENF, compared to DBF, sites. Averaged across metrics, phenological variability was roughly comparable in spring and autumn, both across (17 d) and within (9 d) sites. However, patterns of interannual variation in fluxes were less well explained by the derived phenological metrics than were patterns of spatial variation in fluxes. Also, the observed pattern strongly depended on the metric used, with flux-derived metrics

  15. A phenological timetable of oak growth under experimental drought and air warming.

    Directory of Open Access Journals (Sweden)

    Thomas M Kuster

    Full Text Available Climate change is expected to increase temperature and decrease summer precipitation in Central Europe. Little is known about how warming and drought will affect phenological patterns of oaks, which are considered to possess excellent adaptability to these climatic changes. Here, we investigated bud burst and intra-annual shoot growth of Quercus robur, Q. petraea and Q. pubescens grown on two different forest soils and exposed to air warming and drought. Phenological development was assessed over the course of three growing seasons. Warming advanced bud burst by 1-3 days °C⁻¹ and led to an earlier start of intra-annual shoot growth. Despite this phenological shift, total time span of annual growth and shoot biomass were not affected. Drought changed the frequency and intensity of intra-annual shoot growth and advanced bud burst in the subsequent spring of a severe summer drought by 1-2 days. After re-wetting, shoot growth recovered within a few days, demonstrating the superior drought tolerance of this tree genus. Our findings show that phenological patterns of oaks are modified by warming and drought but also suggest that ontogenetic factors and/or limitations of water and nutrients counteract warming effects on the biomass and the entire span of annual shoot growth.

  16. Reproductive phenology of coastal plain Atlantic forest vegetation: comparisons from seashore to foothills.

    Science.gov (United States)

    Staggemeier, Vanessa Graziele; Morellato, Leonor Patrícia Cerdeira

    2011-11-01

    The diversity of tropical forest plant phenology has called the attention of researchers for a long time. We continue investigating the factors that drive phenological diversity on a wide scale, but we are unaware of the variation of plant reproductive phenology at a fine spatial scale despite the high spatial variation in species composition and abundance in tropical rainforests. We addressed fine scale variability by investigating the reproductive phenology of three contiguous vegetations across the Atlantic rainforest coastal plain in Southeastern Brazil. We asked whether the vegetations differed in composition and abundance of species, the microenvironmental conditions and the reproductive phenology, and how their phenology is related to regional and local microenvironmental factors. The study was conducted from September 2007 to August 2009 at three contiguous sites: (1) seashore dominated by scrub vegetation, (2) intermediary covered by restinga forest and (3) foothills covered by restinga pre-montane transitional forest. We conducted the microenvironmental, plant and phenological survey within 30 transects of 25 m × 4 m (10 per site). We detected significant differences in floristic, microenvironment and reproductive phenology among the three vegetations. The microenvironment determines the spatial diversity observed in the structure and composition of the flora, which in turn determines the distinctive flowering and fruiting peaks of each vegetation (phenological diversity). There was an exchange of species providing flowers and fruits across the vegetation complex. We conclude that plant reproductive patterns as described in most phenological studies (without concern about the microenvironmental variation) may conceal the fine scale temporal phenological diversity of highly diverse tropical vegetation. This phenological diversity should be taken into account when generating sensor-derived phenologies and when trying to understand tropical vegetation

  17. Review: advances in in situ and satellite phenological observations in Japan

    Science.gov (United States)

    Nagai, Shin; Nasahara, Kenlo Nishida; Inoue, Tomoharu; Saitoh, Taku M.; Suzuki, Rikie

    2016-04-01

    To accurately evaluate the responses of spatial and temporal variation of ecosystem functioning (evapotranspiration and photosynthesis) and services (regulating and cultural services) to the rapid changes caused by global warming, we depend on long-term, continuous, near-surface, and satellite remote sensing of phenology over wide areas. Here, we review such phenological studies in Japan and discuss our current knowledge, problems, and future developments. In contrast with North America and Europe, Japan has been able to evaluate plant phenology along vertical and horizontal gradients within a narrow area because of the country's high topographic relief. Phenological observation networks that support scientific studies and outreach activities have used near-surface tools such as digital cameras and spectral radiometers. Differences in phenology among ecosystems and tree species have been detected by analyzing the seasonal variation of red, green, and blue digital numbers (RGB values) extracted from phenological images, as well as spectral reflectance and vegetation indices. The relationships between seasonal variations in RGB-derived indices or spectral characteristics and the ecological and CO2 flux measurement data have been well validated. In contrast, insufficient satellite remote-sensing observations have been conducted because of the coarse spatial resolution of previous datasets, which could not detect the heterogeneous plant phenology that results from Japan's complex topography and vegetation. To improve Japanese phenological observations, multidisciplinary analysis and evaluation will be needed to link traditional phenological observations with "index trees," near-surface and satellite remote-sensing observations, "citizen science" (observations by citizens), and results published on the Internet.

  18. Fabrication and Characterization of 5 vol.% (Al2O3p + 8 vol.% (Al2O3f/A336 Hybrid Micron and Nano-Composites

    Directory of Open Access Journals (Sweden)

    Ren Luyang

    2017-01-01

    Full Text Available Hybrid composites are fabricated by adding two reinforcements into matrix materials so that the expected excellent properties can be achieved through the combined advantages of short fibres, and different size particles (micron or nano, which provide a high degree of design freedom. In this paper, hybrid preforms were produced with the different size reinforcement of the Al2O3 particles and short fibres. The Al-Si alloy-based hybrid composites reinforced by 5 vol. % Al2O3 particles and 8 vol. % Al2O3 fibres were fabricated by preform-squeezing casting route. The structure and performance of composite materials were studied with Transmission Electron Microscopy (TEM and Scanning Electron Microscopy (SEM. The results show that the reinforcements, both particles and fibres, distribute homogeneously in the matrix materials, and the properties of composites are found to improve in comparison with the matrix Al-Si alloy.

  19. Generation and Evaluation of a Global Land Surface Phenology Product from Suomi-NPP VIIRS Observations

    Science.gov (United States)

    Zhang, X.; Liu, L.; Yan, D.; Moon, M.; Liu, Y.; Henebry, G. M.; Friedl, M. A.; Schaaf, C.

    2017-12-01

    Land surface phenology (LSP) datasets have been produced from a variety of coarse spatial resolution satellite observations at both regional and global scales and spanning different time periods since 1982. However, the LSP product generated from NASA's MODerate Resolution Imaging Spectroradiometer (MODIS) data at a spatial resolution of 500m, which is termed Land Cover Dynamics (MCD12Q2), is the only global product operationally produced and freely accessible at annual time steps from 2001. Because MODIS instrument is aging and will be replaced by the Visible Infrared Imaging Radiometer Suite (VIIRS), this research focuses on the generation and evaluation of a global LSP product from Suomi-NPP VIIRS time series observations that provide continuity with the MCD12Q2 product. Specifically, we generate 500m VIIRS global LSP data using daily VIIRS Nadir BRDF (bidirectional reflectance distribution function)-Adjusted reflectances (NBAR) in combination with land surface temperature, snow cover, and land cover type as inputs. The product provides twelve phenological metrics (seven phenological dates and five phenological greenness magnitudes), along with six quality metrics characterizing the confidence and quality associated with phenology retrievals at each pixel. In this paper, we describe the input data and algorithms used to produce this new product, and investigate the impact of VIIRS data time series quality on phenology detections across various climate regimes and ecosystems. As part of our analysis, the VIIRS LSP is evaluated using PhenoCam imagery in North America and Asia, and using higher spatial resolution satellite observations from Landsat 8 over an agricultural area in the central USA. We also explore the impact of high frequency cloud cover on the VIIRS LSP product by comparing with phenology detected from the Advanced Himawari Imager (AHI) onboard Himawari-8. AHI is a new geostationary sensor that observes land surface every 10 minutes, which increases

  20. Phenological Changes in the Southern Hemisphere

    Science.gov (United States)

    Chambers, Lynda E.; Altwegg, Res; Barbraud, Christophe; Barnard, Phoebe; Beaumont, Linda J.; Crawford, Robert J. M.; Durant, Joel M.; Hughes, Lesley; Keatley, Marie R.; Low, Matt; Morellato, Patricia C.; Poloczanska, Elvira S.; Ruoppolo, Valeria; Vanstreels, Ralph E. T.; Woehler, Eric J.; Wolfaardt, Anton C.

    2013-01-01

    Current evidence of phenological responses to recent climate change is substantially biased towards northern hemisphere temperate regions. Given regional differences in climate change, shifts in phenology will not be uniform across the globe, and conclusions drawn from temperate systems in the northern hemisphere might not be applicable to other regions on the planet. We conduct the largest meta-analysis to date of phenological drivers and trends among southern hemisphere species, assessing 1208 long-term datasets from 89 studies on 347 species. Data were mostly from Australasia (Australia and New Zealand), South America and the Antarctic/subantarctic, and focused primarily on plants and birds. This meta-analysis shows an advance in the timing of spring events (with a strong Australian data bias), although substantial differences in trends were apparent among taxonomic groups and regions. When only statistically significant trends were considered, 82% of terrestrial datasets and 42% of marine datasets demonstrated an advance in phenology. Temperature was most frequently identified as the primary driver of phenological changes; however, in many studies it was the only climate variable considered. When precipitation was examined, it often played a key role but, in contrast with temperature, the direction of phenological shifts in response to precipitation variation was difficult to predict a priori. We discuss how phenological information can inform the adaptive capacity of species, their resilience, and constraints on autonomous adaptation. We also highlight serious weaknesses in past and current data collection and analyses at large regional scales (with very few studies in the tropics or from Africa) and dramatic taxonomic biases. If accurate predictions regarding the general effects of climate change on the biology of organisms are to be made, data collection policies focussing on targeting data-deficient regions and taxa need to be financially and logistically

  1. Phenological changes in the southern hemisphere.

    Directory of Open Access Journals (Sweden)

    Lynda E Chambers

    Full Text Available Current evidence of phenological responses to recent climate change is substantially biased towards northern hemisphere temperate regions. Given regional differences in climate change, shifts in phenology will not be uniform across the globe, and conclusions drawn from temperate systems in the northern hemisphere might not be applicable to other regions on the planet. We conduct the largest meta-analysis to date of phenological drivers and trends among southern hemisphere species, assessing 1208 long-term datasets from 89 studies on 347 species. Data were mostly from Australasia (Australia and New Zealand, South America and the Antarctic/subantarctic, and focused primarily on plants and birds. This meta-analysis shows an advance in the timing of spring events (with a strong Australian data bias, although substantial differences in trends were apparent among taxonomic groups and regions. When only statistically significant trends were considered, 82% of terrestrial datasets and 42% of marine datasets demonstrated an advance in phenology. Temperature was most frequently identified as the primary driver of phenological changes; however, in many studies it was the only climate variable considered. When precipitation was examined, it often played a key role but, in contrast with temperature, the direction of phenological shifts in response to precipitation variation was difficult to predict a priori. We discuss how phenological information can inform the adaptive capacity of species, their resilience, and constraints on autonomous adaptation. We also highlight serious weaknesses in past and current data collection and analyses at large regional scales (with very few studies in the tropics or from Africa and dramatic taxonomic biases. If accurate predictions regarding the general effects of climate change on the biology of organisms are to be made, data collection policies focussing on targeting data-deficient regions and taxa need to be financially

  2. Dynamics of structures '89. Vol. 1 and 2

    International Nuclear Information System (INIS)

    1989-01-01

    The proceedings, comprising 3 volumes published by the Plzen Centre of the Czechoslovak Society for Science and Technology (Vol. 1 and 2) and by Skoda Works in Plzen (Vol. 3), contain 107 papers, out of which 8 fall within the INIS Subject Scope; these deal with problems related to the earthquake resistance of nuclear power plants. Attention is paid to the evaluation of seismic characteristics of nuclear power plant equipment, to the equipment testing and to calculations of its dynamic characteristics under simulated seismic stress. (Z.M.)

  3. Physics at LEP2. Vol. 1

    International Nuclear Information System (INIS)

    Altarelli, G.; Sjoestrand, T.; Zwirner, F.

    1996-01-01

    This is the final report of the Workshop on Physics at LEP2, held at CERN during 1995. The first part of vol. 1 is devoted to aspects of machine physics of particular relevance to experiments, including the energy, luminosity and interaction regions, as well as the measurement of beam energy. The second part of vol. 1 is a relatively concise, but fairly complete, handbook on the physics of e + e - annihilation above the WW threshold and up to √s∼200 GeV. It contains discussions on WW cross-sections and distributions, W mass determination, Standard Model processes, QCD and gamma-gamma physics, as well as aspects of discovery physics, such as Higgs, new particle searches, triple gauge boson couplings and Z'. The second volume contains a review of the existing Monte Carlo generators for LEP2 physics. These include generators for WW physics, QCD and gamma-gamma processes, Bhabha scattering and discovery physics. A special effort was made to co-ordinate the different parts, with a view to achieving a systematic and balanced review of the subject, rather than just publishing a collection of separate contributions. (orig.)

  4. A background to risk analysis. Vol. 2

    International Nuclear Information System (INIS)

    Taylor, J.R.

    1979-01-01

    This 4-volumes report gives a background of ideas, principles and examples which might be of use in developing practical methods for risk analysis. Some of the risk analysis techniques described are somewhat experimental. The report is written in an introductory style, but where some point needs further justification or evaluation, this is given in the form of a chapter appendix. In this way, it is hoped that the report can serve two purposes, - as a basis for starting risk analysis work and as a basis for discussing effectiveness of risk analysis procedures. The report should be seen as a preliminary stage, prior to a program of industrial trials of risk analysis methods. Vol. 2 treats generic methods of qualitative failure analysis. (BP)

  5. Update on Plans to Establish a National Phenology Network in the U.S.A.

    Science.gov (United States)

    Betancourt, J.; Schwartz, M.; Breshears, D.; Cayan, D.; Dettinger, M.; Inouye, D.; Post, E.; Reed, B.; Gray, S.

    2005-12-01

    The passing of the seasons is the most pervasive source of climatic and biological variability on Earth, yet phenological monitoring has been spotty worldwide. Formal phenological networks were recently established in Europe and Canada, and we are now following their lead in organizing a National Phenology Network (NPN) for the U.S.A. With support from federal agencies (NSF, USGS, NPS, USDA-FS, EPA, NOAA, NASA), on Aug. 22-26 we organized a workshop in Tucson, Arizona to begin planning a national-scale, multi-tiered phenological network. A prototype for a web-based NPN and preliminary workshop results are available at http://www.npn.uwm.edu. The main goals of NPN will be to: (1) facilitate thorough understanding of phenological phenomena, including causes and effects; (2) provide ground truthing to make the most of heavy public investment in remote sensing data; (3) allow detection and prediction of environmental change for a wide of variety of applications; (4) harness the power of mass participation and engage tens of thousands of "citizen scientists" in meeting national needs in Education, Health, Commerce, Natural Resources and Agriculture; (5) develop a model system for substantive collaboration across different levels of government, academia and the private sector. Just as the national networks of weather stations and stream gauges are critical for providing weather, climate and water-related information, NPN will help safeguard and procure goods and services that ecosystems provide. We expect that NPN will consist of a four-tiered, expandable structure: 1) a backbone network linked to existing weather stations, run by recruited public observers; 2) A smaller, second tier of intensive observations, run by scientists at established research sites; 3) a much larger network of observations made by citizen scientists; and 4) remote sensing observations that can be validated with surface observations, thereby providing wall-to-wall coverage for the U.S.A. Key to

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

    Science.gov (United States)

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

    2015-01-01

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

  7. Old Plants, New Tricks: Phenological Research Using Herbarium Specimens.

    Science.gov (United States)

    Willis, Charles G; Ellwood, Elizabeth R; Primack, Richard B; Davis, Charles C; Pearson, Katelin D; Gallinat, Amanda S; Yost, Jenn M; Nelson, Gil; Mazer, Susan J; Rossington, Natalie L; Sparks, Tim H; Soltis, Pamela S

    2017-07-01

    The timing of phenological events, such as leaf-out and flowering, strongly influence plant success and their study is vital to understanding how plants will respond to climate change. Phenological research, however, is often limited by the temporal, geographic, or phylogenetic scope of available data. Hundreds of millions of plant specimens in herbaria worldwide offer a potential solution to this problem, especially as digitization efforts drastically improve access to collections. Herbarium specimens represent snapshots of phenological events and have been reliably used to characterize phenological responses to climate. We review the current state of herbarium-based phenological research, identify potential biases and limitations in the collection, digitization, and interpretation of specimen data, and discuss future opportunities for phenological investigations using herbarium specimens. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Temporal coherence of phenological and climatic rhythmicity in Beijing

    Science.gov (United States)

    Chen, Xiaoqiu; Zhang, Weiqi; Ren, Shilong; Lang, Weiguang; Liang, Boyi; Liu, Guohua

    2017-10-01

    Using woody plant phenological data in the Beijing Botanical Garden from 1979 to 2013, we revealed three levels of phenology rhythms and examined their coherence with temperature rhythms. First, the sequential and correlative rhythm shows that occurrence dates of various phenological events obey a certain time sequence within a year and synchronously advance or postpone among years. The positive correlation between spring phenophase dates is much stronger than that between autumn phenophase dates and attenuates as the time interval between two spring phenophases increases. This phenological rhythm can be explained by positive correlation between above 0 °C mean temperatures corresponding to different phenophase dates. Second, the circannual rhythm indicates that recurrence interval of a phenophase in the same species in two adjacent years is about 365 days, which can be explained by the 365-day recurrence interval in the first and last dates of threshold temperatures. Moreover, an earlier phenophase date in the current year may lead to a later phenophase date in the next year through extending recurrence interval. Thus, the plant phenology sequential and correlative rhythm and circannual rhythm are interacted, which mirrors the interaction between seasonal variation and annual periodicity of temperature. Finally, the multi-year rhythm implies that phenophase dates display quasi-periodicity more than 1 year. The same 12-year periodicity in phenophase and threshold temperature dates confirmed temperature controls of the phenology multi-year rhythm. Our findings provide new perspectives for examining phenological response to climate change and developing comprehensive phenology models considering temporal coherence of phenological and climatic rhythmicity.

  9. PERPHECLIM ACCAF Project - Perennial fruit crops and forest phenology evolution facing climatic changes

    Science.gov (United States)

    Garcia de Cortazar-Atauri, Iñaki; Audergon, Jean Marc; Bertuzzi, Patrick; Anger, Christel; Bonhomme, Marc; Chuine, Isabelle; Davi, Hendrik; Delzon, Sylvain; Duchêne, Eric; Legave, Jean Michel; Raynal, Hélène; Pichot, Christian; Van Leeuwen, Cornelis; Perpheclim Team

    2015-04-01

    Phenology is a bio-indicator of climate evolutions. Measurements of phenological stages on perennial species provide actually significant illustrations and assessments of the impact of climate change. Phenology is also one of the main key characteristics of the capacity of adaptation of perennial species, generating questions about their consequences on plant growth and development or on fruit quality. Predicting phenology evolution and adaptative capacities of perennial species need to override three main methodological limitations: 1) existing observations and associated databases are scattered and sometimes incomplete, rendering difficult implementation of multi-site study of genotype-environment interaction analyses; 2) there are not common protocols to observe phenological stages; 3) access to generic phenological models platforms is still very limited. In this context, the PERPHECLIM project, which is funded by the Adapting Agriculture and Forestry to Climate Change Meta-Program (ACCAF) from INRA (French National Institute of Agronomic Research), has the objective to develop the necessary infrastructure at INRA level (observatories, information system, modeling tools) to enable partners to study the phenology of various perennial species (grapevine, fruit trees and forest trees). Currently the PERPHECLIM project involves 27 research units in France. The main activities currently developed are: define protocols and observation forms to observe phenology for various species of interest for the project; organizing observation training; develop generic modeling solutions to simulate phenology (Phenological Modelling Platform and modelling platform solutions); support in building research projects at national and international level; develop environment/genotype observation networks for fruit trees species; develop an information system managing data and documentation concerning phenology. Finally, PERPHECLIM project aims to build strong collaborations with public

  10. Schostakowitsch. Orchesterlieder (Vol. 2), Neeme Järvi / Werner Pfister

    Index Scriptorium Estoniae

    Pfister, Werner

    1996-01-01

    Uuest heliplaadist "Schostakowitsch. Orchesterlieder (Vol. 2): Sechs Romanzen op. 21, Sechs Gedichte op. 143a, Suite auf Verse von Michelangelo Buonarroti op. 145a. Göteborger Sinfoniker, Neeme Järvi". DG CD 447 085-2 (WD: 71'06") DDD

  11. Pan European Phenological database (PEP725): a single point of access for European data

    Science.gov (United States)

    Templ, Barbara; Koch, Elisabeth; Bolmgren, Kjell; Ungersböck, Markus; Paul, Anita; Scheifinger, Helfried; Rutishauser, This; Busto, Montserrat; Chmielewski, Frank-M.; Hájková, Lenka; Hodzić, Sabina; Kaspar, Frank; Pietragalla, Barbara; Romero-Fresneda, Ramiro; Tolvanen, Anne; Vučetič, Višnja; Zimmermann, Kirsten; Zust, Ana

    2018-02-01

    The Pan European Phenology (PEP) project is a European infrastructure to promote and facilitate phenological research, education, and environmental monitoring. The main objective is to maintain and develop a Pan European Phenological database (PEP725) with an open, unrestricted data access for science and education. PEP725 is the successor of the database developed through the COST action 725 "Establishing a European phenological data platform for climatological applications" working as a single access point for European-wide plant phenological data. So far, 32 European meteorological services and project partners from across Europe have joined and supplied data collected by volunteers from 1868 to the present for the PEP725 database. Most of the partners actively provide data on a regular basis. The database presently holds almost 12 million records, about 46 growing stages and 265 plant species (including cultivars), and can be accessed via http://www.pep725.eu/. Users of the PEP725 database have studied a diversity of topics ranging from climate change impact, plant physiological question, phenological modeling, and remote sensing of vegetation to ecosystem productivity.

  12. Pan European Phenological database (PEP725): a single point of access for European data

    Science.gov (United States)

    Templ, Barbara; Koch, Elisabeth; Bolmgren, Kjell; Ungersböck, Markus; Paul, Anita; Scheifinger, Helfried; Rutishauser, This; Busto, Montserrat; Chmielewski, Frank-M.; Hájková, Lenka; Hodzić, Sabina; Kaspar, Frank; Pietragalla, Barbara; Romero-Fresneda, Ramiro; Tolvanen, Anne; Vučetič, Višnja; Zimmermann, Kirsten; Zust, Ana

    2018-06-01

    The Pan European Phenology (PEP) project is a European infrastructure to promote and facilitate phenological research, education, and environmental monitoring. The main objective is to maintain and develop a Pan European Phenological database (PEP725) with an open, unrestricted data access for science and education. PEP725 is the successor of the database developed through the COST action 725 "Establishing a European phenological data platform for climatological applications" working as a single access point for European-wide plant phenological data. So far, 32 European meteorological services and project partners from across Europe have joined and supplied data collected by volunteers from 1868 to the present for the PEP725 database. Most of the partners actively provide data on a regular basis. The database presently holds almost 12 million records, about 46 growing stages and 265 plant species (including cultivars), and can be accessed via http://www.pep725.eu/ . Users of the PEP725 database have studied a diversity of topics ranging from climate change impact, plant physiological question, phenological modeling, and remote sensing of vegetation to ecosystem productivity.

  13. Phenological Records

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Phenology is the scientific study of periodic biological phenomena, such as flowering, breeding, and migration, in relation to climatic conditions. The few records...

  14. Phenology, dichogamy, and floral synchronization in a northern red oak (Quercus rubra) seed orchard

    Science.gov (United States)

    Lisa W. Alexander; Keith E. Woeste

    2016-01-01

    We developed a novel scoring system to assess spring phenology in a northern red oak (Quercus rubra L.) clonal seed orchard. The system was used to score from 304 to 364 ramets for three reproductive seasons and to place clones into early, intermediate, and late phenology classes. Although the absolute number of clones in each phenological class...

  15. A Comparative Study on Satellite- and Model-Based Crop Phenology in West Africa

    Directory of Open Access Journals (Sweden)

    Elodie Vintrou

    2014-02-01

    Full Text Available Crop phenology is essential for evaluating crop production in the food insecure regions of West Africa. The aim of the paper is to study whether satellite observation of plant phenology are consistent with ground knowledge of crop cycles as expressed in agro-simulations. We used phenological variables from a MODIS Land Cover Dynamics (MCD12Q2 product and examined whether they reproduced the spatio-temporal variability of crop phenological stages in Southern Mali. Furthermore, a validated cereal crop growth model for this region, SARRA-H (System for Regional Analysis of Agro-Climatic Risks, provided precise agronomic information. Remotely-sensed green-up, maturity, senescence and dormancy MODIS dates were extracted for areas previously identified as crops and were compared with simulated leaf area indices (LAI temporal profiles generated using the SARRA-H crop model, which considered the main cropping practices. We studied both spatial (eight sites throughout South Mali during 2007 and temporal (two sites from 2002 to 2008 differences between simulated crop cycles and determined how the differences were indicated in satellite-derived phenometrics. The spatial comparison of the phenological indicator observations and simulations showed mainly that (i the satellite-derived start-of-season (SOS was detected approximately 30 days before the model-derived SOS; and (ii the satellite-derived end-of-season (EOS was typically detected 40 days after the model-derived EOS. Studying the inter-annual difference, we verified that the mean bias was globally consistent for different climatic conditions. Therefore, the land cover dynamics derived from the MODIS time series can reproduce the spatial and temporal variability of different start-of-season and end-of-season crop species. In particular, we recommend simultaneously using start-of-season phenometrics with crop models for yield forecasting to complement commonly used climate data and provide a better

  16. The Phenological Network of Catalonia: an historical perspective

    Science.gov (United States)

    Busto, Montserrat; Cunillera, Jordi; de Yzaguirre, Xavier

    2017-04-01

    The Meteorological Service of Catalonia (SMC) began systematic phenological observation in 1932. Forty-four observers registered the phenophases of 45 plant species, the first or last sighting of six bird species and the first sighting of one species of butterfly. The study First results of phenological observation in Catalonia was published in 1936, showing the different behaviour of the vegetal species and birds according to geographical location. The SMC worked against the military fascist uprising during the Spanish Civil War (1936-1939). Therefore, once the war was finished, the organisation was quickly closed by the Franco dictatorship and the National Meteorological Service became the official institution in Spain. This organization created the Spanish Phenological Network in 1943 following similar standards to the former Catalan network. The reintroduction of democracy and the return of the Catalan self-government structures (1977) allowed the re-foundation of the SMC in 1996. The Climatology Department needed phenological data to complement the study of climatic indicators and realised the fragile situation of phenology observations in Catalonia, with very few operational series. Following a preliminary analysis of the different systems of recording and saving data, the Phenological network of Catalonia (Fenocat) was re-established in 2013. Fenocat is an active partner of the Pan European Phenology Database (PEP725) that uses BBCH-scale coding and the USA National Phenology Network observation system. It is an example of citizen science. As at December 2016, Fenocat had recorded more than 450,000 data. The extension of summer climatic conditions in the Western Mediterranean region has resulted in repetition of phenopases in the same year, such as the second flowering of the holm oak (Quercus ilex), almond tree (Prunus dulcis) and sweet cherry tree (Prunus avium), or the delay in the departure data of the swallow (Hirundo rustica) and hoopoe (Upupa epops

  17. Gender and Behaviour - Vol 5, No 2 (2007)

    African Journals Online (AJOL)

    Gender and Behaviour. ... Gender and Behaviour - Vol 5, No 2 (2007) ... Home Type, Age and Gender on The Antisocial Behaviour of Secondary School Students. ... Gender-Wise Comparison on Emotional Intelligence and Marital Satisfaction.

  18. Comparing MODIS and near-surface vegetation indexes for monitoring tropical dry forest phenology along a successional gradient using optical phenology towers

    Science.gov (United States)

    Rankine, C.; Sánchez-Azofeifa, G. A.; Guzmán, J. Antonio; Espirito-Santo, M. M.; Sharp, Iain

    2017-10-01

    Tropical dry forests (TDFs) present strong seasonal greenness signals ideal for tracking phenology and primary productivity using remote sensing techniques. The tightly synchronized relationship these ecosystems have with water availability offer a valuable natural experiment for observing the complex interactions between the atmosphere and the biosphere in the tropics. To investigate how well the MODIS vegetation indices (normalized difference vegetation index (NDVI) and the enhanced vegetation index (EVI)) represented the phenology of different successional stages of naturally regenerating TDFs, within a widely conserved forest fragment in the semi-arid southeast of Brazil, we installed several canopy towers with radiometric sensors to produce high temporal resolution near-surface vegetation greenness indices. Direct comparison of several years of ground measurements with a combined Aqua/Terra 8 day satellite product showed similar broad temporal trends, but MODIS often suffered from cloud contamination during the onset of the growing season and occasionally during the peak growing season. The strength of the in-situ and MODIS linear relationship was greater for NDVI than for EVI across sites but varied with forest stand age. Furthermore, we describe the onset dates and duration of canopy development phases for three years of in-situ monitoring. A seasonality analysis revealed significant discrepancies between tower and MODIS phenology transitions dates, with up to five weeks differences in growing season length estimation. Our results indicate that 8 and 16 day MODIS satellite vegetation monitoring products are suitable for tracking general patterns of tropical dry forest phenology in this region but are not temporally sufficient to characterize inter-annual differences in phenology phase onset dates or changes in productivity due to mid-season droughts. Such rapid transitions in canopy greenness are important indicators of climate change sensitivity of these

  19. Shostakovich: The Orchestral Songs Vol. 2 / Michael Tanner

    Index Scriptorium Estoniae

    Tanner, Michael

    1996-01-01

    Uuest heliplaadist "Shostakovich: The Orchestral Songs Vol. 2: Six Romances on texts by Japanese poets, Op. 21. Six Poems on Marina Tsvetayeva, Op. 143. Suite on Verses of Michelangelo, Op. 145. Gothenburg Symphony Orchestra, Neeme Järvi". DG 447 085-2GH (71 minutes:DDD)

  20. Historical Phenological Observations: Past Climate Impact Analyses and Climate Reconstructions

    Science.gov (United States)

    Rutishauser, T.; Luterbacher, J.; Meier, N.; Jeanneret, F.; Pfister, C.; Wanner, H.

    2007-12-01

    Plant phenological observations have been found an important indicator of climate change impacts on seasonal and interannual vegetation development for the late 20th/early 21st century. Our contribution contains three parts that are essential for the understanding (part 1), the analysis (part 2) and the application (part 3) of historical phenological observations in global change research. First, we propose a definition for historical phenonolgy (Rutishauser, 2007). We shortly portray the first appearance of phenological observations in Medieval philosophical and literature sources, the usage and application of this method in the Age of Enlightenment (Carl von Linné, Charles Morren), as well as the development in the 20th century (Schnelle, Lieth) to present-day networks (COST725, USA-NPN) Second, we introduce a methodological approach to estimate 'Statistical plants' from historical phenological observations (Rutishauser et al., JGR-Biogeoscience, in press). We combine spatial averaging methods and regression transfer modeling to estimate 'statistical plant' dates from historical observations that often contain gaps, changing observers and changing locations. We apply the concept to reconstruct a statistical 'Spring plant' as the weighted mean of the flowering date of cherry and apple tree and beech budburst of Switzerland 1702- 2005. Including dating total data uncertainty we estimate 10 at interannual and 3.4 days at decadal time scales. Third, we apply two long-term phenological records to describe plant phenological response to spring temperature and reconstruct warm-season temperatures from grape harvest dates (Rutishauser et al, submitted; Meier et al, GRL, in press).

  1. Examining spring phenology of forest understory using digital photography

    Science.gov (United States)

    Liang Liang; Mark D. Schwartz; Songlin Fei

    2011-01-01

    Phenology is an important indicator of forest health in relation to energy/nutrient cycles and species interactions. Accurate characterization of forest understory phenology is a crucial part of forest phenology observation. In this study, ground plots set up in a temperate mixed forest in Wisconsin were observed with a visible-light digital camera during spring 2007....

  2. Neeme Järvi. "The Early Recordings", vol. 1 a 6. / Hulot, Jean-Claude

    Index Scriptorium Estoniae

    Hulot, Jean-Claude

    1998-01-01

    Uuest heliplaadist "Neeme Järvi. "The Early Recordings", vol. 1 a 6. Paganini: Concerto pour violon no. 1; Tchaikovski: Concerto pour violon op. 35; Concerto pour piano no. 1; Saint-Saens: Concerto pour piano no. 2; Beethoven: Concerto pour piano no. 4; R. Strauss: Till Eulenspiegels lustige Streiche. Don Juan; Cherubini: Requiem en re mineur; Chostakovitch: Fidelite, 8 ballades pour choeur d'hommes op. 136; Haydn: Concerto pour violoncelle no. 2; Tchaikovski: Variations Rococo. Pezzo capriccioso. Andante cantabile. Nocturne. Choeur d'hommes Academique de l'Etat d'Estonie, Orchestre Philharmonique de Moscou, Orchestre Symphonique d'URSS, Grand Orchestre Symphonique de la Radio d'URSS, Orchestre Symphonique de la Radio d'Estonie, Gustav Ernesaks, Neeme Järvi. Melodiya 74 321 40 719-2 a 40 724-2, distribution BMG (6 CD:96 F chacun)

  3. Creative Artist: A Journal of Theatre and Media Studies - Vol 8, No 2 ...

    African Journals Online (AJOL)

    Creative Artist: A Journal of Theatre and Media Studies - Vol 8, No 2 (2014) ... Social Media Use And Real-life Social Relationships: (A Study of Nnamdi ... The Impacts of Slavery and Colonialism on African Traditional Music and Dance ...

  4. Proceedings of the second international conference on environmental impact assessment of all economical activities. Vol. 2

    International Nuclear Information System (INIS)

    1993-01-01

    Proceedings of the conference consist of 3 volumes: Vol. 1 - 'Environmental Impact Assessment of all Economical Activities including Industry'; Vol. 2 - 'Air Pollution Control and Prevention'; Vol. 3 - Waste Management and Environmental Problems in Construction Industry'. Out of 32 papers contained in Vol. 2, 4 were inputted to INIS. They deal with nuclear fusion as a potential energy source, with environmental aspects of disposal of ashes from power plants in the Czech Republic, and with land reclamation after mining activities. (Z.S.)

  5. Phenological records as a complement to aerobiological data

    Science.gov (United States)

    Tormo, Rafael; Silva, Inmaculada; Gonzalo, Ángela; Moreno, Alfonsa; Pérez, Remedios; Fernández, Santiago

    2011-01-01

    Phenological studies in combination with aerobiological studies enable one to observe the relationship between the release of pollen and its presence in the atmosphere. To obtain a suitable comparison between the daily variation of airborne pollen concentrations and flowering, it is necessary for the level of accuracy of both sets of data to be as similar as possible. To analyse the correlation between locally observed flowering data and pollen counts in pollen traps in order to set pollen information forecasts, pollen was sampled using a Burkard volumetric pollen trap working continuously from May 1993. For the phenological study we selected the main pollen sources of the six pollen types most abundant in our area: Cupressaceae, Platanus, Quercus, Plantago, Olea, and Poaceae with a total of 35 species. We selected seven sites to register flowering or pollination, two with semi-natural vegetation, the rest being urban sites. The sites were visited weekly from March to June in 2007, and from January to June in 2008 and 2009. Pollen shedding was checked at each visit, and recorded as the percentage of flowers or microsporangia in that state. There was an association between flowering phenology and airborne pollen records for some of the pollen types ( Platanus, Quercus, Olea and Plantago). Nevertheless, for the other types (Cupressaceae and Poaceae) the flowering and airborne pollen peaks did not coincide, with up to 1 week difference in phase. Some arguments are put forward in explanation of this phenomenon. Phenological studies have shown that airborne pollen results from both local and distant sources, although the pollen peaks usually appear when local sources are shedding the greatest amounts of pollen. Resuspension phenomena are probably more important than long-distance transport in explaining the presence of airborne pollen outside the flowering period. This information could be used to improve pollen forecasts.

  6. African Health Sciences - Vol 13, No 2 (2013)

    African Journals Online (AJOL)

    African Health Sciences. ... African Health Sciences - Vol 13, No 2 (2013) ... S Musisi, D Akena, E Nakimuli-Mpungu, C Abbo, J Okello, 205-218 .... Alcohol consumption and cigarette smoking pattern among brothelbased female sex workers in ...

  7. Trends in land surface phenology and atmospheric CO2 seasonality in the Northern Hemisphere terrestrial ecosystems

    Science.gov (United States)

    Gonsamo, A.; Chen, J. M.

    2017-12-01

    Northern terrestrial ecosystems have shown global warming-induced advances in start, delays in end, and thus increased lengths of growing season and gross photosynthesis in recent decades. The tradeoffs between seasonal dynamics of two opposing fluxes, CO2 uptake through photosynthesis and release through respiration, determine the influence of the terrestrial ecosystems on the atmospheric CO2 concentration and 13C/12C isotope ratio seasonality. Atmospheric CO2 and 13C/12C seasonality is controlled by vegetation phenology, but is not identical because growth will typically commence some time before and terminate some time after the net carbon exchange changes sign in spring and autumn, respectively. Here, we use 34-year satellite normalized difference vegetation index (NDVI) observations to determine how changes in vegetation productivity and phenology affect both the atmospheric CO2 and 13C/12C seasonality. Differences and similarities in recent trends of CO2 and 13C/12C seasonality and vegetation phenology will be discussed. Furthermore, we use the NDVI observations, and atmospheric CO2 and 13C/12C data to show the trends and variability of the timing of peak season plant activity. Preliminary results show that the peak season plant activity of the Northern Hemisphere extra-tropical terrestrial ecosystems is shifting towards spring, largely in response to the warming-induced advance of the start of growing season. Besides, the spring-ward shift of the peak plant activity is contributing the most to the increasing peak season productivity. In other words, earlier start of growing season is highly linked to earlier arrival of peak of season and higher NDVI. Changes in the timing of peak season plant activity are expected to disrupt the synchrony of biotic interaction and exert strong biophysical feedbacks on climate by modifying the surface albedo and energy budget.

  8. 40 CFR 96.253 - Recordation of CAIR SO2 allowances.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Recordation of CAIR SO2 allowances. 96... (CONTINUED) NOX BUDGET TRADING PROGRAM AND CAIR NOX AND SO2 TRADING PROGRAMS FOR STATE IMPLEMENTATION PLANS CAIR SO2 Allowance Tracking System § 96.253 Recordation of CAIR SO2 allowances. (a)(1) After a...

  9. Afican Health Sciences Vol 9 No 2.pmd

    African Journals Online (AJOL)

    Administrator

    African Health Sciences Vol 9 No 2 June 2009 ... Background:The under five mortality rate (U5MR) is measure of wellbeing and decreasing the U5MR by two .... under three scenarios 1-3. ... Negative indicates increase in childhood mortalities.

  10. Predicting phenology by integrating ecology, evolution and climate science

    Science.gov (United States)

    Pau, Stephanie; Wolkovich, Elizabeth M.; Cook, Benjamin I.; Davies, T. Jonathan; Kraft, Nathan J.B.; Bolmgren, Kjell; Betancourt, Julio L.; Cleland, Elsa E.

    2011-01-01

    Forecasting how species and ecosystems will respond to climate change has been a major aim of ecology in recent years. Much of this research has focused on phenology — the timing of life-history events. Phenology has well-demonstrated links to climate, from genetic to landscape scales; yet our ability to explain and predict variation in phenology across species, habitats and time remains poor. Here, we outline how merging approaches from ecology, climate science and evolutionary biology can advance research on phenological responses to climate variability. Using insight into seasonal and interannual climate variability combined with niche theory and community phylogenetics, we develop a predictive approach for species' reponses to changing climate. Our approach predicts that species occupying higher latitudes or the early growing season should be most sensitive to climate and have the most phylogenetically conserved phenologies. We further predict that temperate species will respond to climate change by shifting in time, while tropical species will respond by shifting space, or by evolving. Although we focus here on plant phenology, our approach is broadly applicable to ecological research of plant responses to climate variability.

  11. Digital herbarium archives as a spatially extensive, taxonomically discriminate phenological record; a comparison to MODIS satellite imagery

    Science.gov (United States)

    Park, Isaac W.

    2012-11-01

    This study demonstrates that phenological information included in digital herbarium archives can produce annual phenological estimates correlated to satellite-derived green wave phenology at a regional scale (R = 0.183, P = 0.03). Thus, such records may be utilized in a fashion similar to other annual phenological records and, due to their longer duration and ability to discriminate among the various components of the plant community, hold significant potential for use in future research to supplement the deficiencies of other data sources as well as address a wide array of important issues in ecology and bioclimatology that cannot be addressed easily using more traditional methods.

  12. Interannual variability of plant phenology in tussock tundra: modelling interactions of plant productivity, plant phenology, snowmelt and soil thaw

    NARCIS (Netherlands)

    Wijk, van M.T.; Williams, M.; Laundre, J.A.; Shaver, G.R.

    2003-01-01

    We present a linked model of plant productivity, plant phenology, snowmelt and soil thaw in order to estimate interannual variability of arctic plant phenology and its effects on plant productivity. The model is tested using 8 years of soil temperature data, and three years of bud break data of

  13. Morphological constraints on changing avian migration phenology.

    Science.gov (United States)

    Møller, A P; Rubolini, D; Saino, N

    2017-06-01

    Many organisms at northern latitudes have responded to climate warming by advancing their spring phenology. Birds are known to show earlier timing of spring migration and reproduction in response to warmer springs. However, species show heterogeneous phenological responses to climate warming, with those that have not advanced or have delayed migration phenology experiencing population declines. Although some traits (such as migration distance) partly explain heterogeneity in phenological responses, the factors affecting interspecies differences in the responsiveness to climate warming have yet to be fully explored. In this comparative study, we investigate whether variation in wing aspect ratio (reflecting relative wing narrowness), an ecomorphological trait that is strongly associated with flight efficiency and migratory behaviour, affects the ability to advance timing of spring migration during 1960-2006 in a set of 80 European migratory bird species. Species with larger aspect ratio (longer and narrower wings) showed smaller advancement of timing of spring migration compared to species with smaller aspect ratio (shorter and wider wings) while controlling for phylogeny, migration distance and other life-history traits. In turn, migration distance positively predicted aspect ratio across species. Hence, species that are better adapted to migration appear to be more constrained in responding phenologically to rapid climate warming by advancing timing of spring migration. Our findings corroborate the idea that aspect ratio is a major evolutionary correlate of migration, and suggest that selection for energetically efficient flights, as reflected by high aspect ratio, may hinder phenotypically plastic/microevolutionary adjustments of migration phenology to ongoing climatic changes. © 2017 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2017 European Society For Evolutionary Biology.

  14. Comparison of phenology models for predicting the onset of growing season over the Northern Hemisphere.

    Directory of Open Access Journals (Sweden)

    Yang Fu

    Full Text Available Vegetation phenology models are important for examining the impact of climate change on the length of the growing season and carbon cycles in terrestrial ecosystems. However, large uncertainties in present phenology models make accurate assessment of the beginning of the growing season (BGS a challenge. In this study, based on the satellite-based phenology product (i.e. the V005 MODIS Land Cover Dynamics (MCD12Q2 product, we calibrated four phenology models, compared their relative strength to predict vegetation phenology; and assessed the spatial pattern and interannual variability of BGS in the Northern Hemisphere. The results indicated that parameter calibration significantly influences the models' accuracy. All models showed good performance in cool regions but poor performance in warm regions. On average, they explained about 67% (the Growing Degree Day model, 79% (the Biome-BGC phenology model, 73% (the Number of Growing Days model and 68% (the Number of Chilling Days-Growing Degree Day model of the BGS variations over the Northern Hemisphere. There were substantial differences in BGS simulations among the four phenology models. Overall, the Biome-BGC phenology model performed best in predicting the BGS, and showed low biases in most boreal and cool regions. Compared with the other three models, the two-phase phenology model (NCD-GDD showed the lowest correlation and largest biases with the MODIS phenology product, although it could catch the interannual variations well for some vegetation types. Our study highlights the need for further improvements by integrating the effects of water availability, especially for plants growing in low latitudes, and the physiological adaptation of plants into phenology models.

  15. Comparison of phenology models for predicting the onset of growing season over the Northern Hemisphere.

    Science.gov (United States)

    Fu, Yang; Zhang, Haicheng; Dong, Wenjie; Yuan, Wenping

    2014-01-01

    Vegetation phenology models are important for examining the impact of climate change on the length of the growing season and carbon cycles in terrestrial ecosystems. However, large uncertainties in present phenology models make accurate assessment of the beginning of the growing season (BGS) a challenge. In this study, based on the satellite-based phenology product (i.e. the V005 MODIS Land Cover Dynamics (MCD12Q2) product), we calibrated four phenology models, compared their relative strength to predict vegetation phenology; and assessed the spatial pattern and interannual variability of BGS in the Northern Hemisphere. The results indicated that parameter calibration significantly influences the models' accuracy. All models showed good performance in cool regions but poor performance in warm regions. On average, they explained about 67% (the Growing Degree Day model), 79% (the Biome-BGC phenology model), 73% (the Number of Growing Days model) and 68% (the Number of Chilling Days-Growing Degree Day model) of the BGS variations over the Northern Hemisphere. There were substantial differences in BGS simulations among the four phenology models. Overall, the Biome-BGC phenology model performed best in predicting the BGS, and showed low biases in most boreal and cool regions. Compared with the other three models, the two-phase phenology model (NCD-GDD) showed the lowest correlation and largest biases with the MODIS phenology product, although it could catch the interannual variations well for some vegetation types. Our study highlights the need for further improvements by integrating the effects of water availability, especially for plants growing in low latitudes, and the physiological adaptation of plants into phenology models.

  16. RICE CROP MAPPING USING SENTINEL-1A PHENOLOGICAL METRICS

    Directory of Open Access Journals (Sweden)

    C. F. Chen

    2016-06-01

    Full Text Available Rice is the most important food crop in Vietnam, providing food more than 90 million people and is considered as an essential source of income for majority of rural populations. Monitoring rice-growing areas is thus important to developing successful strategies for food security in the country. This paper aims to develop an approach for crop acreage estimation from multi-temporal Sentinel-1A data. We processed the data for two main cropping seasons (e.g., winter–spring, summer–autumn in the Mekong River Delta (MRD, Vietnam through three main steps: (1 data pre-processing, (3 rice classification based on crop phenological metrics, and (4 accuracy assessment of the mapping results. The classification results compared with the ground reference data indicated the overall accuracy of 86.2% and Kappa coefficient of 0.72. These results were reaffirmed by close correlation between the government’s rice area statistics for such crops (R2 > 0.95. The values of relative error in area obtained for the winter–spring and summer–autumn were -3.6% and 6.7%, respectively. This study demonstrates the potential application of multi-temporal Sentinel-1A data for rice crop mapping using information of crop phenology in the study region.

  17. Pituophis ruthveni (Louisiana pinesnake) Reproduction/breeding phenology

    Science.gov (United States)

    Josh B. Pierce; Craig Rudolph; Christopher A. Melder; Beau B. Gregory

    2016-01-01

    Determing the reproductive phenology of snakes is important since it marks a time period where snakes are particularly vulnerable to predation. In addition, knowledge of reproductive phenology may help captive breeding programs specify appropriate times to pair snakes for reproduction.

  18. Ghana Medical Journal - Vol 47, No 2 (2013)

    African Journals Online (AJOL)

    Ghana Medical Journal - Vol 47, No 2 (2013). Journal Home > Archives ... DOWNLOAD FULL TEXT. AB Olokoba, W Gashau, S Bwala, A Adamu, FK Salawu, 79-81 ... DOWNLOAD FULL TEXT. EY Bonney, NA Addo, NAA Ntim, F Addo-Yobo, P Bondzie, KE Aryee, J Barnor, J brandful, V Bekoe, SA Ohene, W Ampofo, 82-86 ...

  19. Tracking vegetation phenology across diverse North American biomes using PhenoCam imagery: A new, publicly-available dataset

    Science.gov (United States)

    Richardson, A. D.

    2015-12-01

    Vegetation phenology controls the seasonality of many ecosystem processes, as well as numerous biosphere-atmosphere feedbacks. Phenology is highly sensitive to climate change and variability, and is thus a key aspect of global change ecology. The goal of the PhenoCam network is to serve as a long-term, continental-scale, phenological observatory. The network uses repeat digital photography—images captured using conventional, visible-wavelength, automated digital cameras—to characterize vegetation phenology in diverse ecosystems across North America and around the world. At present, imagery from over 200 research sites, spanning a wide range of ecoregions, climate zones, and plant functional types, is currently being archived and processed in near-real-time through the PhenoCam project web page (http://phenocam.sr.unh.edu/). Data derived from PhenoCam imagery have been previously used to evaluate satellite phenology products, to constrain and test new phenology models, to understand relationships between canopy phenology and ecosystem processes, and to study the seasonal changes in leaf-level physiology that are associated with changes in leaf color. I will describe a new, publicly-available phenological dataset, derived from over 600 site-years of PhenoCam imagery. For each archived image (ca. 5 million), we extracted RGB (red, green, blue) color channel information, with means and other statistics calculated across a region-of-interest (ROI) delineating a specific vegetation type. From the high-frequency (typically, 30 minute) imagery, we derived time series characterizing vegetation color, including "canopy greenness", processed to 1- and 3-day intervals. For ecosystems with a single annual cycle of vegetation activity, we derived estimates, with uncertainties, for the start, middle, and end of spring and autumn phenological transitions. Given the lack of multi-year, standardized, and geographically distributed phenological data for North America, we

  20. Climate change, phenology, and butterfly host plant utilization.

    Science.gov (United States)

    Navarro-Cano, Jose A; Karlsson, Bengt; Posledovich, Diana; Toftegaard, Tenna; Wiklund, Christer; Ehrlén, Johan; Gotthard, Karl

    2015-01-01

    Knowledge of how species interactions are influenced by climate warming is paramount to understand current biodiversity changes. We review phenological changes of Swedish butterflies during the latest decades and explore potential climate effects on butterfly-host plant interactions using the Orange tip butterfly Anthocharis cardamines and its host plants as a model system. This butterfly has advanced its appearance dates substantially, and its mean flight date shows a positive correlation with latitude. We show that there is a large latitudinal variation in host use and that butterfly populations select plant individuals based on their flowering phenology. We conclude that A. cardamines is a phenological specialist but a host species generalist. This implies that thermal plasticity for spring development influences host utilization of the butterfly through effects on the phenological matching with its host plants. However, the host utilization strategy of A. cardamines appears to render it resilient to relatively large variation in climate.

  1. Jolivet: Complete Flute Music, Vol. 2 / Guy S. Rickards

    Index Scriptorium Estoniae

    Rickards, Guy S.

    1996-01-01

    Uuest heliplaadist "Jolivet: Complete Flute Music, Vol. 2. Kroumata Percussion Ensemble, Tapiola Sinfonietta, Paavo Järvi". BIS CD 739 (64 minutes: DDD). Item marked from CD630 (6/94), CD272, remainder new to UK

  2. New limits for the 2 νββ decay of 96Zr to excited nuclear states of 96Mo

    Science.gov (United States)

    Finch, Sean; Tornow, Werner

    2015-10-01

    The final results from our search for the 2 νββ decay of 96Zr to excited 0+ and 2+ states of 96Mo are presented. Such measurements provide valuable test cases for 2 νββ -decay nuclear matrix element calculations, which in turn are used to tune 0 νββ -decay nuclear matrix element calculations. After undergoing double- β decay to an excited state, the excited daughter nucleus decays to the ground state, emitting two coincident γ rays. These two γ rays are detected in coincidence by two HPGe detectors sandwiching the 96Zr sample, with a NaI veto in anti-coincidence. This experimental apparatus, located at the Kimballton Underground Research Facility (KURF), has previously measured the 2 νββ decay of 100Mo and 150Nd to excited nuclear states. Experimental limits on the T1 / 2 and corresponding nuclear matrix element are presented for each of these decays. As a byproduct of this experiment, limits were also set on the single- β decay of 96Zr. Supported by DOE Grant: DE-FG02-97ER41033.

  3. Using a phenological network to assess weather influences on first appearance of butterflies in the Netherlands

    NARCIS (Netherlands)

    Kolk, Van Der Henk Jan; Wallis de Vries, Michiel; Vliet, Van Arnold J.H.

    2016-01-01

    Phenological responses of butterflies to temperature have been demonstrated in several European countries by using data from standardized butterfly monitoring schemes. Recently, phenological networks have enabled volunteers to record phenological observations at project websites. In this study,

  4. First-year Progress and Future Directions of the USA National Phenology Network

    Science.gov (United States)

    Weltzin, J. F.; Losleben, M. V.

    2008-12-01

    Background Periodic plant and animal cycles driven by seasonal variations in climate (i.e., phenology) set the stage for dynamics of ecosystem processes, determine land surface properties, control biosphere-atmosphere interactions, and affect food production, health, conservation, and recreation. Phenological data and models have applications related to scientific research, education and outreach, as well as to stakeholders interested in agriculture, tourism and recreation, human health, and natural resource conservation and management. The predictive potential of phenology requires a new data resource-a national network of integrated phenological observations and the tools to access and analyze them at multiple scales. The USA National Phenology Network (USA-NPN) is an emerging and exciting partnership between federal agencies, the academic community, and the general public to monitor and understand the influence of seasonal cycles on the Nation's resources. The USA-NPN will establish a wall-to-wall science and monitoring initiative focused on phenology as a tool to understand how plants, animals and landscapes respond to climate variation, and as a tool to facilitate human adaptation to ongoing and potential future climate change. Results The National Coordinating Office of the USA-NPN began operation in August 2007 at the University of Arizona, Tucson, AZ. This first year of operation produced many new phenology products and venues for phenology research and citizen involvement, as well as identification of future directions for the USA NPN. Products include a new web-site (www.usanpn.org) that went live in June 2008; the web-site includes a tool for on-line data entry, and serves as a clearinghouse for products and information to facilitate research and communication related to phenology. The new core Plant Phenology Program includes profiles for 185 vetted local, regional, and national plant species with descriptions and monitoring protocols, as well as

  5. Mizan Law Review - Vol 5, No 2 (2011)

    African Journals Online (AJOL)

    Mizan Law Review - Vol 5, No 2 (2011) ... Ethiopian Law of International Carriage by Air: An Overview · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT ... Comment: Overview of the Core Changes in the New Ethiopian Urban Land Leasehold Proclamation · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT

  6. Research in Hospitality Management - Vol 5, No 2 (2015)

    African Journals Online (AJOL)

    Research in Hospitality Management - Vol 5, No 2 (2015) ... Hotel quality in the European Capital of Culture: Leeuwarden 2018 · EMAIL FREE FULL ... Consumer patronage and willingness-to-pay at different levels of restaurant attributes: A ...

  7. International Journal of Development and Policy Studies - Vol 2, No ...

    African Journals Online (AJOL)

    International Journal of Development and Policy Studies - Vol 2, No 1 (2006) .... Locating oppressive use of language: a study of linguistic violence on nigerian ... trafficking - poverty link based on urban development and planning process ...

  8. Consequences of Hatch Phenology on Stages of Fish Recruitment.

    Directory of Open Access Journals (Sweden)

    David M Bogner

    Full Text Available Little is known about how hatch phenology (e.g., the start, peak, and duration of hatching could influence subsequent recruitment of freshwater fishes into a population. We used two commonly sympatric fish species that exhibit different hatching phenologies to examine recruitment across multiple life stages. Nine yellow perch (Perca flavescens and bluegill (Lepomis macrochirus annual cohorts were sampled from 2004 through 2013 across larval, age-0, age-1, and age-2 life stages in a Nebraska (U.S.A. Sandhill lake. Yellow perch hatched earlier in the season and displayed a more truncated hatch duration compared to bluegill. The timing of hatch influenced recruitment dynamics for both species but important hatching metrics were not similar between species across life stages. A longer hatch duration resulted in greater larval yellow perch abundance but greater age-1 bluegill abundance. In contrast, bluegill larval and age-0 abundances were greater during years when hatching duration was shorter and commenced earlier, whereas age-0 yellow perch abundance was greater when hatching occurred earlier. As a result of hatch phenology, yellow perch recruitment variability was minimized sooner (age-0 life stage than bluegill (age-1 life stage. Collectively, hatch phenology influenced recruitment dynamics across multiple life stages but was unique for each species. Understanding the complexities of when progeny enter an environment and how this influences eventual recruitment into a population will be critical in the face of ongoing climate change.

  9. International Journal of Health Research - Vol 2, No 4 (2009)

    African Journals Online (AJOL)

    International Journal of Health Research - Vol 2, No 4 (2009) ... Psychosocial characteristics of patients admitted to a drug rehabilitation unit in Nigeria · EMAIL ... Hepatoprotective and antioxidant activities of fruit pulp of limonia acidissima linn ...

  10. Accuracy and precision in the calculation of phenology metrics

    DEFF Research Database (Denmark)

    Ferreira, Ana Sofia; Visser, Andre; MacKenzie, Brian

    2014-01-01

    a phenology metric is first determined from a noise- and gap-free time series, and again once it has been modified. We show that precision is a greater concern than accuracy for many of these metrics, an important point that has been hereto overlooked in the literature. The variability in precision between...... phenology metrics is substantial, but it can be improved by the use of preprocessing techniques (e.g., gap-filling or smoothing). Furthermore, there are important differences in the inherent variability of the metrics that may be crucial in the interpretation of studies based upon them. Of the considered......Phytoplankton phenology (the timing of seasonal events) is a commonly used indicator for evaluating responses of marine ecosystems to climate change. However, phenological metrics are vulnerable to observation-(bloom amplitude, missing data, and observational noise) and analysis-related (temporal...

  11. Improving models to predict phenological responses to global change

    Energy Technology Data Exchange (ETDEWEB)

    Richardson, Andrew D. [Harvard College, Cambridge, MA (United States)

    2015-11-25

    The term phenology describes both the seasonal rhythms of plants and animals, and the study of these rhythms. Plant phenological processes, including, for example, when leaves emerge in the spring and change color in the autumn, are highly responsive to variation in weather (e.g. a warm vs. cold spring) as well as longer-term changes in climate (e.g. warming trends and changes in the timing and amount of rainfall). We conducted a study to investigate the phenological response of northern peatland communities to global change. Field work was conducted at the SPRUCE experiment in northern Minnesota, where we installed 10 digital cameras. Imagery from the cameras is being used to track shifts in plant phenology driven by elevated carbon dioxide and elevated temperature in the different SPRUCE experimental treatments. Camera imagery and derived products (“greenness”) is being posted in near-real time on a publicly available web page (http://phenocam.sr.unh.edu/webcam/gallery/). The images will provide a permanent visual record of the progression of the experiment over the next 10 years. Integrated with other measurements collected as part of the SPRUCE program, this study is providing insight into the degree to which phenology may mediate future shifts in carbon uptake and storage by peatland ecosystems. In the future, these data will be used to develop improved models of vegetation phenology, which will be tested against ground observations collected by a local collaborator.

  12. Host-race formation: promoted by phenology, constrained by heritability.

    Science.gov (United States)

    Whipple, A V; Abrahamson, W G; Khamiss, M A; Heinrich, P L; Urian, A G; Northridge, E M

    2009-04-01

    Host-race formation is promoted by genetic trade-offs in the ability of herbivores to use alternate hosts, including trade-offs due to differential timing of host-plant availability. We examined the role of phenology in limiting host-plant use in the goldenrod gall fly (Eurosta solidaginis) by determining: (1) whether phenology limits alternate host use, leading to a trade-off that could cause divergent selection on Eurosta emergence time and (2) whether Eurosta has the genetic capacity to respond to such selection in the face of existing environmental variation. Experiments demonstrated that oviposition and gall induction on the alternate host, Solidago canadensis, were the highest on young plants, whereas the highest levels of gall induction on the normal host, Solidago gigantea, occurred on intermediate-age plants. These findings indicate a phenological trade-off for host-plant use that sets up the possibility of divergent selection on emergence time. Heritability, estimated by parent-offspring regression, indicated that host-race formation is impeded by the amount of genetic variation, relative to environmental, for emergence time.

  13. Phenology of the reproductive development of Elaeis oleifera (Kunth Cortes

    Directory of Open Access Journals (Sweden)

    Leidy Paola Moreno

    2015-04-01

    Full Text Available The phenological stages of oil palm can be coded using the BBCH scale, which has three digits due to the inclusion of intermediate stages between the principal and secondary stages in order to provide greater detail on each developmental stage. For the phenological description of the reproductive development of Elaeis oleifera, the principal stages used were emergence of inflorescence, flowering, fruit growth and development, and fruit ripening. The observations were made in Colombia over a 12 month-period on E. oleifera palms planted in 1991; the observations were made on the daily course or depending on the development stage. The duration of each phenological stage was measured in days. Thus, the appearance of new leaves took 20.1±2.8 days, reaching preanthesis I (601 took 145.09±19.61 days, from this stage to preanthesis II (602 took 7.50±1.50 days, then to preanthesis III (603 took 7.39±1.56 days and finally to anthesis (607 took 5.74±1.32 days. At the population level, it was found that the phenology cycle of inflorescence is annual and that the production of flowers and the opening of inflorescences with pistils is asynchronous.

  14. Phenology for science, resource management, decision making, and education

    Science.gov (United States)

    Nolan, V.P.; Weltzin, J.F.

    2011-01-01

    Fourth USA National Phenology Network (USA-NPN) Research Coordination Network (RCN) Annual Meeting and Stakeholders Workshop; Milwaukee, Wisconsin, 21-22 September 2010; Phenology, the study of recurring plant and animal life cycle events, is rapidly emerging as a fundamental approach for understanding how ecological systems respond to environmental variation and climate change. The USA National Phenology Network (USA-NPN; http://www.usanpn.org) is a large-scale network of governmental and nongovernmental organizations, academic institutions, resource management agencies, and tribes. The network is dedicated to conducting and promoting repeated and integrated plant and animal phenological observations, identifying linkages with other relevant biological and physical data sources, and developing and distributing the tools to analyze these data at local to national scales. The primary goal of the USA-NPN is to improve the ability of decision makers to design strategies for climate adaptation.

  15. Long-term phenology and variability of Southern Africa

    CSIR Research Space (South Africa)

    Steenkamp, K

    2008-11-01

    Full Text Available and classification of vegetation, (ii) studying the impact of climate change, and influence of rainfall variability (iii) monitoring Satellite-derived phenology and (iv) detecting changes in land use/ land cover. This study analyzed vegetation phenology across...

  16. Global-Scale Associations of Vegetation Phenology with Rainfall and Temperature at a High Spatio-Temporal Resolution

    Directory of Open Access Journals (Sweden)

    Nicholas Clinton

    2014-08-01

    Full Text Available Phenology response to climatic variables is a vital indicator for understanding changes in biosphere processes as related to possible climate change. We investigated global phenology relationships to precipitation and land surface temperature (LST at high spatial and temporal resolution for calendar years 2008–2011. We used cross-correlation between MODIS Enhanced Vegetation Index (EVI, MODIS LST and Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks (PERSIANN gridded rainfall to map phenology relationships at 1-km spatial resolution and weekly temporal resolution. We show these data to be rich in spatiotemporal information, illustrating distinct phenology patterns as a result of complex overlapping gradients of climate, ecosystem and land use/land cover. The data are consistent with broad-scale, coarse-resolution modeled ecosystem limitations to moisture, temperature and irradiance. We suggest that high-resolution phenology data are useful as both an input and complement to land use/land cover classifiers and for understanding climate change vulnerability in natural and anthropogenic landscapes.

  17. Effects of recent warm and cold spells on European plant phenology

    Science.gov (United States)

    Menzel, A.; Estrella, N.; Seifert, H.

    2009-04-01

    Numerous studies have concurrently documented a progressively earlier start for vegetation activity in spring and a lengthening of the growing season during the last 2 to 5 decades in the temperate northern hemisphere. In contrast to climatic factors influencing autumn phenology, the climate signal controlling spring and summer phenology is fairly well understood: nearly all phenophases correlate with temperatures in the preceding 1 to 3 months. The changes currently experienced by emergence of vegetation may reach 6 to 8 d per °C. But how will this well-known, often linearly described relationship change in case of more frequent and more stronger temperature extremes? We thus studied the temperature response of European phenological records to cold and warm spells using the COST725 data base (www.cost725.org). We restricted our analysis to the time period 1951-2006 due to the relatively better coverage of Europe by phenological records. Up to now, 20 European countries contributed more than 7 Mio. phenological observations to this data base including 64 species and 22 different phases. The phenological observations compiled originated from different sources and phenological networks. Unfortunately there is no entire coverage and the data are very lumped. Cold and warm spells were identified using daily mean temperature data (1951-2006) on a 0.5° grid for Europe provided by the EU-FP6 project ENSEMBLES (http://www.ensembles-eu.org, http://eca.knmi.nl). The study area covered Europe and was limited to 40°E. For the whole study period, mean monthly and seasonal mean temperatures well as the corresponding standard deviations were calculated for each grid point. The annual monthly or seasonal temperature at a grid point was defined as cold (very cold, warm, very warm) by its deviation from the long-term average (more than 1.5 or 3sd, respectively). Warm and cold spells were selected when either the percentages of crossing 1.5sd were greater than 50% for the total

  18. Communicating Research Through Student Involvement in Phenological Investigations

    Science.gov (United States)

    Sparrow, E. B.; Kopplin, M.; Gazal, R. M.; Robin, J. H.; Boger, R. A.

    2011-12-01

    Phenology plays a key role in the environment and ecosystem. Primary and secondary students around the world have been collecting vegetation phenology data and contributing to ongoing scientific investigations. They have increased research capacity by increasing spatial coverage of ground observations that can be useful for validation of remotely sensed data. The green-up and green-down phenology measurement protocols developed at the University of Alaska Fairbanks (UAF) as part of the Global Learning and Observations to Benefit the Environment (GLOBE) program, have been used in more than 250 schools in over 20 countries. In addition to contributing their data, students have conducted their own investigations and presented them at science fairs and symposiums, and international conferences. An elementary school student in Alaska conducted a comprehensive study on the green-down rates of native and introduced trees and shrubs. Her project earned her a one-year college scholarship at UAF. Students from the Model Secondary School for the Deaf in Washington, D. C. and from the Indiana School for the Deaf collaborated on a comparative green-up study, and were chosen to present at an international conference where students from more than 20 countries participated. Similarly, students in Thailand presented at national conferences, their studies such as "The Relationship between Environmental Conditions and Green-down of Teak Trees (Tectona grandis L.)" at Roong Aroon School, Bangkok and "The Comparison of Budburst and Green-up of Leab Trees (Ficus infectoria Roxb.) at Rob Wiang and Mae Khao Tom Sub-district in Chiang Rai Province". Some challenges in engaging students in phenological studies include the mismatch in timing of the start and end of the plant growing season with that of the school year in northern latitudes and the need for scientists and teachers to work with students to ensure accurate measurements. However these are outweighed by benefits to the scientists

  19. Evaluating Heavy Metal Stress Levels in Rice Based on Remote Sensing Phenology.

    Science.gov (United States)

    Liu, Tianjiao; Liu, Xiangnan; Liu, Meiling; Wu, Ling

    2018-03-14

    Heavy metal pollution of croplands is a major environmental problem worldwide. Methods for accurately and quickly monitoring heavy metal stress have important practical significance. Many studies have explored heavy metal stress in rice in relation to physiological function or physiological factors, but few studies have considered phenology, which can be sensitive to heavy metal stress. In this study, we used an integrated Normalized Difference Vegetation Index (NDVI) time-series image set to extract remote sensing phenology. A phenological indicator relatively sensitive to heavy metal stress was chosen from the obtained phenological periods and phenological parameters. The Dry Weight of Roots (WRT), which directly affected by heavy metal stress, was simulated by the World Food Study (WOFOST) model; then, a feature space based on the phenological indicator and WRT was established for monitoring heavy metal stress. The results indicated that the feature space can distinguish the heavy metal stress levels in rice, with accuracy greater than 95% for distinguishing the severe stress level. This finding provides scientific evidence for combining rice phenology and physiological characteristics in time and space, and the method is useful to monitor heavy metal stress in rice.

  20. Responses of rubber leaf phenology to climatic variations in Southwest China

    Science.gov (United States)

    Zhai, De-Li; Yu, Haiying; Chen, Si-Chong; Ranjitkar, Sailesh; Xu, Jianchu

    2017-11-01

    The phenology of rubber trees (Hevea brasiliensis) could be influenced by meteorological factors and exhibits significant changes under different geoclimates. In the sub-optimal environment in Xishuangbanna, rubber trees undergo lengthy periods of defoliation and refoliation. The timing of refoliation from budburst to leaf aging could be affected by powdery mildew disease (Oidium heveae), which negatively impacts seed and latex production. Rubber trees are most susceptible to powdery mildew disease at the copper and leaf changing stages. Understanding and predicting leaf phenology of rubber trees are helpful to develop effective means of controlling the disease. This research investigated the effect of several meteorological factors on different leaf phenological stages in a sub-optimal environment for rubber cultivation in Jinghong, Yunnan in Southwest China. Partial least square regression was used to quantify the relationship between meteorological factors and recorded rubber phenologies from 2003 to 2011. Minimum temperature in December was found to be the critical factor for the leaf phenology development of rubber trees. Comparing the delayed effects of minimum temperature, the maximum temperature, diurnal temperature range, and sunshine hours were found to advancing leaf phenologies. A comparatively lower minimum temperature in December would facilitate the advancing of leaf phenologies of rubber trees. Higher levels of precipitation in February delayed the light green and the entire process of leaf aging. Delayed leaf phenology was found to be related to severe rubber powdery mildew disease. These results were used to build predictive models that could be applied to early warning systems of rubber powdery mildew disease.

  1. The USA National Phenology Network; taking the pulse of our planet

    Science.gov (United States)

    Weltzin, Jake F.

    2011-01-01

    People have tracked phenology for centuries and for the most practical reasons: it helped them know when to hunt and fish, when to plant and harvest crops, and when to navigate waterways. Now phenology is being used as a tool to assess climate change and its effects on both natural and modified ecosystems. How is the timing of events in plant and animal life cycles, like flowering or migration, responding to climate change? And how are those responses, in turn, affecting people and ecosystems? The USA National Phenology Network (the Network) is working to answer these questions for science and society by promoting a broad understanding of plant and animal phenology and their relationship to environmental change. The Network is a consortium of organizations and individuals that collect, share, and use phenology data, models, and related information to enable scientists, resource managers, and the public to adapt in response to changing climates and environments. In addition, the Network encourages people of all ages and backgrounds to observe and record phenology as a way to discover and explore the nature and pace of our dynamic world. The National Coordinating Office (NCO) of the Network is a resource center that facilitates and encourages widespread collection, integration, and sharing of phenology data and related information (for example, meteorological and hydrological data). The NCO develops and promotes standardized methods for field data collection and maintains several online user interfaces for data upload and download, as well as data exploration, visualization, and analysis. The NCO also facilitates basic and applied research related to phenology, the development of decision-support tools for resource managers and planners, and the design of educational and outreach materials

  2. Continental-scale patterns of Cecropia reproductive phenology: evidence from herbarium specimens.

    Science.gov (United States)

    Zalamea, Paul-Camilo; Munoz, François; Stevenson, Pablo R; Paine, C E Timothy; Sarmiento, Carolina; Sabatier, Daniel; Heuret, Patrick

    2011-08-22

    Plant phenology is concerned with the timing of recurring biological events. Though phenology has traditionally been studied using intensive surveys of a local flora, results from such surveys are difficult to generalize to broader spatial scales. In this study, contrastingly, we assembled a continental-scale dataset of herbarium specimens for the emblematic genus of Neotropical pioneer trees, Cecropia, and applied Fourier spectral and cospectral analyses to investigate the reproductive phenology of 35 species. We detected significant annual, sub-annual and continuous patterns, and discuss the variation in patterns within and among climatic regions. Although previous studies have suggested that pioneer species generally produce flowers continually throughout the year, we found that at least one third of Cecropia species are characterized by clear annual flowering behaviour. We further investigated the relationships between phenology and climate seasonality, showing strong associations between phenology and seasonal variations in precipitation and temperature. We also verified our results against field survey data gathered from the literature. Our findings indicate that herbarium material is a reliable resource for use in the investigation of large-scale patterns in plant phenology, offering a promising complement to local intensive field studies.

  3. Variation of Main Phenophases in Phenological Calendar in East China and Their Response to Climate Change

    Directory of Open Access Journals (Sweden)

    Fengyi Zheng

    2016-01-01

    Full Text Available Based on the phenological data from China Phenological Observation Network, we compiled the phenological calendars of 3 phenological observation stations (Shanghai, Nanjing, and Hefei in East China for 1987–1996 and 2003–2012 according to the sequences of mean phenophases. We calculated the correlated coefficient and the root mean square error (RMSE between phenophases and the beginning of meteorological seasons to determine the beginning date of phenological season. By comparing new phenological calendars with the old ones, we discussed the variation of phenophases and their responses to temperature. The conclusions are as follows. (1 The beginning dates of spring and summer advanced, while those of autumn and winter delayed. Thus, summers got longer and winters got shorter. (2 The beginning time of the four phenological seasons was advancing during 1987–1996, while it was delaying during 2003–2012. (3 Most spring and summer phenophases occur earlier and most autumn and winter phenophases occur later in 2003–2012 than in 1987–1996. (4 The beginning time of phenological seasons was significantly correlated with temperature. The phenological sensitivities to temperature ranged from −6.49 to −6.55 days/°C in spring, −3.65 to −5.02 days/°C in summer, 8.13 to 10.27 days/°C in autumn, and 4.76 to 10.00 days/°C in winter.

  4. Synchrony, compensatory dynamics, and the functional trait basis of phenological diversity in a tropical dry forest tree community: effects of rainfall seasonality

    Science.gov (United States)

    Lasky, Jesse R.; Uriarte, María; Muscarella, Robert

    2016-11-01

    Interspecific variation in phenology is a key axis of functional diversity, potentially mediating how communities respond to climate change. The diverse drivers of phenology act across multiple temporal scales. For example, abiotic constraints favor synchronous reproduction (positive covariance among species), while biotic interactions can favor synchrony or compensatory dynamics (negative covariance). We used wavelet analyses to examine phenology of community flower and seed production for 45 tree species across multiple temporal scales in a tropical dry forest in Puerto Rico with marked rainfall seasonality. We asked three questions: (1) do species exhibit synchronous or compensatory temporal dynamics in reproduction, (2) do interspecific differences in phenology reflect variable responses to rainfall, and (3) is interspecific variation in phenology and response to a major drought associated with functional traits that mediate responses to moisture? Community-level flowering was synchronized at seasonal scales (˜5-6 mo) and at short scales (˜1 mo, following rainfall). However, seed rain exhibited significant compensatory dynamics at intraseasonal scales (˜3 mo), suggesting interspecific variation in temporal niches. Species with large leaves (associated with sensitivity to water deficit) peaked in reproduction synchronously with the peak of seasonal rainfall (˜5 mo scale). By contrast, species with high wood specific gravity (associated with drought resistance) tended to flower in drier periods. Flowering of tall species and those with large leaves was most tightly linked to intraseasonal (˜2 mo scale) rainfall fluctuations. Although the 2015 drought dramatically reduced community-wide reproduction, functional traits were not associated with the magnitude of species-specific declines. Our results suggest opposing drivers of synchronous versus compensatory dynamics at different temporal scales. Phenology associations with functional traits indicated that

  5. Sophia: An African Journal of Philosophy - Vol 10, No 2 (2008)

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    Sophia: An African Journal of Philosophy - Vol 10, No 2 (2008) ... Spiritual intelligence (SQ), leadership and good governance: A treatise ... Traditional religion of Ogbaland: Distinguishing characteristics · EMAIL FULL TEXT EMAIL FULL TEXT

  6. Global Journal of Medical Sciences - Vol 10, No 1-2 (2011)

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    Global Journal of Medical Sciences - Vol 10, No 1-2 (2011) ... Implications for Global Standards to Promote International Collaboration and Advanced ... Clinical Nursing Research: A Tool for Professional Development · EMAIL FREE FULL ...

  7. Tracking global change at local scales: Phenology for science, outreach, conservation

    Science.gov (United States)

    Sharron, Ed; Mitchell, Brian

    2011-06-01

    A Workshop Exploring the Use of Phenology Studies for Public Engagement; New Orleans, Louisiana, 14 March 2011 ; During a George Wright Society Conference session that was led by the USA National Phenology Network (USANPN; http://www.usanpn.org) and the National Park Service (NPS), professionals from government organizations, nonprofits, and higher-education institutions came together to explore the possibilities of using phenology monitoring to engage the public. One of the most visible effects of global change on ecosystems is shifts in phenology: the timing of biological events such as leafing and flowering, maturation of agricultural plants, emergence of insects, and migration of birds. These shifts are already occurring and reflect biological responses to climate change at local to regional scales. Changes in phenology have important implications for species ecology and resource management and, because they are place-based and tangible, serve as an ideal platform for education, outreach, and citizen science.

  8. Operational data products to support phenological research and applications at local to continental scales

    Science.gov (United States)

    Weltzin, J. F.

    2017-12-01

    Phenological data from a variety of platforms - across a range of spatial and temporal scales - are required to support research, natural resource management, and policy- and decision-making in a changing world. Observational and modeled phenological data, especially when integrated with associated biophysical data (e.g., climate, land-use/land-cover, hydrology) has great potential to provide multi-faceted information critical to decision support systems, vulnerability and risk assessments, change detection applications, and early-warning and forecasting systems for natural and modified ecosystems. The USA National Phenology Network (USA-NPN; www.usanpn.org) is a national-scale science and monitoring initiative focused on understanding the drivers and feedback effects of phenological variation in changing environments. The Network maintains a centralized database of over 10M ground-based observations of plants and animals for 1954-present, and leverages these data to produce operational data products for use by a variety of audiences, including researchers and resource managers. This presentation highlights our operational data products, including the tools, maps, and services that facilitate discovery, accessibility and usability of integrated phenological information. We describe (1) the data download tool, a customizable GUI that provides geospatially referenced raw, bounded or summarized organismal and climatological data and associated metadata (including calendars, time-series curves, and XY graphs), (2) the visualization tool, which provides opportunities to explore, visualize and export or download both organismal and modeled (gridded) products at daily time-steps and relatively fine spatial resolutions ( 2.5 km to 4 km) for the period 1980 to 6 days into the future, and (3) web services that enable custom query and download of map, feature and cover services in a variety of standard formats. These operational products facilitate scaling of integrated

  9. The plant phenology monitoring design for the National Ecological Observatory Network

    Science.gov (United States)

    Elmendorf, Sarah C; Jones, Katherine D; Cook, Benjamin I.; Diez, Jeffrey M.; Enquist, Carolyn A.F.; Hufft, Rebecca A.; Jones, Matthew O.; Mazer, Susan J.; Miller-Rushing, Abraham J.; Moore, David J. P.; Schwartz, Mark D.; Weltzin, Jake F.

    2016-01-01

    Phenology is an integrative science that comprises the study of recurring biological activities or events. In an era of rapidly changing climate, the relationship between the timing of those events and environmental cues such as temperature, snowmelt, water availability or day length are of particular interest. This article provides an overview of the plant phenology sampling which will be conducted by the U.S. National Ecological Observatory Network NEON, the resulting data, and the rationale behind the design. Trained technicians will conduct regular in situ observations of plant phenology at all terrestrial NEON sites for the 30-year life of the observatory. Standardized and coordinated data across the network of sites can be used to quantify the direction and magnitude of the relationships between phenology and environmental forcings, as well as the degree to which these relationships vary among sites, among species, among phenophases, and through time. Vegetation at NEON sites will also be monitored with tower-based cameras, satellite remote sensing and annual high-resolution airborne remote sensing. Ground-based measurements can be used to calibrate and improve satellite-derived phenometrics. NEON’s phenology monitoring design is complementary to existing phenology research efforts and citizen science initiatives throughout the world and will produce interoperable data. By collocating plant phenology observations with a suite of additional meteorological, biophysical and ecological measurements (e.g., climate, carbon flux, plant productivity, population dynamics of consumers) at 47 terrestrial sites, the NEON design will enable continentalscale inference about the status, trends, causes and ecological consequences of phenological change.

  10. Phenology Atlas of Czechia in preparation - aim & content

    Science.gov (United States)

    Hajkova, L.; Nekovar, J.; Novak, M.; Richterova, D.

    2009-09-01

    The main task is to create Phenology Atlas of Czechia for the period 1991 - 2010 by using geographic information systems. The general outputs will be maps (average phenophase onset at different altitudes), graphs (evaluation of phenophase onset in time) and tables (statistical results) with text, picture and botanical specification. The publication will be divided into 6 main chapters (Introduction, Phenology in Czechia & Europe, Methodology of observation, Field crops & Fruit trees & Wild plants, Phenology regionalisation, Temporal and Spatial variability). The essantial emphasis will be enforced on wild plants especially allergology important plants and phenophases. CHMI phenological and meteorological data will be used as an input data. This publication will be allocated for general public, supposed size B4, 270 - 300 pages. The research project is proposed for 3 years (2009 - 2011). In the presentation will be given several examples of Atlas content (Norway Spruce and Birch phenophases from Transaction of CHMI Nr.50, 2007).

  11. First Plant Phenological Records in the Carpathians and their Possible Use

    Science.gov (United States)

    Tekusova, M.; Horecká, V.; Mikulová, K.

    2009-04-01

    Phenological observations have a long history. The long time series come from Korea and some other parts of Asia, while wine harvest dates form the oldest phenological data sets in Europe. One of them started as early as 1457 year in Vienna, i.e. on the border of the Carpathian region. However, the first systematic phenological observations started in the south Carpathians almost four hundred years later following the establishment of the phenological network in Austria and later in the Hungarian Kingdom. A medical doctor P. Wierbitzky did first phenological observations in the Carpathian region in the beginning of thirties of the nineteenth century in Orawicza. The first systematic observations and records of plant development in this region are connected with the establishment of Austrian Institute for Meteorology and Geomagnetism since 1851. Although the historical significance of these observations is high, the data recorded are of lower quality, frequently interrupted and fragmented. Further development of phenological observations came with the introduction of the methodology of the observations introduced by Karl Fritsch in the beginning of the sixties of the nineteenth century mainly with the establishment of Hungarian Meteorological Service in 1871. These historical data were recorded and published in the yearbooks and, despite of the fragmentary character of the records, they are usable for some evaluations. This article brings the description of the data sets of systematic phenological network in the Carpathian region and considers some possible phenological evaluations. The phenological observations were done in some cases at the same localities as the climatologic observations but the number of phenological stations was quite lower in several years. The historical plant phenological records were based in many cases on the observation of four phenological phases: leafing, flowering, ripening and fall of leaves. Both the volume and the quality of the

  12. Phenological mismatch in coastal western Alaska may increase summer season greenhouse gas uptake

    Science.gov (United States)

    Kelsey, Katharine C.; Leffler, A. Joshua; Beard, Karen H.; Choi, Ryan T.; Schmutz, Joel A.; Welker, Jeffery M.

    2018-04-01

    High latitude ecosystems are prone to phenological mismatches due to climate change- driven advances in the growing season and changing arrival times of migratory herbivores. These changes have the potential to alter biogeochemical cycling and contribute to feedbacks on climate change by altering greenhouse gas (GHG) emissions of carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) through large regions of the Arctic. Yet the effects of phenological mismatches on gas fluxes are currently unexplored. We used a three-year field experiment that altered the start of the growing season and timing of grazing to investigate how phenological mismatch affects GHG exchange. We found early grazing increased mean GHG emission to the atmosphere despite lower CH4 emissions due to grazing-induced changes in vegetation structure that increased uptake of CO2. In contrast, late grazing reduced GHG emissions because greater plant productivity led to an increase in CO2 uptake that overcame the increase in CH4 emission. Timing of grazing was an important control on both CO2 and CH4 emissions, and net GHG exchange was the result of opposing fluxes of CO2 and CH4. N2O played a negligible role in GHG flux. Advancing the growing season had a smaller effect on GHG emissions than changes to timing of grazing in this study. Our results suggest that a phenological mismatch that delays timing of grazing relative to the growing season, a change which is already developing along in western coastal Alaska, will reduce GHG emissions to the atmosphere through increased CO2 uptake despite greater CH4 emissions.

  13. Phenological mismatch in coastal western Alaska may increase summer season greenhouse gas uptake

    Science.gov (United States)

    Kelsey, Katharine C.; Leffler, A. Joshua; Beard, Karen H.; Choi, Ryan T.; Schmutz, Joel A.; Welker, Jeffery M.

    2018-01-01

    High latitude ecosystems are prone to phenological mismatches due to climate change- driven advances in the growing season and changing arrival times of migratory herbivores. These changes have the potential to alter biogeochemical cycling and contribute to feedbacks on climate change by altering greenhouse gas (GHG) emissions of carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) through large regions of the Arctic. Yet the effects of phenological mismatches on gas fluxes are currently unexplored. We used a three-year field experiment that altered the start of the growing season and timing of grazing to investigate how phenological mismatch affects GHG exchange. We found early grazing increased mean GHG emission to the atmosphere despite lower CH4 emissions due to grazing-induced changes in vegetation structure that increased uptake of CO2. In contrast, late grazing reduced GHG emissions because greater plant productivity led to an increase in CO2 uptake that overcame the increase in CH4 emission. Timing of grazing was an important control on both CO2 and CH4 emissions, and net GHG exchange was the result of opposing fluxes of CO2 and CH4. N2O played a negligible role in GHG flux. Advancing the growing season had a smaller effect on GHG emissions than changes to timing of grazing in this study. Our results suggest that a phenological mismatch that delays timing of grazing relative to the growing season, a change which is already developing along in western coastal Alaska, will reduce GHG emissions to the atmosphere through increased CO2 uptake despite greater CH4 emissions.

  14. Baltische Musik für Streichorchester (Vol. 2) / Hans-Christian Dadelsen

    Index Scriptorium Estoniae

    Dadelsen, Hans-Christian

    1995-01-01

    Uuest heliplaadist "Baltische Musik für Streichorchester (Vol. 2). Ostrobothnian Chamber Orchestra, Juha Kangas". Finlandia/East West Records CD 4509-9789-2 (WD: 64'34") Plaadil ka Erkki-Sven Tüüri teos "Insula Deserta"

  15. Statistical rice yield modeling using blended MODIS-Landsat based crop phenology metrics in Taiwan

    Science.gov (United States)

    Chen, C. R.; Chen, C. F.; Nguyen, S. T.; Lau, K. V.

    2015-12-01

    Taiwan is a populated island with a majority of residents settled in the western plains where soils are suitable for rice cultivation. Rice is not only the most important commodity, but also plays a critical role for agricultural and food marketing. Information of rice production is thus important for policymakers to devise timely plans for ensuring sustainably socioeconomic development. Because rice fields in Taiwan are generally small and yet crop monitoring requires information of crop phenology associating with the spatiotemporal resolution of satellite data, this study used Landsat-MODIS fusion data for rice yield modeling in Taiwan. We processed the data for the first crop (Feb-Mar to Jun-Jul) and the second (Aug-Sep to Nov-Dec) in 2014 through five main steps: (1) data pre-processing to account for geometric and radiometric errors of Landsat data, (2) Landsat-MODIS data fusion using using the spatial-temporal adaptive reflectance fusion model, (3) construction of the smooth time-series enhanced vegetation index 2 (EVI2), (4) rice yield modeling using EVI2-based crop phenology metrics, and (5) error verification. The fusion results by a comparison bewteen EVI2 derived from the fusion image and that from the reference Landsat image indicated close agreement between the two datasets (R2 > 0.8). We analysed smooth EVI2 curves to extract phenology metrics or phenological variables for establishment of rice yield models. The results indicated that the established yield models significantly explained more than 70% variability in the data (p-value 0.8), in both cases. The root mean square error (RMSE) and mean absolute error (MAE) used to measure the model accuracy revealed the consistency between the estimated yields and the government's yield statistics. This study demonstrates advantages of using EVI2-based phenology metrics (derived from Landsat-MODIS fusion data) for rice yield estimation in Taiwan prior to the harvest period.

  16. Journal of Business Research - Vol 6, No 1-2 (2012)

    African Journals Online (AJOL)

    Journal of Business Research - Vol 6, No 1-2 (2012) ... Economic Cost of Breast Cancer in Ghana: The Komfo Anokye Teaching Hospital ... Capital Adequacy and the Performance of Ghanaian Banks · EMAIL FULL TEXT EMAIL FULL TEXT

  17. Studies in Gender and Development in Africa - Vol 2 (2008)

    African Journals Online (AJOL)

    Studies in Gender and Development in Africa - Vol 2 (2008) ... I don't love my husband” Advice Columns as Teaching Resource for Gender and Sexuality: Experiences from the University of Cape Coast, Ghana ... Current Issue Atom logo

  18. Green leaf phenology at Landsat resolution: scaling from the plot to satellite

    Science.gov (United States)

    Fisher, J. I.; Mustard, J. F.; Vadeboncour, M.

    2005-12-01

    Despite the large number of in situ, plot-level phenological measurements and satellite-derived phenological studies, there has been little success to date in merging these records temporally or spatially. In particular, while most phenological patterns and trends derived from satellites appear realistic and coherent, they may not reflect spatial and temporal patterns at the plot level. An obvious explanation is the drastic scale difference from plot-level to most satellite observations. In this research, we bridge this scale gap through higher resolution satellite records (Landsat) and quantify the accuracy of satellite-derived metrics with direct field measurements. We compiled fifty-seven Landsat scenes from southern New England (P12 R51) from 1984 to 2002. Green vegetation areal abundance for each scene was derived from spectral mixture analysis and a single set of endmembers. The leaf area signal was fit with a logistic-growth simulating sigmoid curve to derive phenological markers (half-maximum leaf-onset and offset). Spring leaf-onset dates in homogenous stands of deciduous forests displayed significant and persistent local variability. The local variability was validated with multiple springtime ground observations (r2 = 0.91). The highest degree of verified small-scale variation occurred where contiguous forests displayed leaf-onset gradients of 10-14 days over short distances (example, our results indicate that deciduous forests in the Providence, RI metropolitan area leaf out 5-7 days earlier than comparable rural areas. In preliminary work, we validated the Landsat-derived metrics with similar analyses of MODIS and AVHRR, and demonstrate that aggregating diverse local phenologies into coarse grids may convolute interpretations. Despite these complications, the platform-independent curve-fit methodology may be extended across platforms and field data. The methodologically consistent approach, in tandem with Landsat data, allows us to effectively scale

  19. Shifts in frog size and phenology: Testing predictions of climate change on a widespread anuran using data from prior to rapid climate warming.

    Science.gov (United States)

    Sheridan, Jennifer A; Caruso, Nicholas M; Apodaca, Joseph J; Rissler, Leslie J

    2018-01-01

    Changes in body size and breeding phenology have been identified as two major ecological consequences of climate change, yet it remains unclear whether climate acts directly or indirectly on these variables. To better understand the relationship between climate and ecological changes, it is necessary to determine environmental predictors of both size and phenology using data from prior to the onset of rapid climate warming, and then to examine spatially explicit changes in climate, size, and phenology, not just general spatial and temporal trends. We used 100 years of natural history collection data for the wood frog, Lithobates sylvaticus with a range >9 million km 2 , and spatially explicit environmental data to determine the best predictors of size and phenology prior to rapid climate warming (1901-1960). We then tested how closely size and phenology changes predicted by those environmental variables reflected actual changes from 1961 to 2000. Size, phenology, and climate all changed as expected (smaller, earlier, and warmer, respectively) at broad spatial scales across the entire study range. However, while spatially explicit changes in climate variables accurately predicted changes in phenology, they did not accurately predict size changes during recent climate change (1961-2000), contrary to expectations from numerous recent studies. Our results suggest that changes in climate are directly linked to observed phenological shifts. However, the mechanisms driving observed body size changes are yet to be determined, given the less straightforward relationship between size and climate factors examined in this study. We recommend that caution be used in "space-for-time" studies where measures of a species' traits at lower latitudes or elevations are considered representative of those under future projected climate conditions. Future studies should aim to determine mechanisms driving trends in phenology and body size, as well as the impact of climate on population

  20. Phenological change in a spring ephemeral: implications for pollination and plant reproduction.

    Science.gov (United States)

    Gezon, Zachariah J; Inouye, David W; Irwin, Rebecca E

    2016-05-01

    Climate change has had numerous ecological effects, including species range shifts and altered phenology. Altering flowering phenology often affects plant reproduction, but the mechanisms behind these changes are not well-understood. To investigate why altering flowering phenology affects plant reproduction, we manipulated flowering phenology of the spring herb Claytonia lanceolata (Portulacaceae) using two methods: in 2011-2013 by altering snow pack (snow-removal vs. control treatments), and in 2013 by inducing flowering in a greenhouse before placing plants in experimental outdoor arrays (early, control, and late treatments). We measured flowering phenology, pollinator visitation, plant reproduction (fruit and seed set), and pollen limitation. Flowering occurred approx. 10 days earlier in snow-removal than control plots during all years of snow manipulation. Pollinator visitation patterns and strength of pollen limitation varied with snow treatments, and among years. Plants in the snow removal treatment were more likely to experience frost damage, and frost-damaged plants suffered low reproduction despite lack of pollen limitation. Plants in the snow removal treatment that escaped frost damage had higher pollinator visitation rates and reproduction than controls. The results of the array experiment supported the results of the snow manipulations. Plants in the early and late treatments suffered very low reproduction due either to severe frost damage (early treatment) or low pollinator visitation (late treatment) relative to control plants. Thus, plants face tradeoffs with advanced flowering time. While early-flowering plants can reap the benefits of enhanced pollination services, they do so at the cost of increased susceptibility to frost damage that can overwhelm any benefit of flowering early. In contrast, delayed flowering results in dramatic reductions in plant reproduction through reduced pollination. Our results suggest that climate change may constrain the

  1. South African Journal of Animal Science - Vol 30, No 2 (2000)

    African Journals Online (AJOL)

    South African Journal of Animal Science - Vol 30, No 2 (2000) ... Relationship between performance measurements and sale price of Dorper rams in the Northern Cape ... Factors affecting goat production in a communal farming system in the ...

  2. Influence of spring phenology on seasonal and annual carbon balance in two contrasting New England forests

    Science.gov (United States)

    Andrew D. Richardson; David Y. Hollinger; D. Bryan Dail; John T. Lee; J. William Munger; John O' Keefe

    2009-01-01

    Spring phenology is thought to exert a major influence on the carbon (C) balance of temperate and boreal ecosystems. We investigated this hypothesis using four spring onset phenological indicators in conjunction with surface-atmosphere CO2 exchange data from the conifer-dominated Howland Forest and deciduous-dominated Harvard Forest AmeriFlux...

  3. MODIS phenology image service ArcMap toolbox

    Science.gov (United States)

    Talbert, Colin; Kern, Tim J.; Morisette, Jeff; Brown, Don; James, Kevin

    2013-01-01

    Seasonal change is important to consider when managing conservation areas at landscape scales. The study of such patterns throughout the year is referred to as phenology. Recurring life-cycle events that are initiated and driven by environmental factors include animal migration and plant flowering. Phenological events capture public attention, such as fall color change in deciduous forests, the first flowering in spring, and for those with allergies, the start of the pollen season. These events can affect our daily lives, provide clues to help understand and manage ecosystems, and provide evidence of how climate variability can affect the natural cycle of plants and animals. Phenological observations can be gathered at a range of scales, from plots smaller than an acre to landscapes of hundreds to thousands of acres. Linking these observations to diverse disciplines such as evolutionary biology or climate sciences can help further research in species and ecosystem responses to climate change scenarios at appropriate scales. A cooperative study between the National Park Service (NPS), the U.S. Geological Survey (USGS), and the National Aeronautics and Space Administration (NASA) has been exploring how satellite information can be used to summarize phenological patterns observed at the park or landscape scale and how those summaries can be presented to both park managers and visitors. This study specifically addressed seasonal changes in plants, including the onset of growth, photosynthesis in the spring, and the senescence of deciduous vegetation in the fall. The primary objective of the work is to demonstrate that seasonality even in protected areas changes considerably across years. A major challenge is to decouple natural variability from possible trends—directional change that can lead to a permanent and radically different ecosystem state. Trends can be either a gradual degradation of the landscape (often from external influences) or steady improvement (by

  4. Greater temperature sensitivity of plant phenology at colder sites

    DEFF Research Database (Denmark)

    Prevey, Janet; Vellend, Mark; Ruger, Nadja

    2017-01-01

    Warmer temperatures are accelerating the phenology of organisms around the world. Temperature sensitivity of phenology might be greater in colder, higher latitude sites than in warmer regions, in part because small changes in temperature constitute greater relative changes in thermal balance...

  5. Climate change and unequal phenological changes across four trophic levels: constraints or adaptations?

    Science.gov (United States)

    Both, Christiaan; van Asch, Margriet; Bijlsma, Rob G; van den Burg, Arnold B; Visser, Marcel E

    2009-01-01

    1. Climate change has been shown to affect the phenology of many organisms, but interestingly these shifts are often unequal across trophic levels, causing a mismatch between the phenology of organisms and their food. 2. We consider two alternative hypotheses: consumers are constrained to adjust sufficiently to the lower trophic level, or prey species react more strongly than their predators to reduce predation. We discuss both hypotheses with our analyses of changes in phenology across four trophic levels: tree budburst, peak biomass of herbivorous caterpillars, breeding phenology of four insectivorous bird species and an avian predator. 3. In our long-term study, we show that between 1988 and 2005, budburst advanced (not significantly) with 0.17 d yr(-1), while between 1985 and 2005 both caterpillars (0.75 d year(-1)) and the hatching date of the passerine species (range for four species: 0.36-0.50 d year(-1)) have advanced, whereas raptor hatching dates showed no trend. 4. The caterpillar peak date was closely correlated with budburst date, as were the passerine hatching dates with the peak caterpillar biomass date. In all these cases, however, the slopes were significantly less than unity, showing that the response of the consumers is weaker than that of their food. This was also true for the avian predator, for which hatching dates were not correlated with the peak availability of fledgling passerines. As a result, the match between food demand and availability deteriorated over time for both the passerines and the avian predators. 5. These results could equally well be explained by consumers' insufficient responses as a consequence of constraints in adapting to climate change, or by them trying to escape predation from a higher trophic level, or both. Selection on phenology could thus be both from matches of phenology with higher and lower levels, and quantifying these can shed new light on why some organisms do adjust their phenology to climate change, while

  6. Evaluation of Capacity on a High Throughput Vol-oxidizer for Operability

    International Nuclear Information System (INIS)

    Kim, Young Hwan; Park, Geun Il; Lee, Jung Won; Jung, Jae Hoo; Kim, Ki Ho; Lee, Yong Soon; Lee, Do Youn; Kim, Su Sung

    2010-01-01

    KAERI is developing a pyro-process. As a piece of process equipment, a high throughput vol-oxidizer which can handle a several tens kg HM/batch was developed to supply U 3 O 8 powders to an electrolytic reduction(ER) reactor. To increase the reduction yield, UO 2 pellets should be converted into uniform powders. In this paper, we aim at the evaluation of a high throughput vol-oxidizer for operability. The evaluation consisted of 3 targets, a mechanical motion test, a heating test and hull separation test. In order to test a high throughput vol-oxidizer, By using a control system, mechanical motion tests of the vol-oxidizer were conducted, and heating rates were analyzed. Also the separation tests of hulls for recovery rate were conducted. The test results of the vol-oxidizer are going to be applied for operability. A study on the characteristics of the volatile gas produced during a vol-oxidation process is not included in this study

  7. Cross-scale phenological data integration to benefit resource management and monitoring

    Science.gov (United States)

    Richardson, Andrew D.; Weltzin, Jake F.; Morisette, Jeffrey T.

    2017-01-01

    Climate change is presenting new challenges for natural resource managers charged with maintaining sustainable ecosystems and landscapes. Phenology, a branch of science dealing with seasonal natural phenomena (bird migration or plant flowering in response to weather changes, for example), bridges the gap between the biosphere and the climate system. Phenological processes operate across scales that span orders of magnitude—from leaf to globe and from days to seasons—making phenology ideally suited to multiscale, multiplatform data integration and delivery of information at spatial and temporal scales suitable to inform resource management decisions.A workshop report: Workshop held June 2016 to investigate opportunities and challenges facing multi-scale, multi-platform integration of phenological data to support natural resource management decision-making.

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

    Science.gov (United States)

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

    2018-02-01

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

  9. A study on land surface phenology in eastern China based on SPOT/VGT datasets

    International Nuclear Information System (INIS)

    Han, Guifeng; Xie, Hongxia

    2014-01-01

    Vegetation phenology provides a relevant indicator of the response of terrestrial ecosystems to climate change. In this study, vegetation phenology measurements were extracted and the spatial distributions were investigated using time series SPOT/VGT NDVI datasets for eastern China. Four phenology measurements were analyzed: the start of the growing season (SOS), the end of the growing season (EOS), the length of the growing season (GSL) and the time of the peak NDVI. The SOS in the northern part of the study area occurred earlier than in the rest of the study area due to larger amounts of cropland. The EOS showed a strong latitudinal pattern, especially in the southern portion of the study area. The GSL also showed a clear spatial pattern along the latitudinal gradient from north to south. The time of peak NDVI did not show a spatial pattern along the latitudinal gradient, which is likely due to the influence of vegetation types and the types of farming systems. In addition, there were no significant correlations between longitude and the four phenology measurements. SOS does not correlate with latitude, longitude or altitude, but EOS, GSL and the time of peak NDVI all correlated with latitude and altitude

  10. Influence of spring phenology on seasonal and annual carbon balance in two contrasting New England forests.

    Science.gov (United States)

    Richardson, Andrew D; Hollinger, David Y; Dail, D Bryan; Lee, John T; Munger, J William; O'keefe, John

    2009-03-01

    Spring phenology is thought to exert a major influence on the carbon (C) balance of temperate and boreal ecosystems. We investigated this hypothesis using four spring onset phenological indicators in conjunction with surface-atmosphere CO(2) exchange data from the conifer-dominated Howland Forest and deciduous-dominated Harvard Forest AmeriFlux sites. All phenological measures, including CO(2) source-sink transition dates, could be well predicted on the basis of a simple two-parameter spring warming model, indicating good potential for improving the representation of phenological transitions and their dynamic responsiveness to climate variability in land surface models. The date at which canopy-scale photosynthetic capacity reached a threshold value of 12 micromol m(-2) s(-1) was better correlated with spring and annual flux integrals than were either deciduous or coniferous bud burst dates. For all phenological indicators, earlier spring onset consistently, but not always significantly, resulted in higher gross primary productivity (GPP) and ecosystem respiration (RE) for both seasonal (spring months, April-June) and annual flux integrals. The increase in RE was less than that in GPP; depending on the phenological indicator used, a one-day advance in spring onset increased springtime net ecosystem productivity (NEP) by 2-4 g C m(-2) day(-1). In general, we could not detect significant differences between the two forest types in response to earlier spring, although the response to earlier spring was generally more pronounced for Harvard Forest than for Howland Forest, suggesting that future climate warming may favor deciduous species over coniferous species, at least in this region. The effect of earlier spring tended to be about twice as large when annual rather than springtime flux integrals were considered. This result is suggestive of both immediate and lagged effects of earlier spring onset on ecosystem C cycling, perhaps as a result of accelerated N cycling

  11. Budburst phenology of white birch in industrially polluted areas

    International Nuclear Information System (INIS)

    Kozlov, Mikhail V.; Eraenen, Janne K.; Zverev, Vitali E.

    2007-01-01

    Effects of environmental contamination on plant seasonal development have only rarely been properly documented. Monitoring of leaf growth in mountain birch, Betula pubescens subsp. czerepanovii, around a nickel-copper smelter at Monchegorsk hinted advanced budburst phenology in most polluted sites. However, under laboratory conditions budburst of birch twigs cut in late winter from trees naturally growing around three point polluters (nickel-copper smelter at Monchegorsk, aluminium factory at Kandalaksha, and iron pellet plant at Kostomuksha) showed no relationship with distance from the emission source. In a greenhouse experiment, budburst phenology of mountain birch seedlings grown in unpolluted soil did not depend on seedling origin (from heavily polluted vs. clean sites), whereas seedlings in metal-contaminated soil demonstrated delayed budburst. These results allow to attribute advanced budburst phenology of white birch in severely polluted sites to modified microclimate, rather than to pollution impact on plant physiology or genetics. - Advanced budburst phenology in white birch in severely polluted sites is explained by modified microclimate, not by pollution impact on plant physiology

  12. Engage the Public in Phenology Monitoring: Lessons Learned from the USA National Phenology Network

    Science.gov (United States)

    Crimmins, T. M.; Lebuhn, G.; Miller-Rushing, A. J.

    2009-12-01

    The USA National Phenology Network (USA-NPN) is a recently established network that brings together citizen scientists, government agencies, non-profit groups, educators and students of all ages to monitor the impacts of climate change on plants and animals in the United States. Though a handful of observers participated in the USA-NPN monitoring program in 2008, 2009 was the first truly operational year for the program. With a goal of 100,000 observers for this nationwide effort, we are working to engage participants both directly and through established organizations and agencies. The first year of operational monitoring and program advertisement has yielded many insights that are shaping how we move forward. In this presentation, we will highlight some of our most prominent “lessons learned” from our experience engaging participants, mainly through partnerships with organizations and agencies. One successful partnership that the USA-NPN established in 2009 was with the Great Sunflower Project, a citizen science effort focused on tracking bee activity. By piggy-backing on this established program, we were able to invite tens of thousands of self-selected individuals to learn about plant phenology and to contribute to the program. A benefit to the Great Sunflower Project was that monitoring phenology of their sunflowers gave observers something to do while waiting for the plant to attract bees. Observers’ experiences, data, and comments from the 2009 season are yielding insights into how this partnership can be strengthened and USA-NPN and GSP goals can more effectively be met. A second partnership initiated in 2009 was with the US National Park Service (NPS). Partnering with federal and state agencies offers great opportunities for data collection and education. In return, agencies stand to gain information that can directly influence management decisions. However, such efforts necessitate careful planning and execution. Together the USA-NPN and NPS drafted

  13. Radiotracers in medical applications, vols 1-2

    International Nuclear Information System (INIS)

    Rayudu, G.V.S.

    1983-01-01

    These volumes will serve as a basis for instruction and reference for professionals such as radiopharmaceutical chemists, radiopharmacologists, radiopharmacists, radiobiochemists, and others involved in the medical applications of radiotracers. Vol. I: Topics include radiohalogenated compounds, including radioiodine; Tc-labeled compounds; and in-house prepared radiopharmaceuticals. The charge particle range vs. energy in every element is tabulated for protons for cyclotrons users. Discussions are also provided on nonimaging radiotracer methods; 11 C, 13 N, 15 O, 67 Ga. 111 In, 75 Se, /SUP 123m/ Te compounds; radioactive noble gases; and miscellaneous radiotracers for imaging. Vol. II: Pertinent nuclear science data such as radiation dosimetry, radionuclide production modes, radionuclides for therapy, human experimentation regulations and consent forms, and radiotracer laboratory designs are presented

  14. Trends and Variability in Temperature Sensitivity of Lilac Flowering Phenology

    Science.gov (United States)

    Wang, Huanjiong; Dai, Junhu; Rutishauser, This; Gonsamo, Alemu; Wu, Chaoyang; Ge, Quansheng

    2018-03-01

    The responses of plant phenology to temperature variability have many consequences for ecological processes, agriculture, forestry, and human health. Temperature sensitivity (ST) of phenology could measure how and to what degree plant could phenologically track climate change. The long-term trends and spatial patterns in ST have been well studied for vegetative phenology such as leaf unfolding, but trends to be expected for reproductive phenology in the future remain unknown. Here we investigate trends and factors driving the temporal variation of ST of first bloom date (FBD). Using the long-term FBD records during 1963-2013 for common lilac (Syringa vulgaris) from 613 stations in Europe, we compared changes in ST from the beginning to the end of the study period. The Spearman partial correlations were used to assess the importance of four influencing factors. The results showed that the temporal changes in ST of FBD varied considerably among time scales. Mean ST decreased significantly by 0.92 days °C-1 from 1963-1972 to 2004-2013 (P plant species in other climates and environments using similar methods to our study.

  15. Predicting adaptation of phenology in response to climate change, an insect herbivore example

    NARCIS (Netherlands)

    Van Asch, M.; van Tienderen, P.H.; Holleman, L.J.M.; Visser, M.E.

    2007-01-01

    Climate change has led to an advance in phenology in many species. Synchrony in phenology between different species within a food chain may be disrupted if an increase in temperature affects the phenology of the different species differently, as is the case in the winter moth egg hatch–oak bud burst

  16. Predicting adaptation of phenology in response to climate change, an insect herbivore example

    NARCIS (Netherlands)

    van Asch, M.; van Tienderen, P.H.; Holleman, L.J.M.; Visser, M.E.

    2007-01-01

    Climate change has led to an advance in phenology in many species. Synchrony in phenology between different species within a food chain may be disrupted if an increase in temperature affects the phenology of the different species differently, as is the case in the winter moth egg hatch - oak bud

  17. The extent of shifts in vegetation phenology between rural and urban areas within a human-dominated region.

    Science.gov (United States)

    Dallimer, Martin; Tang, Zhiyao; Gaston, Kevin J; Davies, Zoe G

    2016-04-01

    Urbanization is one of the major environmental challenges facing the world today. One of its particularly pressing effects is alterations to local and regional climate through, for example, the Urban Heat Island. Such changes in conditions are likely to have an impact on the phenology of urban vegetation, which will have knock-on implications for the role that urban green infrastructure can play in delivering multiple ecosystem services. Here, in a human-dominated region, we undertake an explicit comparison of vegetation phenology between urban and rural zones. Using satellite-derived MODIS-EVI data from the first decade of the 20th century, we extract metrics of vegetation phenology (date of start of growing season, date of end of growing season, and length of season) for Britain's 15 largest cities and their rural surrounds. On average, urban areas experienced a growing season 8.8 days longer than surrounding rural zones. As would be expected, there was a significant decline in growing season length with latitude (by 3.4 and 2.4 days/degree latitude in rural and urban areas respectively). Although there is considerable variability in how phenology in urban and rural areas differs across our study cities, we found no evidence that built urban form influences the start, end, or length of the growing season. However, the difference in the length of the growing season between rural and urban areas was significantly negatively associated with the mean disposable household income for a city. Vegetation in urban areas deliver many ecosystem services such as temperature mitigation, pollution removal, carbon uptake and storage, the provision of amenity value for humans and habitat for biodiversity. Given the rapid pace of urbanization and ongoing climate change, understanding how vegetation phenology will alter in the future is important if we wish to be able to manage urban greenspaces effectively.

  18. Land surface phenology of Northeast China during 2000-2015: temporal changes and relationships with climate changes.

    Science.gov (United States)

    Zhang, Yue; Li, Lin; Wang, Hongbin; Zhang, Yao; Wang, Naijia; Chen, Junpeng

    2017-10-01

    As an important crop growing area, Northeast China (NEC) plays a vital role in China's food security, which has been severely affected by climate change in recent years. Vegetation phenology in this region is sensitive to climate change, and currently, the relationship between the phenology of NEC and climate change remains unclear. In this study, we used a satellite-derived normalized difference vegetation index (NDVI) to obtain the temporal patterns of the land surface phenology in NEC from 2000 to 2015 and validated the results using ground phenology observations. We then explored the relationships among land surface phenology, temperature, precipitation, and sunshine hours for relevant periods. Our results showed that the NEC experienced great phenological changes in terms of spatial heterogeneity during 2000-2015. The spatial patterns of land surface phenology mainly changed with altitude and land cover type. In most regions of NEC, the start date of land surface phenology had advanced by approximately 1.0 days year -1 , and the length of land surface phenology had been prolonged by approximately 1.0 days year -1 except for the needle-leaf and cropland areas, due to the warm conditions. We found that a distinct inter-annual variation in land surface phenology related to climate variables, even if some areas presented non-significant trends. Land surface phenology was coupled with climate variables and distinct responses at different combinations of temperature, precipitation, sunshine hours, altitude, and anthropogenic influence. These findings suggest that remote sensing and our phenology extracting methods hold great potential for helping to understand how land surface phenology is sensitive to global climate change.

  19. African Journal of Finance and Management - Vol 8, No 2 (2000)

    African Journals Online (AJOL)

    African Journal of Finance and Management - Vol 8, No 2 (2000) ... Effects of Mergers and Acquisitions to Shareholders' Wealth: Evidence from the United Kingdom. ... Matching Managerial Skills and Behaviour with Business Strategy - ...

  20. Impact of some climatic and phenological parameters on the ...

    African Journals Online (AJOL)

    In the first year, in control clones,climatic and phenological parameters explain 52.80% callogenesis variations, against 31.50% for SE. Therefore,climate and phenology significantly influence callogenesis, but not SE. For further industrial production of secondary metabolites such as butter, the obromin and chocolate aroma ...

  1. Phylogenetic conservatism and trait correlates of spring phenological responses to climate change in northeast China.

    Science.gov (United States)

    Du, Yanjun; Chen, Jingru; Willis, Charles G; Zhou, Zhiqiang; Liu, Tong; Dai, Wujun; Zhao, Yuan; Ma, Keping

    2017-09-01

    Climate change has resulted in major changes in plant phenology across the globe that includes leaf-out date and flowering time. The ability of species to respond to climate change, in part, depends on their response to climate as a phenological cue in general. Species that are not phenologically responsive may suffer in the face of continued climate change. Comparative studies of phenology have found phylogeny to be a reliable predictor of mean leaf-out date and flowering time at both the local and global scales. This is less true for flowering time response (i.e., the correlation between phenological timing and climate factors), while no study to date has explored whether the response of leaf-out date to climate factors exhibits phylogenetic signal. We used a 52-year observational phenological dataset for 52 woody species from the Forest Botanical Garden of Heilongjiang Province, China, to test phylogenetic signal in leaf-out date and flowering time, as well as, the response of these two phenological traits to both temperature and winter precipitation. Leaf-out date and flowering time were significantly responsive to temperature for most species, advancing, on average, 3.11 and 2.87 day/°C, respectively. Both leaf-out and flowering, and their responses to temperature exhibited significant phylogenetic signals. The response of leaf-out date to precipitation exhibited no phylogenetic signal, while flowering time response to precipitation did. Native species tended to have a weaker flowering response to temperature than non-native species. Earlier leaf-out species tended to have a greater response to winter precipitation. This study is the first to assess phylogenetic signal of leaf-out response to climate change, which suggests, that climate change has the potential to shape the plant communities, not only through flowering sensitivity, but also through leaf-out sensitivity.

  2. MJZ VOL 37 NO 2.CDR

    African Journals Online (AJOL)

    MJZ

    Women are 1.9 times more likely to suffer depression than. 2 men . Postnatal or postpartum depression (PND) is the onset of depressive symptoms in women within .... HIV. Negative. Positive. 1. 1.22 (0.50-2.96). 1. 1.77 (0.68-4.61). Table 2. Risk factors for depression and severe depression, adjusted odds ratios. 81. Medical ...

  3. Topography-mediated controls on local vegetation phenology estimated from MODIS vegetation index

    Science.gov (United States)

    Taehee Hwang; Conghe Song; James Vose; Lawrence Band

    2011-01-01

    Forest canopy phenology is an important constraint on annual water and carbon budgets, and responds to regional interannual climate variation. In steep terrain, there are complex spatial variations in phenology due to topographic influences on microclimate, community composition, and available soil moisture. In this study, we investigate spatial patterns of phenology...

  4. Nonlinear flowering responses to climate: are species approaching their limits of phenological change?

    Science.gov (United States)

    Iler, Amy M.; Høye, Toke T.; Inouye, David W.; Schmidt, Niels M.

    2013-01-01

    Many alpine and subalpine plant species exhibit phenological advancements in association with earlier snowmelt. While the phenology of some plant species does not advance beyond a threshold snowmelt date, the prevalence of such threshold phenological responses within plant communities is largely unknown. We therefore examined the shape of flowering phenology responses (linear versus nonlinear) to climate using two long-term datasets from plant communities in snow-dominated environments: Gothic, CO, USA (1974–2011) and Zackenberg, Greenland (1996–2011). For a total of 64 species, we determined whether a linear or nonlinear regression model best explained interannual variation in flowering phenology in response to increasing temperatures and advancing snowmelt dates. The most common nonlinear trend was for species to flower earlier as snowmelt advanced, with either no change or a slower rate of change when snowmelt was early (average 20% of cases). By contrast, some species advanced their flowering at a faster rate over the warmest temperatures relative to cooler temperatures (average 5% of cases). Thus, some species seem to be approaching their limits of phenological change in response to snowmelt but not temperature. Such phenological thresholds could either be a result of minimum springtime photoperiod cues for flowering or a slower rate of adaptive change in flowering time relative to changing climatic conditions. PMID:23836793

  5. South African Journal of Higher Education - Vol 16, No 2 (2002)

    African Journals Online (AJOL)

    South African Journal of Higher Education - Vol 16, No 2 (2002) ... Rewarding quality teaching in higher education: the evading dream? ... Employers' perceptions of the profile of MBA graduates · EMAIL FULL TEXT EMAIL FULL TEXT

  6. International Journal of Natural and Applied Sciences - Vol 5, No 2 ...

    African Journals Online (AJOL)

    International Journal of Natural and Applied Sciences - Vol 5, No 2 (2009) ... Illustration of decimation in digital signal processing (DSP) systems using ... of diesel polluted soils on hydrocarbon-utilizing microbial counts and oil degradation ...

  7. Effects of flowering phenology and synchrony on the reproductive success of a long-flowering shrub

    Science.gov (United States)

    Rodríguez-Pérez, Javier; Traveset, Anna

    2016-01-01

    Flowering phenology and synchrony with biotic and abiotic resources are crucial traits determining the reproductive success in insect-pollinated plants. In seasonal climates, plants flowering for long periods should assure reproductive success when resources are more predictable. In this work, we evaluated the relationship between flowering phenology and synchrony and reproductive success in Hypericum balearicum, a shrub flowering all year round but mainly during spring and summer. We studied two contrasting localities (differing mostly in rainfall) during 3 years, and at different biological scales spanning from localities to individual flowers and fruits. We first monitored (monthly) flowering phenology and reproductive success (fruit and seed set) of plants, and assessed whether in the locality with higher rainfall plants had longer flowering phenology and synchrony and relatively higher reproductive success within or outside the flowering peak. Secondly, we censused pollinators on H. balearicum individuals and measured reproductive success along the flowering peak of each locality to test for an association between (i) richness and abundance of pollinators and (ii) fruit and seed set, and seed weight. We found that most flowers (∼90 %) and the highest fruit set (∼70 %) were produced during the flowering peak of each locality. Contrary to expectations, plants in the locality with lower rainfall showed more relaxed flowering phenology and synchrony and set more fruits outside the flowering peak. During the flowering peak of each locality, the reproductive success of early-flowering individuals depended on a combination of both pollinator richness and abundance and rainfall; by contrast, reproductive success of late-flowering individuals was most dependent on rainfall. Plant species flowering for long periods in seasonal climates, thus, appear to be ideal organisms to understand how flowering phenology and synchrony match with biotic and abiotic resources, and

  8. Standardized phenology monitoring methods to track plant and animal activity for science and resource management applications

    Science.gov (United States)

    Denny, Ellen G.; Gerst, Katharine L.; Miller-Rushing, Abraham J.; Tierney, Geraldine L.; Crimmins, Theresa M.; Enquist, Carolyn A.F.; Guertin, Patricia; Rosemartin, Alyssa H.; Schwartz, Mark D.; Thomas, Kathryn A.; Weltzin, Jake F.

    2014-01-01

    Phenology offers critical insights into the responses of species to climate change; shifts in species’ phenologies can result in disruptions to the ecosystem processes and services upon which human livelihood depends. To better detect such shifts, scientists need long-term phenological records covering many taxa and across a broad geographic distribution. To date, phenological observation efforts across the USA have been geographically limited and have used different methods, making comparisons across sites and species difficult. To facilitate coordinated cross-site, cross-species, and geographically extensive phenological monitoring across the nation, the USA National Phenology Network has developed in situ monitoring protocols standardized across taxonomic groups and ecosystem types for terrestrial, freshwater, and marine plant and animal taxa. The protocols include elements that allow enhanced detection and description of phenological responses, including assessment of phenological “status”, or the ability to track presence–absence of a particular phenophase, as well as standards for documenting the degree to which phenological activity is expressed in terms of intensity or abundance. Data collected by this method can be integrated with historical phenology data sets, enabling the development of databases for spatial and temporal assessment of changes in status and trends of disparate organisms. To build a common, spatially, and temporally extensive multi-taxa phenological data set available for a variety of research and science applications, we encourage scientists, resources managers, and others conducting ecological monitoring or research to consider utilization of these standardized protocols for tracking the seasonal activity of plants and animals.

  9. Strong evidence for changing fish reproductive phenology under climate warming on the Tibetan Plateau.

    Science.gov (United States)

    Tao, Juan; He, Dekui; Kennard, Mark J; Ding, Chengzhi; Bunn, Stuart E; Liu, Chunlong; Jia, Yintao; Che, Rongxiao; Chen, Yifeng

    2018-05-01

    Phenological responses to climate change have been widely observed and have profound and lasting effects on ecosystems and biodiversity. However, compared to terrestrial ecosystems, the long-term effects of climate change on species' phenology are poorly understood in aquatic ecosystems. Understanding the long-term changes in fish reproductive phenology is essential for predicting population dynamics and for informing management strategies, but is currently hampered by the requirement for intensive field observations and larval identification. In this study, a very low-frequency sampling of juveniles and adults combined with otolith measurements (long axis length of the first annulus; LAFA) of an endemic Tibetan Plateau fish (Gymnocypris selincuoensis) was used to examine changes in reproductive phenology associated with climate changes from the 1970s to 2000s. Assigning individual fish to their appropriate calendar year class was assisted by dendrochronological methods (crossdating). The results demonstrated that LAFA was significantly and positively associated with temperature and growing season length. To separate the effects of temperature and the growing season length on LAFA growth, measurements of larval otoliths from different sites were conducted and revealed that daily increment additions were the main contributor (46.3%), while temperature contributed less (12.0%). Using constructed water-air temperature relationships and historical air temperature records, we found that the reproductive phenology of G. selincuoensis was strongly advanced in the spring during the 1970s and 1990s, while the increased growing season length in the 2000s was mainly due to a delayed onset of winter. The reproductive phenology of G. selincuoensis advanced 2.9 days per decade on average from the 1970s to 2000s, and may have effects on recruitment success and population dynamics of this species and other biota in the ecosystem via the food web. The methods used in this study

  10. Does flower phenology mirror the slowdown of global warming?

    Science.gov (United States)

    Jochner, Susanne; Menzel, Annette

    2015-01-01

    Although recent global warming trends in air temperature are not as pronounced as those observed only one decade ago, global mean temperature is still at a very high level. Does plant phenology – which is believed to be a suitable indicator of climate change – respond in a similar way, that is, does it still mirror recent temperature variations? We explored in detail long-term flowering onset dates of snowdrop, cherry, and lime tree and relevant spring temperatures at three sites in Germany (1901–2012) using the Bayesian multiple change-point approach. We investigated whether mean spring temperature changes were amplified or slowed down in the past decade and how plant phenology responded to the most recent temperature changes. Incorporating records with different end points (i.e., 2002 and 2012), we compared differences in trends and inferred possible differences caused by extrapolating phenological and meteorological data. The new multiple-change point approach is characterized by an enhanced structure and greater flexibility compared to the one change point model. However, the highest model probabilities for phenological (meteorological) records were still obtained for the one change point (linear) model. Marked warming trends in the recent decade were only revealed for mean temperatures of March to May, here better described with one or two change point models. In the majority of cases analyzed, changes in temperatures were well mirrored by phenological changes. However, temperatures in March to May were linked to less strongly advancing onset dates for lime tree flowering during the period 1901-2012, pointing to the likely influence of photoperiodic constraints or unfulfilled chilling requirements. Due to the slowdown of temperature increase, analyses conducted on records ending in 2002 demonstrated distinct differences when compared with records ending in 2012. Extrapolation of trends could therefore (along with the choice of the statistical method

  11. Circumpolar analysis of the Adélie Penguin reveals the importance of environmental variability in phenological mismatch

    Science.gov (United States)

    Youngflesh, Casey; Jenouvrier, Stephanie; Li, Yun; Ji, Rubao; Ainley, David G.; Ballard, Grant; Barbraud, Christophe; Delord, Karine; Dugger, Catherine; Emmerson, Loiuse M.; Fraser, William R.; Hinke, Jefferson T.; Lyver, Phil O'B.; Olmastroni, Silvia; Southwell, Colin J.; Trivelpiece, Susan G.; Trivelpiece, Wayne Z.; Lynch, Heather J.

    2017-01-01

    Evidence of climate-change-driven shifts in plant and animal phenology have raised concerns that certain trophic interactions may be increasingly mismatched in time, resulting in declines in reproductive success. Given the constraints imposed by extreme seasonality at high latitudes and the rapid shifts in phenology seen in the Arctic, we would also expect Antarctic species to be highly vulnerable to climate-change-driven phenological mismatches with their environment. However, few studies have assessed the impacts of phenological change in Antarctica. Using the largest database of phytoplankton phenology, sea-ice phenology, and Adélie Penguin breeding phenology and breeding success assembled to date, we find that, while a temporal match between Penguin breeding phenology and optimal environmental conditions sets an upper limit on breeding success, only a weak relationship to the mean exists. Despite previous work suggesting that divergent trends in Adélie Penguin breeding phenology are apparent across the Antarctic continent, we find no such trends. Furthermore, we find no trend in the magnitude of phenological mismatch, suggesting that mismatch is driven by interannual variability in environmental conditions rather than climate-change-driven trends, as observed in other systems. We propose several criteria necessary for a species to experience a strong climate-change-driven phenological mismatch, of which several may be violated by this system.

  12. Variations in global land surface phenology: a comparison of satellite optical and passive microwave data

    Science.gov (United States)

    Tong, X.; Tian, F.; Brandt, M.; Zhang, W.; Liu, Y.; Fensholt, R.

    2017-12-01

    Changes in vegetation phenological events are among the most sensitive biological responses to climate change. In last decades, facilitating by satellite remote sensing techniques, land surface phenology (LSP) have been monitored at global scale using proxy approaches as tracking the temporal change of a satellite-derived vegetation index. However, the existing global assessments of changes in LSP are all established on the basis of leaf phenology using NDVI derived from optical sensors, being responsive to vegetation canopy cover and greenness. Instead, the vegetation optical depth (VOD) parameter from passive microwave sensors, which is sensitive to the aboveground vegetation water content by including as well the woody components in the observations, provides an alternative, independent and comprehensive means for global vegetation phenology monitoring. We used the unique long-term global VOD record available for the period 1992-2012 to monitoring the dynamics of LSP metrics (length of season, start of season and end of season) in comparison with the dynamics of LSP metrics derived from the latest GIMMS NDVI3G V1. We evaluated the differences in the linear trends of LSP metrics between two datasets. Currently, our results suggest that the level of seasonality variation of vegetation water content is less than the vegetation greenness. We found significant phenological changes in vegetation water content in African woodlands, where has been reported with little leaf phenological change regardless of the delays in rainfall onset. Therefore, VOD might allow us to detect temporal shifts in the timing difference of vegetation water storage vs. leaf emergence and to see if some ecophysiological thresholds seem to be reached, that could cause species turnover as climate change-driven alterations to the African monsoon proceed.

  13. Networked web-cameras monitor congruent seasonal development of birches with phenological field observations

    Science.gov (United States)

    Peltoniemi, Mikko; Aurela, Mika; Böttcher, Kristin; Kolari, Pasi; Loehr, John; Karhu, Jouni; Kubin, Eero; Linkosalmi, Maiju; Melih Tanis, Cemal; Nadir Arslan, Ali

    2017-04-01

    Ecosystems' potential to provide services, e.g. to sequester carbon is largely driven by the phenological cycle of vegetation. Timing of phenological events is required for understanding and predicting the influence of climate change on ecosystems and to support various analyses of ecosystem functioning. We established a network of cameras for automated monitoring of phenological activity of vegetation in boreal ecosystems of Finland. Cameras were mounted on 14 sites, each site having 1-3 cameras. In this study, we used cameras at 11 of these sites to investigate how well networked cameras detect phenological development of birches (Betula spp.) along the latitudinal gradient. Birches are interesting focal species for the analyses as they are common throughout Finland. In our cameras they often appear in smaller quantities within dominant species in the images. Here, we tested whether small scattered birch image elements allow reliable extraction of color indices and changes therein. We compared automatically derived phenological dates from these birch image elements to visually determined dates from the same image time series, and to independent observations recorded in the phenological monitoring network from the same region. Automatically extracted season start dates based on the change of green color fraction in the spring corresponded well with the visually interpreted start of season, and field observed budburst dates. During the declining season, red color fraction turned out to be superior over green color based indices in predicting leaf yellowing and fall. The latitudinal gradients derived using automated phenological date extraction corresponded well with gradients based on phenological field observations from the same region. We conclude that already small and scattered birch image elements allow reliable extraction of key phenological dates for birch species. Devising cameras for species specific analyses of phenological timing will be useful for

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

    Science.gov (United States)

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

    2012-01-01

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

  15. Egyptian Journal of Medical Human Genetics - Vol 13, No 2 (2012)

    African Journals Online (AJOL)

    Egyptian Journal of Medical Human Genetics - Vol 13, No 2 (2012) ... as independent indicators for B-CLL: Correlation to response to treatment and disease ... Profile of disorders of sexual differentiation in the Northeast region of Cairo, Egypt ...

  16. Potential and Limitations of Low-Cost Unmanned Aerial Systems for Monitoring Altitudinal Vegetation Phenology in the Tropics

    Science.gov (United States)

    Silva, T. S. F.; Torres, R. S.; Morellato, P.

    2017-12-01

    Vegetation phenology is a key component of ecosystem function and biogeochemical cycling, and highly susceptible to climatic change. Phenological knowledge in the tropics is limited by lack of monitoring, traditionally done by laborious direct observation. Ground-based digital cameras can automate daily observations, but also offer limited spatial coverage. Imaging by low-cost Unmanned Aerial Systems (UAS) combines the fine resolution of ground-based methods with and unprecedented capability for spatial coverage, but challenges remain in producing color-consistent multitemporal images. We evaluated the applicability of multitemporal UAS imaging to monitor phenology in tropical altitudinal grasslands and forests, answering: 1) Can very-high resolution aerial photography from conventional digital cameras be used to reliably monitor vegetative and reproductive phenology? 2) How is UAS monitoring affected by changes in illumination and by sensor physical limitations? We flew imaging missions monthly from Feb-16 to Feb-17, using a UAS equipped with an RGB Canon SX260 camera. Flights were carried between 10am and 4pm, at 120-150m a.g.l., yielding 5-10cm spatial resolution. To compensate illumination changes caused by time of day, season and cloud cover, calibration was attempted using reference targets and empirical models, as well as color space transformations. For vegetative phenological monitoring, multitemporal response was severely affected by changes in illumination conditions, strongly confounding the phenological signal. These variations could not be adequately corrected through calibration due to sensor limitations. For reproductive phenology, the very-high resolution of the acquired imagery allowed discrimination of individual reproductive structures for some species, and its stark colorimetric differences to vegetative structures allowed detection of the reproductive timing on the HSV color space, despite illumination effects. We conclude that reliable

  17. Disaggregating tree and grass phenology in tropical savannas

    Science.gov (United States)

    Zhou, Qiang

    Savannas are mixed tree-grass systems and as one of the world's largest biomes represent an important component of the Earth system affecting water and energy balances, carbon sequestration and biodiversity as well as supporting large human populations. Savanna vegetation structure and its distribution, however, may change because of major anthropogenic disturbances from climate change, wildfire, agriculture, and livestock production. The overstory and understory may have different water use strategies, different nutrient requirements and have different responses to fire and climate variation. The accurate measurement of the spatial distribution and structure of the overstory and understory are essential for understanding the savanna ecosystem. This project developed a workflow for separating the dynamics of the overstory and understory fractional cover in savannas at the continental scale (Australia, South America, and Africa). Previous studies have successfully separated the phenology of Australian savanna vegetation into persistent and seasonal greenness using time series decomposition, and into fractions of photosynthetic vegetation (PV), non-photosynthetic vegetation (NPV) and bare soil (BS) using linear unmixing. This study combined these methods to separate the understory and overstory signal in both the green and senescent phenological stages using remotely sensed imagery from the MODIS (MODerate resolution Imaging Spectroradiometer) sensor. The methods and parameters were adjusted based on the vegetation variation. The workflow was first tested at the Australian site. Here the PV estimates for overstory and understory showed best performance, however NPV estimates exhibited spatial variation in validation relationships. At the South American site (Cerrado), an additional method based on frequency unmixing was developed to separate green vegetation components with similar phenology. When the decomposition and frequency methods were compared, the frequency

  18. Intraspecific priority effects modify compensatory responses to changes in hatching phenology in an amphibian.

    Science.gov (United States)

    Murillo-Rincón, Andrea P; Kolter, Nora A; Laurila, Anssi; Orizaola, Germán

    2017-01-01

    In seasonal environments, modifications in the phenology of life-history events can alter the strength of time constraints experienced by organisms. Offspring can compensate for a change in timing of hatching by modifying their growth and development trajectories. However, intra- and interspecific interactions may affect these compensatory responses, in particular if differences in phenology between cohorts lead to significant priority effects (i.e. the competitive advantage that early-hatching individuals have over late-hatching ones). Here, we conducted a factorial experiment to determine whether intraspecific priority effects can alter compensatory phenotypic responses to hatching delay in a synchronic breeder by rearing moor frog (Rana arvalis) tadpoles in different combinations of phenological delay and food abundance. Tadpoles compensated for the hatching delay by speeding up their development, but only when reared in groups of individuals with identical hatching phenology. In mixed phenology groups, strong competitive effects by non-delayed tadpoles prevented the compensatory responses and delayed larvae metamorphosed later than in single phenology treatments. Non-delayed individuals gained advantage from developing with delayed larvae by increasing their developmental and growth rates as compared to single phenology groups. Food shortage prolonged larval period and reduced mass at metamorphosis in all treatments, but it did not prevent compensatory developmental responses in larvae reared in single phenology groups. This study demonstrates that strong intraspecific priority effects can constrain the compensatory growth and developmental responses to phenological change, and that priority effects can be an important factor explaining the maintenance of synchronic life histories (i.e. explosive breeding) in seasonal environments. © 2016 The Authors. Journal of Animal Ecology © 2016 British Ecological Society.

  19. Connecting phenological predictions with population growth rates for mountain pine beetle, an outbreak insect

    Science.gov (United States)

    James A. Powell; Barbara J. Bentz

    2009-01-01

    It is expected that a significant impact of global warming will be disruption of phenology as environmental cues become disassociated from their selective impacts. However there are few, if any, models directly connecting phenology with population growth rates. In this paper we discuss connecting a distributional model describing mountain pine beetle phenology with a...

  20. Land Surface Phenology from MODIS: Characterization of the Collection 5 Global Land Cover Dynamics Product

    Science.gov (United States)

    Ganguly, Sangram; Friedl, Mark A.; Tan, Bin; Zhang, Xiaoyang; Verma, Manish

    2010-01-01

    Information related to land surface phenology is important for a variety of applications. For example, phenology is widely used as a diagnostic of ecosystem response to global change. In addition, phenology influences seasonal scale fluxes of water, energy, and carbon between the land surface and atmosphere. Increasingly, the importance of phenology for studies of habitat and biodiversity is also being recognized. While many data sets related to plant phenology have been collected at specific sites or in networks focused on individual plants or plant species, remote sensing provides the only way to observe and monitor phenology over large scales and at regular intervals. The MODIS Global Land Cover Dynamics Product was developed to support investigations that require regional to global scale information related to spatiotemporal dynamics in land surface phenology. Here we describe the Collection 5 version of this product, which represents a substantial refinement relative to the Collection 4 product. This new version provides information related to land surface phenology at higher spatial resolution than Collection 4 (500-m vs. 1-km), and is based on 8-day instead of 16-day input data. The paper presents a brief overview of the algorithm, followed by an assessment of the product. To this end, we present (1) a comparison of results from Collection 5 versus Collection 4 for selected MODIS tiles that span a range of climate and ecological conditions, (2) a characterization of interannual variation in Collections 4 and 5 data for North America from 2001 to 2006, and (3) a comparison of Collection 5 results against ground observations for two forest sites in the northeastern United States. Results show that the Collection 5 product is qualitatively similar to Collection 4. However, Collection 5 has fewer missing values outside of regions with persistent cloud cover and atmospheric aerosols. Interannual variability in Collection 5 is consistent with expected ranges of

  1. Object-based Dimensionality Reduction in Land Surface Phenology Classification

    Directory of Open Access Journals (Sweden)

    Brian E. Bunker

    2016-11-01

    Full Text Available Unsupervised classification or clustering of multi-decadal land surface phenology provides a spatio-temporal synopsis of natural and agricultural vegetation response to environmental variability and anthropogenic activities. Notwithstanding the detailed temporal information available in calibrated bi-monthly normalized difference vegetation index (NDVI and comparable time series, typical pre-classification workflows average a pixel’s bi-monthly index within the larger multi-decadal time series. While this process is one practical way to reduce the dimensionality of time series with many hundreds of image epochs, it effectively dampens temporal variation from both intra and inter-annual observations related to land surface phenology. Through a novel application of object-based segmentation aimed at spatial (not temporal dimensionality reduction, all 294 image epochs from a Moderate Resolution Imaging Spectroradiometer (MODIS bi-monthly NDVI time series covering the northern Fertile Crescent were retained (in homogenous landscape units as unsupervised classification inputs. Given the inherent challenges of in situ or manual image interpretation of land surface phenology classes, a cluster validation approach based on transformed divergence enabled comparison between traditional and novel techniques. Improved intra-annual contrast was clearly manifest in rain-fed agriculture and inter-annual trajectories showed increased cluster cohesion, reducing the overall number of classes identified in the Fertile Crescent study area from 24 to 10. Given careful segmentation parameters, this spatial dimensionality reduction technique augments the value of unsupervised learning to generate homogeneous land surface phenology units. By combining recent scalable computational approaches to image segmentation, future work can pursue new global land surface phenology products based on the high temporal resolution signatures of vegetation index time series.

  2. An observation-based progression modeling approach to spring and autumn deciduous tree phenology

    Science.gov (United States)

    Yu, Rong; Schwartz, Mark D.; Donnelly, Alison; Liang, Liang

    2016-03-01

    It is important to accurately determine the response of spring and autumn phenology to climate change in forest ecosystems, as phenological variations affect carbon balance, forest productivity, and biodiversity. We observed phenology intensively throughout spring and autumn in a temperate deciduous woodlot at Milwaukee, WI, USA, during 2007-2012. Twenty-four phenophase levels in spring and eight in autumn were recorded for 106 trees, including white ash, basswood, white oak, boxelder, red oak, and hophornbeam. Our phenological progression models revealed that accumulated degree-days and day length explained 87.9-93.4 % of the variation in spring canopy development and 75.8-89.1 % of the variation in autumn senescence. In addition, the timing of community-level spring and autumn phenophases and the length of the growing season from 1871 to 2012 were reconstructed with the models developed. All simulated spring phenophases significantly advanced at a rate from 0.24 to 0.48 days/decade ( p ≤ 0.001) during the 1871-2012 period and from 1.58 to 2.00 days/decade ( p coloration) and 0.50 (full-leaf coloration) days/decade ( p coloration and leaf fall, and suggested accelerating simulated ecosystem responses to climate warming over the last four decades in comparison to the past 142 years.

  3. Phenological shifts conserve thermal niches in North American birds and reshape expectations for climate-driven range shifts.

    Science.gov (United States)

    Socolar, Jacob B; Epanchin, Peter N; Beissinger, Steven R; Tingley, Morgan W

    2017-12-05

    Species respond to climate change in two dominant ways: range shifts in latitude or elevation and phenological shifts of life-history events. Range shifts are widely viewed as the principal mechanism for thermal niche tracking, and phenological shifts in birds and other consumers are widely understood as the principal mechanism for tracking temporal peaks in biotic resources. However, phenological and range shifts each present simultaneous opportunities for temperature and resource tracking, although the possible role for phenological shifts in thermal niche tracking has been widely overlooked. Using a canonical dataset of Californian bird surveys and a detectability-based approach for quantifying phenological signal, we show that Californian bird communities advanced their breeding phenology by 5-12 d over the last century. This phenological shift might track shifting resource peaks, but it also reduces average temperatures during nesting by over 1 °C, approximately the same magnitude that average temperatures have warmed over the same period. We further show that early-summer temperature anomalies are correlated with nest success in a continental-scale database of bird nests, suggesting avian thermal niches might be broadly limited by temperatures during nesting. These findings outline an adaptation surface where geographic range and breeding phenology respond jointly to constraints imposed by temperature and resource phenology. By stabilizing temperatures during nesting, phenological shifts might mitigate the need for range shifts. Global change ecology will benefit from further exploring phenological adjustment as a potential mechanism for thermal niche tracking and vice versa.

  4. Phenological change detection while accounting for abrupt and gradual trends in satellite image time series

    NARCIS (Netherlands)

    Verbesselt, J.; Hyndman, R.; Zeileis, A.; Culvenor, D.

    2010-01-01

    A challenge in phenology studies is understanding what constitutes phenological change amidst background variation. The majority of phenological studies have focused on extracting critical points in the seasonal growth cycle, without exploiting the full temporal detail. The high degree of

  5. 40 CFR 96.288 - CAIR SO2 allowance allocations to CAIR SO2 opt-in units.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false CAIR SO2 allowance allocations to CAIR SO2 opt-in units. 96.288 Section 96.288 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NOX BUDGET TRADING PROGRAM AND CAIR NOX AND SO2 TRADING PROGRAMS FOR...

  6. Phenological models for the beginning of apple blossom in Germany

    Energy Technology Data Exchange (ETDEWEB)

    Chmielewski, Frank M.; Bluemel, Klaus; Henniges, Yvonne [Humboldt-Univ. of Berlin (Germany). Agricultural Climatology; Blanke, Michael [Univ. of Bonn (Germany). Dept. of Horticultural Science; Weber, Roland W.S. [Fruit Growing Research Institute Jork (Germany); Zoth, Michael [Competence Centre Fruit Growing Bodensee, Ravensburg-Bavendorf (Germany)

    2011-10-15

    Five phenological models (M1-M5) were examined with respect to their suitability to calculate the beginning of apple blossom in Germany, the most important fruit crop in Western Europe. Blossoming is the most sensitive period, e.g.to frost, and determines the fruit set of the apple trees. Phenological observations and temperature data from the German Weather Service in the period 1961-2005 were used to fit these five models. For the calculations data from, 5,630 phenological and 523 temperature stations were attributed to a 10 km x 10 km grid using second order universal kriging. Model parameters were optimised on 3,672 grid points for the nationwide approach for Germany and on 148 points for 11 fruit growing regions. Root mean square errors (RMSE) between modelled and observed apple blossom data varied from 4.2 to 5.0 days for the internal and from 4.6 to 5.6 days for the external verification on the basis of phenological records from three fruit growing research centres. The very simple statistical model approach M5 had the advantage of causing the least effort to calculate the bloom date, but it never performed better than any of the best mechanistic models M1-M4. Also, the 'thermal time model' M1 and the sequential model M2 were both easy to handle which makes them a preferable choice for predictions and management decisions in apple orchards. These two models M1 and M2 are also suitable to be implemented in yield models and water budget models in order to replace the use of fixed developmental stages by dynamical calculations. The two combined chilling/forcing models M2 - a sequential model - and M3 - a parallel model - exhibited the lowest average RMSE. Both models (M2 and M3) could preferably be used to project the impact of climate change on the beginning of apple blossom, since these models can compensate a possible lack of chilling by a higher demand for forcing. The present study showed that a) all five models were able to calculate the

  7. Phenology of seed and leaves rain in response to periodic climatic variability in a seasonal wet tropical forest

    Science.gov (United States)

    Matteo, D.; Wright, S. J.; Davies, S. J.; Muller-Landau, H. C.; Wolfe, B.; Detto, M.

    2016-12-01

    Phenology, by controlling the rhythms of plants, plays a fundamental role in regulating access to resources, ecosystem processes, competition among species, interactions with consumers and feedbacks to the climate. In high biodiverse tropical forests, where phenology of flowering and leafing are complex, an adequate representation of phenology must take into account a given set of climatic, edaphic and biotic factors. Climatic factors are particularly important because plants may use them as cues for timing different phenological phases and be influenced by their intensity. Climatic variability can be periodic, if events occur with regular frequency, or aperiodic. One prominent periodic large-scale pattern that causes unusual weather is ENSO event. In general, Central America tends to be dry and warm during a mature phase of an ENSO event, which usually peaks between October and January with a frequency of 2-3 events per decade. Because in many tropical areas the effect of ENSO is highly prominent, it is plausible that plants have adapted their growth and reproduction mechanisms to synchronize ENSO phases, in a similar way that plants do during the seasonal cycle. We used a long dataset (30+ years) of fruits and leaves rains of tropical trees and lianas to determine ecosystem response and species specific response of these phenological events to local climate variability corresponding to the modes of ENSO. Specifically, we tested the hypothesis that phenological responses to ENSO are similar to response to seasonal cycles, i.e., higher litterfall before a warm-dry phase and higher fruiting after such phase, with strong correlation between seeds and leaves. At sub-community level, we evaluated whether evergreen and deciduous, biotic and abiotic dispersers and free and climbing life forms, have the same response to ENSO in terms of leaves and seeds rain. At species level we tested the hypothesis that species with low photosynthetic capacity leaves are more responsive

  8. Automated processing of webcam images for phenological classification.

    Science.gov (United States)

    Bothmann, Ludwig; Menzel, Annette; Menze, Bjoern H; Schunk, Christian; Kauermann, Göran

    2017-01-01

    Along with the global climate change, there is an increasing interest for its effect on phenological patterns such as start and end of the growing season. Scientific digital webcams are used for this purpose taking every day one or more images from the same natural motive showing for example trees or grassland sites. To derive phenological patterns from the webcam images, regions of interest are manually defined on these images by an expert and subsequently a time series of percentage greenness is derived and analyzed with respect to structural changes. While this standard approach leads to satisfying results and allows to determine dates of phenological change points, it is associated with a considerable amount of manual work and is therefore constrained to a limited number of webcams only. In particular, this forbids to apply the phenological analysis to a large network of publicly accessible webcams in order to capture spatial phenological variation. In order to be able to scale up the analysis to several hundreds or thousands of webcams, we propose and evaluate two automated alternatives for the definition of regions of interest, allowing for efficient analyses of webcam images. A semi-supervised approach selects pixels based on the correlation of the pixels' time series of percentage greenness with a few prototype pixels. An unsupervised approach clusters pixels based on scores of a singular value decomposition. We show for a scientific webcam that the resulting regions of interest are at least as informative as those chosen by an expert with the advantage that no manual action is required. Additionally, we show that the methods can even be applied to publicly available webcams accessed via the internet yielding interesting partitions of the analyzed images. Finally, we show that the methods are suitable for the intended big data applications by analyzing 13988 webcams from the AMOS database. All developed methods are implemented in the statistical software

  9. Automated processing of webcam images for phenological classification.

    Directory of Open Access Journals (Sweden)

    Ludwig Bothmann

    Full Text Available Along with the global climate change, there is an increasing interest for its effect on phenological patterns such as start and end of the growing season. Scientific digital webcams are used for this purpose taking every day one or more images from the same natural motive showing for example trees or grassland sites. To derive phenological patterns from the webcam images, regions of interest are manually defined on these images by an expert and subsequently a time series of percentage greenness is derived and analyzed with respect to structural changes. While this standard approach leads to satisfying results and allows to determine dates of phenological change points, it is associated with a considerable amount of manual work and is therefore constrained to a limited number of webcams only. In particular, this forbids to apply the phenological analysis to a large network of publicly accessible webcams in order to capture spatial phenological variation. In order to be able to scale up the analysis to several hundreds or thousands of webcams, we propose and evaluate two automated alternatives for the definition of regions of interest, allowing for efficient analyses of webcam images. A semi-supervised approach selects pixels based on the correlation of the pixels' time series of percentage greenness with a few prototype pixels. An unsupervised approach clusters pixels based on scores of a singular value decomposition. We show for a scientific webcam that the resulting regions of interest are at least as informative as those chosen by an expert with the advantage that no manual action is required. Additionally, we show that the methods can even be applied to publicly available webcams accessed via the internet yielding interesting partitions of the analyzed images. Finally, we show that the methods are suitable for the intended big data applications by analyzing 13988 webcams from the AMOS database. All developed methods are implemented in the

  10. Plant Phenology Site Phenometrics + Accumulated Growing Degree Day Calculations for the continental United States (2009-2016)

    Data.gov (United States)

    Department of the Interior — This datafile consists of a subset of plant phenology observations drawn from the USA National Phenology Network’s National Phenology Database (www.usanpn.org). The...

  11. PHENOLOGY OF Copernicia prunifera (ARECACEAE IN A CAATINGA AREA OF RIO GRANDE DO NORTE

    Directory of Open Access Journals (Sweden)

    Talita Geovanna Fernandes Rocha

    2015-12-01

    Full Text Available The objective of this study was to evaluate the vegetative and reproductive phenology of Copernicia prunifera (carnauba wax in natural populations correlated with climate variables. The study was conducted in a native area, located in the Campus of Academic Unit Specialized in Agricultural Sciences of UFRN in the municipality of Macaíba, RN. The evaluations were made between May 2010 and December 2012, totaling 67 fortnightly observations of vegetative phenophases and reproductive. The relationship between the occurrence of each phenophase and climate variables (air temperature, precipitation, relative humidity, wind speed and radiation were tested by Spearman correlation, performed with the climate data of the first (rS1, second (rS2, third (rS3 and fourth (rS4 phenological fortnight prior to the event. Individuals of C. prunifera are asynchronous with leaf loss and emission of new leaves all the time. Flowering is subanual, i.e. occurs more than once a year. There is a positive relationship between the intensity of unripe fruits and higher temperature with delay of three (rS3 = 0.261; P < 0.005 to four fortnights (rS4 = 0.276; P < 0.005 to the phenological event. We observed also significant positive correlations between temperature and number of trees with ripe fruits. Thus, it is assumed that the species studied was influenced by aspects of morphology and physiology, with environmental factors interfering secondarily.

  12. Incorporating genetic variation into a model of budburst phenology of coast Douglas-fir (Pseudotsuga menziesii var

    Science.gov (United States)

    Peter J. Gould; Constance A. Harrington; Bradley J. St Clair

    2011-01-01

    Models to predict budburst and other phenological events in plants are needed to forecast how climate change may impact ecosystems and for the development of mitigation strategies. Differences among genotypes are important to predicting phenological events in species that show strong clinal variation in adaptive traits. We present a model that incorporates the effects...

  13. Model Development to Predict Phenological scale of Table Grapes (cvs. Thompson, Crimson and Superior Seedless and Red Globe using Growing Degree Days

    Directory of Open Access Journals (Sweden)

    Nicolas Verdugo-Vásquez

    2017-09-01

    Full Text Available Phenological models have been made mainly for winegrape cultivars, despite the economic importance of table grapes. The aim of this work was to develop and validate models for predicting phenological scales of table grapes (cvs. Thompson, Crimson and Superior Seedless and Red Globe grown under semi-arid conditions. Measurements of phenology were carried out weekly from budburst to harvest during four growing seasons (2009-2013. Phenology models were developed using the Mitscherlich monomolecular equation where the dependent and independent variables were the Eichhorn and Lorenz phenological (ELP scale modified by Coombe and the growing degree days (GDD, respectively. Results indicated that there were strong non-linear correlations between the ELP scale and GDD for the four cultivars with coefficient of determinations (R2 ranging between 0.97-0.99. Also, validation indicated that the models were able to predict ELP scale with a root mean square (RMSE and mean absolute error (MAE ranging between 2.1-2.4 and 1.35-1.69, respectively. The prediction variability (expressed in days was between 4.4-19.4 days, obtaining the best results for the flowering period. This study suggested that the phenological models based on GDD could be useful planning tools for farming, especially from budburst to veraison of table grape cultivars.

  14. Seasonality of weather and tree phenology in a tropical evergreen mountain rain forest.

    Science.gov (United States)

    Bendix, J; Homeier, J; Cueva, E Ortiz; Emck, P; Breckle, S-W; Richter, M; Beck, E

    2006-07-01

    Flowering and fruiting as phenological events of 12 tree species in an evergreen tropical mountain rain forest in southern Ecuador were examined over a period of 3-4 years. Leaf shedding of two species was observed for 12 months. Parallel to the phenological recordings, meteorological parameters were monitored in detail and related to the flowering and fruiting activity of the trees. In spite of the perhumid climate of that area, a high degree of intra- and inter-specific synchronisation of phenological traits was apparent. With the exception of one species that flowered more or less continuously, two groups of trees could be observed, one of which flowered during the less humid months (September to October) while the second group started to initiate flowers towards the end of that phase and flowered during the heavy rains (April to July). As reflected by correlation coefficients, the all-time series of meteorological parameters showed a distinct seasonality of 8-12 months, apparently following the quasi-periodic oscillation of precipitation and related cloudiness. As revealed by power spectrum analysis and Markov persistence, rainfall and minimum temperature appear to be the only parameters with a periodicity free of long-term variations. The phenological events of most of the plant species showed a similar periodicity of 8-12 months, which followed the annual oscillation of relatively less and more humid periods and thus was in phase or in counter-phase with the oscillations of the meteorological parameters. Periods of unusual cold or dryness, presumably resulting from underlying longer-term trends or oscillations (such as ENSO), affected the homogeneity of quasi-12-month flowering events, fruit maturation and also the production of germinable seeds. Some species show underlying quasi-2-year-oscillations, for example that synchronise with the development of air temperature; others reveal an underlying decrease or increase in flowering activity over the

  15. Climate and the complexity of migratory phenology: sexes, migratory distance, and arrival distributions

    Science.gov (United States)

    Macmynowski, Dena P.; Root, Terry L.

    2007-05-01

    The intra- and inter-season complexity of bird migration has received limited attention in climatic change research. Our phenological analysis of 22 species collected in Chicago, USA, (1979 2002) evaluates the relationship between multi-scalar climate variables and differences (1) in arrival timing between sexes, (2) in arrival distributions among species, and (3) between spring and fall migration. The early migratory period for earliest arriving species (i.e., short-distance migrants) and earliest arriving individuals of a species (i.e., males) most frequently correlate with climate variables. Compared to long-distance migrant species, four times as many short-distance migrants correlate with spring temperature, while 8 of 11 (73%) of long-distance migrant species’ arrival is correlated with the North Atlantic Oscillation (NAO). While migratory phenology has been correlated with NAO in Europe, we believe that this is the first documentation of a significant association in North America. Geographically proximate conditions apparently influence migratory timing for short-distance migrants while continental-scale climate (e.g., NAO) seemingly influences the phenology of Neotropical migrants. The preponderance of climate correlations is with the early migratory period, not the median of arrival, suggesting that early spring conditions constrain the onset or rate of migration for some species. The seasonal arrival distribution provides considerable information about migratory passage beyond what is apparent from statistical analyses of phenology. A relationship between climate and fall phenology is not detected at this location. Analysis of the within-season complexity of migration, including multiple metrics of arrival, is essential to detect species’ responses to changing climate as well as evaluate the underlying biological mechanisms.

  16. Declining effect of warm temperature on spring phenology of tree species at low elevation in the Alps

    Science.gov (United States)

    Asse, Daphné; Randin, Christophe; Chuine, Isabelle

    2017-04-01

    Mountain regions are particularly exposed to climate change and temperature. In the Alps increased twice faster than in the northern hemisphere during the 20th century. As an immediate response, spring phenological phases of plant species such as budburst and flowering, have tended to occur earlier. In 2004, the CREA (Centre de Recherches sur les Ecosystèmes d'Altitude, Chamonix, France) initiated the citizen science program Phenoclim, which aims at assessing the long-term effects of climate changes on plant phenology over the entire French Alps. Sixty sites with phenological observations were equipped with temperature stations across a large elevational gradient. Here we used phenological records for five tree species (birch, ash, hazel, spruce and larch) combined with measurements or projections of temperature. We first tested the effects of geographic and topo-climatic factors on the timing of spring phenological phases. We then tested the hypothesis that a lack of chilling temperature during winter delayed dormancy release and subsequently spring phenological phases. Our data are currently being used to calibrate process-based phenological models to test to which extent soil temperature and photoperiod affect the timing of spring phenological phases. We found that growing degree-days was the best predictor of the timing of spring phenological phases, with a significant contribution of chilling. Our results also suggest that spring phenological phases were consistently delayed at low elevation by a lack of chilling in fall during warm years for the three deciduous species. Key words: Spring phenology, elevation gradients, citizen science, empirical and process-based modeling

  17. Journal of Computer Science and Its Application - Vol 20, No 2 (2013)

    African Journals Online (AJOL)

    Journal of Computer Science and Its Application - Vol 20, No 2 (2013) ... Fuzzy analysis and adaptive anthropometry model for object identification in surveillance system ... Natural language processing techniques for automatic test questions ...

  18. Species- and community-level responses combine to drive phenology of lake phytoplankton

    Science.gov (United States)

    Walters, Annika; Sagrario, María de los Ángeles González; Schindler, Daniel E.

    2013-01-01

    Global change is leading to shifts in the seasonal timing of growth and maturation for primary producers. Remote sensing is increasingly used to measure the timing of primary production in both aquatic and terrestrial ecosystems, but there is often a poor correlation between these results and direct observations of life-history responses of individual species. One explanation may be that in addition to phenological shifts, global change is also causing shifts in community composition among species with different seasonal timing of growth and maturation. We quantified how shifts in species phenology and in community composition translated into phenological change in a diverse phytoplankton community from 1962-2000. During this time the aggregate community spring-summer phytoplankton peak has shifted 63 days earlier. The mean taxon shift was only 3 days earlier and shifts in taxa phenology explained only 40% of the observed community phenological shift. The remaining community shift was attributed to dominant early season taxa increasing in abundance while a dominant late season taxon decreased in abundance. In diverse producer communities experiencing multiple stressors, changes in species composition must be considered to fully understand and predict shifts in the seasonal timing of primary production.

  19. Changes in vegetation phenology on the Mongolian Plateau and their climatic determinants.

    Science.gov (United States)

    Miao, Lijuan; Müller, Daniel; Cui, Xuefeng; Ma, Meihong

    2017-01-01

    Climate change affects the timing of phenological events, such as the start, end, and length of the growing season of vegetation. A better understanding of how the phenology responded to climatic determinants is important in order to better anticipate future climate-ecosystem interactions. We examined the changes of three phenological events for the Mongolian Plateau and their climatic determinants. To do so, we derived three phenological metrics from remotely sensed vegetation indices and associated these with climate data for the period of 1982 to 2011. The results suggested that the start of the growing season advanced by 0.10 days yr-1, the end was delayed by 0.11 days yr-1, and the length of the growing season expanded by 6.3 days during the period from 1982 to 2011. The delayed end and extended length of the growing season were observed consistently in grassland, forest, and shrubland, while the earlier start was only observed in grassland. Partial correlation analysis between the phenological events and the climate variables revealed that higher temperature was associated with an earlier start of the growing season, and both temperature and precipitation contributed to the later ending. Overall, our findings suggest that climate change will substantially alter the vegetation phenology in the grasslands of the Mongolian Plateau, and likely also in biomes with similar environmental conditions, such as other semi-arid steppe regions.

  20. Phenological plasticity will not help all species adapt to climate change.

    Science.gov (United States)

    Duputié, Anne; Rutschmann, Alexis; Ronce, Ophélie; Chuine, Isabelle

    2015-08-01

    Concerns are rising about the capacity of species to adapt quickly enough to climate change. In long-lived organisms such as trees, genetic adaptation is slow, and how much phenotypic plasticity can help them cope with climate change remains largely unknown. Here, we assess whether, where and when phenological plasticity is and will be adaptive in three major European tree species. We use a process-based species distribution model, parameterized with extensive ecological data, and manipulate plasticity to suppress phenological variations due to interannual, geographical and trend climate variability, under current and projected climatic conditions. We show that phenological plasticity is not always adaptive and mostly affects fitness at the margins of the species' distribution and climatic niche. Under current climatic conditions, phenological plasticity constrains the northern range limit of oak and beech and the southern range limit of pine. Under future climatic conditions, phenological plasticity becomes strongly adaptive towards the trailing edges of beech and oak, but severely constrains the range and niche of pine. Our results call for caution when interpreting geographical variation in trait means as adaptive, and strongly point towards species distribution models explicitly taking phenotypic plasticity into account when forecasting species distribution under climate change scenarios. © 2015 John Wiley & Sons Ltd.

  1. The spatial pattern of leaf phenology and its response to climate change in China.

    Science.gov (United States)

    Dai, Junhu; Wang, Huanjiong; Ge, Quansheng

    2014-05-01

    Leaf phenology has been shown to be one of the most important indicators of the effects of climate change on biological systems. Few such studies have, however, been published detailing the relationship between phenology and climate change in Asian contexts. With the aim of quantifying species' phenological responsiveness to temperature and deepening understandings of spatial patterns of phenological and climate change in China, this study analyzes the first leaf date (FLD) and the leaf coloring date (LCD) from datasets of four woody plant species, Robinia pseudoacacia, Ulmus pumila, Salix babylonica, and Melia azedarach, collected from 1963 to 2009 at 47 Chinese Phenological Observation Network (CPON) stations spread across China (from 21° to 50° N). The results of this study show that changes in temperatures in the range of 39-43 days preceding the date of FLD of these plants affected annual variations in FLD, while annual variations in temperature in the range of 71-85 days preceding LCD of these plants affected the date of LCD. Average temperature sensitivity of FLD and LCD for these plants was -3.93 to 3.30 days °C(-1) and 2.11 to 4.43 days °C⁻¹, respectively. Temperature sensitivity of FLD was found to be stronger at lower latitudes or altitude as well as in more continental climates, while the response of LCD showed no consistent pattern. Within the context of significant warming across China during the study period, FLD was found to have advanced by 5.44 days from 1960 to 2009; over the same period, LCD was found to have been delayed by 4.56 days. These findings indicate that the length of the growing season of the four plant species studied was extended by a total of 10.00 days from 1960 to 2009. They also indicate that phenological response to climate is highly heterogeneous spatially.

  2. Monitoring Phenology of Ailanthus altissima in North West Isfahan

    Directory of Open Access Journals (Sweden)

    A. Shahbazi

    2013-12-01

    Full Text Available Major climate changes problems in the world have attracted attentions to the phenology and have improved studies in this field. Quantitative investigation of phenology, through recording the colour of different parts of plants can be a complement for quantitative method in determining exact appearance of the phenomena. In the present study the phenological characteristics of Ailanthus altissima has been identified, using two different methods including descriptive and digital repeated photography. In descriptive observations four trees in the campus of Isfahan University of Technology has been biweekly recorded for seven years and appearance of the phenomena has been registered. Digital photography of different parts of tree was accomplished for four years. The photo spectrum of the leaf and fruit of the tree were produced and the colors were analyzed in RGB system, with the resolution of eight bites (28 for each color. By determining the proportion of each primary color the tint was achieved, which can be easily interpreted. For determining the effect of temperature on colour changing in time, the 2G-RB Index was used. According to the descriptive observations of the flowering occurs from the beginning of May to the beginning of June and fruiting occurs in late June. In colour changing diagrams the intersection of green wavelength with red in late October exhibits a revolution in leaves colour. In the fruit colour diagrams, the first intersection takes place in coincidence with the appearance of green fruits and the second coincidence with the changing of colour from green to brown. Quantitative analysis indicates a significant correlation (P ≥ 0.05 between temperature and 2G-RB Index for both leaf and fruit.

  3. Comparing growth phenology of co-occurring deciduous and evergreen conifers exposed to drought

    OpenAIRE

    Swidrak, Irene; Schuster, Roman; Oberhuber, Walter

    2013-01-01

    Plant phenological events are influenced by climate factors such as temperature and rainfall. To evaluate phenological responses to water availability in a Spring Heath-Pine wood (Erico-Pinetum typicum), the focus of this study was to determine intra-annual dynamics of apical and lateral growth of co-occurring early successional Larix decidua and Pinus sylvestris and late successional Picea abies exposed to drought. The effect of reduced plant water availability on growth phenology was invest...

  4. Using ground observations of a digital camera in the VIS-NIR range for quantifying the phenology of Mediterranean woody species

    Science.gov (United States)

    Weil, Gilad; Lensky, Itamar M.; Levin, Noam

    2017-10-01

    The spectral reflectance of most plant species is quite similar, and thus the feasibility of identifying most plant species based on single date multispectral data is very low. Seasonal phenological patterns of plant species may enable to face the challenge of using remote sensing for mapping plant species at the individual level. We used a consumer-grade digital camera with near infra-red capabilities in order to extract and quantify vegetation phenological information in four East Mediterranean sites. After illumination corrections and other noise reduction steps, the phenological patterns of 1839 individuals representing 12 common species were analyzed, including evergreen trees, winter deciduous trees, semi-deciduous summer shrubs and annual herbaceous patches. Five vegetation indices were used to describe the phenology: relative green and red (green/red chromatic coordinate), excess green (ExG), normalized difference vegetation index (NDVI) and green-red vegetation index (GRVI). We found significant differences between the phenology of the various species, and defined the main phenological groups using agglomerative hierarchical clustering. Differences between species and sites regarding the start of season (SOS), maximum of season (MOS) and end of season (EOS) were displayed in detail, using ExG values, as this index was found to have the lowest percentage of outliers. An additional visible band spectral index (relative red) was found as useful for characterizing seasonal phenology, and had the lowest correlation with the other four vegetation indices, which are more sensitive to greenness. We used a linear mixed model in order to evaluate the influences of various factors on the phenology, and found that unlike the significant effect of species and individuals on SOS, MOS and EOS, the sites' location did not have a direct significant effect on the timing of phenological events. In conclusion, the relative advantage of the proposed methodology is the

  5. Environmental Drivers of NDVI-Based Vegetation Phenology in Central Asia

    Directory of Open Access Journals (Sweden)

    Jahan Kariyeva

    2011-02-01

    Full Text Available Through the application and use of geospatial data, this study aimed to detect and characterize some of the key environmental drivers contributing to landscape-scale vegetation response patterns in Central Asia. The objectives of the study were to identify the variables driving the year-to-year vegetation dynamics in three regional landscapes (desert, steppe, and mountainous; and to determine if the identified environmental drivers can be used to explain the spatial-temporal variability of these spatio-temporal dynamics over time. It was posed that patterns of change in terrestrial phenology, derived from the 8 km bi-weekly time series of Normalized Difference Vegetation Index (NDVI data acquired by the Advanced Very High Resolution Radiometer (AVHRR satellites (1981–2008, can be explained through a multi-scale analysis of a suite of environmental drivers. Multiple linear stepwise regression analyses were used to test the hypotheses and address the objectives of the study. The annually computed phenological response variables or pheno-metricstime (season start, season length, and an NDVI-based productivity metric were modeled as a function of ten environmental factors relating to soil, topography, and climate. Each of the three studied regional landscapes was shown to be governed by a distinctive suite of environmental drivers. The phenological responses of the steppe landscapes were affected by the year-to-year variation in temperature regimes. The phenology of the mountainous landscapes was influenced primarily by the elevation gradient. The phenological responses of desert landscapes were demonstrated to have the greatest variability over time and seemed to be affected by soil carbon content and year-to-year variation of both temperature regimes and winter precipitation patterns. Amounts and scales of observed phenological variability over time (measured through coefficient of variation for each pheno-metrictime in each of the regional

  6. Towards an improved Land Surface Phenology mapping using a new MODIS product: A case study of Bavarian Forest National Park

    Science.gov (United States)

    Misra, Gourav; Buras, Allan; Asam, Sarah; Menzel, Annette

    2017-04-01

    State Ministry of the Environment and Consumer Protection. References: 1. Fisher, J.I.; Mustard, J.F. Cross-scalar satellite phenology from ground, Landsat, and MODIS data. Remote Sens. Environ. 2007, 109, 261-273. 2. Misra, G.; Buras, A.; Menzel, A. Effects of Different Methods on the Comparison be-tween Land Surface and Ground Phenology—A Methodological Case Study from South-Western Germany. Remote Sens. 2016, 8, 753. 3. Asam, S.; Callegari, M.; Fiore, G.; Matiu, M.; De Gregorio, L.; Jacob, A.; Staab, J.; Men-zel, A.; Notarnicola, C. Analysis of spatiotemporal variations of climate, snow cover and plant phenology over the Alps. 2017 (in preparation). 4. Stöckli, R.; Rutishauser, T.; Dragoni, D.; O'Keefe, J.; Thornton, P. E.; Jolly, M.; Lu, L.; Denning, A. S. Remote sensing data assimilation for a prognostic phenology model. Journal of Geophysical Research: Biogeosciences. 2008, 113.

  7. Herbarium specimens can reveal impacts of climate change on plant phenology; a review of methods and applications.

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    Jones, Casey A; Daehler, Curtis C

    2018-01-01

    Studies in plant phenology have provided some of the best evidence for large-scale responses to recent climate change. Over the last decade, more than thirty studies have used herbarium specimens to analyze changes in flowering phenology over time, although studies from tropical environments are thus far generally lacking. In this review, we summarize the approaches and applications used to date. Reproductive plant phenology has primarily been analyzed using two summary statistics, the mean flowering day of year and first-flowering day of year, but mean flowering day has proven to be a more robust statistic. Two types of regression models have been applied to test for associations between flowering, temperature and time: flowering day regressed on year and flowering day regressed on temperature. Most studies analyzed the effect of temperature by averaging temperatures from three months prior to the date of flowering. On average, published studies have used 55 herbarium specimens per species to characterize changes in phenology over time, but in many cases fewer specimens were used. Geospatial grid data are increasingly being used for determining average temperatures at herbarium specimen collection locations, allowing testing for finer scale correspondence between phenology and climate. Multiple studies have shown that inferences from herbarium specimen data are comparable to findings from systematically collected field observations. Understanding phenological responses to climate change is a crucial step towards recognizing implications for higher trophic levels and large-scale ecosystem processes. As herbaria are increasingly being digitized worldwide, more data are becoming available for future studies. As temperatures continue to rise globally, herbarium specimens are expected to become an increasingly important resource for analyzing plant responses to climate change.

  8. The potential of satellite-observed crop phenology to enhance yield gap assessments in smallholder landscapes

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    John M A Duncan

    2015-08-01

    Full Text Available Many of the undernourished people on the planet obtain their entitlements to food via agricultural-based livelihood strategies, often on underperforming croplands and smallholdings. In this context, expanding cropland extent is not a viable strategy for smallholders to meet their food needs. Therefore, attention must shift to increasing productivity on existing plots and ensuring yield gaps do not widen. Thus, supporting smallholder farmers to sustainably increase the productivity of their lands is one part of a complex solution to realising universal food security. However, the information (e.g. location and causes of cropland underperformance required to support measures to close yield gaps in smallholder landscapes are often not available. This paper reviews the potential of crop phenology, observed from satellites carrying remote sensing sensors, to fill this information gap. It is suggested that on a theoretical level phenological approaches can reveal greater intra-cropland thematic detail, and increase the accuracy of crop extent maps and crop yield estimates. However, on a practical level the spatial mismatch between the resolution at which crop phenology can be estimated from satellite remote sensing data and the scale of yield variability in smallholder croplands inhibits its use in this context. Similarly, the spatial coverage of remote sensing-derived phenology offers potential for integration with ancillary spatial datasets to identify causes of yield gaps. To reflect the complexity of smallholder cropping systems requires ancillary datasets at fine spatial resolutions which, often, are not available. This further precludes the use of crop phenology in attempts to unpick the causes of yield gaps. Research agendas should focus on generating fine spatial resolution crop phenology, either via data fusion or through new sensors (e.g. Sentinel-2 in smallholder croplands. This has potential to transform the applied use of remote sensing

  9. Observing Spring and Fall Phenology in a Deciduous Forest with Aerial Drone Imagery

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    Stephen Klosterman

    2017-12-01

    Full Text Available Plant phenology is a sensitive indicator of the effects of global change on terrestrial ecosystems and controls the timing of key ecosystem functions including photosynthesis and transpiration. Aerial drone imagery and photogrammetric techniques promise to advance the study of phenology by enabling the creation of distortion-free orthomosaics of plant canopies at the landscape scale, but with branch-level image resolution. The main goal of this study is to determine the leaf life cycle events corresponding to phenological metrics derived from automated analyses based on color indices calculated from drone imagery. For an oak-dominated, temperate deciduous forest in the northeastern USA, we find that plant area index (PAI correlates with a canopy greenness index during spring green-up, and a canopy redness index during autumn senescence. Additionally, greenness and redness metrics are significantly correlated with the timing of budburst and leaf expansion on individual trees in spring. However, we note that the specific color index for individual trees must be carefully chosen if new foliage in spring appears red, rather than green—which we observed for some oak trees. In autumn, both decreasing greenness and increasing redness correlate with leaf senescence. Maximum redness indicates the beginning of leaf fall, and the progression of leaf fall correlates with decreasing redness. We also find that cooler air temperature microclimates near a forest edge bordering a wetland advance the onset of senescence. These results demonstrate the use of drones for characterizing the organismic-level variability of phenology in a forested landscape and advance our understanding of which phenophase transitions correspond to color-based metrics derived from digital image analysis.

  10. Observing Spring and Fall Phenology in a Deciduous Forest with Aerial Drone Imagery.

    Science.gov (United States)

    Klosterman, Stephen; Richardson, Andrew D

    2017-12-08

    Plant phenology is a sensitive indicator of the effects of global change on terrestrial ecosystems and controls the timing of key ecosystem functions including photosynthesis and transpiration. Aerial drone imagery and photogrammetric techniques promise to advance the study of phenology by enabling the creation of distortion-free orthomosaics of plant canopies at the landscape scale, but with branch-level image resolution. The main goal of this study is to determine the leaf life cycle events corresponding to phenological metrics derived from automated analyses based on color indices calculated from drone imagery. For an oak-dominated, temperate deciduous forest in the northeastern USA, we find that plant area index (PAI) correlates with a canopy greenness index during spring green-up, and a canopy redness index during autumn senescence. Additionally, greenness and redness metrics are significantly correlated with the timing of budburst and leaf expansion on individual trees in spring. However, we note that the specific color index for individual trees must be carefully chosen if new foliage in spring appears red, rather than green-which we observed for some oak trees. In autumn, both decreasing greenness and increasing redness correlate with leaf senescence. Maximum redness indicates the beginning of leaf fall, and the progression of leaf fall correlates with decreasing redness. We also find that cooler air temperature microclimates near a forest edge bordering a wetland advance the onset of senescence. These results demonstrate the use of drones for characterizing the organismic-level variability of phenology in a forested landscape and advance our understanding of which phenophase transitions correspond to color-based metrics derived from digital image analysis.

  11. Refined shape model fitting methods for detecting various types of phenological information on major U.S. crops

    Science.gov (United States)

    Sakamoto, Toshihiro

    2018-04-01

    Crop phenological information is a critical variable in evaluating the influence of environmental stress on the final crop yield in spatio-temporal dimensions. Although the MODIS (Moderate Resolution Imaging Spectroradiometer) Land Cover Dynamics product (MCD12Q2) is widely used in place of crop phenological information, the definitions of MCD12Q2-derived phenological events (e.g. green-up date, dormancy date) were not completely consistent with those of crop development stages used in statistical surveys (e.g. emerged date, harvested date). It has been necessary to devise an alternative method focused on detecting continental-scale crop developmental stages using a different approach. Therefore, this study aimed to refine the Shape Model Fitting (SMF) method to improve its applicability to multiple major U.S. crops. The newly-refined SMF methods could estimate the timing of 36 crop-development stages of major U.S. crops, including corn, soybeans, winter wheat, spring wheat, barley, sorghum, rice, and cotton. The newly-developed calibration process did not require any long-term field observation data, and could calibrate crop-specific phenological parameters, which were used as coefficients in estimated equation, by using only freely accessible public data. The calibration of phenological parameters was conducted in two steps. In the first step, the national common phenological parameters, referred to as X0[base], were calibrated by using the statistical data of 2008. The SMF method coupled using X0[base] was named the rSMF[base] method. The second step was a further calibration to gain regionally-adjusted phenological parameters for each state, referred to as X0[local], by using additional statistical data of 2015 and 2016. The rSMF method using the X0[local] was named the rSMF[local] method. This second calibration process improved the estimation accuracy for all tested crops. When applying the rSMF[base] method to the validation data set (2009-2014), the root

  12. The Use of Geostatistics in the Study of Floral Phenology of Vulpia geniculata (L. Link

    Directory of Open Access Journals (Sweden)

    Eduardo J. León Ruiz

    2012-01-01

    Full Text Available Traditionally phenology studies have been focused on changes through time, but there exist many instances in ecological research where it is necessary to interpolate among spatially stratified samples. The combined use of Geographical Information Systems (GIS and Geostatistics can be an essential tool for spatial analysis in phenological studies. Geostatistics are a family of statistics that describe correlations through space/time and they can be used for both quantifying spatial correlation and interpolating unsampled points. In the present work, estimations based upon Geostatistics and GIS mapping have enabled the construction of spatial models that reflect phenological evolution of Vulpia geniculata (L. Link throughout the study area during sampling season. Ten sampling points, scattered troughout the city and low mountains in the “Sierra de Córdoba” were chosen to carry out the weekly phenological monitoring during flowering season. The phenological data were interpolated by applying the traditional geostatitical method of Kriging, which was used to ellaborate weekly estimations of V. geniculata phenology in unsampled areas. Finally, the application of Geostatistics and GIS to create phenological maps could be an essential complement in pollen aerobiological studies, given the increased interest in obtaining automatic aerobiological forecasting maps.

  13. Phenological response of an Arizona dryland forest to short-term climatic extremes

    Science.gov (United States)

    Walker, Jessica; de Beurs, Kirsten; Wynne, Randolph

    2015-01-01

    Baseline information about dryland forest phenology is necessary to accurately anticipate future ecosystem shifts. The overarching goal of our study was to investigate the variability of vegetation phenology across a dryland forest landscape in response to climate alterations. We analyzed the influence of site characteristics and climatic conditions on the phenological patterns of an Arizona, USA, ponderosa pine (Pinus ponderosa) forest during a five-year period (2005 to 2009) that encompassed extreme wet and dry precipitation regimes. We assembled 80 synthetic Landsat images by applying the spatial and temporal adaptive reflectance fusion method (STARFM) to 500 m MODIS and 30 m Landsat-5 Thematic Mapper (TM) data. We tested relationships between site characteristics and the timing of peak Normalized Difference Vegetation Index (NDVI) to assess the effect of climatic stress on the green-up of individual pixels during or after the summer monsoon. Our results show that drought-induced stress led to a fragmented phenological response that was highly dependent on microsite parameters, as both the spatial autocorrelation of peak timing and the number of significant site variables increased during the drought year. Pixels at lower elevations and with higher proportions of herbaceous vegetation were more likely to exhibit dynamic responses to changes in precipitation conditions. Our study demonstrates the complexity of responses within dryland forest ecosystems and highlights the need for standardized monitoring of phenology trends in these areas. The spatial and temporal variability of phenological signals may provide a quantitative solution to the problem of how to evaluate dryland land surface trends across time.

  14. Phenological Response of an Arizona Dryland Forest to Short-Term Climatic Extremes

    Directory of Open Access Journals (Sweden)

    Jessica Walker

    2015-08-01

    Full Text Available Baseline information about dryland forest phenology is necessary to accurately anticipate future ecosystem shifts. The overarching goal of our study was to investigate the variability of vegetation phenology across a dryland forest landscape in response to climate alterations. We analyzed the influence of site characteristics and climatic conditions on the phenological patterns of an Arizona, USA, ponderosa pine (Pinus ponderosa forest during a five-year period (2005 to 2009 that encompassed extreme wet and dry precipitation regimes. We assembled 80 synthetic Landsat images by applying the spatial and temporal adaptive reflectance fusion method (STARFM to 500 m MODIS and 30 m Landsat-5 Thematic Mapper (TM data. We tested relationships between site characteristics and the timing of peak Normalized Difference Vegetation Index (NDVI to assess the effect of climatic stress on the green-up of individual pixels during or after the summer monsoon. Our results show that drought-induced stress led to a fragmented phenological response that was highly dependent on microsite parameters, as both the spatial autocorrelation of peak timing and the number of significant site variables increased during the drought year. Pixels at lower elevations and with higher proportions of herbaceous vegetation were more likely to exhibit dynamic responses to changes in precipitation conditions. Our study demonstrates the complexity of responses within dryland forest ecosystems and highlights the need for standardized monitoring of phenology trends in these areas. The spatial and temporal variability of phenological signals may provide a quantitative solution to the problem of how to evaluate dryland land surface trends across time.

  15. Leaf Phenology of Amazonian Canopy Trees as Revealed by Spectral and Physiochemical Measurements

    Science.gov (United States)

    Chavana-Bryant, C.; Gerard, F. F.; Malhi, Y.; Enquist, B. J.; Asner, G. P.

    2013-12-01

    The phenological dynamics of terrestrial ecosystems reflect the response of the Earth's biosphere to inter- and intra-annual dynamics of climatic and hydrological regimes. Some Dynamic Global Vegetation Models (GDVMs) have predicted that by 2050 the Amazon rainforest will begin to dieback (Cox et al. 2000, Nature) or that the ecosystem will become unsustainable (Salazar et al. 2007, GRL). One major component in DGVMs is the simulation of vegetation phenology, however, modelers are challenged with the estimation of tropical phenology which is highly complex. Current modeled phenology is based on observations of temperate vegetation and accurate representation of tropical phenology is long overdue. Remote sensing (RS) data are a key tool in monitoring vegetation dynamics at regional and global scales. Of the many RS techniques available, time-series analysis of vegetation indices (VIs) has become the most common approach in monitoring vegetation phenology (Samanta et al. 2010, GRL; Bradley et al. 2011, GCB). Our research focuses on investigating the influence that age related variation in the spectral reflectance and physiochemical properties of leaves may have on VIs of tropical canopies. In order to do this, we collected a unique leaf and canopy phenological dataset at two different Amazonian sites: Inselberg, French Guyana (FG) and Tambopata, Peru (PE). Hyperspectral reflectance measurements were collected from 4,102 individual leaves sampled to represent different leaf ages and vertical canopy positions (top, mid and low canopy) from 20 different canopy tree species (8 in FG and 12 in PE). These leaf spectra were complemented with 1) leaf physical measurements: fresh and dry weight, area and thickness, LMA and LWC and 2) leaf chemical measurements: %N, %C, %P, C:N and d13C. Canopy level observations included top-of-canopy reflectance measurements obtained using a multispectral 16-band radiometer, leaf demography (tot. number and age distribution) and branch

  16. Using Linear and Non-Linear Temporal Adjustments to Align Multiple Phenology Curves, Making Vegetation Status and Health Directly Comparable

    Science.gov (United States)

    Hargrove, W. W.; Norman, S. P.; Kumar, J.; Hoffman, F. M.

    2017-12-01

    National-scale polar analysis of MODIS NDVI allows quantification of degree of seasonality expressed by local vegetation, and also selects the most optimum start/end of a local "phenological year" that is empirically customized for the vegetation that is growing at each location. Interannual differences in timing of phenology make direct comparisons of vegetation health and performance between years difficult, whether at the same or different locations. By "sliding" the two phenologies in time using a Procrustean linear time shift, any particular phenological event or "completion milestone" can be synchronized, allowing direct comparison of differences in timing of other remaining milestones. Going beyond a simple linear translation, time can be "rubber-sheeted," compressed or dilated. Considering one phenology curve to be a reference, the second phenology can be "rubber-sheeted" to fit that baseline as well as possible by stretching or shrinking time to match multiple control points, which can be any recognizable phenological events. Similar to "rubber sheeting" to georectify a map inside a GIS, rubber sheeting a phenology curve also yields a warping signature that shows at every time and every location how many days the adjusted phenology is ahead or behind the phenological development of the reference vegetation. Using such temporal methods to "adjust" phenologies may help to quantify vegetation impacts from frost, drought, wildfire, insects and diseases by permitting the most commensurate quantitative comparisons with unaffected vegetation.

  17. The effects of short- and long-term air pollutants on plant phenology and leaf characteristics

    International Nuclear Information System (INIS)

    Jochner, Susanne; Markevych, Iana; Beck, Isabelle; Traidl-Hoffmann, Claudia

    2015-01-01

    Pollution adversely affects vegetation; however, its impact on phenology and leaf morphology is not satisfactorily understood yet. We analyzed associations between pollutants and phenological data of birch, hazel and horse chestnut in Munich (2010) along with the suitability of leaf morphological parameters of birch for monitoring air pollution using two datasets: cumulated atmospheric concentrations of nitrogen dioxide and ozone derived from passive sampling (short-term exposure) and pollutant information derived from Land Use Regression models (long-term exposure). Partial correlations and stepwise regressions revealed that increased ozone (birch, horse chestnut), NO_2, NO_x and PM levels (hazel) were significantly related to delays in phenology. Correlations were especially high when rural sites were excluded suggesting a better estimation of long-term within-city pollution. In situ measurements of foliar characteristics of birch were not suitable for bio-monitoring pollution. Inconsistencies between long- and short-term exposure effects suggest some caution when interpreting short-term data collected within field studies. - Highlights: • We present results of a field survey examining pollution effects on vegetation. • Particularly ozone was significantly associated with delays in spring phenology. • Leaf morphology of birch was found to be inadequate for bio-monitoring pollution. • Inconsistencies between long-/short-term exposure effects suggest caution. - Pollutants were significantly associated with delays in spring phenology. However, inconsistencies between long- and short-term exposure effects suggest some caution when interpreting results.

  18. Changes in vegetation phenology on the Mongolian Plateau and their climatic determinants.

    Directory of Open Access Journals (Sweden)

    Lijuan Miao

    Full Text Available Climate change affects the timing of phenological events, such as the start, end, and length of the growing season of vegetation. A better understanding of how the phenology responded to climatic determinants is important in order to better anticipate future climate-ecosystem interactions. We examined the changes of three phenological events for the Mongolian Plateau and their climatic determinants. To do so, we derived three phenological metrics from remotely sensed vegetation indices and associated these with climate data for the period of 1982 to 2011. The results suggested that the start of the growing season advanced by 0.10 days yr-1, the end was delayed by 0.11 days yr-1, and the length of the growing season expanded by 6.3 days during the period from 1982 to 2011. The delayed end and extended length of the growing season were observed consistently in grassland, forest, and shrubland, while the earlier start was only observed in grassland. Partial correlation analysis between the phenological events and the climate variables revealed that higher temperature was associated with an earlier start of the growing season, and both temperature and precipitation contributed to the later ending. Overall, our findings suggest that climate change will substantially alter the vegetation phenology in the grasslands of the Mongolian Plateau, and likely also in biomes with similar environmental conditions, such as other semi-arid steppe regions.

  19. Journal of Agriculture, Forestry and the Social Sciences - Vol 5, No 2 ...

    African Journals Online (AJOL)

    Journal of Agriculture, Forestry and the Social Sciences - Vol 5, No 2 (2007) ... Marketing Of Bushmeat In Peri-Urban Areas Of Ibadan Metropolis Of Oyo State, ... Sport Fisheries Potentials Of Agbokim Waterfalls, Cross River State, Nigeria ...

  20. Bulletin of the Chemical Society of Ethiopia - Vol 3, No 2 (1989)

    African Journals Online (AJOL)

    Bulletin of the Chemical Society of Ethiopia - Vol 3, No 2 (1989) ... Synthesis and characterization of gold (III) halide complexes of some pyridine ... Molluscicidal activities of some alkaloids · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT

  1. Browse Title Index

    African Journals Online (AJOL)

    Items 51 - 100 of 132 ... Vol 30, No 2 (2013), Growth, phenological and yield responses of a .... capacity and physicochemical properties of pomegranate grown in different ... soil nitrogen content using narrow-band indices from Eucalyptus ...

  2. Alteration of Hormonal Levels in a Rootless Epiphytic Bromeliad in Different Phenological Phases.

    Science.gov (United States)

    Mercier; Endres

    1999-11-01

    Major changes in indole-3-acetic acid (IAA) and cytokinin (CK) levels occur at different phenological phases of Tillandsia recurvata shoots. This epiphytic rootless bromeliad was chosen as suitable material for hormonal analysis because CK synthesis is restricted to the shoots, thus avoiding problems in the interpretation of results caused by translocation and interconversion of CK forms between roots and leaves encountered in plants with both organs. Young plants of T. recurvata have weak apical dominance because side shoots appeared early in development, and branch growth was correlated with a strong increase in the level of zeatin. The flowering phase was characterized by a significant increase in free base CKs, zeatin, and isopentenyladenine compared with the levels found in adult vegetative shoots. In contrast, both free-base CKs declined in the fruiting phenological phase, and the IAA level increased dramatically. It was concluded that in phases characterized by intense organ formation, such as in the juvenile and flowering stages, there was an enhancement of CK content, mainly caused by zeatin, leading to a lower IAA/CK ratio. Higher ratios were correlated with phases that showed no organogenesis, such as adult and fruiting phenologies.

  3. Phenology of the Hemlock Woolly Adelgid (Hemiptera: Adelgidae) in Northern Georgia

    Science.gov (United States)

    Shimar V. Joseph; Albert E. Mayfield; Mark J. Dalusky; Christopher Asaro; C. Wayne. Berisford

    2011-01-01

    Understanding the seasonal phenology of an insect pest in a specific geographic region is essential for optimizing the timing of management actions or research activities. We examined the phenology of hemlock woolly adelgid, Adelges tsugae Annand, near the southern limit of the range of eastern hemlock, Tsuga canadensis (L.) Carriere, in the Appalachians of northern...

  4. Challenging a 15-year-old claim: The North Atlantic Oscillation index as a predictor of spring migration phenology of birds.

    Science.gov (United States)

    Haest, Birgen; Hüppop, Ommo; Bairlein, Franz

    2018-04-01

    Many migrant bird species that breed in the Northern Hemisphere show advancement in spring arrival dates. The North Atlantic Oscillation (NAO) index is one of the climatic variables that have been most often investigated and shown to be correlated with these changes in spring arrival. Although the NAO is often claimed to be a good predictor or even to have a marked effect on interannual changes in spring migration phenology of Northern Hemisphere breeding birds, the results on relations between spring migration phenology and NAO show a large variety, ranging from no, over weak, to a strong association. Several factors, such as geographic location, migration phase, and the NAO index time window, have been suggested to partly explain these observed differences in association. A combination of a literature meta-analysis, and a meta-analysis and sliding time window analysis of a dataset of 23 short- and long-distance migrants from the constant-effort trapping garden at Helgoland, Germany, however, paints a completely different picture. We found a statistically significant overall effect size of the NAO on spring migration phenology (coefficient = -0.14, SE = 0.054), but this on average only explains 0%-6% of the variance in spring migration phenology across all species. As such, the value and biological meaning of the NAO as a general predictor or explanatory variable for climate change effects on migration phenology of birds, seems highly questionable. We found little to no definite support for previously suggested factors, such as geographic location, migration phenology phase, or the NAO time window, to explain the heterogeneity in correlation differences. We, however, did find compelling evidence that the lack of accounting for trends in both time series has led to strongly inflated (spurious) correlations in many studies (coefficient = -0.13, SE = 0.019). © 2017 John Wiley & Sons Ltd.

  5. Long-term shifts in the phenology of rare and endemic Rocky Mountain plants.

    Science.gov (United States)

    Munson, Seth M; Sher, Anna A

    2015-08-01

    • Mountainous regions support high plant productivity, diversity, and endemism, yet are highly vulnerable to climate change. Historical records and model predictions show increasing temperatures across high elevation regions including the Southern Rocky Mountains, which can have a strong influence on the performance and distribution of montane plant species. Rare plant species can be particularly vulnerable to climate change because of their limited abundance and distribution.• We tracked the phenology of rare and endemic species, which are identified as imperiled, across three different habitat types with herbarium records to determine if flowering time has changed over the last century, and if phenological change was related to shifts in climate.• We found that the flowering date of rare species has accelerated 3.1 d every decade (42 d total) since the late 1800s, with plants in sagebrush interbasins showing the strongest accelerations in phenology. High winter temperatures were associated with the acceleration of phenology in low elevation sagebrush and barren river habitats, whereas high spring temperatures explained accelerated phenology in the high elevation alpine habitat. In contrast, high spring temperatures delayed the phenology of plant species in the two low-elevation habitats and precipitation had mixed effects depending on the season.• These results provide evidence for large shifts in the phenology of rare Rocky Mountain plants related to climate, which can have strong effects on plant fitness, the abundance of associated wildlife, and the future of plant conservation in mountainous regions. © 2015 Botanical Society of America, Inc.

  6. Phenological observations made by the I. R. Bohemian Patriotic-Economic Society, 1828-1847

    Science.gov (United States)

    Brázdil, Rudolf; Bělínová, Monika; Rožnovský, Jaroslav

    2011-08-01

    Scholarly and economic management societies played an important role in the beginnings of meteorological observations in Central Europe. In Bohemia, one such was the "Imperial Royal Patriotic-Economic Society of Bohemia" which, as well as making meteorological observations, organised a network of phenological stations and published the results of their observations from 1828 to 1847. The phenological observations covered 31 different forest plants, fruit trees and field-crops. Some of the phenological stations continued to make observations within the network of the Central Institute for Meteorology and Earth Magnetism established in Vienna in 1851. Analysis of the above observations led to the collation of information on the temporal and spatial distribution of the observed phenological characteristics (beginning of budding and/or foliage, beginning and end of flowering, ripeness of seeds and fruits) in the 1828-1847 period, which was cooler and generally wetter with respect to more recent temperature and precipitation patterns (1961-1990) in the study area. Phenophases of flowering and ripeness for selected plants are presented for the Hradec Králové and Loket stations, showing late onsets in this period in comparison with recent phenological stations located nearby and taking measurements in 1993-2009. Working up this topic makes a contribution to the historical phenology of the nineteenth century in the Czech Lands and in Central Europe as well.

  7. Root phenology at Harvard Forest and beyond

    Science.gov (United States)

    Abramoff, R. Z.; Finzi, A.

    2013-12-01

    Roots are hidden from view and heterogeneously distributed making them difficult to study in situ. As a result, the causes and timing of root production are not well understood. Researchers have long assumed that above and belowground phenology is synchronous; for example, most parameterizations of belowground carbon allocation in terrestrial biosphere models are based on allometry and represent a fixed fraction of net C uptake. However, using results from metaanalysis as well as empirical data from oak and hemlock stands at Harvard Forest, we show that synchronous root and shoot growth is the exception rather than the rule. We collected root and shoot phenology measurements from studies across four biomes (boreal, temperate, Mediterranean, and subtropical). General patterns of root phenology varied widely with 1-5 production peaks in a growing season. Surprisingly, in 9 out of the 15 studies, the first root production peak was not the largest peak. In the majority of cases maximum shoot production occurred before root production (Offset>0 in 32 out of 47 plant sample means). The number of days offset between maximum root and shoot growth was negatively correlated with median annual temperature and therefore differs significantly across biomes (ANOVA, F3,43=9.47, pGrowth form (woody or herbaceous) also influenced the relative timing of root and shoot growth. Woody plants had a larger range of days between root and shoot growth peaks as well as a greater number of growth peaks. To explore the range of phenological relationships within woody plants in the temperate biome, we focused on above and belowground phenology in two common northeastern tree species, Quercus rubra and Tsuga canadensis. Greenness index, rate of stem growth, root production and nonstructural carbohydrate content were measured beginning in April 2012 through August 2013 at the Harvard Forest in Petersham, MA, USA. Greenness and stem growth were highest in late May and early June with one clear

  8. 49. Meeting of the Chemical Societies: Proceedings of the contributions. Vol. 2

    International Nuclear Information System (INIS)

    Uher, M.; Benes, P.; Carsky, J.; Chodak, I.; Kuruc, J.; Romancik, V.; Stasko, A. Slovak Technical Univ., Bratislava

    1995-09-01

    The publication has been set up as a abstracts of the meeting dealing with chemical problems. The book (Vol. 2) consists of the sections: (C) Physical chemistry; (D) History of the chemistry; (E) Food chemistry and technology; (D) Environmental chemistry; (E) Nuclear chemistry and radioecology; (H) Synthetic polymers

  9. Satellite time-series data for vegetation phenology detection and environmental assessment in Southeast Asia

    Science.gov (United States)

    Suepa, Tanita

    The relationship between temporal and spatial data is considered the major advantage of remote sensing in research related to biophysical characteristics. With temporally formatted remote sensing products, it is possible to monitor environmental changes as well as global climate change through time and space by analyzing vegetation phenology. Although a number of different methods have been developed to determine the seasonal cycle using time series of vegetation indices, these methods were not designed to explore and monitor changes and trends of vegetation phenology in Southeast Asia (SEA). SEA is adversely affected by impacts of climate change, which causes considerable environmental problems, and the increase in agricultural land conversion and intensification also adds to those problems. Consequently, exploring and monitoring phenological change and environmental impacts are necessary for a better understanding of the ecosystem dynamics and environmental change in this region. This research aimed to investigate inter-annual variability of vegetation phenology and rainfall seasonality, analyze the possible drivers of phenological changes from both climatic and anthropogenic factors, assess the environmental impacts in agricultural areas, and develop an enhanced visualization method for phenological information dissemination. In this research, spatio-temporal patterns of vegetation phenology were analyzed by using MODIS-EVI time series data over the period of 2001-2010. Rainfall seasonality was derived from TRMM daily rainfall rate. Additionally, this research assessed environmental impacts of GHG emissions by using the environmental model (DNDC) to quantify emissions from rice fields in Thailand. Furthermore, a web mapping application was developed to present the output of phenological and environmental analysis with interactive functions. The results revealed that satellite time-series data provided a great opportunity to study regional vegetation variability

  10. Spatiotemporal Variability of Land Surface Phenology in China from 2001–2014

    Directory of Open Access Journals (Sweden)

    Zhaohui Luo

    2017-01-01

    Full Text Available Land surface phenology is a highly sensitive and simple indicator of vegetation dynamics and climate change. However, few studies on spatiotemporal distribution patterns and trends in land surface phenology across different climate and vegetation types in China have been conducted since 2000, a period during which China has experienced remarkably strong El Niño events. In addition, even fewer studies have focused on changes of the end of season (EOS and length of season (LOS despite their importance. In this study, we used four methods to reconstruct Moderate Resolution Imaging Spectroradiometer (MODIS Enhanced Vegetation Index (EVI dataset and chose the best smoothing result to estimate land surface phenology. Then, the phenophase trends were analyzed via the Mann-Kendall method. We aimed to assess whether trends in land surface phenology have continued since 2000 in China at both national and regional levels. We also sought to determine whether trends in land surface phenology in subtropical or high altitude areas are the same as those observed in high latitude areas and whether those trends are uniform among different vegetation types. The result indicated that the start of season (SOS was progressively delayed with increasing latitude and altitude. In contrast, EOS exhibited an opposite trend in its spatial distribution, and LOS showed clear spatial patterns over this region that decreased from south to north and from east to west at a national scale. The trend of SOS was advanced at a national level, while the trend in Southern China and the Tibetan Plateau was opposite to that in Northern China. The transaction zone of the SOS within Northern China and Southern China occurred approximately between 31.4°N and 35.2°N. The trend in EOS and LOS were delayed and extended, respectively, at both national and regional levels except that of LOS in the Tibetan Plateau, which was shortened by delayed SOS onset more than by delayed EOS onset. The

  11. Vegetation coupling to global climate: Trajectories of vegetation change and phenology modeling from satellite observations

    Science.gov (United States)

    Fisher, Jeremy Isaac

    Important systematic shifts in ecosystem function are often masked by natural variability. The rich legacy of over two decades of continuous satellite observations provides an important database for distinguishing climatological and anthropogenic ecosystem changes. Examples from semi-arid Sudanian West Africa and New England (USA) illustrate the response of vegetation to climate and land-use. In Burkina Faso, West Africa, pastoral and agricultural practices compete for land area, while degradation may follow intensification. The Nouhao Valley is a natural experiment in which pastoral and agricultural land uses were allocated separate, coherent reserves. Trajectories of annual net primary productivity were derived from 18 years of coarse-grain (AVHRR) satellite data. Trends suggested that pastoral lands had responded rigorously to increasing rainfall after the 1980's droughts. A detailed analysis at Landsat resolution (30m) indicated that the increased vegetative cover was concentrated in the river basins of the pastoral region, implying a riparian wood expansion. In comparison, riparian cover was reduced in agricultural regions. We suggest that broad-scale patterns of increasing semi-arid West African greenness may be indicative of climate variability, whereas local losses may be anthropogenic in nature. The contiguous deciduous forests, ocean proximity, topography, and dense urban developments of New England provide an ideal landscape to examine influences of climate variability and the impact of urban development vegetation response. Spatial and temporal patterns of interannual climate variability were examined via green leaf phenology. Phenology, or seasonal growth and senescence, is driven by deficits of light, temperature, and water. In temperate environments, phenology variability is driven by interannual temperature and precipitation shifts. Average and interannual phenology analyses across southern New England were conducted at resolutions of 30m (Landsat

  12. A meta-analysis of cambium phenology and growth: linear and non-linear patterns in conifers of the northern hemisphere.

    Science.gov (United States)

    Rossi, Sergio; Anfodillo, Tommaso; Cufar, Katarina; Cuny, Henri E; Deslauriers, Annie; Fonti, Patrick; Frank, David; Gricar, Jozica; Gruber, Andreas; King, Gregory M; Krause, Cornelia; Morin, Hubert; Oberhuber, Walter; Prislan, Peter; Rathgeber, Cyrille B K

    2013-12-01

    Ongoing global warming has been implicated in shifting phenological patterns such as the timing and duration of the growing season across a wide variety of ecosystems. Linear models are routinely used to extrapolate these observed shifts in phenology into the future and to estimate changes in associated ecosystem properties such as net primary productivity. Yet, in nature, linear relationships may be special cases. Biological processes frequently follow more complex, non-linear patterns according to limiting factors that generate shifts and discontinuities, or contain thresholds beyond which responses change abruptly. This study investigates to what extent cambium phenology is associated with xylem growth and differentiation across conifer species of the northern hemisphere. Xylem cell production is compared with the periods of cambial activity and cell differentiation assessed on a weekly time scale on histological sections of cambium and wood tissue collected from the stems of nine species in Canada and Europe over 1-9 years per site from 1998 to 2011. The dynamics of xylogenesis were surprisingly homogeneous among conifer species, although dispersions from the average were obviously observed. Within the range analysed, the relationships between the phenological timings were linear, with several slopes showing values close to or not statistically different from 1. The relationships between the phenological timings and cell production were distinctly non-linear, and involved an exponential pattern. The trees adjust their phenological timings according to linear patterns. Thus, shifts of one phenological phase are associated with synchronous and comparable shifts of the successive phases. However, small increases in the duration of xylogenesis could correspond to a substantial increase in cell production. The findings suggest that the length of the growing season and the resulting amount of growth could respond differently to changes in environmental conditions.

  13. A remotely sensed pigment index reveals photosynthetic phenology in evergreen conifers.

    Science.gov (United States)

    Gamon, John A; Huemmrich, K Fred; Wong, Christopher Y S; Ensminger, Ingo; Garrity, Steven; Hollinger, David Y; Noormets, Asko; Peñuelas, Josep

    2016-11-15

    In evergreen conifers, where the foliage amount changes little with season, accurate detection of the underlying "photosynthetic phenology" from satellite remote sensing has been difficult, presenting challenges for global models of ecosystem carbon uptake. Here, we report a close correspondence between seasonally changing foliar pigment levels, expressed as chlorophyll/carotenoid ratios, and evergreen photosynthetic activity, leading to a "chlorophyll/carotenoid index" (CCI) that tracks evergreen photosynthesis at multiple spatial scales. When calculated from NASA's Moderate Resolution Imaging Spectroradiometer satellite sensor, the CCI closely follows the seasonal patterns of daily gross primary productivity of evergreen conifer stands measured by eddy covariance. This discovery provides a way of monitoring evergreen photosynthetic activity from optical remote sensing, and indicates an important regulatory role for carotenoid pigments in evergreen photosynthesis. Improved methods of monitoring photosynthesis from space can improve our understanding of the global carbon budget in a warming world of changing vegetation phenology.

  14. How training citizen scientists affects the accuracy and precision of phenological data

    Science.gov (United States)

    Feldman, Richard E.; Žemaitė, Irma; Miller-Rushing, Abraham J.

    2018-05-01

    Monitoring plant and animal phenology is a critical step to anticipating and predicting changes in species interactions and biodiversity. Because phenology necessarily involves frequent and repeated observations over time, citizen scientists have become a vital part of collecting phenological data. However, there is still concern over the accuracy and precision of citizen science data. It is possible that training citizen scientists can improve data quality though there are few comparisons of trained and untrained citizen scientists in the ability of each to accurately and precisely measure phenology. We assessed how three types of observers—experts, trained citizen scientists that make repeated observations, and untrained citizen scientists making once-per-year observations—differ in quantifying temporal change in flower and fruit abundance of American mountain ash trees (Sorbus americana Marsh.) and arthropods in Acadia National Park, Maine, USA. We found that trained more so than untrained citizen science observers over- or under-estimated abundances leading to precise but inaccurate characterizations of phenological patterns. Our results suggest a new type of bias induced by repeated observations: A type of learning takes place that reduces the independence of observations taken on different trees or different dates. Thus, in this and many other cases, having individuals make one-off observations of marked plants may produce data as good if not better than individuals making repeated observations. For citizen science programs related to phenology, our results underscore the importance of (a) attracting the most number of observers possible even if they only make one observation, (b) producing easy-to-use and informative data sheets, and (c) carefully planning effective training programs that are, perhaps, repeated at different points during the data collection period.

  15. Egyptian Journal of Medical Human Genetics - Vol 12, No 2 (2011)

    African Journals Online (AJOL)

    Egyptian Journal of Medical Human Genetics - Vol 12, No 2 (2011) ... Serum interferon-alpha level in first degree relatives of systemic lupus erythematosus patients: Correlation with autoantibodies titers · EMAIL FREE FULL TEXT EMAIL FREE FULL ... LB Salah, CB Salem, F B'Chir, K Bouraoui, F Broly, S Saguem, 183-186.

  16. Climate-associated phenological advances in bee pollinators and bee-pollinated plants

    Science.gov (United States)

    Bartomeus, Ignasi; Ascher, John S.; Wagner, David; Danforth, Bryan N.; Colla, Sheila; Kornbluth, Sarah; Winfree, Rachael

    2011-01-01

    The phenology of many ecological processes is modulated by temperature, making them potentially sensitive to climate change. Mutualistic interactions may be especially vulnerable because of the potential for phenological mismatching if the species involved do not respond similarly to changes in temperature. Here we present an analysis of climate-associated shifts in the phenology of wild bees, the most important pollinators worldwide, and compare these shifts to published studies of bee-pollinated plants over the same time period. We report that over the past 130 y, the phenology of 10 bee species from northeastern North America has advanced by a mean of 10.4 ± 1.3 d. Most of this advance has taken place since 1970, paralleling global temperature increases. When the best available data are used to estimate analogous rates of advance for plants, these rates are not distinguishable from those of bees, suggesting that bee emergence is keeping pace with shifts in host-plant flowering, at least among the generalist species that we investigated. PMID:22143794

  17. Reconstructing patterns of temperature, phenology, and frost damage over 124 years: spring damage risk is increasing.

    Science.gov (United States)

    Augspurger, Carol K

    2013-01-01

    Climate change, with both warmer spring temperatures and greater temperature fluctuations, has altered phenologies, possibly leading to greater risk of spring frost damage to temperate deciduous woody plants. Phenological observations of 20 woody species from 1993 to 2012 in Trelease Woods, Champaign County, Illinois, USA, were used to identify years with frost damage to vegetative and reproductive phases. Local temperature records were used in combination with the phenological observations to determine what combinations of the two were associated with damage. Finally, a long-term temperature record (1889-1992) was evaluated to determine if the frequency of frost damage has risen in recent decades. Frost Frost damage occurred in five years in the interior and in three additional years at only the forest edge. The degree of damage varied with species, life stage, tissue (vegetative or reproductive), and phenological phase. Common features associated with the occurrence of damage to interior plants were (1) a period of unusual warm temperatures in March, followed by (2) a frost event in April with a minimum temperature frost damage increased significantly, from 0.03 during 1889-1979 to 0.21 during 1980-2012. When the criteria were "softened" to frost damage events more common.

  18. Detecting Inter-Annual Variations in the Phenology of Evergreen Conifers Using Long-Term MODIS Vegetation Index Time Series

    Directory of Open Access Journals (Sweden)

    Laura Ulsig

    2017-01-01

    Full Text Available Long-term observations of vegetation phenology can be used to monitor the response of terrestrial ecosystems to climate change. Satellite remote sensing provides the most efficient means to observe phenological events through time series analysis of vegetation indices such as the Normalized Difference Vegetation Index (NDVI. This study investigates the potential of a Photochemical Reflectance Index (PRI, which has been linked to vegetation light use efficiency, to improve the accuracy of MODIS-based estimates of phenology in an evergreen conifer forest. Timings of the start and end of the growing season (SGS and EGS were derived from a 13-year-long time series of PRI and NDVI based on a MAIAC (multi-angle implementation of atmospheric correction processed MODIS dataset and standard MODIS NDVI product data. The derived dates were validated with phenology estimates from ground-based flux tower measurements of ecosystem productivity. Significant correlations were found between the MAIAC time series and ground-estimated SGS (R2 = 0.36–0.8, which is remarkable since previous studies have found it difficult to observe inter-annual phenological variations in evergreen vegetation from satellite data. The considerably noisier NDVI product could not accurately predict SGS, and EGS could not be derived successfully from any of the time series. While the strongest relationship overall was found between SGS derived from the ground data and PRI, MAIAC NDVI exhibited high correlations with SGS more consistently (R2 > 0.6 in all cases. The results suggest that PRI can serve as an effective indicator of spring seasonal transitions, however, additional work is necessary to confirm the relationships observed and to further explore the usefulness of MODIS PRI for detecting phenology.

  19. Potential and limitations of using digital repeat photography to track structural and physiological phenology in Mediterranean tree-grass ecosystems

    Science.gov (United States)

    Luo, Yunpeng; EI-Madany, Tarek; Filippa, Gianluca; Carrara, Arnaud; Cremonese, Edoardo; Galvagno, Marta; Hammer, Tiana; Pérez-Priego, Oscar; Reichstein, Markus; Martín Isabel, Pilar; González Cascón, Rosario; Migliavacca, Mirco

    2017-04-01

    Tree-Grass ecosystems are global widely distributed (16-35% of the land surface). However, its phenology (especially in water-limited areas) has not yet been well characterized and modeled. By using commercial digital cameras, continuous and relatively vast phenology data becomes available, which provides a good opportunity to monitor and develop a robust method used to extract the important phenological events (phenophases). Here we aimed to assess the usability of digital repeat photography for three Tree-Grass Mediterranean ecosystems over two different growing seasons (Majadas del Tietar, Spain) to extract critical phenophases for grass and evergreen broadleaved trees (autumn regreening of grass- Start of growing season; resprouting of tree leaves; senescence of grass - End of growing season), assess their uncertainty, and to correlate them with physiological phenology (i.e. phenology of ecosystem scale fluxes such as Gross Primary Productivity, GPP). We extracted green chromatic coordinates (GCC) and camera based normalized difference vegetation index (Camera-NDVI) from an infrared enabled digital camera using the "Phenopix" R package. Then we developed a novel method to retrieve important phenophases from GCC and Camera-NDVI from various region of interests (ROIs) of the imagery (tree areas, grass, and both - ecosystem) as well as from GPP, which was derived from Eddy Covariance tower in the same experimental site. The results show that, at ecosystem level, phenophases derived from GCC and Camera-NDVI are strongly correlated (R2 = 0.979). Remarkably, we observed that at the end of growing season phenophases derived from GCC were systematically advanced (ca. 8 days) than phenophase from Camera-NDVI. By using the radiative transfer model Soil Canopy Observation Photochemistry and Energy (SCOPE) we demonstrated that this delay is related to the different sensitivity of GCC and NDVI to the fraction of green/dry grass in the canopy, resulting in a systematic

  20. The phenological development of Themeda triandra, Elyonurus ...

    African Journals Online (AJOL)

    The phenological development of Themeda triandra, Elyonurus argenteus and ... fire or drought may have a detrimental effect on leaf, shoot and seed production. ... Keywords: afrikaans; botany; carbohydrate; crude protein content; cutting; ...

  1. Impact of climate change on the timing of strawberry phenological processes in the Baltic States

    Directory of Open Access Journals (Sweden)

    Līga Bethere

    2016-02-01

    Full Text Available Climate change has been shown to impact aspects of agriculture and phenology. This study aims to quantify changes in the timing of garden strawberry blooms and harvests in the Baltic States using Regional Climate Models (RCMs. First, parameters for a strawberry phenology model based on the growing degree day (GDD methodology were determined. Growing degree days were calculated using a modified sine wave method that estimates the diurnal temperature cycle from the daily maximum and minimum temperature. Model parameters include the base temperature and the required cumulative GDD sum, estimated from phenological and meteorological observations in Latvia for the years 2010–2013 via iterative calibration. Then an ensemble of bias-corrected RCM results (ENSEMBLES project was used as input to the phenological model to estimate the timing of strawberry phenological processes for the years 1951–2099. The results clearly show that strawberry phenological processes can be expected to occur earlier in the future, with a significant change in regional patterns. Differences between coastal and inland regions are expected to decrease over time. The uncertainty of the results was estimated using the RCM ensemble spread, with northern coastal locations showing the largest spread.

  2. Detecting mismatches of bird migration stopover and tree phenology in response to changing climate

    Science.gov (United States)

    Kellermann, Jherime L.; van Riper, Charles

    2015-01-01

    Migratory birds exploit seasonal variation in resources across latitudes, timing migration to coincide with the phenology of food at stopover sites. Differential responses to climate in phenology across trophic levels can result in phenological mismatch; however, detecting mismatch is sensitive to methodology. We examined patterns of migrant abundance and tree flowering, phenological mismatch, and the influence of climate during spring migration from 2009 to 2011 across five habitat types of the Madrean Sky Islands in southeastern Arizona, USA. We used two metrics to assess phenological mismatch: synchrony and overlap. We also examined whether phenological overlap declined with increasing difference in mean event date of phenophases. Migrant abundance and tree flowering generally increased with minimum spring temperature but depended on annual climate by habitat interactions. Migrant abundance was lowest and flowering was highest under cold, snowy conditions in high elevation montane conifer habitat while bird abundance was greatest and flowering was lowest in low elevation riparian habitat under the driest conditions. Phenological synchrony and overlap were unique and complementary metrics and should both be used when assessing mismatch. Overlap declined due to asynchronous phenologies but also due to reduced migrant abundance or flowering when synchrony was actually maintained. Overlap declined with increasing difference in event date and this trend was strongest in riparian areas. Montane habitat specialists may be at greatest risk of mismatch while riparian habitat could provide refugia during dry years for phenotypically plastic species. Interannual climate patterns that we observed match climate change projections for the arid southwest, altering stopover habitat condition.

  3. The Avenging Females: A Comparative Analysis of Kill Bill Vol.1-2, Death Proof and Sympathy for Lady Vengeance

    Directory of Open Access Journals (Sweden)

    Basak Göksel Demiray

    2012-04-01

    Full Text Available This paper provides a comparative analysis of Quentin Tarantino’s Kill Bill Vol.1-2 (2003, 2004, Death Proof (2007 and Park Chan Wook’s Sympathy for Lady Vengeance (Chinjeolhan Geumjassi, 2005. The primary objectives of this study are: (1 to reveal the gender-biases inherent to the fundamental discursive structures of the foregoing films; (2 to compare and contrast the films through an analysis of the ‘gaze(s’ and possible ‘pleasures’,  which are inherent in their narratives, in relation to Laura Mulvey’s and Carol Clover’s approaches; and (3 to distinguish Kill Bill Vol.1-2 from the foregoing two and the ‘avenging female’ clichés of the other horror/violence movies in the context of the replaced positionings of its protagonist and antagonist inherent in its distinct narrative style.

  4. High Arctic plant phenology is determined by snowmelt patterns but duration of phenological periods is fixed

    DEFF Research Database (Denmark)

    Semenchuk, Philipp R.; Gillespie, Mark A K; Rumpf, Sabine B.

    2016-01-01

    The duration of specific periods within a plant's life cycle are critical for plant growth and performance. In the High Arctic, the start of many of these phenological periods is determined by snowmelt date, which may change in a changing climate. It has been suggested that the end of these periods...

  5. Linking phenology and biomass productivity in South Dakota mixed-grass prairie

    Science.gov (United States)

    Rigge, Matthew; Smart, Alexander; Wylie, Bruce; Gilmanov, Tagir; Johnson, Patricia

    2013-01-01

    Assessing the health of rangeland ecosystems based solely on annual biomass production does not fully describe plant community condition; the phenology of production can provide inferences on species composition, successional stage, and grazing impacts. We evaluate the productivity and phenology of western South Dakota mixed-grass prairie using 2000 to 2008 Moderate Resolution Imaging Spectrometer (MODIS) normalized difference vegetation index (NDVI) satellite imagery at 250 m spatial resolution. Growing season NDVI images were integrated weekly to produce time-integrated NDVI (TIN), a proxy of total annual biomass production, and integrated seasonally to represent annual production by cool (C3) and warm (C4) season species. Additionally, a variety of phenological indicators including cool season percentage of TIN were derived from the seasonal profiles of NDVI. Cool season percentage and TIN were combined to generate vegetation classes, which served as proxies of plant community condition. TIN decreased with precipitation from east to west across the study area. Alternatively, cool season percentage increased from east to west, following patterns related to the reliability (interannual coefficient of variation [CV]) and quantity of mid-summer precipitation. Cool season TIN averaged 76.8% of total. Seasonal accumulation of TIN corresponded closely (R2 > 0.90) to that of gross photosynthesis data from a carbon flux tower. Field-collected biomass and community composition data were strongly related to the TIN and cool season percentage products. The patterns of vegetation classes were responsive to topographic, edaphic, and land management influences on plant communities. Accurate maps of biomass production, cool/warm season composition, and vegetation classes can improve the efficiency of land management by adjusting stocking rates and season of use to maximize rangeland productivity and achieve conservation objectives. Further, our results clarify the spatial and

  6. Bud burst and flowering phenology in a mixed oak forest from Eastern Romania

    Directory of Open Access Journals (Sweden)

    Ecaterina Nicoleta Chesnoiu

    2009-12-01

    Full Text Available Bud burst and flowering phenology have been observed in year 2008 in a natural white oak species complex situated in eastern Romania. A total of 300 mature individuals was mapped and identified based on leaf morphology. The community consists of four oak species: Quercus pedunculiflora, Q. robur, Q. pubescens and Q. petraea. A set of 28 individuals could not be unambiguously classified to one or another species. Data on bud burst showed a normal distribution and the differences among species were small. The "very late" flushing was recorded on 15th of April, three weeks later when compared to early flushing individuals. The time period between the bud burst and the complete development of leaves was nearly the same in all oak species, varying on average, between 18.4 and 20.6 days. The spatial distribution of phenological groups within the complex appears to be non-randomly, because in many parts of the study plot exist groups in which most of the trees belong to the same phenological category. Our results indicate an overlap in flowering time for all oak species which occur in the area. The data support the hypothesis that interspecific gene flow is possible between closely related oak species.

  7. Organization of marine phenology data in support of planning and conservation in ocean and coastal ecosystems

    Science.gov (United States)

    Thomas, Kathryn A.; Fornwall, Mark D.; Weltzin, Jake F.; Griffis, R.B.

    2014-01-01

    Among the many effects of climate change is its influence on the phenology of biota. In marine and coastal ecosystems, phenological shifts have been documented for multiple life forms; however, biological data related to marine species' phenology remain difficult to access and is under-used. We conducted an assessment of potential sources of biological data for marine species and their availability for use in phenological analyses and assessments. Our evaluations showed that data potentially related to understanding marine species' phenology are available through online resources of governmental, academic, and non-governmental organizations, but appropriate datasets are often difficult to discover and access, presenting opportunities for scientific infrastructure improvement. The developing Federal Marine Data Architecture when fully implemented will improve data flow and standardization for marine data within major federal repositories and provide an archival repository for collaborating academic and public data contributors. Another opportunity, largely untapped, is the engagement of citizen scientists in standardized collection of marine phenology data and contribution of these data to established data flows. Use of metadata with marine phenology related keywords could improve discovery and access to appropriate datasets. When data originators choose to self-publish, publication of research datasets with a digital object identifier, linked to metadata, will also improve subsequent discovery and access. Phenological changes in the marine environment will affect human economics, food systems, and recreation. No one source of data will be sufficient to understand these changes. The collective attention of marine data collectors is needed—whether with an agency, an educational institution, or a citizen scientist group—toward adopting the data management processes and standards needed to ensure availability of sufficient and useable marine data to understand

  8. Leaf morphophysiology of a Neotropical mistletoe is shaped by seasonal patterns of host leaf phenology.

    Science.gov (United States)

    Scalon, Marina Corrêa; Rossatto, Davi Rodrigo; Domingos, Fabricius Maia Chaves Bicalho; Franco, Augusto Cesar

    2016-04-01

    Several mistletoe species are able to grow and reproduce on both deciduous and evergreen hosts, suggesting a degree of plasticity in their ability to cope with differences in intrinsic host functions. The aim of this study was to investigate the influence of host phenology on mistletoe water relations and leaf gas exchange. Mistletoe Passovia ovata parasitizing evergreen (Miconia albicans) hosts and P. ovata parasitizing deciduous (Byrsonima verbascifolia) hosts were sampled in a Neotropical savanna. Photosynthetic parameters, diurnal cycles of stomatal conductance, pre-dawn and midday leaf water potential, and stomatal anatomical traits were measured during the peak of the dry and wet seasons, respectively. P. ovata showed distinct water-use strategies that were dependent on host phenology. For P. ovata parasitizing the deciduous host, water use efficiency (WUE; ratio of photosynthetic rate to transpirational water loss) was 2-fold lower in the dry season than in the wet season; in contrast, WUE was maintained at the same level during the wet and dry seasons in P. ovata parasitizing the evergreen host. Generally, mistletoe and host diurnal cycles of stomatal conductance were linked, although there were clear differences in leaf water potential, with mistletoe showing anisohydric behaviour and the host showing isohydric behaviour. Compared to mistletoes attached to evergreen hosts, those parasitizing deciduous hosts had a 1.4-fold lower stomatal density and 1.2-fold wider stomata on both leaf surfaces, suggesting that the latter suffered less intense drought stress. This is the first study to show morphophysiological differences in the same mistletoe species parasitizing hosts of different phenological groups. Our results provide evidence that phenotypical plasticity (anatomical and physiological) might be essential to favour the use of a greater range of hosts.

  9. Phenology of Some Phanerogams (Trees and Shrubs of Northwestern Punjab, India

    Directory of Open Access Journals (Sweden)

    Gurveen Kaur

    2013-01-01

    Full Text Available Plants perform various vegetative and reproductive functions throughout the year in order to persist in their habitats. The study of these events including their timing and how the environment influences the timing of these events is known as phenology. This study of the timing of seasonal biological activities of plants is very important to know about plant’s survival and its reproductive success. The variation in the phenological activities is due to change in different abiotic conditions. This paper deals with the study of phenological activities like bud formation, flowering time, fruiting time, and seed formation for some leguminous plants of Amritsar, Punjab (a state in the northwest of India for three consecutive years from 2009 till 2011.

  10. Bud burst and flowering phenology in a mixed oak forest from Eastern Romania

    Directory of Open Access Journals (Sweden)

    Ecaterina Nicoleta Chesnoiu

    2009-11-01

    Full Text Available Bud burst and flowering phenology have been observed in year 2008 ina natural white oak species complex situated in eastern Romania. A total of 300 mature individuals was mapped and identified based on leaf morphology. The community consists of four oak species: Quercus pedunculiflora, Q. robur, Q. pubescens and Q. petraea. A set of 28 individuals could not be unambiguously classified to one or another species. Data on bud burst showed a normal distribution and the differences among species were small. The "very late" flushing was recorded on 15th of April, three weeks later when compared to early flushing individuals. The time period between the bud burst and the complete development of leaves was nearly the same in all oak species, varying on average, between 18.4 and 20.6 days. The spatialdistribution of phenological groups within the complex appears to be non-randomly, because in many parts of the study plot exist groups in which most of the trees belong to the same phenological category. Our results indicate an overlap in flowering time for all oak species which occur in the area. The data support the hypothesis that interspecific gene flow is possible between closely related oak species.

  11. Recent changes in phenology over the northern high latitudes detected from multi-satellite data

    International Nuclear Information System (INIS)

    Zeng Heqing; Jia Gensuo; Epstein, Howard

    2011-01-01

    Phenology of vegetation is a sensitive and valuable indicator of the dynamic responses of terrestrial ecosystems to climate change. Therefore, to better understand and predict ecosystems dynamics, it is important to reduce uncertainties in detecting phenological changes. Here, changes in phenology over the past several decades across the northern high-latitude region (≥60°N) were examined by calibrating and analyzing time series of the Moderate Resolution Imaging Spectroradiometer (MODIS) and the Advanced Very High Resolution Radiometer (AVHRR). Over the past decade (2000–10), an expanded length of the growing season (LOS) was detected by MODIS, largely due to an earlier start of the growing season (SOS) by 4.7 days per decade and a delayed end of the growing season (EOS) by 1.6 days per decade over the northern high latitudes. There were significant differences between North America and Eurasia in phenology from 2000 to 2010 based on MODIS data (SOS: df = 21, F = 49.02, p < 0.0001; EOS: df = 21, F = 49.25, p < 0.0001; LOS: df = 21, F = 79.40, p < 0.0001). In northern America, SOS advanced by 11.5 days per decade, and EOS was delayed by 2.2 days per decade. In Eurasia, SOS advanced by 2.7 days per decade, and EOS was delayed by 3.5 days per decade. SOS has likely advanced due to the warming Arctic during April and May. Our results suggest that in recent decades the longer vegetation growing seasons can be attributed to more advanced SOS rather than delayed EOS. AVHRR detected longer LOS over the past three decades, largely related to delayed EOS rather than advanced SOS. These two datasets are significantly different in key phenological parameters (SOS: df = 17, F = 14.63, p = 0.0015; EOS: df = 17, F = 38.69, p < 0.0001; LOS: df = 17, F = 16.47, p = 0.0009) from 2000 to 2008 over the northern high latitudes. Thus, further inter-calibration between the sensors is needed to resolve the inconsistency and to better understand long-term trends of vegetation growth

  12. A new herbarium-based method for reconstructing the phenology of plant species across large areas.

    Science.gov (United States)

    Lavoie, Claude; Lachance, Daniel

    2006-04-01

    Phenological data have recently emerged as particularly effective tools for studying the impact of climate change on plants, but long phenological records are rare. The lack of phenological observations can nevertheless be filled by herbarium specimens as long as some correction procedures are applied to take into account the different climatic conditions associated with sampling locations. In this study, we propose a new herbarium-based method for reconstructing the flowering dates of plant species that have been collected across large areas. Coltsfoot (Tussilago farfara L.) specimens from southern Quebec were used to test the method. Flowering dates for coltsfoot herbarium specimens were adjusted according to the date of disappearance of snow cover in the region where they were collected and compared using a reference point (the date of earliest snowmelt). In southern Quebec, coltsfoot blooms earlier at present (15-31 d) than during the first part of the 20th century. This phenomenon is likely associated with the climate warming trends recorded in this region in the last century, especially during the last three decades when the month of April became warmer, thereby favoring very early-flowering cases. The earlier flowering of coltsfoot is, however, only noticeable in large urban areas (Montreal, Quebec City), suggesting a strong urban heat island effect on the flowering of this plant. Herbarium specimens are useful phenological indicators; however, the databases should be carefully examined prior to analysis to detect biases or trends associated with sampling locations.

  13. Synergistic Use of Citizen Science and Remote Sensing for Continental-Scale Measurements of Forest Tree Phenology

    Directory of Open Access Journals (Sweden)

    Andrew J. Elmore

    2016-06-01

    Full Text Available There is great potential value in linking geographically dispersed multitemporal observations collected by lay volunteers (or “citizen scientists” with remotely-sensed observations of plant phenology, which are recognized as useful indicators of climate change. However, challenges include a large mismatch in spatial scale and diverse sources of uncertainty in the two measurement types. These challenges must be overcome if the data from each source are to be compared and jointly used to understand spatial and temporal variation in phenology, or if remote observations are to be used to predict ground-based observations. We investigated the correlation between land surface phenology derived from Moderate Resolution Imaging Spectrometer (MODIS data and citizen scientists’ phenology observations from the USA National Phenology Network (NPN. The volunteer observations spanned 2004 to 2013 and represented 25 plant species and nine phenophases. We developed quality control procedures that removed observations outside of an a priori determined acceptable period and observations that were made more than 10 days after a preceding observation. We found that these two quality control steps improved the correlation between ground- and remote-observations, but the largest improvement was achieved when the analysis was restricted to forested MODIS pixels. These results demonstrate a high degree of correlation between the phenology of individual trees (particularly dominant forest trees such as quaking aspen, white oak, and American beech and the phenology of the surrounding forested landscape. These results provide helpful guidelines for the joint use of citizen scientists’ observations and remote sensing phenology in work aimed at understanding continental scale variation and temporal trends.

  14. Detecting inter-annual variability in the phenological characteristics of southern Africa’s vegetation using satellite imagery

    CSIR Research Space (South Africa)

    Wessels, Konrad J

    2011-01-01

    Full Text Available provides consistent measurements of vegetation greenness which captures phenological cycles and vegetation function. Understanding the inter-annual variability in phenology is imperative, as phenological changes will be one of the first signs of the impact...

  15. Intra- and interspecific variation in tropical tree and liana phenology derived from Unmanned Aerial Vehicle images

    Science.gov (United States)

    Bohlman, S.; Park, J.; Muller-Landau, H. C.; Rifai, S. W.; Dandois, J. P.

    2017-12-01

    Phenology is a critical driver of ecosystem processes. There is strong evidence that phenology is shifting in temperate ecosystems in response to climate change, but tropical tree and liana phenology remains poorly quantified and understood. A key challenge is that tropical forests contain hundreds of plant species with a wide variety of phenological patterns. Satellite-based observations, an important source of phenology data in northern latitudes, are hindered by frequent cloud cover in the tropics. To quantify phenology over a large number of individuals and species, we collected bi-weekly images from unmanned aerial vehicles (UAVs) in the well-studied 50-ha forest inventory plot on Barro Colorado Island, Panama. Between October 2014 and December 2015 and again in May 2015, we collected a total of 35 sets of UAV images, each with continuous coverage of the 50-ha plot, where every tree ≥ 1 cm DBH is mapped. Spectral, texture, and image information was extracted from the UAV images for individual tree crowns, which was then used as inputs for a machine learning algorithm to predict percent leaf and branch cover. We obtained the species identities of 2000 crowns in the images via field mapping. The objectives of this study are to (1) determined if machine learning algorithms, applied to UAV images, can effectively quantify changes in leaf cover, which we term "deciduousness; (2) determine how liana cover effects deciduousness and (3) test how well UAV-derived deciduousness patterns match satellite-derived temporal patterns. Machine learning algorithms trained on a variety of image parameters could effectively determine leaf cover, despite variation in lighting and viewing angles. Crowns with higher liana cover have less overall deciduousness (tree + liana together) than crowns with lower liana cover. Individual crown deciduousness, summed over all crowns measured in the 50-ha plot, showed a similar seasonal pattern as MODIS EVI composited over 10 years. However

  16. La Serra d'Almos (Tarragona): an example of phenological data rescue and preservation in Catalonia

    Science.gov (United States)

    Busto, Montserrat; Cunillera, Jordi; de Yzaguirre, Xavi; Borrell, Josep

    2016-04-01

    The interruption of important phenological series and the progressive disappearance of phenological observations in Catalonia led the Meteorological Service of Catalonia (SMC) to design and impulse a new phenological network promoted by the Climate Change Unit of this Met Service. The "Fenocat" network was born in March 2013, and currently has around fifty observers distributed throughout Catalonia that observe plants, birds and butterflies. We are providing data from different plant phenophases to PEP725 database. Besides this new phenological network (Fenocat), one of the aims of SMC is to rescue and preserve historical data from different observation points in Catalonia. We show in this poster the example of rescue and preservation of phenological data from la Serra d'Almos (in Tivissa, near Tarragona, Catalonia, NE Iberian Peninsula), an observation series that began in 1973. After digitalization process and quality control tasks, we show preliminary results of this phenological series, and we compare them with those of similar European series. We show the evolution trends for different observed species, such as almond tree (Prunus dulcis), hazel (Corylus avellana), plum (Prunus domestica), olive tree (Olea europea), apple tree (Malus domestica) or vineyard (Vitis vinifera).

  17. Analyzing the Velocity of Vegetation Phenology Over the Tibetan Plateau Using Gimms NDVI3g Data

    Science.gov (United States)

    Zhou, Y. K.

    2018-05-01

    Global environmental change is rapidly altering the dynamics of terrestrial vegetation, and phenology is a classic proxy to detect the response of vegetation to the changes. On the Tibetan Plateau, the earlier spring and delayed autumn vegetation phenology is widely reported. Remotely sensed NDVI can serve as a good data source for vegetation phenology study. Here GIMMS NDVI3g data was used to detect vegetation phenology status on the Tibetan Plateau. The spatial and temporal gradients are combined to depict the velocity of vegetation expanding process. This velocity index represents the instantaneous local velocity along the Earth's surface needed to maintain constant vegetation condition. This study found that NDVI velocity show a complex spatial pattern. A considerable number of regions display a later starting of growing season (SOS) and earlier end of growing season (EOS) reflected by the velocity change, particularly in the central part of the plateau. Nearly 74 % vegetation experienced a shortened growing season length. Totally, the magnitude of the phenology velocity is at a small level that reveals there is not a significant variation of vegetation phenology under the climate change context.

  18. Toward a Probabilistic Phenological Model for Wheat Growing Degree Days (GDD)

    Science.gov (United States)

    Rahmani, E.; Hense, A.

    2017-12-01

    Are there deterministic relations between phenological and climate parameters? The answer is surely `No'. This answer motivated us to solve the problem through probabilistic theories. Thus, we developed a probabilistic phenological model which has the advantage of giving additional information in terms of uncertainty. To that aim, we turned to a statistical analysis named survival analysis. Survival analysis deals with death in biological organisms and failure in mechanical systems. In survival analysis literature, death or failure is considered as an event. By event, in this research we mean ripening date of wheat. We will assume only one event in this special case. By time, we mean the growing duration from sowing to ripening as lifetime for wheat which is a function of GDD. To be more precise we will try to perform the probabilistic forecast for wheat ripening. The probability value will change between 0 and 1. Here, the survivor function gives the probability that the not ripened wheat survives longer than a specific time or will survive to the end of its lifetime as a ripened crop. The survival function at each station is determined by fitting a normal distribution to the GDD as the function of growth duration. Verification of the models obtained is done using CRPS skill score (CRPSS). The positive values of CRPSS indicate the large superiority of the probabilistic phonologic survival model to the deterministic models. These results demonstrate that considering uncertainties in modeling are beneficial, meaningful and necessary. We believe that probabilistic phenological models have the potential to help reduce the vulnerability of agricultural production systems to climate change thereby increasing food security.

  19. Season Spotter: Using Citizen Science to Validate and Scale Plant Phenology from Near-Surface Remote Sensing

    Directory of Open Access Journals (Sweden)

    Margaret Kosmala

    2016-09-01

    Full Text Available The impact of a rapidly changing climate on the biosphere is an urgent area of research for mitigation policy and management. Plant phenology is a sensitive indicator of climate change and regulates the seasonality of carbon, water, and energy fluxes between the land surface and the climate system, making it an important tool for studying biosphere–atmosphere interactions. To monitor plant phenology at regional and continental scales, automated near-surface cameras are being increasingly used to supplement phenology data derived from satellite imagery and data from ground-based human observers. We used imagery from a network of phenology cameras in a citizen science project called Season Spotter to investigate whether information could be derived from these images beyond standard, color-based vegetation indices. We found that engaging citizen science volunteers resulted in useful science knowledge in three ways: first, volunteers were able to detect some, but not all, reproductive phenology events, connecting landscape-level measures with field-based measures. Second, volunteers successfully demarcated individual trees in landscape imagery, facilitating scaling of vegetation indices from organism to ecosystem. And third, volunteers’ data were used to validate phenology transition dates calculated from vegetation indices and to identify potential improvements to existing algorithms to enable better biological interpretation. As a result, the use of citizen science in combination with near-surface remote sensing of phenology can be used to link ground-based phenology observations to satellite sensor data for scaling and validation. Well-designed citizen science projects targeting improved data processing and validation of remote sensing imagery hold promise for providing the data needed to address grand challenges in environmental science and Earth observation.

  20. Soil-structure interaction Vol.2. Influence of lift-off

    International Nuclear Information System (INIS)

    Miller, C.A.

    1986-04-01

    This study has been performed for the Nuclear Regulatory Commission (NRC) by the Structural Analysis Division of Brookhaven National Laboratory (BNL). The study was conducted during the fiscal year 1985 on the program entitled 'Benchmarking of Structural Engineering Problems' sponsored by NRC. The program considered three separate but complementary problems, each associated with the soil-structure interaction (SSI) phase of the seismic response analysis of nuclear plant facilities. The reports are presented in three separate volumes. The general title for the reports is 'Soil Structure Interaction' with the following subtitles: Vol. 1 Influence of Layering by A.J. Philippacopoulos, Vol. 2 Influence of Lift-Off by C.A. Miller, Vol. 3 Influence of Ground Water by C.J. Costantino. The two problems presented in Volumes 2 and 3 were conducted at the City University of New York (CUNY) under subcontract to BNL. This report, Volume 2 of the report, presents a summary of the work performed defining the influence liftoff has on the seismic response of nuclear power plant structures. The standard lumped parameter analysis method was modified by representing the lumped soil/structure interaction horizontal and rocking dampers with distributed (over the foundation area) springs and dampers. The distributed springs and dampers are then modified so that they can only transmit compressive stresses. Additional interaction damping is included to account for the energy dissipated as a portion of the foundation which has separated comes back into contact with the soil. The validity of the model is evaluated by comparing predictions made with it to data measured during the SIMQUAKE II experiment. The predictions were found to correlate quite well with the measured data except for some discrepancies at the higher frequencies (greater than 10 cps). This discrepancy was attributed to the relatively crude model used for impact effects. Data is presented which identifies the peak

  1. Phenology of brazil nut (Bertholletia excelsa Humb.& Bonpl., Lecythidaceae in south of Roraima state

    Directory of Open Access Journals (Sweden)

    Helio Tonini

    2011-03-01

    Full Text Available This work was carried out in order to study the phenological pattern of brasil-nut trees in natural forest located in the south of Roraima state, in order to relate the frequency of occurrence of phenophases with rainfall. For the phenological survey 20 adult trees (DBH > 50 cm were selected in a permanent sample plot of 9 ha. The phenological observations occurred fortnightly from February 2006 to February 2009, when data were collected on the presence or absence of events of flowering, fruiting, leaf flushing and leaf fall for each tree. The Index of population synchrony was used for estimating the synchrony of phenological events. The flowering of brasil-nut proved to be regular, annual, long and synchronous and was correlated with the reduction of rainfall. The fruiting was regular and synchronous, and dispersal was correlated with rainfall reduction. The phenological pattern of leaf flushing tended to vary yearly, being around the continual one in 2007 and bimodal in 2006 and 2008. It was noticed a higher proportion of trees falling leaves between August and October which characterizes a period of transition between the dry and the rainy time with sensitive reduction of rainfall.

  2. Phenological behavior of the grapevine (vitis vinifera l., cv cabernet sauvignon in Sutamarchán - Boyacá.

    Directory of Open Access Journals (Sweden)

    Diana Carolina Vargas Herrera

    2013-12-01

    Full Text Available In tropical cold weather, the grapevine presents phenological disorders, difficult agronomic disfavoring vintage quality. With the purpose of establishing phenological cycles determined the duration of the different phases of the development cycle of the grapevine, cv "Cabernet Sauvignon" (Vitis vinifera L. in the vineyard Ain-Karim (5º39` N, 73º95' W, 2110 masl. We determined the average duration of sprouting (SP, flowering (FL, veraison (VE and vintage (VI periods from pruning, and the total cycle of growth, according to the phenological scale Biologische Bundesanstalt Bundessortenamt Chemise (BBCH. To set the average of the process was considered when the plants reached 50% of each event. Determining growing degree days (GDD support the temperature record by a datalogger. Phenological data were subjected to a descriptive analysis as means and standard deviation. The duration of the period between pruning (PR and vintage (VI, with average temperature of 17.87 ° C, had a duration of 183 days after pruning (DAP, accumulating growing degree days 1458.1 (GDD. Flowering occurred at 50 days after pruning (DAP, accumulating 397.7 GDD. Veraison 122 was presented to the accumulation of 578.2 DAP with GDD. While from veraison to maturity 478.9 GDD accumulated in 62 days. Under Sutamarchán agro-climatic conditions, during the investigation, collects, on average, 7.98 degrees daily growth, which implies that for the Cabernet Sauvignon, the total duration of the phenological cycle is 184 days, accumulating 1458.1 GDD.

  3. Cross sections for atomic processes, vol. 2

    International Nuclear Information System (INIS)

    Takayanagi, Kazuo; Suzuki, Hiroshi; Otani, Shunsuke

    1977-09-01

    This data collection book contains the data on all processes involving hydrogen and helium isotopes, their ions, electrons and photons, collected systematically and comprehensively, and is compiled subsequently to Vol. 1 as one of the works of the data collection study group in the Institute of Plasma Physics, Nagoya University, Japan. The items of the contents will include energy level, multiplicately excited state, radiation process, electron collision, ionic collision, recombination, collision of neutral atoms, colliding process involving molecules, and other processes. However, the first edition this time contains energy level, radiation process, electron collision and ionic collision, and the data on remaining items are now under collection. Though some criticisms have been heard about Vol. 1, the authors consider that such comprehensive collection based on systematic classification is the foundation of making a generalized data bank expected to become necessary in future. Thus the data collection book includes all relevant processes, and records the experimental data and theoretically calculated results in principle without modification by selecting them systematically. This year, investigation on data evaluation is taken up also as one of the tasks of the study group. (Wakatsuki, Y.)

  4. Impact of dynamic vegetation phenology on the simulated pan-Arctic land surface state

    Science.gov (United States)

    Teufel, Bernardo; Sushama, Laxmi; Arora, Vivek K.; Verseghy, Diana

    2018-03-01

    The pan-Arctic land surface is undergoing rapid changes in a warming climate, with near-surface permafrost projected to degrade significantly during the twenty-first century. Vegetation-related feedbacks have the potential to influence the rate of degradation of permafrost. In this study, the impact of dynamic phenology on the pan-Arctic land surface state, particularly near-surface permafrost, for the 1961-2100 period, is assessed by comparing two simulations of the Canadian Land Surface Scheme (CLASS)—one with dynamic phenology, modelled using the Canadian Terrestrial Ecosystem Model (CTEM), and the other with prescribed phenology. These simulations are forced by atmospheric data from a transient climate change simulation of the 5th generation Canadian Regional Climate Model (CRCM5) for the Representative Concentration Pathway 8.5 (RCP8.5). Comparison of the CLASS coupled to CTEM simulation to available observational estimates of plant area index, spatial distribution of permafrost and active layer thickness suggests that the model captures reasonably well the overall distribution of vegetation and permafrost. It is shown that the most important impact of dynamic phenology on the land surface occurs through albedo and it is demonstrated for the first time that vegetation control on albedo during late spring and early summer has the highest potential to impact the degradation of permafrost. While both simulations show extensive near-surface permafrost degradation by the end of the twenty-first century, the strong projected response of vegetation to climate warming and increasing CO2 concentrations in the coupled simulation results in accelerated permafrost degradation in the northernmost continuous permafrost regions.

  5. Atmospheric mechanisms governing the spatial and temporal variability of phenological phases in central Europe

    Science.gov (United States)

    Scheifinger, Helfried; Menzel, Annette; Koch, Elisabeth; Peter, Christian; Ahas, Rein

    2002-11-01

    A data set of 17 phenological phases from Germany, Austria, Switzerland and Slovenia spanning the time period from 1951 to 1998 has been made available for analysis together with a gridded temperature data set (1° × 1° grid) and the North Atlantic Oscillation (NAO) index time series. The disturbances of the westerlies constitute the main atmospheric source for the temporal variability of phenological events in Europe. The trend, the standard deviation and the discontinuity of the phenological time series at the end of the 1980s can, to a great extent, be explained by the NAO. A number of factors modulate the influence of the NAO in time and space. The seasonal northward shift of the westerlies overlaps with the sequence of phenological spring phases, thereby gradually reducing its influence on the temporal variability of phenological events with progression of spring (temporal loss of influence). This temporal process is reflected by a pronounced decrease in trend and standard deviation values and common variability with the NAO with increasing year-day. The reduced influence of the NAO with increasing distance from the Atlantic coast is not only apparent in studies based on the data set of the International Phenological Gardens, but also in the data set of this study with a smaller spatial extent (large-scale loss of influence). The common variance between phenological and NAO time series displays a discontinuous drop from the European Atlantic coast towards the Alps. On a local and regional scale, mountainous terrain reduces the influence of the large-scale atmospheric flow from the Atlantic via a proposed decoupling mechanism. Valleys in mountainous terrain have the inclination to harbour temperature inversions over extended periods of time during the cold season, which isolate the valley climate from the large-scale atmospheric flow at higher altitudes. Most phenological stations reside at valley bottoms and are thus largely decoupled in their temporal

  6. Phenological monitoring of Acadia National Park using Landsat, MODIS and VIIRS observations and fused data

    Science.gov (United States)

    Liu, Y.; McDonough MacKenzie, C.; Primack, R.; Zhang, X.; Schaaf, C.; Sun, Q.; Wang, Z.

    2015-12-01

    Monitoring phenology with remotely sensed data has become standard practice in large-plot agriculture but remains an area of research in complex terrain. Landsat data (30m) provides a more appropriate spatial resolution to describe such regions but may only capture a few cloud-free images over a growing period. Daily data from the MODerate resolution Imaging Spectroradiometer(MODIS) and Visible Infrared Imaging Radiometer Suite(VIIRS) offer better temporal acquisitions but at coarse spatial resolutions of 250m to 1km. Thus fused data sets are being employed to provide the temporal and spatial resolutions necessary to accurately monitor vegetation phenology. This study focused on Acadia National Park, Maine, attempts to compare green-up from remote sensing and ground observations over varying topography. Three north-south field transects were established in 2013 on parallel mountains. Along these transects, researchers record the leaf out and flowering phenology for thirty plant species biweekly. These in situ spring phenological observations are compared with the dates detected by Landsat 7, Landsat 8, MODIS, and VIIRS observations, both separately and as fused data, to explore the ability of remotely sensed data to capture the subtle variations due to elevation. Daily Nadir BRDF Adjusted Reflectances(NBAR) from MODIS and VIIRS are fused with Landsat imagery to simulate 30m daily data via the Enhanced Spatial and Temporal Adaptive Reflectance Fusion Model(ESTARFM) algorithm. Piecewise logistic functions are fit to the time series to establish spring leaf-out dates. Acadia National Park, a region frequently affected by coastal clouds, is a particularly useful study area as it falls in a Landsat overlap region and thus offers the possibility of acquiring as many as 4 Landsat observations in a 16 day period. With the recent launch of Sentinel 2A, the community will have routine access to such high spatial and temporal data for phenological monitoring.

  7. Toward a Lake Ice Phenology Derived from VIIRS Data

    Science.gov (United States)

    Sütterlin, Melanie; Duguay-Tetzlaff, Anke; Wunderle, Stefan

    2017-04-01

    Ice cover on lakes plays an essential role in the physical, chemical, and biological processes of freshwater systems (e.g., ice duration controls the seasonal heat budget of lakes), and it also has many economic implications (e.g., for hydroelectricity, transportation, winter tourism). The variability and trends in the seasonal cycle of lake ice (e.g., timing of freeze-up and break-up) represent robust and direct indicators of climate change; they therefore emphasize the importance of monitoring lake ice phenology. Satellite remote sensing has proven its great potential for detecting and measuring the ice cover on lakes. Different remote sensing systems have been successfully used to collect recordings of freeze-up, break-up, and ice thickness and increase the spatial and temporal coverage of ground-based observations. Therefore, within the Global Climate Observing System (GCOS) Swiss project, "Integrated Monitoring of Ice in Selected Swiss Lakes," initiated by MeteoSwiss, satellite images from various sensors and different approaches are used and compared to perform investigations aimed at integrated monitoring of lake ice in Switzerland and contributing to the collection of lake ice phenology recordings. Within the framework of this project, the Remote Sensing Research Group of the University of Bern (RSGB) utilizes data acquired in the fine-resolution imagery (I) bands (1-5) of the Visible Infrared Imaging Radiometer Suite (VIIRS) sensor that is mounted onboard the SUOMI-NPP. Visible and near-infrared reflectances, as well as thermal infrared-derived lake surface water temperatures (LSWT), are used to retrieve lake ice phenology dates. The VIIRS instrument, which combines a high temporal resolution ( 2 times per day) with a reasonable spatial resolution (375 m), is equipped with a single broad-band thermal I-channel (I05). Thus, a single-channel LSWT retrieval algorithm is employed to correct for the atmospheric influence. The single channel algorithm applied in

  8. Analyzing phenological extreme events over the past five decades in Germany

    Science.gov (United States)

    Schleip, Christoph; Menzel, Annette; Estrella, Nicole; Graeser, Philipp

    2010-05-01

    As climate change may alter the frequency and intensity of extreme temperatures, we analysed whether warming of the last 5 decades has already changed the statistics of phenological extreme events. In this context, two extreme value statistical concepts are discussed and applied to existing phenological datasets of German Weather Service (DWD) in order to derive probabilities of occurrence for extreme early or late phenological events. We analyse four phenological groups; "begin of flowering, "leaf foliation", "fruit ripening" and "leaf colouring" as well as DWD indicator phases of the "phenological year". Additionally we put an emphasis on a between-species analysis; a comparison of differences in extreme onsets between three common northern conifers. Furthermore we conducted a within-species analysis with different phases of horse chestnut throughout a year. The first statistical approach fits data to a Gaussian model using traditional statistical techniques, and then analyses the extreme quantile. The key point of this approach is the adoption of an appropriate probability density function (PDF) to the observed data and the assessment of the PDF parameters change in time. The full analytical description in terms of the estimated PDF for defined time steps of the observation period allows probability assessments of extreme values for e.g. annual or decadal time steps. Related with this approach is the possibility of counting out the onsets which fall in our defined extreme percentiles. The estimation of the probability of extreme events on the basis of the whole data set is in contrast to analyses with the generalized extreme value distribution (GEV). The second approach deals with the extreme PDFs itself and fits the GEV distribution to annual minima of phenological series to provide useful estimates about return levels. For flowering and leaf unfolding phases exceptionally early extremes are seen since the mid 1980s and especially for the single years 1961

  9. Tracking vegetation phenology across diverse North American biomes using PhenoCam imagery

    Science.gov (United States)

    Richardson, Andrew D.; Hufkens, Koen; Milliman, Tom; Aubrecht, Donald M.; Chen, Min; Gray, Josh M.; Johnston, Miriam R.; Keenan, Trevor F.; Klosterman, Stephen T.; Kosmala, Margaret; Melaas, Eli K.; Friedl, Mark A.; Frolking, Steve

    2018-03-01

    Vegetation phenology controls the seasonality of many ecosystem processes, as well as numerous biosphere-atmosphere feedbacks. Phenology is also highly sensitive to climate change and variability. Here we present a series of datasets, together consisting of almost 750 years of observations, characterizing vegetation phenology in diverse ecosystems across North America. Our data are derived from conventional, visible-wavelength, automated digital camera imagery collected through the PhenoCam network. For each archived image, we extracted RGB (red, green, blue) colour channel information, with means and other statistics calculated across a region-of-interest (ROI) delineating a specific vegetation type. From the high-frequency (typically, 30 min) imagery, we derived time series characterizing vegetation colour, including “canopy greenness”, processed to 1- and 3-day intervals. For ecosystems with one or more annual cycles of vegetation activity, we provide estimates, with uncertainties, for the start of the “greenness rising” and end of the “greenness falling” stages. The database can be used for phenological model validation and development, evaluation of satellite remote sensing data products, benchmarking earth system models, and studies of climate change impacts on terrestrial ecosystems.

  10. 40 CFR 96.255 - Banking.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Banking. 96.255 Section 96.255 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NOX BUDGET... Tracking System § 96.255 Banking. (a) CAIR SO2 allowances may be banked for future use or transfer in a...

  11. Density dependence and phenological mismatch: consequences for growth and survival of sub-arctic nesting Canada Geese

    Directory of Open Access Journals (Sweden)

    Rodney W. Brook

    2015-06-01

    Full Text Available The extent to which species are plastic in the timing of their reproductive events relative to phenology suggests how climate change might affect their demography. An ecological mismatch between the timing of hatch for avian species and the peak availability in quality and quantity of forage for rapidly growing offspring might ultimately affect recruitment to the breeding population unless individuals can adjust the timing of breeding to adapt to changing phenology. We evaluated effects of goose density, hatch timing relative to forage plant phenology, and weather indices on annual growth of pre-fledging Canada geese (Branta canadensis from 1993-2010 at Akimiski Island, Nunavut. We found effects of both density and hatch timing relative to forage plant phenology; the earlier that eggs hatched relative to forage plant phenology, the larger the mean gosling size near fledging. Goslings were smallest in years when hatch was latest relative to forage plant phenology, and when local abundance of breeding adults was highest. We found no evidence for a trend in relative hatch timing, but it was apparent that in early springs, Canada geese tended to hatch later relative to vegetation phenology, suggesting that geese were not always able to adjust the timing of nesting as rapidly as vegetation phenology was advanced. Analyses using forage biomass information revealed a positive relationship between gosling size and per capita biomass availability, suggesting a causal mechanism for the density effect. The effects of weather parameters explained additional variation in mean annual gosling size, although total June and July rainfall had a small additive effect on gosling size. Modelling of annual first-year survival probability using mean annual gosling size as an annual covariate revealed a positive relationship, suggesting that reduced gosling growth negatively impacts recruitment.

  12. Density dependence and phenological mismatch: consequences for growth and survival of sub-arctic nesting Canada Geese

    Science.gov (United States)

    Brook, Rodney W.; Leafloor, James O.; Douglas, David C.; Abraham, Kenneth F.

    2015-01-01

    The extent to which species are plastic in the timing of their reproductive events relative to phenology suggests how change might affect their demography. An ecological mismatch between the timing of hatch for avian species and the peak availability in quality and quantity of forage for rapidly growing offspring might ultimately affect recruitment to the breeding population unless individuals can adjust the timing of breeding to adapt to changing phenology. We evaluated effects of goose density, hatch timing relative to forage plant phenology, and weather indices on annual growth of pre-fledging Canada geese (Branta canadensis) from 1993-2010 at Akimiski Island, Nunavut. We found effects of both density and hatch timing relative to forage plant phenology; the earlier that eggs hatched relative to forage plant phenology, the larger the mean gosling size near fledging. Goslings were smallest in years when hatch was latest relative to forage plant phenology, and when local abundance of breeding adults was highest. We found no evidence for a trend in relative hatch timing, but it was apparent that in early springs, Canada geese tended to hatch later relative to vegetation phenology, suggesting that geese were not always able to adjust the timing of nesting as rapidly as vegetation phenology was advanced. Analyses using forage biomass information revealed a positive relationship between gosling size and per capita biomass availability, suggesting a causal mechanism for the density effect. The effects of weather parameters explained additional variation in mean annual gosling size, although total June and July rainfall had a small additive effect on gosling size. Modelling of annual first year survival probability using mean annual gosling size as an annual covariate revealed a positive relationship, suggesting that reduced gosling growth negatively impacts recruitment.

  13. Improved Satellite-based Crop Yield Mapping by Spatially Explicit Parameterization of Crop Phenology

    Science.gov (United States)

    Jin, Z.; Azzari, G.; Lobell, D. B.

    2016-12-01

    Field-scale mapping of crop yields with satellite data often relies on the use of crop simulation models. However, these approaches can be hampered by inaccuracies in the simulation of crop phenology. Here we present and test an approach to use dense time series of Landsat 7 and 8 acquisitions data to calibrate various parameters related to crop phenology simulation, such as leaf number and leaf appearance rates. These parameters are then mapped across the Midwestern United States for maize and soybean, and for two different simulation models. We then implement our recently developed Scalable satellite-based Crop Yield Mapper (SCYM) with simulations reflecting the improved phenology parameterizations, and compare to prior estimates based on default phenology routines. Our preliminary results show that the proposed method can effectively alleviate the underestimation of early-season LAI by the default Agricultural Production Systems sIMulator (APSIM), and that spatially explicit parameterization for the phenology model substantially improves the SCYM performance in capturing the spatiotemporal variation in maize and soybean yield. The scheme presented in our study thus preserves the scalability of SCYM, while significantly reducing its uncertainty.

  14. Interannual variability of net ecosystem productivity in forests is explained by carbon flux phenology in autumn

    DEFF Research Database (Denmark)

    Wu, Chaoyang; Chen, Xi Jing; Black, T. Andrew

    2013-01-01

    To investigate the importance of autumn phenology in controlling interannual variability of forest net ecosystem productivity (NEP) and to derive new phenological metrics to explain the interannual variability of NEP. North America and Europe. Flux data from nine deciduous broadleaf forests (DBF......, soil water content and precipitation, were also used to explain the phenological variations. We found that interannual variability of NEP can be largely explained by autumn phenology, i.e. the autumn lag. While variation in neither annual gross primary productivity (GPP) nor in annual ecosystem...

  15. Reproductive phenology of Mauritia flexuosa L. (Arecaceae in a coastal restinga environment in northeastern Brazil

    Directory of Open Access Journals (Sweden)

    F. N. Mendes

    Full Text Available Abstract The buriti, Mauritia flexuosa, is the most common palm in Brazil, where it has considerable ecological and economic importance. However, few data are available on the phenology of the species, mainly in coastal restinga ecosystems. The present study monitored the reproductive phenology of M. flexuosa in the restinga of Barreirinhas, in the Brazilian Northeast, and investigated the relationship between phenophases and climatic variables. The presence/absence of flowers and fruits was recorded monthly in 25 individuals of each sex between August, 2009, and October, 2012. There was no difference in the phenology of male and female specimens, with flowering and fruiting occurring exclusively in the dry season. We believe that the specific abiotic characteristics of the study environment, such as the intense sunlight and availability of water in the soil, contribute to the reproductive success of M. flexuosa in the dry season, with consequent germination and establishment of seedlings occurring during the subsequent rainy season.

  16. Reproductive phenology of Mauritia flexuosa L. (Arecaceae) in a coastal restinga environment in northeastern Brazil.

    Science.gov (United States)

    Mendes, F N; Valente, R M; Rêgo, M M C; Esposito, M C

    2017-03-01

    The buriti, Mauritia flexuosa, is the most common palm in Brazil, where it has considerable ecological and economic importance. However, few data are available on the phenology of the species, mainly in coastal restinga ecosystems. The present study monitored the reproductive phenology of M. flexuosa in the restinga of Barreirinhas, in the Brazilian Northeast, and investigated the relationship between phenophases and climatic variables. The presence/absence of flowers and fruits was recorded monthly in 25 individuals of each sex between August, 2009, and October, 2012. There was no difference in the phenology of male and female specimens, with flowering and fruiting occurring exclusively in the dry season. We believe that the specific abiotic characteristics of the study environment, such as the intense sunlight and availability of water in the soil, contribute to the reproductive success of M. flexuosa in the dry season, with consequent germination and establishment of seedlings occurring during the subsequent rainy season.

  17. Estimating carbon flux phenology with satellite-derived land surface phenology and climate drivers for different biomes: a synthesis of AmeriFlux observations.

    Directory of Open Access Journals (Sweden)

    Wenquan Zhu

    Full Text Available Carbon Flux Phenology (CFP can affect the interannual variation in Net Ecosystem Exchange (NEE of carbon between terrestrial ecosystems and the atmosphere. In this study, we proposed a methodology to estimate CFP metrics with satellite-derived Land Surface Phenology (LSP metrics and climate drivers for 4 biomes (i.e., deciduous broadleaf forest, evergreen needleleaf forest, grasslands and croplands, using 159 site-years of NEE and climate data from 32 AmeriFlux sites and MODIS vegetation index time-series data. LSP metrics combined with optimal climate drivers can explain the variability in Start of Carbon Uptake (SCU by more than 70% and End of Carbon Uptake (ECU by more than 60%. The Root Mean Square Error (RMSE of the estimations was within 8.5 days for both SCU and ECU. The estimation performance for this methodology was primarily dependent on the optimal combination of the LSP retrieval methods, the explanatory climate drivers, the biome types, and the specific CFP metric. This methodology has a potential for allowing extrapolation of CFP metrics for biomes with a distinct and detectable seasonal cycle over large areas, based on synoptic multi-temporal optical satellite data and climate data.

  18. Evaluation of land surface model representation of phenology: an analysis of model runs submitted to the NACP Interim Site Synthesis

    Science.gov (United States)

    Richardson, A. D.; Nacp Interim Site Synthesis Participants

    2010-12-01

    Phenology represents a critical intersection point between organisms and their growth environment. It is for this reason that phenology is a sensitive and robust integrator of the biological impacts of year-to-year climate variability and longer-term climate change on natural systems. However, it is perhaps equally important that phenology, by controlling the seasonal activity of vegetation on the land surface, plays a fundamental role in regulating ecosystem processes, competitive interactions, and feedbacks to the climate system. Unfortunately, the phenological sub-models implemented in most state-of-the-art ecosystem models and land surface schemes are overly simplified. We quantified model errors in the representation of the seasonal cycles of leaf area index (LAI), gross ecosystem photosynthesis (GEP), and net ecosystem exchange of CO2. Our analysis was based on site-level model runs (14 different models) submitted to the North American Carbon Program (NACP) Interim Synthesis, and long-term measurements from 10 forested (5 evergreen conifer, 5 deciduous broadleaf) sites within the AmeriFlux and Fluxnet-Canada networks. Model predictions of the seasonality of LAI and GEP were unacceptable, particularly in spring, and especially for deciduous forests. This is despite an historical emphasis on deciduous forest phenology, and the perception that controls on spring phenology are better understood than autumn phenology. Errors of up to 25 days in predicting “spring onset” transition dates were common, and errors of up to 50 days were observed. For deciduous sites, virtually every model was biased towards spring onset being too early, and autumn senescence being too late. Thus, models predicted growing seasons that were far too long for deciduous forests. For most models, errors in the seasonal representation of deciduous forest LAI were highly correlated with errors in the seasonality of both GPP and NEE, indicating the importance of getting the underlying

  19. Spatiotemporal phenological changes in fall foliage peak coloration in deciduous forest and the responses to climatic variation

    Science.gov (United States)

    Xie, Y.; Wilson, A. M.

    2017-12-01

    Plant phenology studies typically focus on the beginning and end of the growing season in temperate forests. We know too little about fall foliage peak coloration, which is a bioindicator of plant response in autumn to environmental changes, an important visual cue in fall associated with animal activities, and a key element in fall foliage ecotourism. Spatiotemporal changes in timing of fall foliage peak coloration of temperate forests and the associated environmental controls are not well understood. In this study, we examined multiple color indices to estimate Land Surface Phenology (LSP) of fall foliage peak coloration of deciduous forest in the northeastern USA using Moderate Resolution Imaging Spectroradiometer (MODIS) daily imagery from 2000 to 2015. We used long term phenology ground observations to validate our estimated LSP, and found that Visible Atmospherically Resistant Index (VARI) and Plant Senescence Reflectance Index (PSRI) were good metrics to estimate peak and end of leaf coloration period of deciduous forest. During the past 16 years, the length of period with peak fall foliage color of deciduous forest at southern New England and northern Appalachian forests regions became longer (0.3 7.7 days), mainly driven by earlier peak coloration. Northern New England, southern Appalachian forests and Ozark and Ouachita mountains areas had shorter period (‒0.2 ‒9.2 days) mainly due to earlier end of leaf coloration. Changes in peak and end of leaf coloration not only were associated with changing temperature in spring and fall, but also to drought and heat in summer, and heavy precipitation in both summer and fall. The associations between leaf peak coloration phenology and climatic variations were not consistent among ecoregions. Our findings suggested divergent change patterns in fall foliage peak coloration phenology in deciduous forests, and improved our understanding in the environmental control on timing of fall foliage color change.

  20. Decadal declines in avian herbivore reproduction: density-dependent nutrition and phenological mismatch in the Arctic

    Science.gov (United States)

    Ross, Megan V.; Alisaukas, Ray T.; Douglas, David C.; Kellett, Dana K.

    2017-01-01

    A full understanding of population dynamics depends not only on estimation of mechanistic contributions of recruitment and survival, but also knowledge about the ecological processes that drive each of these vital rates. The process of recruitment in particular may be protracted over several years, and can depend on numerous ecological complexities until sexually mature adulthood is attained. We addressed long-term declines (23 breeding seasons, 1992–2014) in the per capita production of young by both Ross's Geese (Chen rossii) and Lesser Snow Geese (Chen caerulescens caerulescens) nesting at Karrak Lake in Canada's central Arctic. During this period, there was a contemporaneous increase from 0.4 to 1.1 million adults nesting at this colony. We evaluated whether (1) density-dependent nutritional deficiencies of pre-breeding females or (2) phenological mismatch between peak gosling hatch and peak forage quality, inferred from NDVI on the brood-rearing areas, may have been behind decadal declines in the per capita production of goslings. We found that, in years when pre-breeding females arrived to the nesting grounds with diminished nutrient reserves, the proportional composition of young during brood-rearing was reduced for both species. Furthermore, increased mismatch between peak gosling hatch and peak forage quality contributed additively to further declines in gosling production, in addition to declines caused by delayed nesting with associated subsequent negative effects on clutch size and nest success. The degree of mismatch increased over the course of our study because of advanced vegetation phenology without a corresponding advance in Goose nesting phenology. Vegetation phenology was significantly earlier in years with warm surface air temperatures measured in spring (i.e., 25 May–30 June). We suggest that both increased phenological mismatch and reduced nutritional condition of arriving females were behind declines in population-level recruitment

  1. Vol draadwerk

    African Journals Online (AJOL)

    Owner

    Die motto van Marius Crous se derde bundel,. Vol draadwerk (2012) is ontleen aan die vader van die psigoanalise, Sigmund Freud, wat lui: “Everywhere I go I find a poet has been there before me.” Vol draadwerk verskyn ses jaar ná sy vorige bundel, Aan 'n beentjie sit en kluif. (2006). Vir sy bundel, Brief uit die kolonies ...

  2. Characterizing spatiotemporal dynamics in phenology of urban ecosystems based on Landsat data

    Energy Technology Data Exchange (ETDEWEB)

    Li, Xuecao; Zhou, Yuyu; Asrar, Ghassem R.; Meng, Lin

    2017-12-01

    Seasonal phenology of vegetation plays an important role in global carbon cycle and ecosystem productivity. In urban environments, vegetation phenology is also important because of its influence on public health (e.g., allergies), and energy demand (e.g. cooling effects). In this study, we studied the potential use of remotely sensed observations (i.e. Landsat data) to derive some phenology indicators for vegetation embedded within the urban core domains in four distinctly different U.S. regions (Washington, D.C., King County in Washington, Polk County in Iowa, and Baltimore City and County in Maryland) during the past three decades. We used all available Landsat observations (circa 3000 scenes) from 1982 to 2015 and a self-adjusting double logistic model to detect and quantify the annual change of vegetation phenophases, i.e. indicators of seasonal changes in vegetation. The proposed model can capture and quantify not only phenophases of dense vegetation in rural areas, but also those of mixed vegetation in urban core domains. The derived phenology indicators show a good agreement with similar indicators derived from the Moderate Resolution Imaging Spectroradiometer (MODIS) and in situ observations, suggesting that the phenology dynamic depicted by the proposed model is reliable. The vegetation phenology and its seasonal and interannual dynamics demonstrate a distinct spatial pattern in urban domains with an earlier (9–14 days) start-of season (SOS) and a later (13–20 days) end-of season (EOS), resulting in an extended (5–30 days) growing season length (GSL) when compared to the surrounding suburban and rural areas in the four study regions. There is a general long-term trend of decreasing SOS (-0.30 day per year), and increasing EOS and GSL (0.50 and 0.90 day per year, respectively) over past three decades for these study regions. The magnitude of these trends varies among the four urban systems due to their diverse local climate conditions, vegetation

  3. No Consistent Evidence for Advancing or Delaying Trends in Spring Phenology on the Tibetan Plateau

    Science.gov (United States)

    Wang, Xufeng; Xiao, Jingfeng; Li, Xin; Cheng, Guodong; Ma, Mingguo; Che, Tao; Dai, Liyun; Wang, Shaoying; Wu, Jinkui

    2017-12-01

    Vegetation phenology is a sensitive indicator of climate change and has significant effects on the exchange of carbon, water, and energy between the terrestrial biosphere and the atmosphere. The Tibetan Plateau, the Earth's "third pole," is a unique region for studying the long-term trends in vegetation phenology in response to climate change because of the sensitivity of its alpine ecosystems to climate and its low-level human disturbance. There has been a debate whether the trends in spring phenology over the Tibetan Plateau have been continuously advancing over the last two to three decades. In this study, we examine the trends in the start of growing season (SOS) for alpine meadow and steppe using the Global Inventory Modeling and Mapping Studies (GIMMS)3g normalized difference vegetation index (NDVI) data set (1982-2014), the GIMMS NDVI data set (1982-2006), the Moderate Resolution Imaging Spectroradiometer (MODIS) NDVI data set (2001-2014), the Satellite Pour l'Observation de la Terre Vegetation (SPOT-VEG) NDVI data set (1999-2013), and the Sea-viewing Wide Field-of-View Sensor (SeaWiFS) NDVI data set (1998-2007). Both logistic and polynomial fitting methods are used to retrieve the SOS dates from the NDVI data sets. Our results show that the trends in spring phenology over the Tibetan Plateau depend on both the NDVI data set used and the method for retrieving the SOS date. There are large discrepancies in the SOS trends among the different NDVI data sets and between the two different retrieval methods. There is no consistent evidence that spring phenology ("green-up" dates) has been advancing or delaying over the Tibetan Plateau during the last two to three decades. Ground-based budburst data also indicate no consistent trends in spring phenology. The responses of SOS to environmental factors (air temperature, precipitation, soil temperature, and snow depth) also vary among NDVI data sets and phenology retrieval methods. The increases in winter and spring

  4. K-12 Phenology Lessons for the Phenocam Project

    Science.gov (United States)

    Bennett, K. F.

    2013-12-01

    Phenology is defined as periodic [or annual] life cycles of plants and animals driven by seasonal environmental changes. Climate change impinges a strong effect on phenology, potentially altering the structure and functioning of ecosystems. In the fall of 2011, the Ashburnham-Westminster Regional School District became the first of five schools to join Harvard University's Phenocam Network with the installation of a webcam to monitor phenology (or 'phenocam') at Overlook Middle School in Ashburnham, Massachusetts. Our school district is now part of a network of near-surface remote sensing phenocams that capture and send images of forest, shrub, and grassland vegetation cover at more than 130 diverse sites in North America. Our phenocam provides a digital image every half hour of the mixed forest canopy north from the school, enabling the detection of changes in canopy development, quantified as canopy 'greenness'. As a part of the Phenocam project, students at the K-12 level have expanded the scope of phenological monitoring protocol that is part of the Harvard Forest Schoolyard Ecology Program, Buds, Leaves, and Global Warming. In this protocol, students work with ecologists at Harvard Forest to monitor buds and leaves on schoolyard trees to determine the length of the growing season, giving them the opportunity to be a part of real and important research concerning the critical environmental issue of climate change. Students involved in the Buds, Leaves, and Global Warming study have the opportunity to compare their ground data on budburst, color change, and leaf drop to the phenocam images, as well as to similar forested sites in locations throughout the United States. Lessons have been developed for comparing student data to phenocam images, canopy greenness time series graphs extracted from the images, and satellite data. Lessons addressing map scale and the Urban Heat Island effect will also be available for teachers. This project will greatly enhance the

  5. Tracking Climate Effects on Plant-Pollinator Interaction Phenology with Satellites and Honey Bee Hives

    Science.gov (United States)

    Esaias, Wayne E.; Nickeson, Jaime E.; Tan, Bin; Ma, Peter L.; Nightingale, Joanne M.; Wolfe, Robert E.

    2011-01-01

    spring HBNF with the "Green-up" metric from the 500 meter MODIS NDVI phenology product, for sites throughout the Eastern US 2000-2009, is well described by a single linear fit (r(exp 2) = 0.72). We conclude.that for the tree-dominated areas of the Eastern US at least the spring HBNF can be tracked very well by MODIS phenology. Analysis of other regions and seasons is presently underway but with more limited data. Spatial patterns in the eastern US and management implications will be presented and discussed.

  6. Phenological cues intrinsic in indigenous knowledge systems for forecasting seasonal climate in the Delta State of Nigeria

    Science.gov (United States)

    Fitchett, Jennifer M.; Ebhuoma, Eromose

    2017-12-01

    Shifts in the timing of phenological events in plants and animals are cited as one of the most robust bioindicators of climate change. Much effort has thus been placed on the collection of phenological datasets, the quantification of the rates of phenological shifts and the association of these shifts with recorded meteorological data. These outputs are of value both in tracking the severity of climate change and in facilitating more robust management approaches in forestry and agriculture to changing climatic conditions. However, such an approach requires meteorological and phenological records spanning multiple decades. For communities in the Delta State of Nigeria, small-scale farming communities do not have access to meteorological records, and the dissemination of government issued daily to seasonal forecasts has only taken place in recent years. Their ability to survive inter-annual to inter-decadal climatic variability and longer-term climatic change has thus relied on well-entrenched indigenous knowledge systems (IKS). An analysis of the environmental cues that are used to infer the timing and amount of rainfall by farmers from three communities in the Delta State reveals a reliance on phenological events, including the croaking of frogs, the appearance of red millipedes and the emergence of fresh rubber tree and cassava leaves. These represent the first recorded awareness of phenology within the Delta State of Nigeria, and a potentially valuable source of phenological data. However, the reliance of these indicators is of concern given the rapid phenological shifts occurring in response to climate change.

  7. Adaptation of reproductive phenology to climate change with ecological feedback via dominance hierarchies.

    Science.gov (United States)

    Johansson, Jacob; Smith, Henrik G; Jonzén, Niclas

    2014-03-01

    Phenological shifts belong to the most commonly observed biological responses to recent climate change. It is, however, often unclear how these shifts are linked to demography and competitive interactions. We develop an eco-evolutionary model to study adaptation of timing of reproduction in organisms with social dominance hierarchies. We focus on residential birds with winter flocks, where success in competition for territories among offspring depends on ranking given by prior residence. We study the effects of environmental change on breeding population densities, ensuing selection pressures and long-term evolutionary equilibria. We consider changes in food peak date, in winter survival, in total reproductive output and in the width of the food distribution. We show that the evolutionarily stable hatching date will advance with increasing winter survival and reproductive output since these parameters increase habitat saturation and post-fledging competition. Increasing the length of the breeding season also selects for earlier hatching date due to the reduced costs for producing offspring with high ranking. Our analysis shows that there is little correlation between short-term and long-term population responses across different scenarios of environmental change. However, short-term population growth consistently predicts selection for earlier reproduction. Hence, the model identifies changed breeding population density as a key factor to understanding phenological adaptation in systems with prior residence advantages. While selection for change in reproductive phenology is often explained by changed seasonal variation in environmental variables, such as food abundance, we show that environmental change without apparent effects on seasonality can critically affect phenological adaptation. Such factors can mask or even override influences of changed seasonality on phenology. The model thus offers a conceptually new set of explanations for understanding phenological

  8. Energetic Physiology Mediates Individual Optimization of Breeding Phenology in a Migratory Arctic Seabird.

    Science.gov (United States)

    Hennin, Holly L; Bêty, Jöel; Legagneux, Pierre; Gilchrist, H Grant; Williams, Tony D; Love, Oliver P

    2016-10-01

    The influence of variation in individual state on key reproductive decisions impacting fitness is well appreciated in evolutionary ecology. Rowe et al. (1994) developed a condition-dependent individual optimization model predicting that three key factors impact the ability of migratory female birds to individually optimize breeding phenology to maximize fitness in seasonal environments: arrival condition, arrival date, and ability to gain in condition on the breeding grounds. While empirical studies have confirmed that greater arrival body mass and earlier arrival dates result in earlier laying, no study has assessed whether individual variation in energetic management of condition gain effects this key fitness-related decision. Using an 8-year data set from over 350 prebreeding female Arctic common eiders (Somateria mollissima), we tested this component of the model by examining whether individual variation in two physiological traits influencing energetic management (plasma triglycerides: physiological fattening rate; baseline corticosterone: energetic demand) predicted individual variation in breeding phenology after controlling for arrival date and body mass. As predicted by the optimization model, individuals with higher fattening rates and lower energetic demand had the earliest breeding phenology (shortest delays between arrival and laying; earliest laying dates). Our results are the first to empirically determine that individual flexibility in prebreeding energetic management influences key fitness-related reproductive decisions, suggesting that individuals have the capacity to optimally manage reproductive investment.

  9. Automated mapping of soybean and corn using phenology

    Science.gov (United States)

    Zhong, Liheng; Hu, Lina; Yu, Le; Gong, Peng; Biging, Gregory S.

    2016-09-01

    For the two of the most important agricultural commodities, soybean and corn, remote sensing plays a substantial role in delivering timely information on the crop area for economic, environmental and policy studies. Traditional long-term mapping of soybean and corn is challenging as a result of the high cost of repeated training data collection, the inconsistency in image process and interpretation, and the difficulty of handling the inter-annual variability of weather and crop progress. In this study, we developed an automated approach to map soybean and corn in the state of Paraná, Brazil for crop years 2010-2015. The core of the approach is a decision tree classifier with rules manually built based on expert interaction for repeated use. The automated approach is advantageous for its capacity of multi-year mapping without the need to re-train or re-calibrate the classifier. Time series MODerate-resolution Imaging Spectroradiometer (MODIS) reflectance product (MCD43A4) were employed to derive vegetation phenology to identify soybean and corn based on crop calendar. To deal with the phenological similarity between soybean and corn, the surface reflectance of the shortwave infrared band scaled to a phenological stage was used to fully separate the two crops. Results suggested that the mapped areas of soybean and corn agreed with official statistics at the municipal level. The resultant map in the crop year 2012 was evaluated using an independent reference data set, and the overall accuracy and Kappa coefficient were 87.2% and 0.804 respectively. As a result of mixed pixel effect at the 500 m resolution, classification results were biased depending on topography. In the flat, broad and highly-cropped areas, uncultivated lands were likely to be identified as soybean or corn, causing over-estimation of cropland area. By contrast, scattered crop fields in mountainous regions with dense natural vegetation tend to be overlooked. For future mapping efforts, it has great

  10. Phenological synchrony and seasonality of understory Rubiaceae in the Atlantic Forest, Bahia, Brazil

    Directory of Open Access Journals (Sweden)

    Heitor Scarpati Liuth

    2013-03-01

    Full Text Available In tropical forests with low seasonality, climatic variables generally exert a weak influence on the phenology of species. The seasonality of phenophases in closely related taxa can be controlled by phylogenetic constraints in such environments. In this study, our aim was to describe the phenology of Rubiaceae in the understory of the Atlantic Forest in the southern part of Bahia, Brazil, as well as to evaluate the seasonality and phenological synchrony of this family. For two years, we observed 90 individuals belonging to 13 species, in an area of 0.2 ha. Leaf flushing and leaf fall did not demonstrate any seasonality, were continuous for most species and correlated with few of the climatic variables. Flowering was seasonal and correlated positively with all climatic variables. Species exhibited seasonality for this phenophase with high flowering overlap among species of Psychotria, indicating an aggregated pattern for this genus. Fruiting was also seasonal and correlated with all the climatic variables, unripe fruit development peaking at the beginning of the season during which humidity is highest and fruit ripening peaking in the season during which humidity is slightly lower. The vegetative and flowering patterns observed in the study area are commonly seen in other tropical forests. The reproductive seasonality of this family can facilitate the attraction of biotic agents, as postulated in the facilitation hypothesis. Our results demonstrate that climatic variables influenced the phenological patterns observed here, although the high reproductive seasonality and interspecific synchrony, especially in congeneric species, raises the possibility that phylogenetic proximity plays a role in the pattern of the family Rubiaceae.

  11. Predicting Phenologic Response to Water Stress and Implications for Carbon Uptake across the Southeast U.S.

    Science.gov (United States)

    Lowman, L.; Barros, A. P.

    2016-12-01

    Representation of plant photosynthesis in modeling studies requires phenologic indicators to scale carbon assimilation by plants. These indicators are typically the fraction of photosynthetically active radiation (FPAR) and leaf area index (LAI) which represent plant responses to light and water availability, as well as temperature constraints. In this study, a prognostic phenology model based on the growing season index is adapted to determine the phenologic indicators of LAI and FPAR at the sub-daily scale based on meteorological and soil conditions. Specifically, we directly model vegetation green-up and die-off responses to temperature, vapor pressure deficit, soil water potential, and incoming solar radiation. The indices are based on the properties of individual plant functional types, driven by observational data and prior modeling applications. First, we describe and test the sensitivity of the carbon uptake response to predicted phenology for different vegetation types. Second, the prognostic phenology model is incorporated into a land-surface hydrology model, the Duke Coupled Hydrology Model with Prognostic Vegetation (DCHM-PV), to demonstrate the impact of dynamic phenology on modeled carbon assimilation rates and hydrologic feedbacks. Preliminary results show reduced carbon uptake rates when incorporating a prognostic phenology model that match well against the eddy-covariance flux tower observations. Additionally, grassland vegetation shows the most variability in LAI and FPAR tied to meteorological and soil conditions. These results highlight the need to incorporate vegetation-specific responses to water limitation in order to accurately estimate the terrestrial carbon storage component of the global carbon budget.

  12. Nitrogen-15 Uptake by Pinus contorta Seedlings in Relation to Phenological Stage and Season

    International Nuclear Information System (INIS)

    Amponsah, Isaac G.; Lieffers, Victor J.; Comeau, Philip G.; Landhaeusser, Simon M.

    2004-01-01

    This study measured the amount of uptake of labeled nitrogen ( 15 N) of lodgepole pine (Pinus contorta Dougl. var. latifolia Engelm) seedlings, at three different phenological stages, in a growth chamber experiment. Thirty days after 15 N application, the amount of 15 N recovered in seedlings as a percentage of the total 15 N fertilizer applied was 4% in early spring, 43% in summer and 33% in autumn. The total 15 N recovered in the plant-pot system ranged from 80 to 96%, and is higher than reported in other studies. Total 15 N recovered from the pot compartment alone ranged from 48 to 95%, suggesting that substantial pools of N remain in the soil. Results suggest that low 15 N uptake in the spring was associated with limited development of new root as a result of low spring soil temperatures. The lack of unsuberized roots in spring could be a key factor decreasing the effectiveness of early spring fertilization in the boreal forest

  13. Phenology and pest status of Agrotis segetum in a changing climate

    DEFF Research Database (Denmark)

    Esbjerg, Peter; Sigsgaard, Lene

    2014-01-01

    Insects are strongly dependent on climatic factors, especially temperature. For this reason, changes in insect phenology are predicted to be one of the many effects of climate change. We analysed the effect of climate warming on Agrotis segetum (Denis & Schiffermüller) in Denmark. Agrotis segetum...

  14. Remotely sensed vegetation phenology for describing and predicting the biomes of South Africa

    CSIR Research Space (South Africa)

    Wessels, Konrad J

    2011-02-01

    Full Text Available the distribution of the recently redefined biomes be predicted based on remotely sensed, phenology and productivity metrics? Ten-day, 1 km, NDVI AVHRR were analysed for the period 1985 to 2000. Phenological metrics such as start, end and length of the growing...

  15. Experimental Whole-Ecosystem Warming Alters Vegetation Phenology in a Boreal Spruce Bog: Initial Results from the SPRUCE Experiment

    Science.gov (United States)

    Richardson, A. D.

    2016-12-01

    Phenology is one of the most robust indicators of the biological impacts of global change. However, the response of phenology to future environmental conditions still remains highly uncertain because of the challenges associated with conducting realistic manipulative experiments. At the SPRUCE (Spruce and Peatland Responses Under Climatic and Environmental Change) experiment in the north-central United States, experimental temperature (0 to +9°C above ambient) and CO2 (ambient and elevated) treatments are being applied to mature, and intact, Picea mariana-Sphagnum spp. bog communities in their native habitat through the use of ten large (approximately 12 m wide, 10 m high) open-topped enclosures. We are tracking vegetation green-up and senescence in these chambers using repeat digital photography. Within each chamber, images are recorded every 30 minutes and uploaded to PhenoCam (http://phenocam.sr.unh.edu), where processed to yield quantitative measures of canopy color. These data are complemented by on-the-ground phenological data collected by human observers. Air warming treatments at SPRUCE began in August 2015. We observed a delay in senescence during autumn 2015 (2-5 days per degree of warming) and an advance in onset during spring 2016 (1-4 days per degree of warming). These patterns are robust across species and methods of phenological observation (i.e. camera-based vs. human observer). And, our results show very little evidence for photoperiod acting as a constraint on the response to warming. Early spring onset and consequent loss of frost hardiness in the warmest chambers proved disadvantageous when a brief period of extreme cold (to -12°C in the control chambers, to -3°C in the +9°C chambers) followed a month of generally mild weather. Foliage mortality for both Larix and Picea was immediate and severe, although both species subsequently re-flushed. These results give support for the hypothesis that warming may enhance the likelihood of spring frost

  16. Carbon exchange of a maize (Zea mays L.) crop: Influence of phenology

    NARCIS (Netherlands)

    Jans, W.W.P.; Jacobs, C.M.J.; Kruijt, B.; Elbers, J.A.; Barendse, S.C.A.; Moors, E.J.

    2010-01-01

    A study was carried out to quantify the carbon budget of a maize (Zea mays L.) crop followed by a rye cover crop in the Netherlands, and to determine the importance of the phenological phases and the fallow phase when modelling the carbon budget. Measurements were made of carbon fluxes, soil

  17. Synchronisms and correlations of spring phenology between apical and lateral meristems in two boreal conifers.

    Science.gov (United States)

    Antonucci, Serena; Rossi, Sergio; Deslauriers, Annie; Lombardi, Fabio; Marchetti, Marco; Tognetti, Roberto

    2015-10-01

    Phenological synchronisms between apical and lateral meristems could clarify some aspects related to the physiological relationships among the different organs of trees. This study correlated the phenological phases of bud development and xylem differentiation during spring 2010-14 in balsam fir (Abies balsamea Mill.) and black spruce [(Picea mariana Mill. (BSP)] of the Monts-Valin National Park (Quebec, Canada) by testing the hypothesis that bud development occurs after the reactivation of xylem growth. From May to September, we conducted weekly monitoring of xylem differentiation using microcores and bud development with direct observations on terminal branches. Synchronism between the beginning of bud development and xylem differentiation was found in both species with significant correlations between the phases of bud and xylem phenology. Degree-day sum was more appropriate in assessing the date of bud growth resumption, while thermal thresholds were more suitable for cambium phenology. Our results provide new knowledge on the dynamics of spring phenology and novel information on the synchronisms between two meristems in coniferous trees. The study demonstrates the importance of precisely defining the phases of bud development in order to correctly analyse the relationships with xylem phenology. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  18. 40 CFR 96.286 - Withdrawal from CAIR SO2 Trading Program.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Withdrawal from CAIR SO2 Trading... PROGRAMS (CONTINUED) NOX BUDGET TRADING PROGRAM AND CAIR NOX AND SO2 TRADING PROGRAMS FOR STATE IMPLEMENTATION PLANS CAIR SO2 Opt-in Units § 96.286 Withdrawal from CAIR SO2 Trading Program. Except as provided...

  19. Molecular phenology in plants: in natura systems biology for the comprehensive understanding of seasonal responses under natural environments.

    Science.gov (United States)

    Kudoh, Hiroshi

    2016-04-01

    Phenology refers to the study of seasonal schedules of organisms. Molecular phenology is defined here as the study of the seasonal patterns of organisms captured by molecular biology techniques. The history of molecular phenology is reviewed briefly in relation to advances in the quantification technology of gene expression. High-resolution molecular phenology (HMP) data have enabled us to study phenology with an approach of in natura systems biology. I review recent analyses of FLOWERING LOCUS C (FLC), a temperature-responsive repressor of flowering, along the six steps in the typical flow of in natura systems biology. The extensive studies of the regulation of FLC have made this example a successful case in which a comprehensive understanding of gene functions has been progressing. The FLC-mediated long-term memory of past temperatures creates time lags with other seasonal signals, such as photoperiod and short-term temperature. Major signals that control flowering time have a phase lag between them under natural conditions, and hypothetical phase lag calendars are proposed as mechanisms of season detection in plants. Transcriptomic HMP brings a novel strategy to the study of molecular phenology, because it provides a comprehensive representation of plant functions. I discuss future perspectives of molecular phenology from the standpoints of molecular biology, evolutionary biology and ecology. © 2015 The Author. New Phytologist © 2015 New Phytologist Trust.

  20. Uncovering a Nuisance Influence of a Phenological Trait of Plants Using a Nonlinear Structural Equation: Application to Days to Heading and Culm Length in Asian Cultivated Rice (Oryza Sativa L.).

    Science.gov (United States)

    Onogi, Akio; Ideta, Osamu; Yoshioka, Takuma; Ebana, Kaworu; Yamasaki, Masanori; Iwata, Hiroyoshi

    2016-01-01

    Phenological traits of plants, such as flowering time, are linked to growth phase transition. Thus, phenological traits often influence other traits through the modification of the duration of growth period. This influence is a nuisance in plant breeding because it hampers genetic evaluation of the influenced traits. Genetic effects on the influenced traits have two components, one that directly affects the traits and one that indirectly affects the traits via the phenological trait. These cannot be distinguished by phenotypic evaluation and ordinary linear regression models. Consequently, if a phenological trait is modified by introgression or editing of the responsible genes, the phenotypes of the influenced traits can change unexpectedly. To uncover the influence of the phenological trait and evaluate the direct genetic effects on the influenced traits, we developed a nonlinear structural equation (NSE) incorporating a nonlinear influence of the phenological trait. We applied the NSE to real data for cultivated rice (Oryza sativa L.): days to heading (DH) as a phenological trait and culm length (CL) as the influenced trait. This showed that CL of the cultivars that showed extremely early heading was shortened by the strong influence of DH. In a simulation study, it was shown that the NSE was able to infer the nonlinear influence and direct genetic effects with reasonable accuracy. However, the NSE failed to infer the linear influence in this study. When no influence was simulated, an ordinary bi-trait linear model (OLM) tended to infer the genetic effects more accurately. In such cases, however, by comparing the NSE and OLM using an information criterion, we could assess whether the nonlinear assumption of the NSE was appropriate for the data analyzed. This study demonstrates the usefulness of the NSE in revealing the phenotypic influence of phenological traits.

  1. Spring phenology at different altitudes is becoming more uniform under global warming in Europe.

    Science.gov (United States)

    Chen, Lei; Huang, Jian-Guo; Ma, Qianqian; Hänninen, Heikki; Rossi, Sergio; Piao, Shilong; Bergeron, Yves

    2018-04-26

    Under current global warming, high-elevation regions are expected to experience faster warming than low-elevation regions. However, due to the lack of studies based on long-term large-scale data, the relationship between tree spring phenology and the elevation-dependent warming is unclear. Using 652k records of leaf unfolding of five temperate tree species monitored during 1951-2013 in situ in Europe, we discovered a nonlinear trend in the altitudinal sensitivity (S A , shifted days per 100 m in altitude) in spring phenology. A delayed leaf unfolding (2.7 ± 0.6 days per decade) was observed at high elevations possibly due to decreased spring forcing between 1951 and 1980. The delayed leaf unfolding at high-elevation regions was companied by a simultaneous advancing of leaf unfolding at low elevations. These divergent trends contributed to a significant increase in the S A (0.36 ± 0.07 days 100/m per decade) during 1951-1980. Since 1980, the S A started to decline with a rate of -0.32 ± 0.07 days 100/m per decade, possibly due to reduced chilling at low elevations and improved efficiency of spring forcing in advancing the leaf unfolding at high elevations, the latter being caused by increased chilling. Our results suggest that due to both different temperature changes at the different altitudes, and the different tree responses to these changes, the tree phenology has shifted at different rates leading to a more uniform phenology at different altitudes during recent decades. © 2018 John Wiley & Sons Ltd.

  2. Seasonal phenology and species composition of the aphid fauna in a northern crop production area.

    Directory of Open Access Journals (Sweden)

    Sascha M Kirchner

    Full Text Available BACKGROUND: The species diversity of aphids and seasonal timing of their flight activity can have significant impacts on crop production, as aphid species differ in their ability to transmit plant viruses and flight timing affects virus epidemiology. The aim of the study was to characterise the species composition and phenology of aphid fauna in Finland in one of the northernmost intensive crop production areas of the world (latitude 64°. METHODOLOGY/PRINCIPAL FINDINGS: Flight activity was monitored in four growing seasons (2007-010 using yellow pan traps (YPTs placed in 4-8 seed potato fields and a Rothamsted suction trap. A total of 58,528 winged aphids were obtained, identified to 83 taxa based on morphology, and 34 species were additionally characterised by DNA barcoding. Seasonal flight activity patterns analysed based on YPT catch fell into three main phenology clusters. Monoecious taxa showed early or middle-season flight activity and belonged to species living on shrubs/trees or herbaceous plants, respectively. Heteroecious taxa occurred over the entire potato growing season (ca. 90 days. Abundance of aphids followed a clear 3-year cycle based on suction trap data covering a decade. Rhopalosiphum padi occurring at the end of the potato growing season was the most abundant species. The flight activity of Aphis fabae, the main vector of Potato virus Y in the region, and Aphis gossypii peaked in the beginning of potato growing season. CONCLUSIONS/SIGNIFICANCE: Detailed information was obtained on phenology of a large number aphid species, of which many are agriculturally important pests acting as vectors of plant viruses. Aphis gossypii is known as a pest in greenhouses, but our study shows that it occurs also in the field, even far in the north. The novel information on aphid phenology and ecology has wide implications for prospective pest management, particularly in light of climate change.

  3. Remote Sensing of Lake Ice Phenology in Alaska

    Science.gov (United States)

    Zhang, S.; Pavelsky, T.

    2017-12-01

    Lake ice phenology (e.g. ice break-up and freeze-up timing) in Alaska is potentially sensitive to climate change. However, there are few current lake ice records in this region, which hinders the comprehensive understanding of interactions between climate change and lake processes. To provide a lake ice database with over a comparatively long time period (2000 - 2017) and large spatial coverage (4000+ lakes) in Alaska, we have developed an algorithm to detect the timing of lake ice using Moderate Resolution Imaging Spectroradiometer (MODIS) satellite data. This approach generally consists of three major steps. First, we use a cloud mask (MOD09GA) to filter out satellite images with heavy cloud contamination. Second, daily MODIS reflectance values (MOD09GQ) of lake surface are used to extract ice pixels from water pixels. The ice status of lakes can be further identified based on the fraction of ice pixels. Third, to improve the accuracy of ice phenology detection, we execute post-processing quality control to reduce false ice events caused by outliers. We validate the proposed algorithm over six lakes by comparing with Landsat-based reference data. Validation results indicate a high correlation between the MODIS results and reference data, with normalized root mean square error (NRMSE) ranging from 1.7% to 4.6%. The time series of this lake ice product is then examined to analyze the spatial and temporal patterns of lake ice phenology.

  4. Global Lake and River Ice Phenology Database

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Global Lake and River Ice Phenology Database contains freeze and thaw/breakup dates as well as other descriptive ice cover data for 865 lakes and rivers in the...

  5. Phenological observations on shrubs to predict weed emergence in turf

    Science.gov (United States)

    Masin, Roberta; Zuin, Maria Clara; Zanin, Giuseppe

    2005-09-01

    Phenology is the study of periodic biological events. If we can find easily recognizable events in common plants that precede or coincide with weed emergences, these plants could be used as indicators. Weed seedlings are usually difficult to detect in turf, so the use of phenological indicators may provide an alternative approach to predict the time when a weed appears and consequently guide management decisions. A study was undertaken to determine whether the phenological phases of some plants could serve as reliable indicators of time of weed emergence in turf. The phenology of six shrubs (Crataegus monogyna Jacq., Forsythia viridissima Lindl., Sambucus nigra L., Syringa vulgaris L., Rosa multiflora Thunb., Ziziphus jujuba Miller) and a perennial herbaceous plant [Cynodon dactylon (L.) Pers.] was observed and the emergence dynamics of four annual weed species [Digitaria sanguinalis (L.) Scop., Eleusine indica (L.) Gaertner, Setaria glauca (L.) Beauv., Setaria viridis (L.) Beauv.] were studied from 1999 to 2004 in northern Italy. A correlation between certain events and weed emergence was verified. S. vulgaris and F. viridissima appear to be the best indicators: there is a quite close correspondence between the appearance of D. sanguinalis and lilac flowering and between the beginning of emergence of E. indica and the end of lilac flowering; emergences of S. glauca and S. viridis were predicted well in relation to the end of forsythia flowering. Base temperatures and starting dates required to calculate the heat unit sums to reach and complete the flowering phase of the indicators were calculated using two different methods and the resultant cumulative growing degree days were compared.

  6. Phenological changes of the most commonly sampled ground beetle (Coleoptera: Carabidae) species in the UK environmental change network

    Science.gov (United States)

    Pozsgai, Gabor; Baird, John; Littlewood, Nick A.; Pakeman, Robin J.; Young, Mark R.

    2018-03-01

    Despite the important roles ground beetles (Coleoptera: Carabidae) play in ecosystems, the highly valued ecosystem services they provide, and ample descriptive documentation of their phenology, the relative impact of various environmental factors on carabid phenology is not well studied. Using the long-term pitfall trap capture data from 12 terrestrial Environmental Change Network (ECN) sites from the UK, we examined how changing climate influenced the phenology of common carabids, and the role particular climate components had on phenological parameters. Of the 28 species included in the analyses, 19 showed earlier start of their activity. This advance was particularly pronounced in the spring, supporting the view that early phenophases have a greater tendency to change and these changes are more directly controlled by temperature than later ones. Autumn activity extended only a few cases, suggesting a photoperiod-driven start of hibernation. No association was found between life-history traits and the ability of species to change their phenology. Air temperatures between April and June were the most important factors determining the start of activity of each species, whilst late season precipitation hastened the cessation of activity. The balance between the advantages and disadvantages of changing phenology on various levels is likely to depend on the species and even on local environmental criteria. The substantially changing phenology of Carabidae may influence their function in ecosystems and the ecosystem services they provide.

  7. Fifteen-year phenological plant species and meteorological trends in central Italy

    Science.gov (United States)

    Orlandi, F.; Ruga, L.; Bonofiglio, T.; Romano, B.; Fornaciari, M.

    2014-07-01

    The present study was carried out in a phenological garden in central Italy that contains vegetative clones of shrubs and trees common to several international phenological gardens, such as Cornus sanguinea L.; Corylus avellana L.; Ligustrum vulgare L.; Robinia pseudoacacia L.; Salix acutifolia Willd. and Sambucus nigra L. Vegetative plant growth monitoring was carried out weekly using common international keys: BBCH07, bud break and leaf unfolding; BBCH19, young unfolded leaf; BBCH91, adult leaves; BBCH93, beginning of leaf colouring. The phenological dates thus obtained provide a model of the development for these different species in relation to the 15-year period of observation (1997-2011). From a meteorological point of view, temperature and precipitation trends were studied, with the highest anomalies during the study period recorded during the first 2 months of the year (January, February). There was relative invariance in the manifestation of the open bud phase and the contemporary advance of the young open leaves phase, particularly from 2006. This was accompanied by shortening of the leaf opening period, which appeared due to more rapid spring temperature increases over the last few years. The advance tendency of the BBCH91 phase showed adult leaves from the first summer weeks with fully green foliage monitored for a long time. Generally, the autumn leaf colouring phase tended to remain constant, with the exception of Salix acutifolia and Sambucus nigra, for which, on the other hand, the first leaf development phases appeared to be most likely influenced by the photoperiod.

  8. Forests and Phenology: Designing the Early Warning System to Understand Forest Change

    Science.gov (United States)

    Pierce, T.; Phillips, M. B.; Hargrove, W. W.; Dobson, G.; Hicks, J.; Hutchins, M.; Lichtenstein, K.

    2010-12-01

    Vegetative phenology is the study of plant development and changes with the seasons, such as the greening-up and browning-down of forests, and how these events are influenced by variations in climate. A National Phenology Data Set, based on Moderate Resolution Imaging Spectroradiometer satellite images covering 2002 through 2009, is now available from work by NASA, the US Forest Service, and Oak Ridge National Laboratory. This new data set provides an easily interpretable product useful for detecting changes to the landscape due to long-term factors such as climate change, as well as finding areas affected by short-term forest threats such as insects or disease. The Early Warning System (EWS) is a toolset being developed by the US Forest Service and the University of North Carolina-Asheville to support distribution and use of the National Phenology Data Set. The Early Warning System will help research scientists, US Forest Service personnel, forest and natural resources managers, decision makers, and the public in the use of phenology data to better understand unexpected change within our nation’s forests. These changes could have multiple natural sources such as insects, disease, or storm damage, or may be due to human-induced events, like thinning, harvest, forest conversion to agriculture, or residential and commercial use. The primary goal of the Early Warning System is to provide a seamless integration between monitoring, detection, early warning and prediction of these forest disturbances as observed through phenological data. The system consists of PC and web-based components that are structured to support four user stages of increasing knowledge and data sophistication. Building Literacy: This stage of the Early Warning System educates potential users about the system, why the system should be used, and the fundamentals about the data the system uses. The channels for this education include a website, interactive tutorials, pamphlets, and other technology

  9. Can Growing Degree Days and Photoperiod Predict Spring Wheat Phenology?

    Directory of Open Access Journals (Sweden)

    Muhammad A. Aslam

    2017-09-01

    Full Text Available Wheat (Triticum aestivum production in the rainfed area of Pothwar Pakistan is extremely vulnerable to high temperature. The expected increase in temperature due to global warming should result in shorter crop life cycles, and thus lower biomass and grain yield. Two major factors control wheat phenological development: temperature and photoperiod. To evaluate wheat development in response to these factors, we conducted experiments that created diverse temperature and daylength conditions by adjusting the crop sowing time. The study was conducted during 2013–14 and 2014–15 using five spring wheat genotypes, four sowing times, at three sites under rainfed management in Pothwar, Pakistan. Wheat crops experienced more cold days with early sowing, but later sowing dates resulted in higher temperatures, especially from anthesis to maturity. These treatments produced large differences in phenology, biomass production, and yield. To investigate whether growing degree days (GDD and photoperiod algorithms could predict wheat phenology under these changing conditions, GDD was calculated based on the method proposed by Wang and Engel while photoperiod followed the approach introduced in the APSIM crop growth model. GDD was calculated separately and in combination with photoperiod from germination to anthesis. For the grain filling period, only GDD was calculated. The observed and predicted number of days to anthesis and maturity were in good agreement, showing that the combination of GDD and photoperiod algorithms provided good estimations of spring wheat phenology under variable temperature and daylength conditions.

  10. Phenology and interspecific association of Forficula auricularia and Forficula pubescens in apple orchards

    Energy Technology Data Exchange (ETDEWEB)

    Lordan, J.; Alegre, S.; Moerkens, R.; Sarasúa, M.J.; Alins, G.

    2015-07-01

    The European earwig Forficula auricularia L. (Dermaptera: Forficulidae) has been widely studied as a key predator of pests in temperate regions, but its phenology and behavior may differ in warmer areas such as the Mediterranean. Here we assessed the phenology, aggregation, and interspecific association of F. auricularia and Forficula pubescens Gené, the only two species found consistently in both ground and canopy shelters in Mediterranean apple orchards. In addition to F. auricularia and F. pubescens, three other earwig species, namely Labidura riparia Pallas, Nala lividipes Dufour and Euborellia moesta Gené, were found occasionally. The mature stages of F. auricularia were observed mainly from May to November in tree shelters and immature ones from October to June in ground shelters. Adult individuals of F. pubescens were observed year-round and nymph instars were detected from April to June in ground as well as in tree shelters. The suitability of the current degree-days models for temperate regions was evaluated for the prediction of European earwig phenology in a Mediterranean climate. Regarding interspecific association, F. auricularia and F. pubescens co-occurred in canopies without apparent competition. This study provides useful weekly data about the phenology of the two earwig species throughout the year that can be used to detect the key periods during which to enhance their populations in pip fruit orchards or to control them in stone fruit crops. Furthermore, our results are of relevance for the development of new phenological models of earwigs in Mediterranean areas where nymphs hibernate, a feature that makes current models inaccurate. (Author)

  11. Phenology and interspecific association of Forficula auricularia and Forficula pubescens in apple orchards

    Directory of Open Access Journals (Sweden)

    Jaume Lordan

    2015-03-01

    Full Text Available The European earwig Forficula auricularia L. (Dermaptera: Forficulidae has been widely studied as a key predator of pests in temperate regions, but its phenology and behavior may differ in warmer areas such as the Mediterranean. Here we assessed the phenology, aggregation, and interspecific association of F. auricularia and Forficula pubescens Gené, the only two species found consistently in both ground and canopy shelters in Mediterranean apple orchards. In addition to F. auricularia and F. pubescens, three other earwig species, namely Labidura riparia Pallas, Nala lividipes Dufour and Euborellia moesta Gené, were found occasionally. The mature stages of F. auricularia were observed mainly from May to November in tree shelters and immature ones from October to June in ground shelters. Adult individuals of F. pubescens were observed year-round and nymph instars were detected from April to June in ground as well as in tree shelters. The suitability of the current degree-days models for temperate regions was evaluated for the prediction of European earwig phenology in a Mediterranean climate. Regarding interspecific association, F. auricularia and F. pubescens co-occurred in canopies without apparent competition. This study provides useful weekly data about the phenology of the two earwig species throughout the year that can be used to detect the key periods during which to enhance their populations in pip fruit orchards or to control them in stone fruit crops. Furthermore, our results are of relevance for the development of new phenological models of earwigs in Mediterranean areas where nymphs hibernate, a feature that makes current models inaccurate.

  12. Space-Derived Phenology, Retrieval and Use for Drought and Food Security Monitoring

    Science.gov (United States)

    Meroni, M.; Kayitakire, F.; Rembold, F.; Urbano, F.; Schucknecht, A.; LEO, O.

    2014-12-01

    Monitoring vegetation conditions is a critical activity for assessing food security in Africa. Rural populations relying on rain-fed agriculture and livestock grazing are highly exposed to large seasonal and inter-annual fluctuations in water availability. Monitoring the state, evolution, and productivity of vegetation, crops and pastures in particular, is important to conduct food emergency responses and plan for a long-term, resilient, development strategy in this area. The timing of onset, the duration, and the intensity of vegetation growth can be retrieved from space observations and used for food security monitoring to assess seasonal vegetation development and forecast the likely seasonal outcome when the season is ongoing. In this contribution we present a set of phenology-based remote sensing studies in support to food security analysis. Key phenological indicators are retrieved using a model-fit approach applied to SOPT-VEGETATION FAPAR time series. Remote-sensing phenology is first used to estimate i) the impact of the drought in the Horn of Africa, ii) crop yield in Tunisia and, iii) rangeland biomass production in Niger. Then the impact of the start and length of vegetation growing period on the total biomass production is assessed over the Sahel. Finally, a probabilistic approach using phenological information to forecast the occurrence of an end-of-season biomass production deficit is applied over the Sahel to map hot-spots of drought-related risk.

  13. Moisture-driven xylogenesis in Pinus ponderosa from a Mojave Desert mountain reveals high phenological plasticity.

    Science.gov (United States)

    Ziaco, Emanuele; Truettner, Charles; Biondi, Franco; Bullock, Sarah

    2018-04-01

    Future seasonal dynamics of wood formation in hyperarid environments are still unclear. Although temperature-driven extension of the growing season and increased forest productivity are expected for boreal and temperate biomes under global warming, a similar trend remains questionable in water-limited regions. We monitored cambial activity in a montane stand of ponderosa pine (Pinus ponderosa) from the Mojave Desert for 2 consecutive years (2015-2016) showing opposite-sign anomalies between warm- and cold-season precipitation. After the wet winter/spring of 2016, xylogenesis started 2 months earlier compared to 2015, characterized by abundant monsoonal (July-August) rainfall and hyperarid spring. Tree size did not influence the onset and ending of wood formation, highlighting a predominant climatic control over xylem phenological processes. Moisture conditions in the previous month, in particular soil water content and dew point, were the main drivers of cambial phenology. Latewood formation started roughly at the same time in both years; however, monsoonal precipitation triggered the formation of more false rings and density fluctuations in 2015. Because of uncertainties in future precipitation patterns simulated by global change models for the Southwestern United States, the dependency of P. ponderosa on seasonal moisture implies a greater conservation challenge than for species that respond mostly to temperature conditions. © 2018 John Wiley & Sons Ltd.

  14. Telecommunications Law Reform. 1980, 96th Congress, 2nd Session.

    Science.gov (United States)

    American Enterprise Inst. for Public Policy Research, Washington, DC.

    Arguments for and against the major legislative proposals pertaining to the reform of the nonbroadcast part of the nation's telecommunications law which are pending before the 96th Congress are analyzed. Background information is given regarding (1) the structure of the domestic telecommunications industry, (2) the regulatory authority which…

  15. Gp96 Peptide Antagonist gp96-II Confers Therapeutic Effects in Murine Intestinal Inflammation

    Directory of Open Access Journals (Sweden)

    Claudia A. Nold-Petry

    2017-12-01

    Full Text Available BackgroundThe expression of heat shock protein gp96 is strongly correlated with the degree of tissue inflammation in ulcerative colitis and Crohn’s disease, thereby leading us to the hypothesis that inhibition of expression via gp96-II peptide prevents intestinal inflammation.MethodsWe employed daily injections of gp96-II peptide in two murine models of intestinal inflammation, the first resulting from five daily injections of IL-12/IL-18, the second via a single intrarectal application of TNBS (2,4,6-trinitrobenzenesulfonic acid. We also assessed the effectiveness of gp96-II peptide in murine and human primary cell culture.ResultsIn the IL-12/IL-18 model, all gp96-II peptide-treated animals survived until day 5, whereas 80% of placebo-injected animals died. gp96-II peptide reduced IL-12/IL-18-induced plasma IFNγ by 89%, IL-1β by 63%, IL-6 by 43% and tumor necrosis factor (TNF by 70% compared to controls. The clinical assessment Disease Activity Index of intestinal inflammation severity was found to be significantly lower in the gp96-II-treated animals when compared to vehicle-injected mice. gp96-II peptide treatment in the TNBS model limited weight loss to 5% on day 7 compared with prednisolone treatment, whereas placebo-treated animals suffered a 20% weight loss. Histological disease severity was reduced equally by prednisolone (by 40% and gp96-II peptide (35%. Mice treated with either gp96-II peptide or prednisolone exhibited improved endoscopic scores compared with vehicle-treated control mice: vascularity, fibrin, granularity, and translucency scores were reduced by up to 49% by prednisolone and by up to 30% by gp96-II peptide. In vitro, gp96-II peptide reduced TLR2-, TLR4- and IL-12/IL-18-induced cytokine expression in murine splenocytes, with declines in constitutive IL-6 (54%, lipopolysaccharide-induced TNF (48%, IL-6 (81% and in Staphylococcus epidermidis-induced TNF (67% and IL-6 (81%, as well as IL-12/IL-18-induced IFNγ (75%. gp

  16. Phenology of Succession: Tracking the Recovery of Dryland Forests after Wildfire Events

    Science.gov (United States)

    Walker, J.; Brown, J. F.; Sankey, J. B.; Wallace, C.; Weltzin, J. F.

    2016-12-01

    The frequency, size, and intensity of forest wildfires in the U.S. Southwest have increased over the past 30 years. In the coming decades, burn effects and altered climatic conditions may increasingly divert vegetation recovery trajectories from pre-disturbance forested ecosystems toward grassland or shrub woodlands. Dryland herbaceous and woody vegetation species exhibit different phenological responses to precipitation, resulting in temporal and spatial shifts in landscape phenology patterns as the proportions of plant functional groups change over time. We have developed time series of Normalized Difference Vegetation Index (NDVI) and Soil-Adjusted Vegetation Index (SAVI) greenness measures derived from satellite imagery from 1984 - 2015 to record the phenological signatures that characterize recovery trajectories towards predominantly grassland, shrubland, or forest land cover types. We leveraged the data and computational resources available through the Google Earth Engine cloud-based platform to analyze time series of Landsat Thematic Mapper and Enhanced Thematic Mapper Plus imagery collected over maturing (40 years or more post-fire) dryland forests in Arizona and New Mexico, USA. These time series provided the basis for long-term comparisons of phenology behavior in different successional trajectories and enabled the assessment of climatic influence on the eventual outcomes.

  17. 9 CFR 96.2 - Prohibition of casings due to African swine fever and bovine spongiform encephalopathy.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Prohibition of casings due to African swine fever and bovine spongiform encephalopathy. 96.2 Section 96.2 Animals and Animal Products ANIMAL... spongiform encephalopathy. (a) Swine casings. The importation of swine casings that originated in or were...

  18. (JASR) Vol. 12, No. 2, 2012 DEPLETING FOREST RESOURCES

    African Journals Online (AJOL)

    HP

    deteriorating forest resources of Nigeria and its impact on climate change. Key words: Forest Resources, ... Mangrove Forest. Sub Total. 905,930 .... South America” Global Biogeographical Cycle vol 9, pp 329-350. Miller, K. R., Reid, W. V., ...

  19. Decadal declines in avian herbivore reproduction: density-dependent nutrition and phenological mismatch in the Arctic.

    Science.gov (United States)

    Ross, Megan V; Alisauskas, Ray T; Douglas, David C; Kellett, Dana K

    2017-07-01

    A full understanding of population dynamics depends not only on estimation of mechanistic contributions of recruitment and survival, but also knowledge about the ecological processes that drive each of these vital rates. The process of recruitment in particular may be protracted over several years, and can depend on numerous ecological complexities until sexually mature adulthood is attained. We addressed long-term declines (23 breeding seasons, 1992-2014) in the per capita production of young by both Ross's Geese (Chen rossii) and Lesser Snow Geese (Chen caerulescens caerulescens) nesting at Karrak Lake in Canada's central Arctic. During this period, there was a contemporaneous increase from 0.4 to 1.1 million adults nesting at this colony. We evaluated whether (1) density-dependent nutritional deficiencies of pre-breeding females or (2) phenological mismatch between peak gosling hatch and peak forage quality, inferred from NDVI on the brood-rearing areas, may have been behind decadal declines in the per capita production of goslings. We found that, in years when pre-breeding females arrived to the nesting grounds with diminished nutrient reserves, the proportional composition of young during brood-rearing was reduced for both species. Furthermore, increased mismatch between peak gosling hatch and peak forage quality contributed additively to further declines in gosling production, in addition to declines caused by delayed nesting with associated subsequent negative effects on clutch size and nest success. The degree of mismatch increased over the course of our study because of advanced vegetation phenology without a corresponding advance in Goose nesting phenology. Vegetation phenology was significantly earlier in years with warm surface air temperatures measured in spring (i.e., 25 May-30 June). We suggest that both increased phenological mismatch and reduced nutritional condition of arriving females were behind declines in population-level recruitment, leading

  20. International congress on forest decline research: State of knowledge and perspectives. Vol. 2. Proceedings

    International Nuclear Information System (INIS)

    Ulrich, B.

    1989-01-01

    In the two lecture volumes of the Proceedings of the International Congress on Forest Decline Research the papers are presented according to the topics of the plenary and poster sessions. The sessions had been devoted to the damage symptoms in forest decline, to the main stressors (atmosphere, climate, soil, biota), to the effects of the stressors (on rhizosphere, on decomposers, and on plants) (see vol. 1), to case studies (in Germany and abroad), to regional comparisons, to critical loads, and to silvicultural measures (see vol. 2). Additionally personal impressions about the forest decline phenomen in Germany and its causes and opinions about the perspective in regard to research needs, to silvicultural practices and to emission control are given. (orig./vhe)

  1. Ecological and methodological drivers of species’ distribution and phenology responses to climate change

    KAUST Repository

    Brown, Christopher J.

    2015-12-10

    Climate change is shifting species’ distribution and phenology. Ecological traits, such as mobility or reproductive mode, explain variation in observed rates of shift for some taxa. However, estimates of relationships between traits and climate responses could be influenced by how responses are measured. We compiled a global dataset of 651 published marine species’ responses to climate change, from 47 papers on distribution shifts and 32 papers on phenology change. We assessed the relative importance of two classes of predictors of the rate of change, ecological traits of the responding taxa and methodological approaches for quantifying biological responses. Methodological differences explained 22% of the variation in range shifts, more than the 7.8% of the variation explained by ecological traits. For phenology change, methodological approaches accounted for 4% of the variation in measurements, whereas 8% of the variation was explained by ecological traits. Our ability to predict responses from traits was hindered by poor representation of species from the tropics, where temperature isotherms are moving most rapidly. Thus, the mean rate of distribution change may be underestimated by this and other global syntheses. Our analyses indicate that methodological approaches should be explicitly considered when designing, analysing and comparing results among studies. To improve climate impact studies, we recommend that: (1) re-analyses of existing time-series state how the existing datasets may limit the inferences about possible climate responses; (2) qualitative comparisons of species’ responses across different studies be limited to studies with similar methodological approaches; (3) meta-analyses of climate responses include methodological attributes as covariates and; (4) that new time series be designed to include detection of early warnings of change or ecologically relevant change. Greater consideration of methodological attributes will improve the

  2. Citizen Science in Grand Teton National Park Reveals Phenological Response of Wildlife to Climate Change and Increases Public Involvement in Earth Science

    Science.gov (United States)

    Bloom, T. D. S.; Riginos, C.

    2017-12-01

    Around the world, phenology —or the timing of ecological events — is shifting as the climate warms. This can lead to a variety of consequences for individual species and for ecological communities as a whole, most notably through asynchronies that can develop between plants and animals that depend upon each other (e.g. nectar-consuming pollinators). Within the Greater Yellowstone Ecosystem (GYE) and Grand Teton National Park (GTNP), there is little understanding of how climate change is affecting plant and animal phenology, yet through detailed scientific and citizen science observation there is tremendous potential to further our knowledge of this topic and increase public awareness. Detailed historic data are rare, but in GTNP we have the opportunity to capitalize on phenology data gathered by Dr. Frank Craighead, Jr. in the 1970s, before significant warming had occurred. We have already gathered, digitized, and quality-controlled Craighead's observations of plant first flowering dates. First flowering date for 87% of a 72-species data set correlate significantly with spring temperatures in the 1970s, suggesting that these plants are now flowering earlier and will continue to flower earlier in the future. Our multi-year project has project has 3 primary goals: (1) initiate a citizen science project, Wildflower Watch GTNP, to train volunteer scientists to collect contemporary phenology data on these species (2) gather further historical records of plant phenology in the region, and (3) model continued phenological changes under future climate change scenarios using satellite derived climate data and on the ground observations. This project simultaneously increases public involvement in climate research, collaborates with the National Park Service to inform management strategies for at-risk species, and furthers scientific understanding of phenological response to climate change in the Rocky Mountains.

  3. The Arabidopsis MYB96 transcription factor plays a role in seed dormancy.

    Science.gov (United States)

    Lee, Hong Gil; Lee, Kyounghee; Seo, Pil Joon

    2015-03-01

    Seed dormancy facilitates to endure environmental disadvantages by confining embryonic growth until the seeds encounter favorable environmental conditions for germination. Abscisic acid (ABA) and gibberellic acid (GA) play a pivotal role in the determination of the seed dormancy state. ABA establishes seed dormancy, while GA triggers seed germination. Here, we demonstrate that MYB96 contributes to the fine-tuning of seed dormancy regulation through the coordination of ABA and GA metabolism. The MYB96-deficient myb96-1 seeds germinated earlier than wild-type seeds, whereas delayed germination was observed in the activation-tagging myb96-1D seeds. The differences in germination rate disappeared after stratification or after-ripening. The MYB96 transcription factor positively regulates ABA biosynthesis genes 9-CIS-EPOXYCAROTENOID DIOXYGENASE 2 (NCED2), NCED5, NCED6, and NCED9, and also affects GA biosynthetic genes GA3ox1 and GA20ox1. Notably, MYB96 directly binds to the promoters of NCED2 and NCED6, primarily modulating ABA biosynthesis, which subsequently influences GA metabolism. In agreement with this, hyperdormancy of myb96-1D seeds was recovered by an ABA biosynthesis inhibitor fluridone, while hypodormancy of myb96-1 seeds was suppressed by a GA biosynthesis inhibitor paclobutrazol (PAC). Taken together, the metabolic balance of ABA and GA underlies MYB96 control of primary seed dormancy.

  4. Divergent phenological response to hydroclimate variability in forested mountain watersheds.

    Science.gov (United States)

    Hwang, Taehee; Band, Lawrence E; Miniat, Chelcy F; Song, Conghe; Bolstad, Paul V; Vose, James M; Love, Jason P

    2014-08-01

    Mountain watersheds are primary sources of freshwater, carbon sequestration, and other ecosystem services. There is significant interest in the effects of climate change and variability on these processes over short to long time scales. Much of the impact of hydroclimate variability in forest ecosystems is manifested in vegetation dynamics in space and time. In steep terrain, leaf phenology responds to topoclimate in complex ways, and can produce specific and measurable shifts in landscape forest patterns. The onset of spring is usually delayed at a specific rate with increasing elevation (often called Hopkins' Law; Hopkins, 1918), reflecting the dominant controls of temperature on greenup timing. Contrary with greenup, leaf senescence shows inconsistent trends along elevation gradients. Here, we present mechanisms and an explanation for this variability and its significance for ecosystem patterns and services in response to climate. We use moderate-resolution imaging spectro-radiometer (MODIS) Normalized Difference Vegetation Index (NDVI) data to derive landscape-induced phenological patterns over topoclimate gradients in a humid temperate broadleaf forest in southern Appalachians. These phenological patterns are validated with different sets of field observations. Our data demonstrate that divergent behavior of leaf senescence with elevation is closely related to late growing season hydroclimate variability in temperature and water balance patterns. Specifically, a drier late growing season is associated with earlier leaf senescence at low elevation than at middle elevation. The effect of drought stress on vegetation senescence timing also leads to tighter coupling between growing season length and ecosystem water use estimated from observed precipitation and runoff generation. This study indicates increased late growing season drought may be leading to divergent ecosystem response between high and low elevation forests. Landscape-induced phenological patterns

  5. Modeling winter moth Operophtera brumata egg phenology

    NARCIS (Netherlands)

    Salis, Lucia; Lof, Marjolein; Asch, van Margriet; Visser, Marcel E.

    2016-01-01

    Understanding the relationship between an insect's developmental rate and temperature is crucial to forecast insect phenology under climate change. In the winter moth Operophtera brumata timing of egg-hatching has severe fitness consequences on growth and reproduction as egg-hatching has to match

  6. Phenology-based Spartina alterniflora mapping in coastal wetland of the Yangtze Estuary using time series of GaoFen satellite no. 1 wide field of view imagery

    Science.gov (United States)

    Ai, Jinquan; Gao, Wei; Gao, Zhiqiang; Shi, Runhe; Zhang, Chao

    2017-04-01

    Spartina alterniflora is an aggressive invasive plant species that replaces native species, changes the structure and function of the ecosystem across coastal wetlands in China, and is thus a major conservation concern. Mapping the spread of its invasion is a necessary first step for the implementation of effective ecological management strategies. The performance of a phenology-based approach for S. alterniflora mapping is explored in the coastal wetland of the Yangtze Estuary using a time series of GaoFen satellite no. 1 wide field of view camera (GF-1 WFV) imagery. First, a time series of the normalized difference vegetation index (NDVI) was constructed to evaluate the phenology of S. alterniflora. Two phenological stages (the senescence stage from November to mid-December and the green-up stage from late April to May) were determined as important for S. alterniflora detection in the study area based on NDVI temporal profiles, spectral reflectance curves of S. alterniflora and its coexistent species, and field surveys. Three phenology feature sets representing three major phenology-based detection strategies were then compared to map S. alterniflora: (1) the single-date imagery acquired within the optimal phenological window, (2) the multitemporal imagery, including four images from the two important phenological windows, and (3) the monthly NDVI time series imagery. Support vector machines and maximum likelihood classifiers were applied on each phenology feature set at different training sample sizes. For all phenology feature sets, the overall results were produced consistently with high mapping accuracies under sufficient training samples sizes, although significantly improved classification accuracies (10%) were obtained when the monthly NDVI time series imagery was employed. The optimal single-date imagery had the lowest accuracies of all detection strategies. The multitemporal analysis demonstrated little reduction in the overall accuracy compared with the

  7. Potential evapotranspiration and its impact on autumn phenological phases of selected plants

    International Nuclear Information System (INIS)

    Palesova, I.

    2011-01-01

    The work deals with the assessment of the impact of water balance on the timing of phenological phases at two locations (Hips and Bukovina), on the selected tree species (hazel (Corylus avellana L.), hornbeam (Carpinus betulus L.), sessile oak (Quercus petraea, Liebl.)). Phenological observations have been held since 2007, and together with measurements of meteorological parameters allow us to evaluate the microclimate in the stands in detail. (authors)

  8. A meta-analysis of cambium phenology and growth: linear and non-linear patterns in conifers of the northern hemisphere

    OpenAIRE

    Rossi, Sergio; Anfodillo, Tommaso; Čufar, Katarina; Cuny, Henri E.; Deslauriers, Annie; Fonti, Patrick; Frank, David; Gričar, Jožica; Gruber, Andreas; King, Gregory M.; Krause, Cornelia; Morin, Hubert; Oberhuber, Walter; Prislan, Peter; Rathgeber, Cyrille B. K.

    2017-01-01

    Background and Aims Ongoing global warming has been implicated in shifting phenological patterns such as the timing and duration of the growing season across a wide variety of ecosystems. Linear models are routinely used to extrapolate these observed shifts in phenology into the future and to estimate changes in associated ecosystem properties such as net primary productivity. Yet, in nature, linear relationships may be special cases. Biological processes frequently follow more complex, non-l...

  9. Intercropping with shrub species that display a 'steady-state' flowering phenology as a strategy for biodiversity conservation in tropical agroecosystems.

    Science.gov (United States)

    Peters, Valerie E

    2014-01-01

    Animal species in the Neotropics have evolved under a lower spatiotemporal patchiness of food resources compared to the other tropical regions. Although plant species with a steady-state flowering/fruiting phenology are rare, they provide predictable food resources and therefore may play a pivotal role in animal community structure and diversity. I experimentally planted a supplemental patch of a shrub species with a steady-state flowering/fruiting phenology, Hamelia patens Jacq., into coffee agroforests to evaluate the contribution of this unique phenology to the structure and diversity of the flower-visiting community. After accounting for the higher abundance of captured animals in the coffee agroforests with the supplemental floral resources, species richness was 21% higher overall in the flower-visiting community in these agroforests compared to control agroforests. Coffee agroforests with the steady-state supplemental floral patch also had 31% more butterfly species, 29% more hummingbird species, 65% more wasps and 85% more bees than control coffee agroforests. The experimental treatment, together with elevation, explained 57% of the variation in community structure of the flower-visiting community. The identification of plant species that can support a high number of animal species, including important ecosystem service providers, is becoming increasingly important for restoration and conservation applications. Throughout the Neotropics plant species with a steady-state flowering/fruiting phenology can be found in all aseasonal forests and thus could be widely tested and suitable species used throughout the tropics to manage for biodiversity and potentially ecosystem services involving beneficial arthropods.

  10. Intercropping with shrub species that display a 'steady-state' flowering phenology as a strategy for biodiversity conservation in tropical agroecosystems.

    Directory of Open Access Journals (Sweden)

    Valerie E Peters

    Full Text Available Animal species in the Neotropics have evolved under a lower spatiotemporal patchiness of food resources compared to the other tropical regions. Although plant species with a steady-state flowering/fruiting phenology are rare, they provide predictable food resources and therefore may play a pivotal role in animal community structure and diversity. I experimentally planted a supplemental patch of a shrub species with a steady-state flowering/fruiting phenology, Hamelia patens Jacq., into coffee agroforests to evaluate the contribution of this unique phenology to the structure and diversity of the flower-visiting community. After accounting for the higher abundance of captured animals in the coffee agroforests with the supplemental floral resources, species richness was 21% higher overall in the flower-visiting community in these agroforests compared to control agroforests. Coffee agroforests with the steady-state supplemental floral patch also had 31% more butterfly species, 29% more hummingbird species, 65% more wasps and 85% more bees than control coffee agroforests. The experimental treatment, together with elevation, explained 57% of the variation in community structure of the flower-visiting community. The identification of plant species that can support a high number of animal species, including important ecosystem service providers, is becoming increasingly important for restoration and conservation applications. Throughout the Neotropics plant species with a steady-state flowering/fruiting phenology can be found in all aseasonal forests and thus could be widely tested and suitable species used throughout the tropics to manage for biodiversity and potentially ecosystem services involving beneficial arthropods.

  11. Morphological and Phenological characterization of Mediterranean species in Northern Sardinia, Italy

    Science.gov (United States)

    Piga, Alessandra; Duce, Pierpaolo; Cesaraccio, Carla

    2016-04-01

    Monitoring of vegetation, in particular methodologies for phenological and biometrical monitoring, are widely implied for climate change studies and their importance for understanding the consequences of global environmental change on vegetation is highlighted in the most recent IPCC reports. It is very likely that, during the next decades, the Mediterranean Regions will cope to the very negative effects of climatic changes. Consequently, due to the climate change impacts and the effects of anthropogenic pressures upon natural resources, these regions are among the most vulnerable ecosystems to the effects of climate change. Therefore, appears to be of crucial importance to better understand the physiological strategies for cope to climate change adaptation for the Mediterranean maquis shrub species which are key information for developing adaptation strategies guidelines. In this work, the biological and reproductive cycle of some Mediterranean species growing in an experimental area located within a nature reserve in the peninsula of Capo Caccia, north-west Sardinia, Italy, was investigated for a period of two years. In particular, the research was focused on: (1) the study of the development processes and the description of phenological phases, and (2) the analysis of the growth processes performed through biometric and floristic composition measurements. Specific BBCH scales for each species were developed. Shoot growth and floristic composition analysis did not show a clear trend in the response of the different species to climatic manipulations but a downward trend in the number of species. The results obtained in this study add useful information on the phenological cycle and growth of the Mediterranean species, improving the knowledge on the mechanisms of adaptation to adverse environmental conditions of these species

  12. Changes in vegetation phenology are not reflected in atmospheric CO2 and 13 C/12 C seasonality.

    Science.gov (United States)

    Gonsamo, Alemu; D'Odorico, Petra; Chen, Jing M; Wu, Chaoyang; Buchmann, Nina

    2017-10-01

    Northern terrestrial ecosystems have shown global warming-induced advances in start, delays in end, and thus increased lengths of growing season and gross photosynthesis in recent decades. The tradeoffs between seasonal dynamics of two opposing fluxes, CO 2 uptake through photosynthesis and release through respiration, determine the influence of the terrestrial ecosystem on the atmospheric CO 2 and 13 C/ 12 C seasonality. Here, we use four CO 2 observation stations in the Northern Hemisphere, namely Alert, La Jolla, Point Barrow, and Mauna Loa Observatory, to determine how changes in vegetation productivity and phenology, respiration, and air temperature affect both the atmospheric CO 2 and 13 C/ 12 C seasonality. Since the 1960s, the only significant long-term trend of CO 2 and 13 C/ 12 C seasonality was observed at the northern most station, Alert, where the spring CO 2 drawdown dates advanced by 0.65 ± 0.55 days yr -1 , contributing to a nonsignificant increase in length of the CO 2 uptake period (0.74 ± 0.67 days yr -1 ). For Point Barrow station, vegetation phenology changes in well-watered ecosystems such as the Canadian and western Siberian wetlands contributed the most to 13 C/ 12 C seasonality while the CO 2 seasonality was primarily linked to nontree vegetation. Our results indicate significant increase in the Northern Hemisphere soil respiration. This means, increased respiration of 13 C depleted plant materials cancels out the 12 C gain from enhanced vegetation activities during the start and end of growing season. These findings suggest therefore that parallel warming-induced increases both in photosynthesis and respiration contribute to the long-term stability of CO 2 and 13 C/ 12 C seasonality under changing climate and vegetation activity. The summer photosynthesis and the soil respiration in the dormant seasons have become more vigorous which lead to increased peak-to-through CO 2 amplitude. As the relative magnitude of the increased

  13. Post-fire phenological behavior and breeding biology of the Spiranthera odoratissima A. St.-Hil. (Rutaceae

    Directory of Open Access Journals (Sweden)

    Mirley Luciene dos Santos

    2008-03-01

    Full Text Available The phenological behavior of species in response to cerrado stricken by fire is little known. A phenological and reproductive biological study of Spiranthera odoratissima was carried out in an anthropized area of cerrado sensu stricto affected by fire in Goiânia County, Goiás, Brazil. Phenolocial observations indicated that the individuals bloomed in synchrony three months after the fire. The phenological rhythms were associated with the seasonal pluviometric effects, a characteristic pattern of shrublet species of the cerrado. Theflowers are white with a sweet odor and are grouped in panicle inflorescences. The blossoming occurs during dusk and begins at around 16h. It offers pollen and nectar to its visitors. The species produces 32.8μl (± 3.4 of nectar with an average concentration of 16.4% (± 0.43 in equivalents of sucrose. The pollination system (phalenophily was proposed based on an analysis of the fl ower’s characteristics. Observed visitors were bees (Apis mellifera Linnaeus, flies, wasps, ants and beetles, but due to the inflorescence behavior, they were considered to be merely resource thieves. It was observed that Trigona spinipes Fabr. can act as a secondary pollinator during the pilling of pollen. The results of manual pollination and the incompatibility index (ISI indicate that the species is xenogamous and self-compatible.

  14. Maize seed coatings and seedling sprayings with chitosan and hydrogen peroxide:their influence on some phenological and biochemical behaviors

    Institute of Scientific and Technical Information of China (English)

    Eva-Guadalupe LIZ(A)RRAGA-PAUL(I)N; Susana-Patricia MIRANDA-CASTRO; Ernesto MORENO-MART(I)NEZ; Alma-Virginia LARA-SAGAH(O)N; Irineo TORRES-PACHECO

    2013-01-01

    Objective:To evaluate the effect of chitosan(CH)and hydrogen peroxide(H2O2)seed coatings and seedling sprinklings on two different maize varieties by measuring their phenology,the H2O2 presence,the catalase (CAT)activity,and the protein quantity.Methods:Seven groups of ten seeds for each maize variety were treated with CH(2%(20 g/L)and 0.2%(2 g/L))or H2O2(8 mmol/L)by coating,sprinkling,or both.Germination and seedling growth were measured.One month after germination,the presence of H2O2 in seedlings in the coated seed treatments was evaluated.Protein content and CAT activity were determined under all treatments.Results:H2O2 seed coating enhanced the germination rate and increased seedling and stem length in the quality protein maize(QPM)variety.Seedlings had a higher emergence velocity under this treatment in both varieties.CH and H2O2 sprinklings did not have an effect on seedling phenology.Exogenous application of H2O2 promoted an increase of endogenous H2O2.CH and H2O2 seedling sprinkling increased the protein content in both maize varieties,while there was no significant effect on the CAT activity of treated seeds and seedlings.Conclusions:CH and H2O2 enhance some phenological and biochemical features of maize depending on their method of application.

  15. Vegetative and reproductive phenological patterns in coastal dunes in S Spain

    Directory of Open Access Journals (Sweden)

    Rodríguez-Gallego, Carmen

    2015-06-01

    Full Text Available The phenology of Mediterranean plant species has been extensively studied in different types of ecosystems. However, very little research has been conducted on dune ecosystems. The aim of this research is the phenological characterization and comparison among phenological patterns in three coastal dunes areas in S Spain. For this purpose, we apply the methodology proposed by Orshan (1989 and NLPCA phenological indexes. Our results show that seasonality of species from coastal dunes in S Spain follows the pattern observed in dry and warm Mediterranean ecosystems. The maximum phenological activity occurs for a period of 7-9 months, mainly in spring and late winter, whereas summer is clearly the most inactive period of the year. Vegetative phenophases predominate over the reproductive. Flowering is mainly early (March-May, but it may extend to summer. Flowering duration has been identified as a key index in the differentiation among coastal dunes with different conditions of Mediterranean macroclimate, whereas the importance of the phenophase sequence index has been shown in order to discriminate sectors within dunes. Using the NLPCA analysis based on phenological indexes, four phenological groups of species have been determined. From a conservation perspective, the identification of these groups point out the utility of developing different strategies of management according to the high diversity of eco- and phenomorphological variability that characterize the coastal dunes.La fenología de las especies vegetales mediterráneas ha sido ampliamente estudiada en diferentes tipos de ecosistemas. Sin embargo, es poco lo que se conoce sobre fenología de dunas costeras. El objetivo del presente trabajo es la caracterización y comparación de patrones fenológicos en tres áreas de dunas costeras del Sur de España. Para ello, se ha aplicado la metodología propuesta por Orshan (1989 así como índices fenológicos NLPCA. Nuestros resultados muestran

  16. Improvement of Alternative Crop Phenology Detection Algorithms using MODIS NDVI Time Series Data in US Corn Belt Region

    Science.gov (United States)

    Lee, J.; Kang, S.; Seo, B.; Lee, K.

    2017-12-01

    Predicting crop phenology is important for understanding of crop development and growth processes and improving the accuracy of crop model. Remote sensing offers a feasible tool for monitoring spatio-temporal patterns of crop phenology in region and continental scales. Various methods have been developed to determine the timing of crop phenological stages using spectral vegetation indices (i.e. NDVI and EVI) derived from satellite data. In our study, it was compared four alternative detection methods to identify crop phenological stages (i.e. the emergence and harvesting date) using high quality NDVI time series data derived from MODIS. Also we investigated factors associated with crop development rate. Temperature and photoperiod are the two main factors which would influence the crop's growth pattern expressed in the VI data. Only the effect of temperature on crop development rate was considered. The temperature response function in the Wang-Engel (WE) model was used, which simulates crop development using nonlinear models with response functions that range from zero to one. It has attempted at the state level over 14 years (2003-2016) in Iowa and Illinois state of USA, where the estimated phenology date by using four methods for both corn and soybean. Weekly crop progress reports produced by the USDA NASS were used to validate phenology detection algorithms effected by temperature. All methods showed substantial uncertainty but the threshold method showed relatively better agreement with the State-level data for soybean phenology.

  17. 49. Meeting of the Chemical Societies: Proceedings of the contributions. Vol. 2; 49. Zjazd chemickych spolocnosti: Zbornik prispevkov, 2. diel.

    Energy Technology Data Exchange (ETDEWEB)

    Uher, M [Slovak Technical Univ., Bratislava (Slovakia). Dept. of Organic Chemistry; Hlouskova, Z [Ceska Chemicka Spolecnost, Prague (Czech Republic); Benes, P [Czech Technical University, Prague (Czech Republic). Dept. Nuclear. Chemistry; Carsky, J [Comenius Univ., Bratislava (Slovakia). Inst. of Medicinal Chemistry, Biochemistry and Clinical Biochemistry; Chodak, I [Slovak Academy of Sciences, Bratislava (Slovakia). Polymer Inst.; Kuruc, J [Comenius Univ., Bratislava (Slovakia). Dept. of Nuclear Chemistry; Romancik, V [Ministry of Environment of the Slovak Republic, Bratislava (Slovakia); [Stasko, A. Slovak Technical Univ., Bratislava (Slovakia). Dept. of Physical Chemistry

    1996-12-31

    The publication has been set up as a abstracts of the meeting dealing with chemical problems. The book (Vol. 2) consists of the sections: (C) Physical chemistry; (D) History of the chemistry; (E) Food chemistry and technology; (D) Environmental chemistry; (E) Nuclear chemistry and radioecology; (H) Synthetic polymers.

  18. Genetic variation in flowering phenology and avoidance of seed predation in native populations of Ulex europaeus.

    Science.gov (United States)

    Atlan, A; Barat, M; Legionnet, A S; Parize, L; Tarayre, M

    2010-02-01

    The genetic variation in flowering phenology may be an important component of a species' capacity to colonize new environments. In native populations of the invasive species Ulex europaeus, flowering phenology has been shown to be bimodal and related to seed predation. The aim of the present study was to determine if this bimodality has a genetic basis, and to investigate whether the polymorphism in flowering phenology is genetically linked to seed predation, pod production and growth patterns. We set up an experiment raising maternal families in a common garden. Based on mixed analyses of variance and correlations among maternal family means, we found genetic differences between the two main flowering types and confirmed that they reduced seed predation in two different ways: escape in time or predator satiation. We suggest that this polymorphism in strategy may facilitate maintain high genetic diversity for flowering phenology and related life-history traits in native populations of this species, hence providing high evolutionary potential for these traits in invaded areas.

  19. Satellite derived forest phenology and its relation with nephropathia epidemica in Belgium.

    Science.gov (United States)

    Barrios, José Miguel; Verstraeten, Willem W; Maes, Piet; Clement, Jan; Aerts, Jean-Marie; Haredasht, Sara Amirpour; Wambacq, Julie; Lagrou, Katrien; Ducoffre, Geneviève; Van Ranst, Marc; Berckmans, Daniel; Coppin, Pol

    2010-06-01

    The connection between nephropathia epidemica (NE) and vegetation dynamics has been emphasized in recent studies. Changing climate has been suggested as a triggering factor of recently observed epidemiologic peaks in reported NE cases. We have investigated whether there is a connection between the NE occurrence pattern in Belgium and specific trends in remotely sensed phenology parameters of broad-leaved forests. The analysis of time series of the MODIS Enhanced Vegetation Index revealed that changes in forest phenology, considered in literature as an effect of climate change, may affect the mechanics of NE transmission.

  20. Long-Term Phenological Shifts in Raptor Migration and Climate

    Science.gov (United States)

    Jaffré, Mikaël; Beaugrand, Grégory; Goberville, Éric; Jiguet, Frédéric; Kjellén, Nils; Troost, Gerard; Dubois, Philippe J.; Leprêtre, Alain; Luczak, Christophe

    2013-01-01

    Climate change is having a discernible effect on many biological and ecological processes. Among observed changes, modifications in bird phenology have been widely documented. However, most studies have interpreted phenological shifts as gradual biological adjustments in response to the alteration of the thermal regime. Here we analysed a long-term dataset (1980-2010) of short-distance migratory raptors in five European regions. We revealed that the responses of these birds to climate-induced changes in autumn temperatures are abrupt and synchronous at a continental scale. We found that when the temperatures increased, birds delayed their mean passage date of autumn migration. Such delay, in addition to an earlier spring migration, suggests that a significant warming may induce an extension of the breeding-area residence time of migratory raptors, which may eventually lead to residency. PMID:24223888

  1. Long-term phenological shifts in raptor migration and climate.

    Directory of Open Access Journals (Sweden)

    Mikaël Jaffré

    Full Text Available Climate change is having a discernible effect on many biological and ecological processes. Among observed changes, modifications in bird phenology have been widely documented. However, most studies have interpreted phenological shifts as gradual biological adjustments in response to the alteration of the thermal regime. Here we analysed a long-term dataset (1980-2010 of short-distance migratory raptors in five European regions. We revealed that the responses of these birds to climate-induced changes in autumn temperatures are abrupt and synchronous at a continental scale. We found that when the temperatures increased, birds delayed their mean passage date of autumn migration. Such delay, in addition to an earlier spring migration, suggests that a significant warming may induce an extension of the breeding-area residence time of migratory raptors, which may eventually lead to residency.

  2. Responses of phenological and physiological stages of spring ...

    African Journals Online (AJOL)

    In order to investigate impact of complementary irrigation on phenological stages, chlorophyll content, radiation absorption and extinction coefficient, as well as some aspects concerning the yield of spring safflower, a split-plot experiment based on randomized complete block design with three replication was conducted at ...

  3. Ecophysiological and phenological strategies in seasonally-dry ecosystems: an ecohydrological approach

    Science.gov (United States)

    Vico, Giulia; Manzoni, Stefano; Thompson, Sally; Molini, Annalisa; Porporato, Amilcare

    2015-04-01

    Seasonally-dry climates are particularly challenging for vegetation, as they are characterized by prolonged dry periods and often marked inter-annual variability. During the dry season plants face predictable physiological stress due to lack of water, whereas the inter-annual variability in rainfall timing and amounts requires plants to develop flexible adaptation strategies. The variety of strategies observed across seasonally-dry (Mediterranean and tropical) ecosystems is indeed wide - ranging from near-isohydric species that adjust stomatal conductance to avoid drought, to anisohydric species that maintain gas exchange during the dry season. A suite of phenological strategies are hypothesized to be associated to ecophysiological strategies. Here we synthetize current knowledge on ecophysiological and phenological adaptations through a comprehensive ecohydrological model linking a soil water balance to a vegetation carbon balance. Climatic regimes are found to select for different phenological strategies that maximize the long-term plant carbon uptake. Inter-annual variability of the duration of the wet season allows coexistence of different drought-deciduous strategies. In contrast, short dry seasons or access to groundwater favour evergreen species. Climatic changes causing more intermittent rainfall and/or shorter wet seasons are predicted to favour drought-deciduous species with opportunistic water use.

  4. Reproductivity and phenology of argan (argania spinosa (L.) skeels) a rare tree endemic to the west of algeria

    International Nuclear Information System (INIS)

    Benaouf, Z.; Arabi, Z.; Miloudi, A.; Souidi, Z.

    2015-01-01

    Argania spinosa in its ecological interest is threefold: forest, forage and fruit (oil production). The regeneration of the argan tree, it is important to know the phenology of this species. The study of phenology helps to know precisely the periods of activity of vegetation for productivity measures (Embryogenesis of the pollen grain, pollen deposition, pollen adhesion, fluorescence microscopy of pollen tube growth and Pollen grain size). Our results on the study of the phenology of two taxa of Argania spinosa (Mascara taxa and Mostaganem taxa), Regarding the phenological behavior of the argan under the effect of environmental conditions, we can mention that some argan trees (of Oggaz and one of Stidia) are early trees bloom twice a year in October and in spring, the author trees are late trees manifest activity during periods of the year. Begin to bloom from February until spring, this period is characterized by the breakdown of flower buds and the appearance of flowers on the twigs of the previous year and those of the current year; the fall of their ripe fruit takes place in Jun of the following year. Argan trees wore two generations of fruit, fruit knotted this season and last season tied fruit maturing. The length of the cycle is detected 9 and 16 months, we believe that a time synchronization in the evolution of physiological behavior argan trees of the two stations with 90 percentage. (author)

  5. PHENOLOGICAL CHARACTERISTICS OF GENOTYPES FROM CATTLEY GUAVA AND GUAVA TREES SUBMITTED TO FRUCTIFICATION PRUNING

    Directory of Open Access Journals (Sweden)

    CINTIA APARECIDA BREMENKAMP

    Full Text Available ABSTRACT Psidium cattleianum Sabine is a species from the Myrtaceae family that serves as an option for the native fruits cultivation, besides being considered a source of resistance to the Meloidogyne enterolobii nematode. Although cattley guava trees from this species produce flower buds in young branches, there are no reports of response to fructification pruning or phenological synchronism with the guava tree. The objective of this paper was the comparative evaluation of the genotype response of strawberry guava trees and guava cultivars to fructification pruning, thus, describing the phenology of both species under the same cultivation conditions. The experiment was conducted under an entirely randomized outline, in 7x2 factorial scheme, being evaluated seven genotypes (three from strawberry guava and four from guava trees, and with pruning performed in two seasons (May 2012 and March 2013, with three repetitions. Fructification pruning was executed by a lopping on all mature branches, from the last growth flow in the woody branch region. Were evaluated budding characteristics and fruit harvesting, as well as number of days from pruning to the observation of the phenological event. Cattley guava tree pruning stimulated fructification of all three genotypes after pruning done on May and two genotypes after the March’s pruning. There has been a sync between the guava cultivars’ flowering and both strawberry guava trees genotypes, when those were pruned on May.

  6. Multiple phenological responses to climate change among 42 plant species in Xi'an, China.

    Science.gov (United States)

    Dai, Junhu; Wang, Huanjiong; Ge, Quansheng

    2013-09-01

    Phenological data of 42 woody plants in a temperate deciduous forest from the Chinese Phenological Observation Network (CPON) and the corresponding meteorological data from 1963 to 2011 in Xi'an, Shaanxi Province, China were collected and analyzed. The first leaf date (FLD), leaf coloring date (LCD) and first flower date (FFD) are revealed as strong biological signals of climatic change. The FLD, LCD and FFD of most species are sensitive to average temperature during a certain period before phenophase onset. Regional precipitation also has a significant impact on phenophases of about half of the species investigated. Affected by climate change, the FLD and FFD of these species have advanced by 5.54 days and 10.20 days on average during 2003-2011 compared with the period 1963-1996, respectively. Meanwhile, the LCD has delayed by 10.59 days, and growing season length has extended 16.13 days. Diverse responses of phenology commonly exist among different species and functional groups during the study period. Especially for FFD, the deviations between the above two periods ranged from -20.68 to -2.79 days; biotic pollination species showed a significantly greater advance than abiotic pollination species. These results were conducive to the understanding of possible changes in both the structure of plant communities and interspecific relationships in the context of climate change.

  7. Phenology of two Ficus species in seasonal semi-deciduous forest in Southern Brazil

    Directory of Open Access Journals (Sweden)

    E. Bianchini

    Full Text Available Abstract We analyzed the phenology of Ficus adhatodifolia Schott ex Spreng. (23 fig tree and F. eximia Schott (12 fig tree for 74 months in a remnant of seasonal semi-deciduous forest (23°27’S and 51°15’W, Southern Brazil and discussed their importance to frugivorous. Leaf drop, leaf flush, syconia production and dispersal were recorded. These phenophases occurred year-round, but seasonal peaks were recorded in both leaf phenophases for F. eximia and leaf flushing for F. adhatodifolia. Climatic variables analyzed were positively correlated with reproductive phenophases of F. adhatodifolia and negatively correlated with the vegetative phenophases of F. eximia. In despite of environmental seasonality, little seasonality in the phenology of two species was observed, especially in the reproductive phenology. Both species were important to frugivorous, but F. adhatodifolia can play a relevant role in the remnant.

  8. Complex responses of spring alpine vegetation phenology to snow cover dynamics over the Tibetan Plateau, China.

    Science.gov (United States)

    Wang, Siyuan; Wang, Xiaoyue; Chen, Guangsheng; Yang, Qichun; Wang, Bin; Ma, Yuanxu; Shen, Ming

    2017-09-01

    Snow cover dynamics are considered to play a key role on spring phenological shifts in the high-latitude, so investigating responses of spring phenology to snow cover dynamics is becoming an increasingly important way to identify and predict global ecosystem dynamics. In this study, we quantified the temporal trends and spatial variations of spring phenology and snow cover across the Tibetan Plateau by calibrating and analyzing time series of the NOAA AVHRR-derived normalized difference vegetation index (NDVI) during 1983-2012. We also examined how snow cover dynamics affect the spatio-temporal pattern of spring alpine vegetation phenology over the plateau. Our results indicated that 52.21% of the plateau experienced a significant advancing trend in the beginning of vegetation growing season (BGS) and 34.30% exhibited a delaying trend. Accordingly, the snow cover duration days (SCD) and snow cover melt date (SCM) showed similar patterns with a decreasing trend in the west and an increasing trend in the southeast, but the start date of snow cover (SCS) showed an opposite pattern. Meanwhile, the spatial patterns of the BGS, SCD, SCS and SCM varied in accordance with the gradients of temperature, precipitation and topography across the plateau. The response relationship of spring phenology to snow cover dynamics varied within different climate, terrain and alpine plant community zones, and the spatio-temporal response patterns were primarily controlled by the long-term local heat-water conditions and topographic conditions. Moreover, temperature and precipitation played a profound impact on diverse responses of spring phenology to snow cover dynamics. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. USA National Phenology Network’s volunteer-contributed observations yield predictive models of phenological transitions

    Science.gov (United States)

    Crimmins, Theresa M.; Crimmins, Michael A.; Gerst, Katherine L.; Rosemartin, Alyssa H.; Weltzin, Jake

    2017-01-01

    In support of science and society, the USA National Phenology Network (USA-NPN) maintains a rapidly growing, continental-scale, species-rich dataset of plant and animal phenology observations that with over 10 million records is the largest such database in the United States. Contributed voluntarily by professional and citizen scientists, these opportunistically collected observations are characterized by spatial clustering, inconsistent spatial and temporal sampling, and short temporal depth. We explore the potential for developing models of phenophase transitions suitable for use at the continental scale, which could be applied to a wide range of resource management contexts. We constructed predictive models of the onset of breaking leaf buds, leaves, open flowers, and ripe fruits – phenophases that are the most abundant in the database and also relevant to management applications – for all species with available data, regardless of plant growth habit, location, geographic extent, or temporal depth of the observations. We implemented a very basic model formulation - thermal time models with a fixed start date. Sufficient data were available to construct 107 individual species × phenophase models. Of these, fifteen models (14%) met our criteria for model fit and error and were suitable for use across the majority of the species’ geographic ranges. These findings indicate that the USA-NPN dataset holds promise for further and more refined modeling efforts. Further, the candidate models that emerged could be used to produce real-time and short-term forecast maps of the timing of such transitions to directly support natural resource management.

  10. Mapping Rubber Plantations and Natural Forests in Xishuangbanna (Southwest China Using Multi-Spectral Phenological Metrics from MODIS Time Series

    Directory of Open Access Journals (Sweden)

    Sebastian van der Linden

    2013-05-01

    Full Text Available We developed and evaluated a new approach for mapping rubber plantations and natural forests in one of Southeast Asia’s biodiversity hot spots, Xishuangbanna in China. We used a one-year annual time series of Moderate Resolution Imaging Spectroradiometer (MODIS, Enhanced Vegetation Index (EVI and short-wave infrared (SWIR reflectance data to develop phenological metrics. These phenological metrics were used to classify rubber plantations and forests with the Random Forest classification algorithm. We evaluated which key phenological characteristics were important to discriminate rubber plantations and natural forests by estimating the influence of each metric on the classification accuracy. As a benchmark, we compared the best classification with a classification based on the full, fitted time series data. Overall classification accuracies derived from EVI and SWIR time series alone were 64.4% and 67.9%, respectively. Combining the phenological metrics from EVI and SWIR time series improved the accuracy to 73.5%. Using the full, smoothed time series data instead of metrics derived from the time series improved the overall accuracy only slightly (1.3%, indicating that the phenological metrics were sufficient to explain the seasonal changes captured by the MODIS time series. The results demonstrate a promising utility of phenological metrics for mapping and monitoring rubber expansion with MODIS.

  11. Multi-scale approach to Euro-Atlantic climatic cycles based on phenological time series, air temperatures and circulation indexes.

    Science.gov (United States)

    Mariani, Luigi; Zavatti, Franco

    2017-09-01

    The spectral periods in North Atlantic Oscillation (NAO), Atlantic Multidecadal Oscillation (AMO) and El Nino Southern Oscillation (ENSO) were analyzed and has been verified how they imprint a time series of European temperature anomalies (ETA), two European temperature time series and some phenological series (dates of cherry flowering and grapevine harvest). Such work had as reference scenario the linear causal chain MCTP (Macroscale Circulation→Temperature→Phenology of crops) that links oceanic and atmospheric circulation to surface air temperature which in its turn determines the earliness of appearance of phenological phases of plants. Results show that in the three segments of the MCTP causal chain are present cycles with the following central period in years (the % of the 12 analyzed time series interested by these cycles are in brackets): 65 (58%), 24 (58%), 20.5 (58%), 13.5 (50%), 11.5 (58%), 7.7 (75%), 5.5 (58%), 4.1 (58%), 3 (50%), 2.4 (67%). A comparison with short term spectral peaks of the four El Niño regions (nino1+2, nino3, nino3.4 and nino4) show that 10 of the 12 series are imprinted by periods around 2.3-2.4yr while 50-58% of the series are imprinted by El Niño periods of 4-4.2, 3.8-3.9, 3-3.1years. The analysis highlights the links among physical and biological variables of the climate system at scales that range from macro to microscale whose knowledge is crucial to reach a suitable understanding of the ecosystem behavior. The spectral analysis was also applied to a time series of spring - summer precipitation in order to evaluate the presence of peaks common with other 12 selected series with result substantially negative which brings us to rule out the existence of a linear causal chain MCPP (Macroscale Circulation→Precipitation→Phenology). Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Phenological characters and genetic divergence in aromatic rices

    African Journals Online (AJOL)

    STORAGESEVER

    2009-07-20

    Jul 20, 2009 ... Phenological properties of a plant are measured in time duration between ... The time interval between sowing and flowering in rice (Oryza sativa L.) ... locally adapted genotypes of aromatic rices have evolved because of natural ... classification of genotypes based on suitable scale is quite imperative to ...

  13. Modelling climate change impacts on viticultural yield, phenology and stress conditions in Europe.

    Science.gov (United States)

    Fraga, Helder; García de Cortázar Atauri, Iñaki; Malheiro, Aureliano C; Santos, João A

    2016-11-01

    Viticulture is a key socio-economic sector in Europe. Owing to the strong sensitivity of grapevines to atmospheric factors, climate change may represent an important challenge for this sector. This study analyses viticultural suitability, yield, phenology, and water and nitrogen stress indices in Europe, for present climates (1980-2005) and future (2041-2070) climate change scenarios (RCP4.5 and 8.5). The STICS crop model is coupled with climate, soil and terrain databases, also taking into account CO 2 physiological effects, and simulations are validated against observational data sets. A clear agreement between simulated and observed phenology, leaf area index, yield and water and nitrogen stress indices, including the spatial differences throughout Europe, is shown. The projected changes highlight an extension of the climatic suitability for grapevines up to 55°N, which may represent the emergence of new winemaking regions. Despite strong regional heterogeneity, mean phenological timings (budburst, flowering, veraison and harvest) are projected to undergo significant advancements (e.g. budburst/harvest can be >1 month earlier), with implications also in the corresponding phenophase intervals. Enhanced dryness throughout Europe is also projected, with severe water stress over several regions in southern regions (e.g. southern Iberia and Italy), locally reducing yield and leaf area. Increased atmospheric CO 2 partially offsets dryness effects, promoting yield and leaf area index increases in central/northern Europe. Future biomass changes may lead to modifications in nitrogen demands, with higher stress in northern/central Europe and weaker stress in southern Europe. These findings are critical decision support systems for stakeholders from the European winemaking sector. © 2016 John Wiley & Sons Ltd.

  14. Partitioning of the net CO2 exchange using an automated chamber system reveals plant phenology as key control of production and respiration fluxes in a boreal peatland.

    Science.gov (United States)

    Järveoja, Järvi; Nilsson, Mats B; Gažovič, Michal; Crill, Patrick M; Peichl, Matthias

    2018-04-30

    The net ecosystem CO 2 exchange (NEE) drives the carbon (C) sink-source strength of northern peatlands. Since NEE represents a balance between various production and respiration fluxes, accurate predictions of its response to global changes require an in depth understanding of these underlying processes. Currently, however, detailed information of the temporal dynamics as well as the separate biotic and abiotic controls of the NEE component fluxes is lacking in peatland ecosystems. In this study, we address this knowledge gap by using an automated chamber system established across natural and trenching-/vegetation removal plots to partition NEE into its production (i.e. gross and net primary production; GPP and NPP) and respiration (i.e. ecosystem, heterotrophic and autotrophic respiration; ER, Rh and Ra) fluxes in a boreal peatland in northern Sweden. Our results showed that daily NEE patterns were driven by GPP while variations in ER were governed by Ra rather than Rh. Moreover, we observed pronounced seasonal shifts in the Ra/Rh and above-/belowground NPP ratios throughout the main phenological phases. Generalized linear model analysis revealed that the greenness index derived from digital images (as a proxy for plant phenology) was the strongest control of NEE, GPP and NPP while explaining considerable fractions also in the variations of ER and Ra. In addition, our data exposed greater temperature sensitivity of NPP compared to Rh resulting in enhanced C sequestration with increasing temperature. Overall, our study suggests that the temporal patterns in NEE and its component fluxes are tightly coupled to vegetation dynamics in boreal peatlands and thus challenges previous studies that commonly identify abiotic factors as key drivers. These findings further emphasize the need for integrating detailed information on plant phenology into process-based models to improve predictions of global change impacts on the peatland C cycle. This article is protected by

  15. The phenological phases of flowering and pollen seasons of spring flowering tree taxa against a background of meteorological conditions in Kraków, Poland

    Directory of Open Access Journals (Sweden)

    Danuta Stępalska

    2016-06-01

    Full Text Available The aim of the study was to compare phenological observations of pollen seasons of selected early spring trees. Special attention was paid to meteorological conditions which favored or did not favor tree flowering and pollen release. For this reason, we used phenological observation, pollen counts, and meteorological data in five sites in the center of Kraków in the period 2009–2011. Phenological phases (5 of four tree species: Alnus glutinosa, Alnus incana, Corylus avellana, and Betula pendula, were analyzed. It was found that in case of A. glutinosa the pollen season often preceded the flowering period, while for A. incana those two phenomena were more correlated. As regards Corylus avellana, the beginning of the pollen season and phenological phases was simultaneous. However, pollen grains occurred in the air longer, even by a dozen or so days. The phenological phases and pollen seasons of Alnus and Corylus were dependent on meteorological conditions. To give the definition of the relationship between pollen concentration and weather conditions, Spearman rank correlation analysis was applied. High Alnus and Corylus pollen concentrations were found on sunny days with a maximum temperature over 10°C and no precipitation, and when the snow cover was gone. In case of Betula, the phenological phases of the full pollination period usually coincided with the periods of high pollen concentrations. However, Betula pollen sometimes appears earlier and stays in the air longer than the flowering period of local trees in the nearest vicinity. This situation indicates long-distance transport or secondary deposition.

  16. Proceedings of the third arab conference on the peaceful uses of atomic energy, vol.a,b

    International Nuclear Information System (INIS)

    El-Mashri, S.M.

    1998-06-01

    The publication has been set up as a textbook for peaceful uses of atomic energy vol.A: (1) reactor,materials,energy; (2) nuclear raw materials; (3) radiocesium-waste; (4) nuclear safety; (5) nuclear physics; (6) radiochemistry; (7) radiobiology; vol.B: (1) nuclear medicine; (2) agriculture and soil science; (3) isotope hydrology; (4) food preservation; (5) insect eradication; (6 )industrial application; (7) nuclear activation analysis; (8) health physics and environmental studies

  17. Proceedings of the third arab conference on the peaceful uses of atomic energy, vol.a,b

    Energy Technology Data Exchange (ETDEWEB)

    El-Mashri, S M [ed.

    1998-06-01

    The publication has been set up as a textbook for peaceful uses of atomic energy vol.A: (1) reactor,materials,energy; (2) nuclear raw materials; (3) radiocesium-waste; (4) nuclear safety; (5) nuclear physics; (6) radiochemistry; (7) radiobiology; vol.B: (1) nuclear medicine; (2) agriculture and soil science; (3) isotope hydrology; (4) food preservation; (5) insect eradication; (6 )industrial application; (7) nuclear activation analysis; (8) health physics and environmental studies.

  18. Satellite Derived Forest Phenology and Its Relation with Nephropathia Epidemica in Belgium

    Directory of Open Access Journals (Sweden)

    José Miguel Barrios

    2010-06-01

    Full Text Available The connection between nephropathia epidemica (NE and vegetation dynamics has been emphasized in recent studies. Changing climate has been suggested as a triggering factor of recently observed epidemiologic peaks in reported NE cases. We have investigated whether there is a connection between the NE occurrence pattern in Belgium and specific trends in remotely sensed phenology parameters of broad-leaved forests. The analysis of time series of the MODIS Enhanced Vegetation Index revealed that changes in forest phenology, considered in literature as an effect of climate change, may affect the mechanics of NE transmission.

  19. Advances in boundary elements. Vol. 1-3

    International Nuclear Information System (INIS)

    Brebbia, C.A.; Connor, J.J.

    1989-01-01

    This book contains some of the edited papers presented at the 11th Boundary Element Conference, held in Cambridge, Massachusetts, during August 1989. The papers are arranged in three different books comprising the following topics: Vol. 1: Computations and Fundamentals - comprises sections on fundamentals, adaptive techniques, error and convergence, numerical methods and computational aspects. (283 p.). Vol. 2: Field and fluid flow solutions - includes the following topics: potential problems, thermal studies, electrical and electromagnetic problems, wave propagation, acoustics and fluid flow. (484 p.). Vol. 3: Stress analysis - deals with advances in linear problems, nonlinear problems, fracture mechanics, contact mechanics, optimization, geomechanics, plates and shells, vibrations and industrial applications. (450 p). (orig./HP)

  20. Meeting of the Chemical Societies: Almanac of the contributions of the fifty-first meeting of the chemical societies. Vol. 3

    International Nuclear Information System (INIS)

    Uher, M.; Benes, P.; Carsky, J.; Ctrnactova, H.; Fecenko, J.; Fellner, P.; Hodul, P.; Koprda, V.; Kratochvil, B.; Krkoska, P.; Kuruc, J.; Lehotay, J.; Matousek, J.; Milichovsky, P.; Omastova, M.; Petrus, L. jr.; Petrus, L. sr.; Schwendt, P.; Silny, P.; Sevcik, P.; Toma, S.; Uherova, R.; Zachar, P.

    1999-09-01

    The publication has been set up as an abstracts of the meeting dealing with different chemical problems. The book (Vol. 3) consists of the sections: (E) Wood, pulp, paper (15 papers); (G) Macromolecular chemistry (42 papers); (H) Organic chemistry, bio-organic chemistry and pharmaceutical chemistry (96 Papers); (I) Food chemistry and biochemistry; (J) Textile, fibres and foil materials

  1. Host tree phenology affects vascular epiphytes at the physiological, demographic and community level

    Science.gov (United States)

    Einzmann, Helena J. R.; Beyschlag, Joachim; Hofhansl, Florian; Wanek, Wolfgang; Zotz, Gerhard

    2015-01-01

    The processes that govern diverse tropical plant communities have rarely been studied in life forms other than trees. Structurally dependent vascular epiphytes, a major part of tropical biodiversity, grow in a three-dimensional matrix defined by their hosts, but trees differ in their architecture, bark structure/chemistry and leaf phenology. We hypothesized that the resulting seasonal differences in microclimatic conditions in evergreen vs. deciduous trees would affect epiphytes at different levels, from organ physiology to community structure. We studied the influence of tree leaf phenology on vascular epiphytes on the Island of Barro Colorado, Panama. Five tree species were selected, which were deciduous, semi-deciduous or evergreen. The crowns of drought-deciduous trees, characterized by sunnier and drier microclimates, hosted fewer individuals and less diverse epiphyte assemblages. Differences were also observed at a functional level, e.g. epiphyte assemblages in deciduous trees had larger proportions of Crassulacean acid metabolism species and individuals. At the population level a drier microclimate was associated with lower individual growth and survival in a xerophytic fern. Some species also showed, as expected, lower specific leaf area and higher δ13C values when growing in deciduous trees compared with evergreen trees. As hypothesized, host tree leaf phenology influences vascular epiphytes at different levels. Our results suggest a cascading effect of tree composition and associated differences in tree phenology on the diversity and functioning of epiphyte communities in tropical lowland forests. PMID:25392188

  2. Analysis and assessment of Shortwave Angle and Slope Index for monitoring rice phenology and hydroperiod.

    Science.gov (United States)

    Tornos, Lucía; Moyano, María Carmen; Huesca, Margarita; Cicuendez, Victor; Recuero, Laura; Domínguez, Jose Antonio; Palacios-Orueta, Alicia

    2014-05-01

    According to the United Nations, more than 50 percent of the world population depends on rice for about 80 percent of its food requirements. Besides, rice fields are important aquatic ecosystems, hosting a great variety of aquatic species. However, environmental issues such as water consumption and the emission of greenhouse gases, as well as the effects of climate change in crops, may endanger their sustainability. In this context, the determination of rice hydroperiod and phenology is necessary for rice monitoring and impact management, and is expected to become more relevant in the near future. The present study has explored the potential of Shortwave Angle Slope Index (SASI), based on the spectral data contained in Moderate Resolution Imaging Spectroradiometer, to monitoring rice paddy fields under different water management practices. SASI is a spectral shape index (SSI), based on the angle formed in SWIR1 vertex with NIR and SWIR2 in the spectrum, and the slope of the line linking NIR and SWIR2 vertices. This index was developed to distinguish between dry soil, wet soil, dry vegetation and green vegetation. It takes large, positive values for dry soil and large, negative values for green vegetation. Two case studies in Spain, the Ebro Delta and Orellana are presented. The behaviour of the index in each zone for the period 2001-2012 has been evaluated to characterize the response of SASI index to phenological and flooding events in rice. The average values and standard deviation of the index for the period 2001-2012 were calculated to identify the significant points of SASI in coincidence with phenological and flooding field data. An algorithm for the detection of significant points was also applied to determine phenological metrics, based on the information obtained. SASI presented similar values for both zones during the rice growing period. Differences arose during the non-growing period when the Delta was flooded for environmental reasons (i

  3. Clusters in Nuclei. Vol. 2

    International Nuclear Information System (INIS)

    Beck, Christian

    2012-01-01

    Following the pioneering discovery of alpha clustering and of molecular resonances, the field of nuclear clustering is today one of those domains of heavy-ion nuclear physics that faces the greatest challenges, yet also contains the greatest opportunities. After many summer schools and workshops, in particular over the last decade, the community of nuclear molecular physicists has decided to collaborate in producing a comprehensive collection of lectures and tutorial reviews covering the field. This second volume follows the successful Lect. Notes Phys. 818 (Vol.1), and comprises six extensive lectures covering the following topics: - Microscopic cluster models - Neutron halo and break-up reactions - Break-up reaction models for two- and three-cluster projectiles - Clustering effects within the di-nuclear model - Nuclear alpha-particle condensates - Clusters in nuclei: experimental perspectives By promoting new ideas and developments while retaining a pedagogical style of presentation throughout, these lectures will serve as both a reference and an advanced teaching manual for future courses and schools in the fields of nuclear physics and nuclear astrophysics. (orig.)

  4. Clusters in Nuclei. Vol. 2

    Energy Technology Data Exchange (ETDEWEB)

    Beck, Christian (ed.) [Strasbourg Univ. (France). Inst. Pluridiciplinaire Hubert Curien

    2012-07-01

    Following the pioneering discovery of alpha clustering and of molecular resonances, the field of nuclear clustering is today one of those domains of heavy-ion nuclear physics that faces the greatest challenges, yet also contains the greatest opportunities. After many summer schools and workshops, in particular over the last decade, the community of nuclear molecular physicists has decided to collaborate in producing a comprehensive collection of lectures and tutorial reviews covering the field. This second volume follows the successful Lect. Notes Phys. 818 (Vol.1), and comprises six extensive lectures covering the following topics: - Microscopic cluster models - Neutron halo and break-up reactions - Break-up reaction models for two- and three-cluster projectiles - Clustering effects within the di-nuclear model - Nuclear alpha-particle condensates - Clusters in nuclei: experimental perspectives By promoting new ideas and developments while retaining a pedagogical style of presentation throughout, these lectures will serve as both a reference and an advanced teaching manual for future courses and schools in the fields of nuclear physics and nuclear astrophysics. (orig.)

  5. Phenological sensitivity to climate across taxa and trophic levels

    DEFF Research Database (Denmark)

    Thackeray, Stephen J.; Henrys, Peter; Hemming, Deborah

    2016-01-01

    Differences in phenological responses to climate change among species can desynchronise ecological interactions and thereby threaten ecosystem function. To assess these threats, we must quantify the relative impact of climate change on species at different trophic levels. Here, we apply a Climate...

  6. European larch phenology in the Alps: can we grasp the role of ecological factors by combining field observations and inverse modelling?

    Science.gov (United States)

    Migliavacca, M.; Cremonese, E.; Colombo, R.; Busetto, L.; Galvagno, M.; Ganis, L.; Meroni, M.; Pari, E.; Rossini, M.; Siniscalco, C.; Morra di Cella, U.

    2008-09-01

    Vegetation phenology is strongly influenced by climatic factors. Climate changes may cause phenological variations, especially in the Alps which are considered to be extremely vulnerable to global warming. The main goal of our study is to analyze European larch ( Larix decidua Mill.) phenology in alpine environments and the role of the ecological factors involved, using an integrated approach based on accurate field observations and modelling techniques. We present 2 years of field-collected larch phenological data, obtained following a specifically designed observation protocol. We observed that both spring and autumn larch phenology is strongly influenced by altitude. We propose an approach for the optimization of a spring warming model (SW) and the growing season index model (GSI) consisting of a model inversion technique, based on simulated look-up tables (LUTs), that provides robust parameter estimates. The optimized models showed excellent agreement between modelled and observed data: the SW model predicts the beginning of the growing season (BGS) with a mean RMSE of 4 days, while GSI gives a prediction of the growing season length (LGS) with a RMSE of 5 days. Moreover, we showed that the original GSI parameters led to consistent errors, while the optimized ones significantly increased model accuracy. Finally, we used GSI to investigate interactions of ecological factors during springtime development and autumn senescence. We found that temperature is the most effective factor during spring recovery while photoperiod plays an important role during autumn senescence: photoperiod shows a contrasting effect with altitude decreasing its influence with increasing altitude.

  7. Evolved Phenological Asynchrony as a Baseline for Climate-change Impacts. (Invited)

    Science.gov (United States)

    Singer, M. C.; Parmesan, C.

    2010-12-01

    Changing climate can disrupt existing phenological relations between interacting species. We might expect the historical baseline for these effects to be precise synchrony between the season at which a consumer most requires food and the time when its resources are most available. When this is the case, change in any direction would be detrimental to the consumer. But is baseline synchrony the appropriate assumption? Here, we develop the theme that the starting point for climate change impacts may often have been asynchrony or mismatch between consumer and resource. To the extent that this has been true, assumptions of baseline synchrony risk mis-detection, mis-estimation, and mis-attribution of climate change impacts. Natural selection can result in asynchrony between exploiter and victim when victims successfully evolve to occupy enemy-free time. Asynchrony can also result from life-history tradedoffs. We illustrate asynchrony arising from tradeoffs for two species: Edith’s checkerspot butterfly and the winter moth. Initial observations of phenological mismatch in both systems were made prior to the onset of major impacts of anthropogenically-driven climate change. Neither species can detect the phenological stage of its host plants with precision. In both species, evolution of life history has involved compromise between maximizing fecundity and minimizing mortality, with the outcome being superficially maladaptive strategies in which many or even most individuals die of starvation through poor synchrony with their host plants. Both species have evolved high-risk life history strategies. While winter moth eggs gamble with their own lives by hatching early, bay checkerspots gamble with the lives of their offspring by growing large and eclosing late as adults. In both cases the result is the evolution of populations in which large numbers of individuals die because, as individuals, they fail to fit their life cycles into the available timespan. Because such a

  8. Climate change impacts on corn phenology and productivity

    Science.gov (United States)

    Climate is changing around the world and will impact future production of all food and feed crops. Corn is no exception to these impacts and to ensure a future supply of this vital crop we must begin to understand how climate impacts both the phenological development of corn and the productivity. Te...

  9. Mismatch between birth date and vegetation phenology slows the demography of roe deer.

    Directory of Open Access Journals (Sweden)

    Floriane Plard

    2014-04-01

    Full Text Available Marked impacts of climate change on biodiversity have frequently been demonstrated, including temperature-related shifts in phenology and life-history traits. One potential major impact of climate change is the modification of synchronization between the phenology of different trophic levels. High phenotypic plasticity in laying date has allowed many bird species to track the increasingly early springs resulting from recent environmental change, but although changes in the timing of reproduction have been well studied in birds, these questions have only recently been addressed in mammals. To track peak resource availability, large herbivores like roe deer, with a widespread distribution across Europe, should also modify their life-history schedule in response to changes in vegetation phenology over time. In this study, we analysed the influence of climate change on the timing of roe deer births and the consequences for population demography and individual fitness. Our study provides a rare quantification of the demographic costs associated with the failure of a species to modify its phenology in response to a changing world. Given these fitness costs, the lack of response of roe deer birth dates to match the increasingly earlier onset of spring is in stark contrast with the marked phenotypic responses to climate change reported in many other mammals. We suggest that the lack of phenotypic plasticity in birth timing in roe deer is linked to its inability to track environmental cues of variation in resource availability for the timing of parturition.

  10. Mismatch Between Birth Date and Vegetation Phenology Slows the Demography of Roe Deer

    Science.gov (United States)

    Plard, Floriane; Gaillard, Jean-Michel; Coulson, Tim; Hewison, A. J. Mark; Delorme, Daniel; Warnant, Claude; Bonenfant, Christophe

    2014-01-01

    Marked impacts of climate change on biodiversity have frequently been demonstrated, including temperature-related shifts in phenology and life-history traits. One potential major impact of climate change is the modification of synchronization between the phenology of different trophic levels. High phenotypic plasticity in laying date has allowed many bird species to track the increasingly early springs resulting from recent environmental change, but although changes in the timing of reproduction have been well studied in birds, these questions have only recently been addressed in mammals. To track peak resource availability, large herbivores like roe deer, with a widespread distribution across Europe, should also modify their life-history schedule in response to changes in vegetation phenology over time. In this study, we analysed the influence of climate change on the timing of roe deer births and the consequences for population demography and individual fitness. Our study provides a rare quantification of the demographic costs associated with the failure of a species to modify its phenology in response to a changing world. Given these fitness costs, the lack of response of roe deer birth dates to match the increasingly earlier onset of spring is in stark contrast with the marked phenotypic responses to climate change reported in many other mammals. We suggest that the lack of phenotypic plasticity in birth timing in roe deer is linked to its inability to track environmental cues of variation in resource availability for the timing of parturition. PMID:24690936

  11. Mapping Deforestation in North Korea Using Phenology-Based Multi-Index and Random Forest

    Directory of Open Access Journals (Sweden)

    Yihua Jin

    2016-12-01

    Full Text Available Phenology-based multi-index with the random forest (RF algorithm can be used to overcome the shortcomings of traditional deforestation mapping that involves pixel-based classification, such as ISODATA or decision trees, and single images. The purpose of this study was to investigate methods to identify specific types of deforestation in North Korea, and to increase the accuracy of classification, using phenological characteristics extracted with multi-index and random forest algorithms. The mapping of deforestation area based on RF was carried out by merging phenology-based multi-indices (i.e., normalized difference vegetation index (NDVI, normalized difference water index (NDWI, and normalized difference soil index (NDSI derived from MODIS (Moderate Resolution Imaging Spectroradiometer products and topographical variables. Our results showed overall classification accuracy of 89.38%, with corresponding kappa coefficients of 0.87. In particular, for forest and farm land categories with similar phenological characteristic (e.g., paddy, plateau vegetation, unstocked forest, hillside field, this approach improved the classification accuracy in comparison with pixel-based methods and other classes. The deforestation types were identified by incorporating point data from high-resolution imagery, outcomes of image classification, and slope data. Our study demonstrated that the proposed methodology could be used for deciding on the restoration priority and monitoring the expansion of deforestation areas.

  12. Intercomparison, interpretation, and assessment of spring phenology in North America estimated from remote sensing for 1982-2006

    NARCIS (Netherlands)

    White, M.A.; Beurs, de K.M.; Didan, K.; Inouye, D.W.; Richardson, A.D.; Jensen, O.P.; Magnuson, J.; O'Keefe, J.; Zhang, G.; Nemani, R.R.; Leeuwen, van W.J.D.; Brown, J.F.; Wit, de A.J.W.; Schaepman, M.E.; Lin, X.; Dettinger, M.; Bailey, A.; Kimball, J.; Schwartz, M.D.; Baldocchi, D.D.; Lee, J.T.; Lauenroth, W.K.

    2009-01-01

    Shifts in the timing of spring phenology are a central feature of global change research. Long-term observations of plant phenology have been used to track vegetation responses to climate variability but are often limited to particular species and locations and may not represent synoptic patterns.

  13. Three Decades of Remote Sensing Based Tropical Forests Phenological Patterns and Trends

    Science.gov (United States)

    Didan, K.

    2010-12-01

    The faint climatic seasonality of tropical rain forests is believed to be the reason these biomes lack strong and detectable seasonality. Forest seasonality is a critical element of ecosystem functions. It moderates the echo-hydrology, carbon, and nutrient exchange of the area. While deciduous forests exhibit distinct and strong seasonality, tropical forests do not, yet they play a large role in the cycling of energy and mass. Tropical forests represent a large percentage of vegetated land and their importance to the Earth system stems from their biological diversity, their habitat role, their role in regulating global weather, and the role they play in carbon storage. While Tropical forests are well buffered by their sheer size, their vulnerability to climate change is exacerbated by the human pressure. All of this begs the questions of what are the patterns and characteristic of tropical forests phenology and are there any detectable trends over the last three decades of synoptic remote sensing. These three decades comprise different episodes of droughts and an ever increasing level of human encroachment. In so far understanding the function and dynamic of these biomes, field studies continue to play a major role, but synoptic remote sensing is emerging as a viable tool to addressing the spatial and temporal scale associated with this problem. Recent studies of Brazilian rainforest with synoptic remote sensing point to a sizable seasonal signal coincident with the dry season. However, these studies were not extensive in time or space and did not look at other rainforests. Using data from AVHRR and MODIS, we generated a 30 year record of the 2 bands Enhance Vegetation Index (EVI2), and analyzed the patterns and trends of land surface phenology across all tropical forests using the homogeneous phenology cluster approach. We chose EVI because of its superior performance over these dense forests, and we selected the homogeneous phenology cluster approach to abate the

  14. Fabrication, structure, and magnetic properties of electrospun Ce{sub 0.96}Fe{sub 0.04}O{sub 2} nanofibers

    Energy Technology Data Exchange (ETDEWEB)

    Sonsupap, Somchai [School of Physics, Suranaree University of Technology, Nakhon Ratchasima (Thailand); Kidkhunthod, Pinit; Chanlek, Narong [Synchrotron Light Research Institute, Nakhon Ratchasima (Thailand); Pinitsoontorn, Supree [Department of Physics, Faculty of Science, Khon Kaen University, Khon Kaen (Thailand); Maensiri, Santi, E-mail: santimaensiri@g.sut.ac.th [School of Physics, Suranaree University of Technology, Nakhon Ratchasima (Thailand); NANOTEC-SUT Center of Excellence on Advanced Functional Nanomaterials, Suranaree University of Technology, Nakhon Ratchasima (Thailand)

    2016-09-01

    Highlights: • Intrinsic ferromagnetism in electrospun nanofibers of Ce{sub 0.96}Fe{sub 0.04}O{sub 2} is reported. • The prepared samples were well characterized by XRD, TEM, XANES, XPS, and VSM. • Ce{sub 0.96}Fe{sub 0.04}O{sub 2} samples are ferromagnetic having Ms of 0.002–0.923 emu/g at 10 kOe. • Oxygen vacancies play an important role to induce room temperature ferromagnetism. • Ferromagnetism observed in Ce{sub 0.96}Fe{sub 0.04}O{sub 2} is intrinsic. - Abstract: We report room temperature ferromagnetism in ∼30–60 nm nanofibers of Ce{sub 0.96}Fe{sub 0.04}O{sub 2} calcined at 500, 600, 700, and 800 °C. The as-spun nanofibers were fabricated by electrospinning technique. Nanofibers of the as-spun and calcined samples were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), X-ray absorption spectroscopy (XAS), and vibrating sample magnetometer (VSM). The XRD and TEM with selected electron diffraction (SEAD) analysis results indicate that the Ce{sub 0.96}Fe{sub 0.04}O{sub 2} nanofibers have a cubic perovskite structure without any secondary phase. The as-spun samples exhibit a diamagnetic behavior, whereas the calcined Ce{sub 0.96}Fe{sub 0.04}O{sub 2} samples are ferromagnetic having the specific magnetizations of 0.002–0.923 emu/g at 10 kOe. The results from XAS spectra show the valence state of Fe{sup 3+} and Fe{sup 2+} mixed in the Ce{sub 0.96}Fe{sub 0.04}O{sub 2} samples indicating oxygen vacancies in the nanofibers. Similarly, the results XPS spectra show that there are oxygen vacancies in the nanofibers as a result of Ce{sup 3+} on the surface. These oxygen vacancies play an important role to induce room temperature ferromagnetism (RT-FM) in the calcined Ce{sub 0.96}Fe{sub 0.04}O{sub 2} nanofibers. Our results indicate that the ferromagnetic properties of Ce{sub 0.96}Fe{sub 0.04}O{sub 2} system are intrinsic and are not a result of

  15. Dynamics of structures '89. Vol. 3

    International Nuclear Information System (INIS)

    1989-01-01

    The proceedings, comprising 3 volumes published by the Plzen Centre of the Czechoslovak Society for Science and Technology (Vol. 1 and 2) and by Skoda Works in Plzen (Vol. 3), contain 107 papers, out of which 8 fall within the INIS Subject Scope; these deal with problems related to the earthquake resistance of nuclear power plants. Attention is paid to the evaluation of seismic characteristics of nuclear power plant equipment, to the equipment testing and to calculations of its dynamic characteristics under simulated seismic stress. (Z.M.)

  16. Phenological differences among selected residents and long-distance migrant bird species in central Europe

    Science.gov (United States)

    Bartošová, Lenka; Trnka, Miroslav; Bauer, Zdeněk; Možný, Martin; Štěpánek, Petr; Žalud, Zdeněk

    2014-07-01

    The phenological responses to climate of residents and migrants (short- and long-distance) differ. Although few previous studies have focussed on this topic, the agree that changes in phenology are more apparent for residents than for long-distance migrants. We analysed the breeding times of two selected residents ( Sitta europaea, Parus major) and one long-distance migrant ( Ficedula albicollis) from 1961 to 2007 in central Europe. The timing of the phenophases of all three bird species showed a significant advance to earlier times. Nevertheless, the most marked shift was observed for the long-distance migrant (1.9 days per decade on average in mean laying date with linearity at the 99.9 % confidence level). In contrast, the shifts shown by the residents were smaller (1.6 days for S. europaea and 1.5 days for P. major also on average in mean laying date for both, with linearity at the 95 % confidence level). Spearman rank correlation coefficients calculated for pairs of phenophases of given bird species in 20-year subsamples (e.g. 1961-1980, 1962-1981) showed higher phenological separation between the residents and the migrant. This separation is most apparent after the 1980s. Thus, our results indicate that the interconnections between the studied phenological stages of the three bird species are becoming weaker.

  17. An interactive toolkit to extract phenological time series data from digital repeat photography

    Science.gov (United States)

    Seyednasrollah, B.; Milliman, T. E.; Hufkens, K.; Kosmala, M.; Richardson, A. D.

    2017-12-01

    Near-surface remote sensing and in situ photography are powerful tools to study how climate change and climate variability influence vegetation phenology and the associated seasonal rhythms of green-up and senescence. The rapidly-growing PhenoCam network has been using in situ digital repeat photography to study phenology in almost 500 locations around the world, with an emphasis on North America. However, extracting time series data from multiple years of half-hourly imagery - while each set of images may contain several regions of interest (ROI's), corresponding to different species or vegetation types - is not always straightforward. Large volumes of data require substantial processing time, and changes (either intentional or accidental) in camera field of view requires adjustment of ROI masks. Here, we introduce and present "DrawROI" as an interactive web-based application for imagery from PhenoCam. DrawROI can also be used offline, as a fully independent toolkit that significantly facilitates extraction of phenological data from any stack of digital repeat photography images. DrawROI provides a responsive environment for phenological scientists to interactively a) delineate ROIs, b) handle field of view (FOV) shifts, and c) extract and export time series data characterizing image color (i.e. red, green and blue channel digital numbers for the defined ROI). The application utilizes artificial intelligence and advanced machine learning techniques and gives user the opportunity to redraw new ROIs every time an FOV shift occurs. DrawROI also offers a quality control flag to indicate noisy data and images with low quality due to presence of foggy weather or snow conditions. The web-based application significantly accelerates the process of creating new ROIs and modifying pre-existing ROI in the PhenoCam database. The offline toolkit is presented as an open source R-package that can be used with similar datasets with time-lapse photography to obtain more data for

  18. Enterocin 96, a Novel Class II Bacteriocin Produced by Enterococcus faecalis WHE 96, Isolated from Munster Cheese▿

    Science.gov (United States)

    Izquierdo, Esther; Wagner, Camille; Marchioni, Eric; Aoude-Werner, Dalal; Ennahar, Saïd

    2009-01-01

    Enterococcus faecalis WHE 96, a strain isolated from soft cheese based on its anti-Listeria activity, produced a 5,494-Da bacteriocin that was purified to homogeneity by ultrafiltration and cation-exchange and reversed-phase chromatographies. The amino acid sequence of this bacteriocin, named enterocin 96, was determined by Edman degradation, and its structural gene was sequenced, revealing a double-glycine leader peptide. After a comparison with other bacteriocins, it was shown that enterocin 96 was a new class II bacteriocin that showed very little similarity with known structures. Enterocin 96 was indeed a new bacteriocin belonging to class II bacteriocins. The activity spectrum of enterocin 96 covered a wide range of bacteria, with strong activity against most gram-positive strains but very little or no activity against gram-negative strains. PMID:19411428

  19. Enterocin 96, a novel class II bacteriocin produced by Enterococcus faecalis WHE 96, isolated from Munster cheese.

    Science.gov (United States)

    Izquierdo, Esther; Wagner, Camille; Marchioni, Eric; Aoude-Werner, Dalal; Ennahar, Saïd

    2009-07-01

    Enterococcus faecalis WHE 96, a strain isolated from soft cheese based on its anti-Listeria activity, produced a 5,494-Da bacteriocin that was purified to homogeneity by ultrafiltration and cation-exchange and reversed-phase chromatographies. The amino acid sequence of this bacteriocin, named enterocin 96, was determined by Edman degradation, and its structural gene was sequenced, revealing a double-glycine leader peptide. After a comparison with other bacteriocins, it was shown that enterocin 96 was a new class II bacteriocin that showed very little similarity with known structures. Enterocin 96 was indeed a new bacteriocin belonging to class II bacteriocins. The activity spectrum of enterocin 96 covered a wide range of bacteria, with strong activity against most gram-positive strains but very little or no activity against gram-negative strains.

  20. Comparing growth phenology of co-occurring deciduous and evergreen conifers exposed to drought.

    Science.gov (United States)

    Swidrak, Irene; Schuster, Roman; Oberhuber, Walter

    2013-12-01

    Plant phenological events are influenced by climate factors such as temperature and rainfall. To evaluate phenological responses to water availability in a Spring Heath-Pine wood (Erico-Pinetum typicum), the focus of this study was to determine intra-annual dynamics of apical and lateral growth of co-occurring early successional Larix decidua and Pinus sylvestris and late successional Picea abies exposed to drought. The effect of reduced plant water availability on growth phenology was investigated by conducting a rainfall exclusion experiment. Timing of key phenological dates (onset, maximum rate, end, duration) of growth processes were compared among species at the rain-sheltered and control plot during 2011 and 2012. Shoot and needle elongation were monitored on lateral branches in the canopy at c . 16 m height and radial growth was recorded by automatic dendrometers at c . 1.3 m height of > 120 yr old trees. Different sequences in aboveground growth phenology were detected among the three species under the same growing conditions. While onset of radial growth in April through early May was considerably preceded by onset of needle growth in Larix decidua (5 - 6 weeks) and shoot growth in Pinus sylvestris ( c . 3 weeks), it occurred quite simultaneously with onset of shoot growth in Picea abies . Low water availability had a minor impact on onset of aboveground growth, which is related to utilization of stored water, but caused premature cessation of aboveground growth. At the control plot mean growing season length was 130 days in Pinus sylvestris , 95 days in Larix decidua and 73 days in Picea abies supporting the hypothesis that early successional species are resource expenders, while late successional species are more efficient in utilizing resources and develop safer life strategies. High synchronicity found in culmination of radial growth in late spring (mid-May through early June) prior to occurrence of more favourable environmental conditions in summer

  1. PHENOLOGY AND YIELD OF THE ‘ROXO DE VALINHOS’ FIG CULTIVAR IN WESTERN POTIGUAR

    Directory of Open Access Journals (Sweden)

    FRANCISCO SIDENE OLIVEIRA SILVA

    2017-01-01

    Full Text Available The ‘Roxo de Valinhos’ fig is one of the most widely grown varieties in the world, however, there are still few studies on the phenology and yield of fig trees, especially in semi-arid regions. This study evaluated the phenology and yield aspects of the ‘Roxo de Valinhos’ fig cultivar in Western Potiguar. The experiment was carried out from July to December 2015 in the didactic orchard of the Federal Rural University of the Semi-Arid, UFERSA. The following phenological aspects were analyzed: pruning at the beginning of budding, emergence and maturity of the first fruit, beginning of harvest, length and diameter of branches, number of fruits per branch, length and diameter of fruits, absolute growth rate, yield per plant, number of fruits per plant, and fruit weight. We used descriptive statistics; for quantitative and qualitative characteristics, we used regression analysis and means test, through Tukey´s test at 5% probability. Fig trees showed good adaptability to semi-arid regions and precocity when compared to fig trees from temperate regions, in all phenological stages; the studied cultivar showed promising results for cultivation in this region.

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

    Science.gov (United States)

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

    2016-01-01

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

  3. Fine Root Growth Phenology, Production, and Turnover in a Northern Hardwood Forest Ecosystem

    Science.gov (United States)

    Dudley J. Raynal

    1994-01-01

    A large part of the nutrient flux in deciduous forests is through fine root turnover, yet this process is seldom measured. As part of a nutrient cycling study, fine root dynamics were studied for two years at Huntington Forest in the Adirondack Mountain region of New York, USA. Root growth phenology was characterized using field rhizotrons, three methods were used to...

  4. An NDVI-Based Vegetation Phenology Is Improved to be More Consistent with Photosynthesis Dynamics through Applying a Light Use Efficiency Model over Boreal High-Latitude Forests

    Directory of Open Access Journals (Sweden)

    Siheng Wang

    2017-07-01

    Full Text Available Remote sensing of high-latitude forests phenology is essential for understanding the global carbon cycle and the response of vegetation to climate change. The normalized difference vegetation index (NDVI has long been used to study boreal evergreen needleleaf forests (ENF and deciduous broadleaf forests. However, the NDVI-based growing season is generally reported to be longer than that based on gross primary production (GPP, which can be attributed to the difference between greenness and photosynthesis. Instead of introducing environmental factors such as land surface or air temperature like previous studies, this study attempts to make VI-based phenology more consistent with photosynthesis dynamics through applying a light use efficiency model. NDVI (MOD13C2 was used as a proxy for both fractional of absorbed photosynthetically active radiation (APAR and light use efficiency at seasonal time scale. Results show that VI-based phenology is improved towards tracking seasonal GPP changes more precisely after applying the light use efficiency model compared to raw NDVI or APAR, especially over ENF.

  5. Nesting biology and phenology of a population of Halictus farinosus Smith (Hymenoptera, Halictidae in northern Utah

    Directory of Open Access Journals (Sweden)

    Jennifer Albert

    2013-04-01

    Full Text Available Nesting biology and phenology in an aggregation of the primitively eusocial ground-nesting bee Halictus farinosus were studied at Green Canyon, Utah from May to August, 2010. Nest architecture was typical of the genus. Nests were small with an average of 3.5 worker and 13.5 reproductive brood per colony. Most workers were mated (77.5% and had ovarian development (73.4%. The queen-worker size differential was moderate (8.8% for head width and 6.2% for wing length, indicating that sociality in this species is of intermediate strength compared to other social Halictus species. Results from 2010 were compared with those from 1977/1978 and 2002. Varying weather patterns in the years of study led to changes in phenological milestones: in the colder and wetter spring of 2010, nesting behavior was delayed by up to two weeks compared to the other years. While nest productivity was comparable among years, in 2010 the size difference between queens and workers was significantly larger than in 2002, indicating an effect of annual variation in weather conditions on social parameters in this species.

  6. Shifts in Arctic phenology in response to climate and anthropogenic factors as detected from multiple satellite time series

    International Nuclear Information System (INIS)

    Zeng, Heqing; Jia, Gensuo; Forbes, Bruce C

    2013-01-01

    There is an urgent need to reduce the uncertainties in remotely sensed detection of phenological shifts of high latitude ecosystems in response to climate changes in past decades. In this study, vegetation phenology in western Arctic Russia (the Yamal Peninsula) was investigated by analyzing and comparing Normalized Difference Vegetation Index (NDVI) time series derived from the Advanced Very High Resolution Radiometer (AVHRR), the Moderate Resolution Imaging Spectroradiometer (MODIS), and SPOT-Vegetation (VGT) during the decade 2000–2010. The spatial patterns of key phenological parameters were highly heterogeneous along the latitudinal gradients based on multi-satellite data. There was earlier SOS (start of the growing season), later EOS (end of the growing season), longer LOS (length of the growing season), and greater MaxNDVI from north to south in the region. The results based on MODIS and VGT data showed similar trends in phenological changes from 2000 to 2010, while quite a different trend was found based on AVHRR data from 2000 to 2008. A significantly delayed EOS (p < 0.01), thus increasing the LOS, was found from AVHRR data, while no similar trends were detected from MODIS and VGT data. There were no obvious shifts in MaxNDVI during the last decade. MODIS and VGT data were considered to be preferred data for monitoring vegetation phenology in northern high latitudes. Temperature is still a key factor controlling spatial phenological gradients and variability, while anthropogenic factors (reindeer husbandry and resource exploitation) might explain the delayed SOS in southern Yamal. Continuous environmental damage could trigger a positive feedback to the delayed SOS. (letter)

  7. Nigerian Journal of Surgical Sciences - Vol 17, No 2 (2007)

    African Journals Online (AJOL)

    An Evaluation of Open Tracheostomy in Oral and Maxillofacial Surgery · EMAIL FULL TEXT EMAIL FULL TEXT DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. V Akinmoladun, J Arotiba, P Onakoya, A Adeyemo, P Sotunmbi, 96-100. http://dx.doi.org/10.4314/njssci.v17i2.38412 ...

  8. Large-scale heterogeneity of Amazonian phenology revealed from 26-year long AVHRR/NDVI time-series

    International Nuclear Information System (INIS)

    Silva, Fabrício B; Shimabukuro, Yosio E; Aragão, Luiz E O C; Anderson, Liana O; Pereira, Gabriel; Cardozo, Franciele; Arai, Egídio

    2013-01-01

    Depiction of phenological cycles in tropical forests is critical for an understanding of seasonal patterns in carbon and water fluxes as well as the responses of vegetation to climate variations. However, the detection of clear spatially explicit phenological patterns across Amazonia has proven difficult using data from the Moderate Resolution Imaging Spectroradiometer (MODIS). In this work, we propose an alternative approach based on a 26-year time-series of the normalized difference vegetation index (NDVI) from the Advanced Very High Resolution Radiometer (AVHRR) to identify regions with homogeneous phenological cycles in Amazonia. Specifically, we aim to use a pattern recognition technique, based on temporal signal processing concepts, to map Amazonian phenoregions and to compare the identified patterns with field-derived information. Our automated method recognized 26 phenoregions with unique intra-annual seasonality. This result highlights the fact that known vegetation types in Amazonia are not only structurally different but also phenologically distinct. Flushing of new leaves observed in the field is, in most cases, associated to a continuous increase in NDVI. The peak in leaf production is normally observed from the beginning to the middle of the wet season in 66% of the field sites analyzed. The phenoregion map presented in this work gives a new perspective on the dynamics of Amazonian canopies. It is clear that the phenology across Amazonia is more variable than previously detected using remote sensing data. An understanding of the implications of this spatial heterogeneity on the seasonality of Amazonian forest processes is a crucial step towards accurately quantifying the role of tropical forests within global biogeochemical cycles. (letter)

  9. Variability and climate change trend in vegetation phenology of recent decades in the Greater Khingan Mountain area, Northeastern China

    Directory of Open Access Journals (Sweden)

    Huan Tang

    2015-09-01

    Full Text Available Vegetation phenology has been used in studies as an indicator of an ecosystem’s responses to climate change. Satellite remote sensing techniques can capture changes in vegetation greenness, which can be used to estimate vegetation phenology. In this study, a long-term vegetation phenology study of the Greater Khingan Mountain area in Northeastern China was performed by using the Global Inventory Modeling and Mapping Studies (GIMMS normalized difference vegetation index version 3 (NDVI3g dataset from the years 1982–2012. After reconstructing the NDVI time series, the start date of the growing season (SOS, the end date of the growing season (EOS and the length of the growing season (LOS were extracted using a dynamic threshold method. The response of the variation in phenology with climatic factors was also analyzed. The results showed that the phenology in the study area changed significantly in the three decades between 1982 and 2012, including a 12.1-day increase in the entire region’s average LOS, a 3.3-day advance in the SOS and an 8.8-day delay in the EOS. However, differences existed between the steppe, forest and agricultural regions, with the LOSs of the steppe region, forest region and agricultural region increasing by 4.40 days, 10.42 days and 1.71 days, respectively, and a later EOS seemed to more strongly affect the extension of the growing season. Additionally, temperature and precipitation were closely correlated with the phenology variations. This study provides a useful understanding of the recent change in phenology and its variability in this high-latitude study area, and this study also details the responses of several ecosystems to climate change.

  10. Effect of understory management on phenological responses of eastern black walnut on an alluvial Arkansas soil

    Science.gov (United States)

    Black walnut (Juglans nigra L.) is commonly grown in agroforestry practices for nuts and/or timber with little knowledge of how understory herbage management might affect tree phenology. We compared black walnut plant type (variety and wild-type) for phenological response in date of budburst, leaf ...

  11. Phenological Characterization of Desert Sky Island Vegetation Communities with Remotely Sensed and Climate Time Series Data

    Directory of Open Access Journals (Sweden)

    Stuart E. Marsh

    2010-01-01

    Full Text Available Climate change and variability are expected to impact the synchronicity and interactions between the Sonoran Desert and the forested sky islands which represent steep biological and environmental gradients. The main objectives were to examine how well satellite greenness time series data and derived phenological metrics (e.g., season start, peak greenness can characterize specific vegetation communities across an elevation gradient, and to examine the interactions between climate and phenological metrics for each vegetation community. We found that representative vegetation types (11, varying between desert scrub, mesquite, grassland, mixed oak, juniper and pine, often had unique seasonal and interannual phenological trajectories and spatial patterns. Satellite derived land surface phenometrics (11 for each of the vegetation communities along the cline showed numerous distinct significant relationships in response to temperature (4 and precipitation (7 metrics. Satellite-derived sky island vegetation phenology can help assess and monitor vegetation dynamics and provide unique indicators of climate variability and patterns of change.

  12. Simulated herbivory advances autumn phenology in Acer rubrum.

    Science.gov (United States)

    Forkner, Rebecca E

    2014-05-01

    To determine the degree to which herbivory contributes to phenotypic variation in autumn phenology for deciduous trees, red maple (Acer rubrum) branches were subjected to low and high levels of simulated herbivory and surveyed at the end of the season to assess abscission and degree of autumn coloration. Overall, branches with simulated herbivory abscised ∼7 % more leaves at each autumn survey date than did control branches within trees. While branches subjected to high levels of damage showed advanced phenology, abscission rates did not differ from those of undamaged branches within trees because heavy damage induced earlier leaf loss on adjacent branch nodes in this treatment. Damaged branches had greater proportions of leaf area colored than undamaged branches within trees, having twice the amount of leaf area colored at the onset of autumn and having ~16 % greater leaf area colored in late October when nearly all leaves were colored. When senescence was scored as the percent of all leaves abscised and/or colored, branches in both treatments reached peak senescence earlier than did control branches within trees: dates of 50 % senescence occurred 2.5 days earlier for low herbivory branches and 9.7 days earlier for branches with high levels of simulated damage. These advanced rates are of the same time length as reported delays in autumn senescence and advances in spring onset due to climate warming. Thus, results suggest that should insect damage increase as a consequence of climate change, it may offset a lengthening of leaf life spans in some tree species.

  13. MEASURING WORKING HOURS INPUT IN VINE GROWING AT WORK ORGANIZATION BASED ON PHENOLOGICAL PHASES

    Directory of Open Access Journals (Sweden)

    J BRAZSIL

    2002-05-01

    Full Text Available Research was based on phenological phases of Italian Riesling, involving differences in labour and financial input for dry, optimal and wet weather. Worktime demand for certain operations in vine growing was determined with an analytic method, work day survey and We worked out alternatives for dry, optimum and wet weather on the basis of phenological phaseses. The worktime demand for the phenological phases with all their operations were analysed and planned in an itemized way based on our findings. We used them to work out the worktime demand for the given vine land for each operation. To analyse differences coming from diverse methods of cultivation and spacing, the material, operational and total costs of hand and mechanized labour were projected for 1 hectare and variance analysis was made.

  14. Variability and Changes in Climate, Phenology, and Gross Primary Production of an Alpine Wetland Ecosystem

    Directory of Open Access Journals (Sweden)

    Xiaoming Kang

    2016-05-01

    Full Text Available Quantifying the variability and changes in phenology and gross primary production (GPP of alpine wetlands in the Qinghai–Tibetan Plateau under climate change is essential for assessing carbon (C balance dynamics at regional and global scales. In this study, in situ eddy covariance (EC flux tower observations and remote sensing data were integrated with a modified, satellite-based vegetation photosynthesis model (VPM to investigate the variability in climate change, phenology, and GPP of an alpine wetland ecosystem, located in Zoige, southwestern China. Two-year EC data and remote sensing vegetation indices showed that warmer temperatures corresponded to an earlier start date of the growing season, increased GPP, and ecosystem respiration, and hence increased the C sink strength of the alpine wetlands. Twelve-year long-term simulations (2000–2011 showed that: (1 there were significantly increasing trends for the mean annual enhanced vegetation index (EVI, land surface water index (LSWI, and growing season GPP (R2 ≥ 0.59, p < 0.01 at rates of 0.002, 0.11 year−1 and 16.32 g·C·m−2·year−1, respectively, which was in line with the observed warming trend (R2 = 0.54, p = 0.006; (2 the start and end of the vegetation growing season (SOS and EOS experienced a continuous advancing trend at a rate of 1.61 days·year−1 and a delaying trend at a rate of 1.57 days·year−1 from 2000 to 2011 (p ≤ 0.04, respectively; and (3 with increasing temperature, the advanced SOS and delayed EOS prolonged the wetland’s phenological and photosynthetically active period and, thereby, increased wetland productivity by about 3.7–4.2 g·C·m−2·year−1 per day. Furthermore, our results indicated that warming and the extension of the growing season had positive effects on carbon uptake in this alpine wetland ecosystem.

  15. Detecting mismatches in the phenology of cotton bollworm larvae and cotton flowering in response to climate change

    Science.gov (United States)

    Huang, Jian; Hao, HongFei

    2018-05-01

    Current evidence suggests that climate change has directly affected the phenology of many invertebrate species associated with agriculture. Such changes in phenology have the potential to cause temporal mismatches between predators and prey and may lead to a disruption in natural pest control ecosystem. Understanding the synchrony between pest insects and host plant responses to climate change is a key step to improve integrated pest management strategies. Cotton bollworm larvae damage cotton, and thus, data from Magaiti County, China, collected during the period of 1990-2015 were analyzed to assess the effects of climate change on cotton bollworm larvae and cotton flowering. The results showed that a warming climate advanced the phenology of cotton bollworm larvae and cotton flowering. However, the phenological rate of change was faster in cotton bollworm larvae than that in cotton flowering, and the larval period was prolonged, resulting in a great increase of the larval population. The abrupt phenological changes in cotton bollworm larvae occurred earlier than that in cotton, and the abrupt phenological changes in cotton flowering occurred earlier than that in larval abundance. However, the timing of abrupt changes in larval abundance all occurred later than that in temperature. Thus, the abrupt changes that occurred in larvae, cotton flowering and climate were asynchronous. The interval days between the cotton flowering date (CFD) and the half-amount larvae date (HLD) expanded by 3.41 and 4.41 days with a 1 °C increase of T mean in May and June, respectively. The asynchrony between cotton bollworm larvae and cotton flowering will likely broaden as the climate changes. The effective temperature in March and April and the end date of larvae (ED) were the primary factors affecting asynchrony.

  16. Detecting mismatches in the phenology of cotton bollworm larvae and cotton flowering in response to climate change.

    Science.gov (United States)

    Huang, Jian; Hao, HongFei

    2018-05-11

    Current evidence suggests that climate change has directly affected the phenology of many invertebrate species associated with agriculture. Such changes in phenology have the potential to cause temporal mismatches between predators and prey and may lead to a disruption in natural pest control ecosystem. Understanding the synchrony between pest insects and host plant responses to climate change is a key step to improve integrated pest management strategies. Cotton bollworm larvae damage cotton, and thus, data from Magaiti County, China, collected during the period of 1990-2015 were analyzed to assess the effects of climate change on cotton bollworm larvae and cotton flowering. The results showed that a warming climate advanced the phenology of cotton bollworm larvae and cotton flowering. However, the phenological rate of change was faster in cotton bollworm larvae than that in cotton flowering, and the larval period was prolonged, resulting in a great increase of the larval population. The abrupt phenological changes in cotton bollworm larvae occurred earlier than that in cotton, and the abrupt phenological changes in cotton flowering occurred earlier than that in larval abundance. However, the timing of abrupt changes in larval abundance all occurred later than that in temperature. Thus, the abrupt changes that occurred in larvae, cotton flowering and climate were asynchronous. The interval days between the cotton flowering date (CFD) and the half-amount larvae date (HLD) expanded by 3.41 and 4.41 days with a 1 °C increase of T mean in May and June, respectively. The asynchrony between cotton bollworm larvae and cotton flowering will likely broaden as the climate changes. The effective temperature in March and April and the end date of larvae (ED) were the primary factors affecting asynchrony.

  17. What prevents phenological adjustment to climate change in migrant bird species? Evidence against the ``arrival constraint'' hypothesis

    Science.gov (United States)

    Goodenough, Anne E.; Hart, Adam G.; Elliot, Simon L.

    2011-01-01

    Phenological studies have demonstrated changes in the timing of seasonal events across multiple taxonomic groups as the climate warms. Some northern European migrant bird populations, however, show little or no significant change in breeding phenology, resulting in synchrony with key food sources becoming mismatched. This phenological inertia has often been ascribed to migration constraints (i.e. arrival date at breeding grounds preventing earlier laying). This has been based primarily on research in The Netherlands and Germany where time between arrival and breeding is short (often as few as 9 days). Here, we test the arrival constraint hypothesis over a 15-year period for a U.K. pied flycatcher ( Ficedula hypoleuca) population where laying date is not constrained by arrival as the period between arrival and breeding is substantial and consistent (average 27 ± 4.57 days SD). Despite increasing spring temperatures and quantifiably stronger selection for early laying on the basis of number of offspring to fledge, we found no significant change in breeding phenology, in contrast with co-occurring resident blue tits ( Cyanistes caeruleus). We discuss possible non-migratory constraints on phenological adjustment, including limitations on plasticity, genetic constraints and competition, as well as the possibility of counter-selection pressures relating to adult survival, longevity or future reproductive success. We propose that such factors need to be considered in conjunction with the arrival constraint hypothesis.

  18. What prevents phenological adjustment to climate change in migrant bird species? Evidence against the "arrival constraint" hypothesis.

    Science.gov (United States)

    Goodenough, Anne E; Hart, Adam G; Elliot, Simon L

    2011-01-01

    Phenological studies have demonstrated changes in the timing of seasonal events across multiple taxonomic groups as the climate warms. Some northern European migrant bird populations, however, show little or no significant change in breeding phenology, resulting in synchrony with key food sources becoming mismatched. This phenological inertia has often been ascribed to migration constraints (i.e. arrival date at breeding grounds preventing earlier laying). This has been based primarily on research in The Netherlands and Germany where time between arrival and breeding is short (often as few as 9 days). Here, we test the arrival constraint hypothesis over a 15-year period for a U.K. pied flycatcher (Ficedula hypoleuca) population where laying date is not constrained by arrival as the period between arrival and breeding is substantial and consistent (average 27 ± 4.57 days SD). Despite increasing spring temperatures and quantifiably stronger selection for early laying on the basis of number of offspring to fledge, we found no significant change in breeding phenology, in contrast with co-occurring resident blue tits (Cyanistes caeruleus). We discuss possible non-migratory constraints on phenological adjustment, including limitations on plasticity, genetic constraints and competition, as well as the possibility of counter-selection pressures relating to adult survival, longevity or future reproductive success. We propose that such factors need to be considered in conjunction with the arrival constraint hypothesis.

  19. Phenological adaptations in Ficus tikoua exhibit convergence with unrelated extra-tropical fig trees.

    Directory of Open Access Journals (Sweden)

    Ting-Ting Zhao

    Full Text Available Flowering phenology is central to the ecology and evolution of most flowering plants. In highly-specific nursery pollination systems, such as that involving fig trees (Ficus species and fig wasps (Agaonidae, any mismatch in timing has serious consequences because the plants must balance seed production with maintenance of their pollinator populations. Most fig trees are found in tropical or subtropical habitats, but the dioecious Chinese Ficus tikoua has a more northerly distribution. We monitored how its fruiting phenology has adapted in response to a highly seasonal environment. Male trees (where fig wasps reproduce had one to three crops annually, whereas many seed-producing female trees produced only one fig crop. The timing of release of Ceratosolen fig wasps from male figs in late May and June was synchronized with the presence of receptive figs on female trees, at a time when there were few receptive figs on male trees, thereby ensuring seed set while allowing remnant pollinator populations to persist. F. tikoua phenology has converged with those of other (unrelated northern Ficus species, but there are differences. Unlike F. carica in Europe, all F. tikoua male figs contain male flowers, and unlike F. pumila in China, but like F. carica, it is the second annual generation of adult wasps that pollinate female figs. The phenologies of all three temperate fig trees generate annual bottlenecks in the size of pollinator populations and for female F. tikoua also a shortage of fig wasps that results in many figs failing to be pollinated.

  20. Phenological Characteristics of the Barred Chicken in Western ...

    African Journals Online (AJOL)

    Between May and June 2011, the growth performance and phenological characteristics of local barred chicken of the Western Highland Cameroon was carried out in the Teaching and Research Farm of the University of Dschang. The data on body weight, body measurements and carcass characteristics were collected on ...

  1. Phenological Shifts in Animals Under Contemporary Climate Change

    NARCIS (Netherlands)

    Visser, M.E.; Roitberg, Bernard D.

    2017-01-01

    One of the best documented impacts of climate change has been on the seasonal timing, or phenology, of species. There are clear shifts in all taxonomic groups in terrestrial, aquatic, and marine environments. There is, however, ample variation in the rate at which species shift in response to warmer

  2. Supersymmetric mechanics. Vol. 2. The attractor mechanism and space time singularities

    International Nuclear Information System (INIS)

    Bellucci, S.; Marrani, A.; Ferrara, S.

    2006-01-01

    This is the second volume in a series of books on the general theme of Supersymmetric Mechanics; the series is based on lectures and discussions held in 2005 and 2006 at the INFN-Laboratori Nazionali di Frascati. The first volume appears as Lect. Notes Physics, Vol. 698 ''Supersymmetric Mechanics, Vol.1: Supersymmetry, Noncommutativity and Matrix Models'' (2006) ISBN: 3-540-33313-4. The present extensive lecture supplies a pedagogical introduction, at the non-expert level, to the attractor mechanism in space-time singularities. In such a framework, supersymmetry seems to be related to dynamical systems with fixed points, describing the equilibrium state and the stability features of the thermodynamics of black holes. After a qualitative overview, explicit examples realizing the attractor mechanism are treated at some length; they include relevant cases of asymptotically flat, maximal and non-maximal, extended supergravities in 4 and 5 dimensions. A number of recent advances along various directions of research on the attractor mechanism are also given. (orig.)

  3. Phenology of species interactions in response to climate change: two case studies of plant-pollinator interactions using long-term data

    Science.gov (United States)

    McKinney, A. M.; Inouye, D. W.

    2012-12-01

    Climate change may alter the temporal overlap among interacting taxa with potential demographic consequences. Evidence of mistimed interactions in response to climate change, especially between plants and pollinators, is mixed, and few long-term datasets exist to test for changes in synchrony. Furthermore, advancements in flowering driven by climate change are especially pronounced at higher latitudes, so that migratory pollinators from lower latitudes may increasingly arrive at breeding grounds after the appearance of floral resources. We explored long-term shifts in phenological synchrony in two plant-pollinator systems:1) syrphid fly and flowering phenology in the Colorado Rocky Mountains, USA (1992-2011) and 2) hummingbird arrival relative to onset of early-season nectar resources in the Colorado Rocky Mountains (1975-2011) and the Santa Catalina Mountains, Arizona, USA (1984-2010). We investigated the abiotic cues associated with the phenology of the activity period of syrphid flies and their floral resources, including degree days above freezing, precipitation, and timing of snowmelt as potential explanatory variables. Timing of snowmelt was the best predictor of the onset of flowering and syrphid emergence. Snowmelt was also the best predictor of the end of flowering, while temperature and precipitation best predicted the end of the syrphid period. Both the onset and end of flowering advanced more rapidly than syrphids in response to earlier snowmelt. These different rates of phenological advancement resulted in increased temporal overlap between the flower and syrphid community in years of early snowmelt, because of longer flowering and fly activity periods during these years. If snowmelt continues to advance, temporal overlap between syrphids and their floral resources is therefore likely to increase. This case study shows that the phenology of interacting taxa may respond differently to climate cues, but that this does not necessarily lead to phenological

  4. Use of MODIS Satellite Images and an Atmospheric Dust Transport Model to Evaluate Juniperus spp. Pollen Phenology and Transport

    Science.gov (United States)

    Luvall, J. C.; Sprigg, W. A.; Levetin, E.; Huete, A.; Nickovic, S.; Pejanovic, G. A.; Vukovic, A.; Van de Water, P. K.; Myers, O. B.; Budge, A. M.; hide

    2011-01-01

    Pollen can be transported great distances. Van de Water et al., 2003 reported Juniperus spp. pollen, a significant aeroallergen was transported 200-600 km. Hence local observations of plant phenology may not be consistent with the timing and source of pollen collected by pollen sampling instruments. Direct detection of pollen via satellite is not practical. A practical alternative combines modeling and phenological observations using ground based sampling and satellite data. The DREAM (Dust REgional Atmospheric Model) is a verified model for atmospheric dust transport modeling using MODIS data products to identify source regions and quantities of dust (Nickovic et al. 2001). The use of satellite data products for studying phenology is well documented (White and Nemani 2006). In the current project MODIS data will provide critical input to the PREAM model providing pollen source location, timing of pollen release, and vegetation type. We are modifying the DREAM model (PREAM - Pollen REgional Atmospheric Model) to incorporate pollen transport. The linkages already exist with DREAM through PHAiRS (Public Health Applications in Remote Sensing) to the public health community. This linkage has the potential to fill this data gap so that the potential association of health effects of pollen can better be tracked for possible linkage with health outcome data which may be associated with asthma, respiratory effects, myocardial infarction, and lost workdays. Juniperus spp. pollen phenology may respond to a wide range of environmental factors such as day length, growing degree-days, precipitation patterns and soil moisture. Species differences are also important. These environmental factors vary over both time and spatial scales. Ground based networks such as the USA National Phenology Network have been established to provide national wide observations of vegetation phenology. However, the density of observers is not adequate to sufficiently document the phenology variability

  5. An optical sensor network for vegetation phenology monitoring and satellite data calibration

    DEFF Research Database (Denmark)

    Eklundh, L.; Jin, H.; Schubert, P.

    2011-01-01

    -board Aqua and Terra satellite platforms. PAR fluxes are partitioned into reflected and absorbed components for the ground and canopy. The measurements demonstrate that the instrumentation provides detailed information about the vegetation phenology and variations in reflectance due to snow cover variations......We present a network of sites across Fennoscandia for optical sampling of vegetation properties relevant for phenology monitoring and satellite data calibration. The network currently consists of five sites, distributed along an N-S gradient through Sweden and Finland. Two sites are located...... and vegetation development. Valuable information about PAR absorption of ground and canopy is obtained that may be linked to vegetation productivity....

  6. samaru-main-vol 11 2011

    African Journals Online (AJOL)

    Library _info_Sc_ 1

    2004-07-11

    Jul 11, 2004 ... Samaru Journal of Information Studies Vol. 11 (1 & 2)2011 ... It is therefore paramount that the library ... source of primary and up to date information, both students and ... entertainment, arts, fashion, law, economy, medicine,.

  7. Phase-dependent outbreak dynamics of geometrid moth linked to host plant phenology.

    Science.gov (United States)

    Jepsen, Jane U; Hagen, Snorre B; Karlsen, Stein-Rune; Ims, Rolf A

    2009-12-07

    Climatically driven Moran effects have often been invoked as the most likely cause of regionally synchronized outbreaks of insect herbivores without identifying the exact mechanism. However, the degree of match between host plant and larval phenology is crucial for the growth and survival of many spring-feeding pest insects, suggesting that a phenological match/mismatch-driven Moran effect may act as a synchronizing agent. We analyse the phase-dependent spatial dynamics of defoliation caused by cyclically outbreaking geometrid moths in northern boreal birch forest in Fennoscandia through the most recent massive outbreak (2000-2008). We use satellite-derived time series of the prevalence of moth defoliation and the onset of the growing season for the entire region to investigate the link between the patterns of defoliation and outbreak spread. In addition, we examine whether a phase-dependent coherence in the pattern of spatial synchrony exists between defoliation and onset of the growing season, in order to evaluate if the degree of matching phenology between the moth and their host plant could be the mechanism behind a Moran effect. The strength of regional spatial synchrony in defoliation and the pattern of defoliation spread were both highly phase-dependent. The incipient phase of the outbreak was characterized by high regional synchrony in defoliation and long spread distances, compared with the epidemic and crash phase. Defoliation spread was best described using a two-scale stratified spread model, suggesting that defoliation spread is governed by two processes operating at different spatial scale. The pattern of phase-dependent spatial synchrony was coherent in both defoliation and onset of the growing season. This suggests that the timing of spring phenology plays a role in the large-scale synchronization of birch forest moth outbreaks.

  8. Glucosinolate profile and distribution among plant tissues and phenological stages of field-grown horseradish.

    Science.gov (United States)

    Agneta, Rosa; Lelario, Filomena; De Maria, Susanna; Möllers, Christian; Bufo, Sabino Aurelio; Rivelli, Anna Rita

    2014-10-01

    Profile and distribution of glucosinolates (GLS) were detected in plant tissues of horseradish at different developmental stages: beginning of vegetative re-growth, flowering and silique formation. The GLS profile varied widely in the different tissues: we identified 17 GLS in roots and sprouts, one of which was not previously characterized in horseradish, i.e. the 2(S)-hydroxy-2-phenylethyl-GLS (glucobarbarin) and/or 2(R)-hydroxy-2-phenylethyl-GLS (epiglucobarbarin), 11 already found in the roots, including the putative 2-methylsulfonyl-oxo-ethyl-GLS, and 5 previously recognized only in the sprouts. Fifteen of those GLS were also identified in young and cauline leaves, 12 in the mature leaves and 13 in the inflorescences. No difference in GLS profile was observed in plant among the phenological stages. Differences in concentrations of GLS, quantified as desulfated, were found in plant. At the beginning of vegetative re-growth, sprouts while showing the same profile of the roots were much richer in GLS having the highest total GLS concentrations (117.5 and 7.7μmolg(-1) dry weight in sprouts and roots, respectively). During flowering and silique forming stages, the roots still maintained lower amount of total GLS (7.4μmolg(-1) of dry weight, on average) with respect to the epigeous tissues, in which mature and young leaves showed the highest total concentrations (70.5 and 73.8μmolg(-1) of dry weight on average, respectively). Regardless of the phenological stages, the aliphatic GLS were always predominant in all tissues (95%) followed by indolic (2.6%) and benzenic (2.4%) GLS. Sinigrin contributed more than 90% of the total GLS concentration. Aliphatic GLS concentrations were much higher in the epigeous tissues, particularly in the mature and young leaves, while benzenic and indolic GLS concentrations were higher in the roots. Through the phenological stages, GLS concentration increased in young and mature leaves and decreased in cauline leaves and inflorescences

  9. Effect of winter cold duration on spring phenology of the orange tip butterfly, Anthocharis cardamines.

    Science.gov (United States)

    Stålhandske, Sandra; Lehmann, Philipp; Pruisscher, Peter; Leimar, Olof

    2015-12-01

    The effect of spring temperature on spring phenology is well understood in a wide range of taxa. However, studies on how winter conditions may affect spring phenology are underrepresented. Previous work on Anthocharis cardamines (orange tip butterfly) has shown population-specific reaction norms of spring development in relation to spring temperature and a speeding up of post-winter development with longer winter durations. In this experiment, we examined the effects of a greater and ecologically relevant range of winter durations on post-winter pupal development of A. cardamines of two populations from the United Kingdom and two from Sweden. By analyzing pupal weight loss and metabolic rate, we were able to separate the overall post-winter pupal development into diapause duration and post-diapause development. We found differences in the duration of cold needed to break diapause among populations, with the southern UK population requiring a shorter duration than the other populations. We also found that the overall post-winter pupal development time, following removal from winter cold, was negatively related to cold duration, through a combined effect of cold duration on diapause duration and on post-diapause development time. Longer cold durations also lead to higher population synchrony in hatching. For current winter durations in the field, the A. cardamines population of southern UK could have a reduced development rate and lower synchrony in emergence because of short winters. With future climate change, this might become an issue also for other populations. Differences in winter conditions in the field among these four populations are large enough to have driven local adaptation of characteristics controlling spring phenology in response to winter duration. The observed phenology of these populations depends on a combination of winter and spring temperatures; thus, both must be taken into account for accurate predictions of phenology.

  10. Modeling winter wheat phenological responses to water deficits in the Unified Plant Growth Model (UPGM) component of the spatially distributed Agricultural Ecosystem Services (AgES) model

    Science.gov (United States)

    Accurately predicting phenology in crop simulation models is critical for correctly simulating crop production. While extensive work in modeling phenology has focused on the temperature response function (resulting in robust phenology models), limited work on quantifying the phenological responses t...

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

    Directory of Open Access Journals (Sweden)

    Santosh Bhandari

    2012-06-01

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

  12. Atmospheric teleconnection influence on North American land surface phenology

    Science.gov (United States)

    Dannenberg, Matthew P.; Wise, Erika K.; Janko, Mark; Hwang, Taehee; Kolby Smith, W.

    2018-03-01

    Short-term forecasts of vegetation activity are currently not well constrained due largely to our lack of understanding of coupled climate-vegetation dynamics mediated by complex interactions between atmospheric teleconnection patterns. Using ecoregion-scale estimates of North American vegetation activity inferred from remote sensing (1982-2015), we examined seasonal and spatial relationships between land surface phenology and the atmospheric components of five teleconnection patterns over the tropical Pacific, north Pacific, and north Atlantic. Using a set of regression experiments, we also tested for interactions among these teleconnection patterns and assessed predictability of vegetation activity solely based on knowledge of atmospheric teleconnection indices. Autumn-to-winter composites of the Southern Oscillation Index (SOI) were strongly correlated with start of growing season timing, especially in the Pacific Northwest. The two leading modes of north Pacific variability (the Pacific-North American, PNA, and West Pacific patterns) were significantly correlated with start of growing season timing across much of southern Canada and the upper Great Lakes. Regression models based on these Pacific teleconnections were skillful predictors of spring phenology across an east-west swath of temperate and boreal North America, between 40°N-60°N. While the North Atlantic Oscillation (NAO) was not strongly correlated with start of growing season timing on its own, we found compelling evidence of widespread NAO-SOI and NAO-PNA interaction effects. These results suggest that knowledge of atmospheric conditions over the Pacific and Atlantic Oceans increases the predictability of North American spring phenology. A more robust consideration of the complexity of the atmospheric circulation system, including interactions across multiple ocean basins, is an important step towards accurate forecasts of vegetation activity.

  13. Arvustuse piirid ja auhinnad : mõtteid kirjanduskriitikast vol 2 / Jan Kaus

    Index Scriptorium Estoniae

    Kaus, Jan, 1971-

    2007-01-01

    Tänapäeva eesti kirjanduskriitikast. Vt. ka vol. 1: Kaus, Jan. Eetika, taburetiefekt ja jätkuv objektivisatsioon, Sirp, 15. juuni., lk. 7. Vastukaja: Raudam, Toomas. Arvustuse piiritused //Sirp (2007) 10. aug., lk. 9

  14. 49 CFR 176.96 - Materials of construction.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Materials of construction. 176.96 Section 176.96 Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS SAFETY... Requirements for Barges § 176.96 Materials of construction. Barges used to transport hazardous materials must...

  15. Discriminating the Mediterranean Pinus spp. using the land surface phenology extracted from the whole MODIS NDVI time series and machine learning algorithms

    Science.gov (United States)

    Rodriguez-Galiano, Victor; Aragones, David; Caparros-Santiago, Jose A.; Navarro-Cerrillo, Rafael M.

    2017-10-01

    Land surface phenology (LSP) can improve the characterisation of forest areas and their change processes. The aim of this work was: i) to characterise the temporal dynamics in Mediterranean Pinus forests, and ii) to evaluate the potential of LSP for species discrimination. The different experiments were based on 679 mono-specific plots for the 5 native species on the Iberian Peninsula: P. sylvestris, P. pinea, P. halepensis, P. nigra and P. pinaster. The entire MODIS NDVI time series (2000-2016) of the MOD13Q1 product was used to characterise phenology. The following phenological parameters were extracted: the start, end and median days of the season, and the length of the season in days, as well as the base value, maximum value, amplitude and integrated value. Multi-temporal metrics were calculated to synthesise the inter-annual variability of the phenological parameters. The species were discriminated by the application of Random Forest (RF) classifiers from different subsets of variables: model 1) NDVI-smoothed time series, model 2) multi-temporal metrics of the phenological parameters, and model 3) multi-temporal metrics and the auxiliary physical variables (altitude, slope, aspect and distance to the coastline). Model 3 was the best, with an overall accuracy of 82%, a kappa coefficient of 0.77 and whose most important variables were: elevation, coast distance, and the end and start days of the growing season. The species that presented the largest errors was P. nigra, (kappa= 0.45), having locations with a similar behaviour to P. sylvestris or P. pinaster.

  16. Machine learning modeling of plant phenology based on coupling satellite and gridded meteorological dataset

    Science.gov (United States)

    Czernecki, Bartosz; Nowosad, Jakub; Jabłońska, Katarzyna

    2018-04-01

    Changes in the timing of plant phenological phases are important proxies in contemporary climate research. However, most of the commonly used traditional phenological observations do not give any coherent spatial information. While consistent spatial data can be obtained from airborne sensors and preprocessed gridded meteorological data, not many studies robustly benefit from these data sources. Therefore, the main aim of this study is to create and evaluate different statistical models for reconstructing, predicting, and improving quality of phenological phases monitoring with the use of satellite and meteorological products. A quality-controlled dataset of the 13 BBCH plant phenophases in Poland was collected for the period 2007-2014. For each phenophase, statistical models were built using the most commonly applied regression-based machine learning techniques, such as multiple linear regression, lasso, principal component regression, generalized boosted models, and random forest. The quality of the models was estimated using a k-fold cross-validation. The obtained results showed varying potential for coupling meteorological derived indices with remote sensing products in terms of phenological modeling; however, application of both data sources improves models' accuracy from 0.6 to 4.6 day in terms of obtained RMSE. It is shown that a robust prediction of early phenological phases is mostly related to meteorological indices, whereas for autumn phenophases, there is a stronger information signal provided by satellite-derived vegetation metrics. Choosing a specific set of predictors and applying a robust preprocessing procedures is more important for final results than the selection of a particular statistical model. The average RMSE for the best models of all phenophases is 6.3, while the individual RMSE vary seasonally from 3.5 to 10 days. Models give reliable proxy for ground observations with RMSE below 5 days for early spring and late spring phenophases. For

  17. Simulating phenological shifts in French temperate forests under two climatic change scenarios and four driving global circulation models

    Science.gov (United States)

    Lebourgeois, François; Pierrat, Jean-Claude; Perez, Vincent; Piedallu, Christian; Cecchini, Sébastien; Ulrich, Erwin

    2010-09-01

    After modeling the large-scale climate response patterns of leaf unfolding, leaf coloring and growing season length of evergreen and deciduous French temperate trees, we predicted the effects of eight future climate scenarios on phenological events. We used the ground observations from 103 temperate forests (10 species and 3,708 trees) from the French Renecofor Network and for the period 1997-2006. We applied RandomForest algorithms to predict phenological events from climatic and ecological variables. With the resulting models, we drew maps of phenological events throughout France under present climate and under two climatic change scenarios (A2, B2) and four global circulation models (HadCM3, CGCM2, CSIRO2 and PCM). We compared current observations and predicted values for the periods 2041-2070 and 2071-2100. On average, spring development of oaks precedes that of beech, which precedes that of conifers. Annual cycles in budburst and leaf coloring are highly correlated with January, March-April and October-November weather conditions through temperature, global solar radiation or potential evapotranspiration depending on species. At the end of the twenty-first century, each model predicts earlier budburst (mean: 7 days) and later leaf coloring (mean: 13 days) leading to an average increase in the growing season of about 20 days (for oaks and beech stands). The A2-HadCM3 hypothesis leads to an increase of up to 30 days in many areas. As a consequence of higher predicted warming during autumn than during winter or spring, shifts in leaf coloring dates appear greater than trends in leaf unfolding. At a regional scale, highly differing climatic response patterns were observed.

  18. Recent lake ice-out phenology within and among lake districts of Alaska, U.S.A.

    Science.gov (United States)

    Arp, Christopher D.; Jones, Benjamin M.; Grosse, Guido

    2013-01-01

    The timing of ice-out in high latitudes is a fundamental threshold for lake ecosystems and an indicator of climate change. In lake-rich regions, the loss of ice cover also plays a key role in landscape and climatic processes. Thus, there is a need to understand lake ice phenology at multiple scales. In this study, we observed ice-out timing on 55 large lakes in 11 lake districts across Alaska from 2007 to 2012 using satellite imagery. Sensor networks in two lake districts validated satellite observations and provided comparison with smaller lakes. Over this 6 yr period, the mean lake ice-out for all lakes was 27 May and ranged from 07 May in Kenai to 06 July in Arctic Coastal Plain lake districts with relatively low inter-annual variability. Approximately 80% of the variation in ice-out timing was explained by the date of 0°C air temperature isotherm and lake area. Shoreline irregularity, watershed area, and river connectivity explained additional variation in some districts. Coherence in ice-out timing within the lakes of each district was consistently strong over this 6 yr period, ranging from r-values of 0.5 to 0.9. Inter-district analysis of coherence also showed synchronous ice-out patterns with the exception of the two arctic coastal districts where ice-out occurs later (June–July) and climatology is sea-ice influenced. These patterns of lake ice phenology provide a spatially extensive baseline describing short-term temporal variability, which will help decipher longer term trends in ice phenology and aid in representing the role of lake ice in land and climate models in northern landscapes.

  19. Flowering phenology, growth forms, and pollination syndromes in tropical dry forest species: Influence of phylogeny and abiotic factors.

    Science.gov (United States)

    Cortés-Flores, Jorge; Hernández-Esquivel, Karen Beatriz; González-Rodríguez, Antonio; Ibarra-Manríquez, Guillermo

    2017-01-01

    Analyses of the influence of temporal variation in abiotic factors on flowering phenology of tropical dry forest species have not considered the possible response of species with different growth forms and pollination syndromes, while controlling for phylogenetic relationships among species. Here, we investigated the relationship between flowering phenology, abiotic factors, and plant functional attributes, while controlling for phylogenetic relationship among species, in a dry forest community in Mexico. We characterized flowering phenology (time and duration) and pollination syndromes of 55 tree species, 49 herbs, 24 shrubs, 15 lianas, and 11 vines. We tested the influence of pollination syndrome, growth form, and abiotic factors on flowering phenology using phylogenetic generalized least squares. We found a relationship between flowering duration and time. Growth form was related to flowering time, and the pollination syndrome had a more significant relationship with flowering duration. Flowering time variation in the community was explained mainly by abiotic variables, without an important phylogenetic effect. Flowering time in lianas and trees was negatively and positively correlated with daylength, respectively. Functional attributes, environmental cues, and phylogeny interact with each other to shape the diversity of flowering patterns. Phenological differentiation among species groups revealed multiples strategies associated with growth form and pollination syndromes that can be important for understanding species coexistence in this highly diverse plant community. © 2017 Botanical Society of America.

  20. Model estimates of leaf area and reference canopy stomatal conductance suggest correlation between phenology and physiology in both trembling aspen and red pine

    Science.gov (United States)

    Mackay, D. S.; Ewers, B. E.; Kruger, E. L.

    2006-12-01

    Phenological variations impact water and carbon fluxes, as evidenced by the large interannual variability of net ecosystem exchange of carbon dioxide and evapotranspiration (ET). In northern Wisconsin we observed daily variations of canopy transpiration from hardwoods from 1.0 to 1.7 mm/day during the leaf unfolding period and 1.7 to 2.6 mm/day with leaves fully out. Correlations between such flux rates and phenology have not been extensively tested and mechanistic connections are in their infancy. Some data suggest that stomatal conductance and photosynthesis increases up to full expansion. Moreover, in conifers, the interaction of phenology and physiology is more complicated than in deciduous trees because needles are retained for several years. Using inverse modeling with a coupled photosynthesis-transpiration model we estimated reference canopy stomatal conductance, Gsref, for red pine (Pinus resinosa), and Gsref and leaf area index, L, for trembling aspen (Populus tremuloides), using 30-min continuous sap flux data spanning a period from just prior to the start of leaf expansion to just after leaf senescence. The red pine showed Gsref ramp up from 105 to 179 mmol m-2 leaf s-1, which represented a 37 to 50 percent increase in Gsref after accounting for maximum possible changes in L. After full leaf out, the trembling aspen were almost immediately defoliated, and then reflushed after three weeks. Model estimates of L reflected this pattern and were consistent with measurements. However, Gsref never exceeded 45 mmol m-2 s-1 prior to defoliation, but peaked at 112 mmol m-2 s-1 after reflushing. These results support the need for further work that aims to separate phenology and physiology.

  1. Phenological Stages of Development of Tribulus terrestris L. (Zygophyllaceae R. Br.) Under the Conditions of the Thracian Lowland Floristic Region of Bulgaria

    OpenAIRE

    SEMERDJIEVA, Ivanka; TAHSINT, Nuretin; YANKOVATSVETKOVA, Elina

    2015-01-01

    The phenological stages of Tribulus terrestris L. in the Thracian Lowland floristic region of Bulgaria were studied. Growth characteristics of the species, the length of the vegetation period and the duration of each phenological stage were studied in three consecutive years. A detailed phonological spectrum was presented. A direct relation was established between the duration of the phenological stages, the calendar periods and the climatic features of the respective year

  2. Hydrological Controls on Floodplain Forest Phenology Assessed using Remotely Sensed Vegetation Indices

    Science.gov (United States)

    Lemon, M. G.; Keim, R.

    2017-12-01

    Although specific controls are not well understood, the phenology of temperate forests is generally thought to be controlled by photoperiod and temperature, although recent research suggests that soil moisture may also be important. The phenological controls of forested wetlands have not been thoroughly studied, and may be more controlled by site hydrology than other forests. For this study, remotely sensed vegetation indices were used to investigate hydrological controls on start-of-season timing, growing season length, and end-of-season timing at five floodplains in Louisiana, Arkansas, and Texas. A simple spring green-up model was used to determine the null spring start of season time for each site as a function of land surface temperature and photoperiod, or two remotely sensed indices: MODIS phenology data product and the MODIS Nadir Bidirectional Reflectance Distribution Function-Adjusted Reflectance (NBAR) product. Preliminary results indicate that topographically lower areas within the floodplain with higher flood frequency experience later start-of-season timing. In addition, start-of-season is delayed in wet years relative to predicted timing based solely on temperature and photoperiod. The consequences for these controls unclear, but results suggest hydrological controls on floodplain ecosystem structure and carbon budgets are likely at least partially expressed by variations in growing season length.

  3. Editor's welcome, PORTAL, Vol. 1, No. 2, July 2004

    Directory of Open Access Journals (Sweden)

    Paul Allatson

    2005-03-01

    Full Text Available Since the highly successful inauguration of PORTAL in January 2004, we have received many kind expressions of support from international studies practitioners in a range of fields, and from such places as Canada, Italy, Mexico, Nigeria, New Zealand, Spain, Trinidad, the U.K., and the U.S.A. Particularly gratifying have been the endorsements of the journal and its publishing aims by people involved in their own electronic publishing enterprises. For their generous responses to PORTAL, the Editorial Committee would like to express its collective appreciation to the following people: Professor Jean-Marie Volet, of the University of Western Australia, and the guiding editor of the ground-breaking e-journal Mots Pluriels (www.arts.uwa.edu.au/MotsPluriels; and Francis Leo Collins, member of the Editorial Committee for the Graduate Journal of Asia Pacific Studies (GJAPS, based in Auckland, New Zealand. PORTAL's readers may be interested in the current call for papers from GJAPS (www.arts.auckland.ac.nz/gjaps, for a special issue on "Imagining the Asia-Pacific" (deadline October 31, 2004. This issue of PORTAL contains essays that cover wide terrain: the Chilean diasporic community in Australia; the world of German intellectuals; contemporary Mexican socio-political movements; rural-urban migration in China; and transnational advocacy networks and election monitoring in the Philippines, Chile, Nicaragua and Mexico. In the cultural section of this issue, we are delighted to present a short story from the noted German Studies scholar Anthony Stephens, and the first half of a beautiful, deeply poetic and haunting novel entitled Son, from the London-based writer and art-critic Jennifer Higgie. The novel’s second and final part will appear in PORTAL vol. 2, no. 1, in January 2005. On a different note, we would like to express our support for the inaugural Ubud Writers and Readers Festival, to be held in Ubud, Bali, from October 11 to 17, 2004. The Festival

  4. Terrestrial biosphere models need better representation of vegetation phenology: results from the North American Carbon Program Site Synthesis

    Science.gov (United States)

    Andrew D. Richardson; Ryan S. Anderson; M. Altaf Arain; Alan G. Barr; Gil Bohrer; Guangsheng Chen; Jing M. Chen; Philippe Ciais; Kenneth J. David; Ankur R. Desai; Michael C. Dietze; Danilo Dragoni; Steven R. Garrity; Christopher M. Gough; Robert Grant; David Hollinger; Hank A. Margolis; Harry McCaughey; Mirco Migliavacca; Russel K. Monson; J. William Munger; Benjamin Poulter; Brett M. Raczka; Daniel M. Ricciuto; Alok K. Sahoo; Kevin Schaefer; Hanqin Tian; Rodrigo Vargas; Hans Verbeeck; Jingfeng Xiao; Yongkang. Xue

    2012-01-01

    Phenology, by controlling the seasonal activity of vegetation on the land surface, plays a fundamental role in regulating photosynthesis and other ecosystem processes, as well as competitive interactions and feedbacks to the climate system. We conducted an analysis to evaluate the representation of phenology, and the associated seasonality of ecosystem-scale CO

  5. Nesting phenology of marine turtles: insights from a regional comparative analysis on green turtle (Chelonia mydas.

    Directory of Open Access Journals (Sweden)

    Mayeul Dalleau

    Full Text Available Changes in phenology, the timing of seasonal activities, are among the most frequently observed responses to environmental disturbances and in marine species are known to occur in response to climate changes that directly affects ocean temperature, biogeochemical composition and sea level. We examined nesting seasonality data from long-term studies at 8 green turtle (Chelonia mydas rookeries that include 21 specific nesting sites in the South-West Indian Ocean (SWIO. We demonstrated that temperature drives patterns of nesting seasonality at the regional scale. We found a significant correlation between mean annual Sea Surface Temperature (SST and dates of peak nesting with rookeries exposed to higher SST having a delayed nesting peak. This supports the hypothesis that temperature is the main factor determining peak nesting dates. We also demonstrated a spatial synchrony in nesting activity amongst multiple rookeries in the northern part of the SWIO (Aldabra, Glorieuses, Mohéli, Mayotte but not with the eastern and southern rookeries (Europa, Tromelin, differences which could be attributed to females with sharply different adult foraging conditions. However, we did not detect a temporal trend in the nesting peak date over the study period or an inter-annual relation between nesting peak date and SST. The findings of our study provide a better understanding of the processes that drive marine species phenology. The findings will also help to predict their ability to cope with climate change and other environmental perturbations. Despite demonstrating this spatial shift in nesting phenology, no trend in the alteration of nesting dates over more than 20 years was found.

  6. Community patterns of tropical tree phenology derived from Unmanned Aerial Vehicle images: intra- and interspecific variation, association with species plant traits, and response to interannual climate variation

    Science.gov (United States)

    Bohlman, Stephanie; Rifai, Sami; Park, John; Dandois, Jonathan; Muller-Landau, Helene

    2017-04-01

    Phenology is a key life history trait of plant species and critical driver of ecosystem processes. There is strong evidence that phenology is shifting in temperate ecosystems in response to climate change, but tropical forest phenology remains poorly quantified and understood. A key challenge is that tropical forests contain hundreds of plant species with a wide variety of phenological patterns, which makes it difficult to collect sufficient ground-based field data to characterize individual tropical tree species phenologies. Satellite-based observations, an important source of phenology data in northern latitudes, are hindered by frequent cloud cover in the tropics. To quantify phenology over a large number of individuals and species, we collected bi-weekly images from unmanned aerial vehicles (UAVs) in the well-studied 50-ha forest inventory plot on Barro Colorado Island, Panama. The objective of this study is to quantify inter- and intra-specific responses of tropical tree leaf phenology to environmental variation over large spatial scales and identify key environmental variables and physiological mechanisms underpinning phenological variation. Between October 2014 and December 2015 and again in May 2015, we collected a total of 35 sets of UAV images, each with continuous coverage of the 50-ha plot, where every tree ≥ 1 cm DBH is mapped. UAV imagery was corrected for exposure, orthorectified, and then processed to extract spectral, texture, and image information for individual tree crowns, which was then used as inputs for a machine learning algorithm that successfully predicted the percentages of leaf, branch, and flower cover for each tree crown (r2=0.76 between observed and predicted percent branch cover for individual tree crowns). We then quantified cumulative annual deciduousness for each crown by fitting a non-parametric curve of flexible shape to its predicted percent branch time series and calculated the area under the curve. We obtained the species

  7. Michele Renee Salzman, Marvina A. Sweeney & William Adler (eds., The Cambridge History of Religions in the Ancient World (2 vols. (New York: Cambridge University Press, 2013

    Directory of Open Access Journals (Sweden)

    Giorgio Baruchello

    2014-03-01

    Full Text Available Review of: Michele Renee Salzman, Marvina A. Sweeney & William Adler (eds., The Cambridge History of Religions in the Ancient World (2 vols. (New York: Cambridge University Press, 2013

  8. Multi-phenology WorldView-2 imagery improves remote sensing of savannah tree species

    Science.gov (United States)

    Madonsela, Sabelo; Cho, Moses Azong; Mathieu, Renaud; Mutanga, Onisimo; Ramoelo, Abel; Kaszta, Żaneta; Kerchove, Ruben Van De; Wolff, Eléonore

    2017-06-01

    Biodiversity mapping in African savannah is important for monitoring changes and ensuring sustainable use of ecosystem resources. Biodiversity mapping can benefit from multi-spectral instruments such as WorldView-2 with very high spatial resolution and a spectral configuration encompassing important spectral regions not previously available for vegetation mapping. This study investigated i) the benefits of the eight-band WorldView-2 (WV-2) spectral configuration for discriminating tree species in Southern African savannah and ii) if multiple-images acquired at key points of the typical phenological development of savannahs (peak productivity, transition to senescence) improve on tree species classifications. We first assessed the discriminatory power of WV-2 bands using interspecies-Spectral Angle Mapper (SAM) via Band Add-On procedure and tested the spectral capability of WorldView-2 against simulated IKONOS for tree species classification. The results from interspecies-SAM procedure identified the yellow and red bands as the most statistically significant bands (p = 0.000251 and p = 0.000039 respectively) in the discriminatory power of WV-2 during the transition from wet to dry season (April). Using Random Forest classifier, the classification scenarios investigated showed that i) the 8-bands of the WV-2 sensor achieved higher classification accuracy for the April date (transition from wet to dry season, senescence) compared to the March date (peak productivity season) ii) the WV-2 spectral configuration systematically outperformed the IKONOS sensor spectral configuration and iii) the multi-temporal approach (March and April combined) improved the discrimination of tress species and produced the highest overall accuracy results at 80.4%. Consistent with the interspecies-SAM procedure, the yellow (605 nm) band also showed a statistically significant contribution in the improved classification accuracy from WV-2. These results highlight the mapping opportunities

  9. Phenologically-tuned MODIS NDVI-based production anomaly estimates for Zimbabwe

    Science.gov (United States)

    Funk, Chris; Budde, Michael E.

    2009-01-01

    For thirty years, simple crop water balance models have been used by the early warning community to monitor agricultural drought. These models estimate and accumulate actual crop evapotranspiration, evaluating environmental conditions based on crop water requirements. Unlike seasonal rainfall totals, these models take into account the phenology of the crop, emphasizing conditions during the peak grain filling phase of crop growth. In this paper we describe an analogous metric of crop performance based on time series of Moderate Resolution Imaging Spectroradiometer (MODIS) Normalized Difference Vegetation Index (NDVI) imagery. A special temporal filter is used to screen for cloud contamination. Regional NDVI time series are then composited for cultivated areas, and adjusted temporally according to the timing of the rainy season. This adjustment standardizes the NDVI response vis-??-vis the expected phenological response of maize. A national time series index is then created by taking the cropped-area weighted average of the regional series. This national time series provides an effective summary of vegetation response in agricultural areas, and allows for the identification of NDVI green-up during grain filling. Onset-adjusted NDVI values following the grain filling period are well correlated with U.S. Department of Agriculture production figures, possess desirable linear characteristics, and perform better than more common indices such as maximum seasonal NDVI or seasonally averaged NDVI. Thus, just as appropriately calibrated crop water balance models can provide more information than seasonal rainfall totals, the appropriate agro-phenological filtering of NDVI can improve the utility and accuracy of space-based agricultural monitoring.

  10. Effects of heavy-metal-contaminated soil on growth, phenology and biomass turnover of Hieracium piloselloides

    International Nuclear Information System (INIS)

    Ryser, Peter; Sauder, Wendy R.

    2006-01-01

    The effects of low levels of heavy metals on plant growth, biomass turnover and reproduction were investigated for Hieracium pilosella. Plants were grown for 12 weeks on substrates with different concentrations of heavy metals obtained by diluting contaminated soils with silica sand. To minimize effects of other soil factors, the substrates were limed, fertilized, and well watered. The more metal-contaminated soil the substrate contained, the lower the leaf production rate and the plant mass were, and the more the phenological development was delayed. Flowering phenology was very sensitive to metals. Leaf life span was reduced at the highest and the lowest metal levels, the latter being a result of advanced seed ripening. Even if the effect of low metal levels on plant growth may be small, the delayed and reduced reproduction may have large effects at population, community and ecosystem level, and contribute to rapid evolution of metal tolerance. - Flowering phenology shows a very sensitive response to heavy metal contamination of soils

  11. Phenological and ecological consequences of changes in winter snowpack in the Colorado Rocky Mountains

    Science.gov (United States)

    Inouye, D. W.; McKinney, A. M.

    2012-12-01

    The date the snowpack disappears in spring is an important seasonal event at high altitudes because it determines the beginning of the growing season, which in turn influences the phenology of plant growth and flowering, and thus the availability of these resources for animal consumers. At our study site at 2,900m in the Colorado Rocky Mountains, the Rocky Mountain Biological Laboratory, snowmelt now averages two weeks earlier than in 1975. Earlier snowmelt results from a combination of lower snowfall (38 cm less since 1975), dust storms (increasing in frequency, which reduces the snowpack albedo), and warmer spring temperatures (April minimum temperature has increased 3.1°C since 1973; 2012 April mean temperature was 3.4°C above the 38-year mean). There is also a trend of increasing annual precipitation falling as rain instead of snow. We have monitored flowering phenology and abundance for about 100 species of plants in permanent plots since 1973, and use this record to look at how the change in timing of snowmelt has affected flowering. There is significant variation among years in flowering phenology (e.g., about six weeks difference between 2011 and 2012), with a mid-season decline in flowering abundance becoming apparent as the growing season starts earlier. The date of the last hard frost has not been changing in concert with the earlier growing season, with the consequence that many species now have flower buds developed that are then damaged or killed by frost. In 2012, snowmelt date was 23 April, and frost events on 27 May (-11.7°C) and 11 June (-5.6°C) did significant damage to vegetation of some species and to flower buds of many species. For example, flower abundance of the aspen sunflower Helianthella quinquenervis was 0.002% of 2011's flowering. In the absence of seed production, the demography of some plant species is likely being affected. Some animal species are also being affected by the changes in length and temperature of winter. New

  12. Backbending in the N = 96 isotones

    International Nuclear Information System (INIS)

    Michel, C.; Vervier, J.

    1981-01-01

    The backbending in the even-even, N = 96 isotones can be quantitatively accounted for by the rotation-alignment of the spins of neutrons in i 13/2 orbits, as shown by comparing the aligned angular momentum and relative Routhian for the s-bands in these isotones and for the i 13/2 bands in the corresponding isotopes with N = 97. The influence of protons on this backbending situation is shown to be indirect, acting through a change of the nuclear deformation, which yields a change of the moment of inertia of the g.s. band and of the non-rigid character of the rotation. The experimental data on the N = 96 and 97 isotones are in reasonable agreement with cranking model calculations. Possible reasons for the inhibition of backbending in the h 9/2 proton bands in the odd-Z, N = 96 isotones, all related to a change of deformation, are presented. (orig.)

  13. Integrating models to investigate critical phenological overlaps in complex ecological interactions: The mountain pine beetle-fungus symbiosis

    Science.gov (United States)

    Audrey Addison; James A. Powell; Barbara J. Bentz; Diana L. Six

    2015-01-01

    The fates of individual species are often tied to synchronization of phenology, however, few methods have been developed for integrating phenological models involving linked species. In this paper, we focus on mountain pine beetle (MPB, Dendroctonus ponderosae) and its two obligate mutualistic fungi, Grosmannia clavigera and Ophiostoma montium. Growth rates of...

  14. Growth and phenology of three dwarf shrub species in a six-year soil warming experiment at the alpine treeline.

    Science.gov (United States)

    Anadon-Rosell, Alba; Rixen, Christian; Cherubini, Paolo; Wipf, Sonja; Hagedorn, Frank; Dawes, Melissa A

    2014-01-01

    Global warming can have substantial impacts on the phenological and growth patterns of alpine and Arctic species, resulting in shifts in plant community composition and ecosystem dynamics. We evaluated the effects of a six-year experimental soil warming treatment (+4°C, 2007-2012) on the phenology and growth of three co-dominant dwarf shrub species growing in the understory of Larix decidua and Pinus uncinata at treeline in the Swiss Alps. We monitored vegetative and reproductive phenology of Vaccinium myrtillus, Vaccinium gaultherioides and Empetrum hermaphroditum throughout the early growing season of 2012 and, following a major harvest at peak season, we measured the biomass of above-ground ramet fractions. For all six years of soil warming we measured annual shoot growth of the three species and analyzed ramet age and xylem ring width of V. myrtillus. Our results show that phenology of the three species was more influenced by snowmelt timing, and also by plot tree species (Larix or Pinus) in the case of V. myrtillus, than by soil warming. However, the warming treatment led to increased V. myrtillus total above-ground ramet biomass (+36% in 2012), especially new shoot biomass (+63% in 2012), as well as increased new shoot increment length and xylem ring width (+22% and +41%, respectively; average for 2007-2012). These results indicate enhanced overall growth of V. myrtillus under soil warming that was sustained over six years and was not caused by an extended growing period in early summer. In contrast, E. hermaphroditum only showed a positive shoot growth response to warming in 2011 (+21%), and V. gaultherioides showed no significant growth response. Our results indicate that V. myrtillus might have a competitive advantage over the less responsive co-occurring dwarf shrub species under future global warming.

  15. Growth and phenology of three dwarf shrub species in a six-year soil warming experiment at the alpine treeline.

    Directory of Open Access Journals (Sweden)

    Alba Anadon-Rosell

    Full Text Available Global warming can have substantial impacts on the phenological and growth patterns of alpine and Arctic species, resulting in shifts in plant community composition and ecosystem dynamics. We evaluated the effects of a six-year experimental soil warming treatment (+4°C, 2007-2012 on the phenology and growth of three co-dominant dwarf shrub species growing in the understory of Larix decidua and Pinus uncinata at treeline in the Swiss Alps. We monitored vegetative and reproductive phenology of Vaccinium myrtillus, Vaccinium gaultherioides and Empetrum hermaphroditum throughout the early growing season of 2012 and, following a major harvest at peak season, we measured the biomass of above-ground ramet fractions. For all six years of soil warming we measured annual shoot growth of the three species and analyzed ramet age and xylem ring width of V. myrtillus. Our results show that phenology of the three species was more influenced by snowmelt timing, and also by plot tree species (Larix or Pinus in the case of V. myrtillus, than by soil warming. However, the warming treatment led to increased V. myrtillus total above-ground ramet biomass (+36% in 2012, especially new shoot biomass (+63% in 2012, as well as increased new shoot increment length and xylem ring width (+22% and +41%, respectively; average for 2007-2012. These results indicate enhanced overall growth of V. myrtillus under soil warming that was sustained over six years and was not caused by an extended growing period in early summer. In contrast, E. hermaphroditum only showed a positive shoot growth response to warming in 2011 (+21%, and V. gaultherioides showed no significant growth response. Our results indicate that V. myrtillus might have a competitive advantage over the less responsive co-occurring dwarf shrub species under future global warming.

  16. Proceedings of the second international conference on environmental impact assessment of all economical activities. Vol. 1

    International Nuclear Information System (INIS)

    1993-01-01

    Proceedings of the conference consist of 3 volumes: Vol. 1 - 'Environmental Impact Assessment of all Economical Activities including Industry'; Vol. 2 - 'Air Pollution Control and Prevention'; Vol. 3 - Waste Management and Environmental Problems in Construction Industry'. Out of 32 papers contained in Vol. 1, 2 were inputted to INIS. They deal with models of radionuclide transport in food chains and the use of aerial monitoring in the study of environmental contamination. (Z.S.)

  17. Analysis of purified gp96 preparations from rat and mouse livers using 2-D gel electrophoresis and tandem mass spectrometry.

    Science.gov (United States)

    Fairburn, B; Muthana, M; Hopkinson, K; Slack, L K; Mirza, S; Georgiou, A S; Espigares, E; Wong, C; Pockley, A G

    2006-09-01

    The stress protein gp96 exhibits a number of immunological activities, the majority of studies into which have used gp96 purified from a variety of tissues. On the basis of 1-D gel electrophoresis, the purity of these preparations has been reported to range between 70% and 99%. This study analyzed gp96 preparations from rat and mouse livers using 2-D gel electrophoresis and liquid chromatography electrospray ionization tandem mass spectrometry (MS-MS). The procedure for purifying gp96 was reproducible, as similar protein profiles were observed in replicate gels of gp96 preparations. The purity of the preparations was typically around 70%, with minor co-purified proteins of varying molecular weights and mobilities being present. Dominant bands at 95-100 kDa in preparations from Wistar rats and C57BL/6 mice were identified as gp96 by ECL Western blotting. Multiple bands having similar, yet distinct molecular weights and differing pI mobility on ECL Western blots were confirmed as being gp96 in preparations from Wistar rats using MS-MS. The most striking feature of the 2-D gel analysis was the presence of additional dominant bands at 55 kDa in preparations from Wistar rats, and at 75-90 kDa in preparations from C57BL/6 mice. These were identified as gp96 by ECL Western blotting and, in the case of preparations from Wistar rats, by MS-MS. Although the lower molecular weight, gp96-related molecules might be partially degraded gp96, their reproducible presence, definition and characteristics suggest that they are alternative, species-specific isoforms of the molecule. A 55 kDa protein which exhibited a lower pI value than gp96 was present in all preparations and this was identified as calreticulin, another putative immunoregulatory molecule. This study confirms the reproducibility of the gp96 purification protocol and reveals the presence of multiple gp96 isoforms, some of which likely result from post-translational modifications such as differential glycosylation and

  18. Phenology, growth, and fecundity as determinants of distribution in closely related nonnative taxa

    Science.gov (United States)

    Marushia, Robin G.; Brooks, Matthew L.; Holt, Jodie S.

    2012-01-01

    Invasive species researchers often ask: Why do some species invade certain habitats while others do not? Ecological theories predict that taxonomically related species may invade similar habitats, but some related species exhibit contrasting invasion patterns. Brassica nigra, Brassica tournefortii, and Hirschfeldia incana are dominant, closely related nonnative species that have overlapping, but dissimilar, distributions. Brassica tournefortii is rapidly spreading in warm deserts of the southwestern United States, whereas B. nigra and H. incana are primarily limited to semiarid and mesic regions. We compared traits of B. tournefortii that might confer invasiveness in deserts with those of related species that have not invaded desert ecosystems. Brassica tournefortii, B. nigra and H. incana were compared in controlled experiments conducted outdoors in a mesic site (Riverside, CA) and a desert site (Blue Diamond, NV), and in greenhouses, over 3 yr. Desert and mesic B. tournefortii populations were also compared to determine whether locally adapted ecotypes contribute to desert invasion. Experimental variables included common garden sites and soil water availability. Response variables included emergence, growth, phenology, and reproduction. There was no evidence for B. tournefortii ecotypes, but B. tournefortii had a more rapid phenology than B. nigra or H. incana. Brassica tournefortii was less affected by site and water availability than B. nigra and H. incana, but was smaller and less fecund regardless of experimental conditions. Rapid phenology allows B. tournefortii to reproduce consistently under variable, stressful conditions such as those found in Southwestern deserts. Although more successful in milder, mesic ecosystems, B. nigra and H. incana may be limited by their ability to reproduce under desert conditions. Rapid phenology and drought response partition invasion patterns of nonnative mustards along a gradient of aridity in the southwestern United States

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

    International Nuclear Information System (INIS)

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

    2014-01-01

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

  20. Local temperatures predict breeding phenology but do not result in breeding synchrony among a community of resident cavity-nesting birds.

    Science.gov (United States)

    Drake, Anna; Martin, Kathy

    2018-02-09

    Weather and ecological factors are known to influence breeding phenology and thus individual fitness. We predicted concordance between weather conditions and annual variation in phenology within a community of eight resident, cavity-nesting bird species over a 17-year period. We show that, although clutch initiation dates for six of our eight species are correlated with local daily maximum temperatures, this common driver does not produce a high degree of breeding synchrony due to species-specific responses to conditions during different periods of the preceding winter or spring. These "critical temperature periods" were positively associated with average lay date for each species, although the interval between critical periods and clutch initiation varied from 4-78 days. The ecological factors we examined (cavity availability and a food pulse) had an additional influence on timing in only one of our eight focal species. Our results have strong implications for understanding heterogeneous wildlife responses to climate change: divergent responses would be expected within communities where species respond to local conditions within different temporal windows, due to differing warming trends between winter and spring. Our system therefore indicates that climate change could alter relative breeding phenology among sympatric species in temperate ecosystems.

  1. Time-Dependent Trapping of Pollinators Driven by the Alignment of Floral Phenology with Insect Circadian Rhythms

    Directory of Open Access Journals (Sweden)

    Jenny Y. Y. Lau

    2017-06-01

    Full Text Available Several evolutionary lineages in the early divergent angiosperm family Annonaceae possess flowers with a distinctive pollinator trapping mechanism, in which floral phenological events are very precisely timed in relation with pollinator activity patterns. This contrasts with previously described angiosperm pollinator traps, which predominantly function as pitfall traps. We assess the circadian rhythms of pollinators independently of their interactions with flowers, and correlate these data with detailed assessments of floral phenology. We reveal a close temporal alignment between patterns of pollinator activity and the floral phenology driving the trapping mechanism (termed ‘circadian trapping’ here. Non-trapping species with anthesis of standard duration (c. 48 h cannot be pollinated effectively by pollinators with a morning-unimodal activity pattern; non-trapping species with abbreviated anthesis (23–27 h face limitations in utilizing pollinators with a bimodal circadian activity; whereas species that trap pollinators (all with short anthesis can utilize a broader range of potential pollinators, including those with both unimodal and bimodal circadian rhythms. In addition to broadening the range of potential pollinators based on their activity patterns, circadian trapping endows other selective advantages, including the possibility of an extended staminate phase to promote pollen deposition, and enhanced interfloral movement of pollinators. The relevance of the alignment of floral phenological changes with peaks in pollinator activity is furthermore evaluated for pitfall trap pollination systems.

  2. variability of in vitro and phenological behaviours of cocoa hybrids

    African Journals Online (AJOL)

    ACSS

    analyse the variability of the in vitro and phenological behaviours of 6 cocoa ... The 4 aforementioned hybrids could be used to produce cocoa aroma, ... hybrids using a multivariate approach. .... 3 clusters and variables was assessed through ... function, and (iv) analysis of the representation quality. Thus, the number of ...

  3. From South to North: flowering phenological responses at different geographical latitudes in 12 European countries

    Science.gov (United States)

    Szabó, Barbara; Lehoczky, Annamária; Filzmoser, Peter; Templ, Matthias; Szentkirályi, Ferenc; Pongrácz, Rita; Ortner, Thomas; Mert, Can; Czúcz, Bálint

    2014-05-01

    Phenological sensitivity of plants strongly depends on regional climate variability, moreover it is also influenced by large-scale atmospheric circulation patterns. Plants in different environmental conditions (determined by geographical latitude and longitude, altitude, continentality) may show diverse responses to climate change. The first results of an international cooperation aiming at the analysis of plant phenological data along a latitudinal gradient over 12 European countries (Macedonia, Bosnia and Herzegovina, Montenegro, Slovenia, Croatia, Hungary, Slovakia, Poland, Lithuania, Latvia, Estonia and Finland) are presented. The spatio-temporal changes in the flowering onset dates of common lilac (Syringa vulgaris L.) during the period of 1970-2000 were analysed. To characterise the environmental conditions driving the phenological responses, climatic variables (atmospheric pressure, air temperature, precipitation) obtained from a gridded observational dataset (E-OBS 9.0) and time series of the North Atlantic Oscillation (NAO) index were used. Preliminary results for this particular species found a gradual advance of mean flowering onsets along latitudes from 40° N to 65° N, at the rate of -0.12 to -0.32 day/year. Significant zonal differences were found in these rates, which can be explained by the sensitivity of flowering to climatic conditions while moving from Mediterranen to boreal regions of Europe. Thus our results were coherent with most observations in the literature, that higher latitudes can exhibit more pronounced responses, particularly in case of spring phenological events.

  4. Dispersal, phenology and predicted abundance of the larger grain ...

    African Journals Online (AJOL)

    The phenology and dispersal of the larger grain borer (LGB) in Africa is described, and comparisons are made between prediction of LGB numbers from laboratory studies and predictions from multiple linear models derived from trapping data in the field. The models were developed in Mexico and Kenya, using ...

  5. Extreme warm temperatures alter forest phenology and productivity in Europe

    Czech Academy of Sciences Publication Activity Database

    Crabbe, Richard A.; Dash, J.; Rodriguez-Galiano, V. F.; Janouš, Dalibor; Pavelka, Marian; Marek, Michal V.

    563-564, sep (2016), s. 486-495 ISSN 0048-9697 Institutional support: RVO:67179843 Keywords : land surface phenology * Envisat MTCI * anomalous temperature * climate variability * lagged effect * forest ecology Subject RIV: EH - Ecology, Behaviour Impact factor: 4.900, year: 2016

  6. USING PASSIVE AND ACTIVE MULTISPECTRAL SENSORS ON THE CORRELATION WITH THE PHENOLOGICAL INDICES OF COTTON

    OpenAIRE

    Souza, Heloisa B.; Baio, Fabio H. R.; Neves, Danilo C.

    2017-01-01

    ABSTRACT: The investment in precision agriculture technologies has been growing as well the investment in vegetation index sensors with different types of data collection. This study aimed to evaluate the NDVI potential use obtained from passive and active multispectral sensors as phenological parameters indicator of cotton growth. The experiment was conducted in cultivated cotton fields during the harvest seasons of 2013/14 and 2014/15. The phenological variables analyzed in the field, were ...

  7. Modeling the Effects of the Urban Built-Up Environment on Plant Phenology Using Fused Satellite Data

    Directory of Open Access Journals (Sweden)

    Norman Gervais

    2017-01-01

    Full Text Available Understanding the effects that the Urban Heat Island (UHI has on plant phenology is important in predicting ecological impacts of expanding cities and the impacts of the projected global warming. However, the underlying methods to monitor phenological events often limit this understanding. Generally, one can either have a small sample of in situ measurements or use satellite data to observe large areas of land surface phenology (LSP. In the latter, a tradeoff exists among platforms with some allowing better temporal resolution to pick up discrete events and others possessing the spatial resolution appropriate for observing heterogeneous landscapes, such as urban areas. To overcome these limitations, we applied the Spatial and Temporal Adaptive Reflectance Model (STARFM to fuse Landsat surface reflectance and MODIS nadir BRDF-adjusted reflectance (NBAR data with three separate selection conditions for input data across two versions of the software. From the fused images, we derived a time-series of high temporal and high spatial resolution synthetic Normalized Difference Vegetation Index (NDVI imagery to identify the dates of the start of the growing season (SOS, end of the season (EOS, and the length of the season (LOS. The results were compared between the urban and exurban developed areas within the vicinity of Ogden, UT and across all three data scenarios. The results generally show an earlier urban SOS, later urban EOS, and longer urban LOS, with variation across the results suggesting that phenological parameters are sensitive to input changes. Although there was strong evidence that STARFM has the potential to produce images capable of capturing the UHI effect on phenology, we recommend that future work refine the proposed methods and compare the results against ground events.

  8. Assessment of the phenology impact on SVAT modelling through a crop growth model over a Mediterranean crop site : Consequences on the water balance under climate change conditions.

    Science.gov (United States)

    Moulin, S.; Garrigues, S.; Olioso, A.; Ruget, F.; Desfonds, V.; Bertrand, N.; Lecharpentier, P.; Ripoche, D.; Launay, M.; Brisson, N.

    2012-04-01

    In the coming years, water resources and vegetation production of Mediterranean areas will be drastically affected by climate changes as well as intense and rapid changes in the land use. The impact of climate and land-use changes on water balance and vegetation production can be analysed and predicted through land surface models, provided that the uncertainties associated to these models and to the data used to run them are evaluated. Vegetation phenology is generally poorly taken into account in land surface models and may be a substantial source of uncertainties for global change scenario studies. In this paper, we discuss the improvement obtained in Soil Vegetation Atmosphere Transfer (SVAT) modelling by taking into account the phenology using a crop growth model, focusing on the water budget, over a Mediterranean crop site. The STICS model (Brisson et al, 1998) is used to simulate crop processes (growth and development, taking into account water and nitrogen exchanges between the environment and the crop). STICS describes the vegetation phenology very accurately and was validated for many types of crop and various pedoclimatic conditions. The SVAT model being analyzed is the a-gs version (Calvet et al., 1998) of the ISBA model (Noilhan et al, 1989), which simulates the photosynthesis and calculates the plant biomass and the Leaf Area Index (LAI) using a simple growth model. In STICS, the phenology is driven by the sum of daily air temperatures, which is quite realistic, while in ISBA, the phenology is driven by the plant carbon assimilation. Measurements (vegetation characteristics, soil properties, agricultural practises, energy and water balance) performed in the lower Rhone valley experimental area (Avignon, France) are used as well as long series of climatic data (past records and future simulations). In a first step, by running STICS and ISBA for maize and wheat crops with long series of climatic data, including future scenarios of climate (CLIMATOR

  9. The influence of life history traits on the phenological response of British butterflies to climate variability since the late-19th century

    OpenAIRE

    Brooks, Stephen J.; Self, Angela; Powney, Gary D.; Pearse, William D.; Penn, Malcolm; Paterson, Gordon L.J.

    2017-01-01

    Many species of plants and animals have advanced their phenology in response to climate warming in recent decades. Most of the evidence available for these shifts is based on data from the last few decades, a period coinciding with rapid climate warming. Baseline data is required to put these recent phenological changes in a long-term context. We analysed the phenological response of 51 resident British butterfly species using data from 83 500 specimens in the collections of the Natural Histo...

  10. Design Principle of A Small Angle Neutron Scattering Spectrometer. Vol. 2

    Energy Technology Data Exchange (ETDEWEB)

    Ashry, A [Dept. of Physics, Faculty of Education, Ain Shams University, Cairo (Egypt)

    1996-03-01

    The design principle of a small angle neutron scattering (SANS) spectrometer is based on producing monochromatic neutron bursts using two phased rotors. The rotors have a number of slots to achieve the highly available intensity of monoenergetic neutrons at the required resolution. The design principle was applied to improve the performance of the pulsed monochromatic double rotor system at ET-RR-1 to operate as SANS spectrometer. It is shown that for rotors having 19 slots each with radius of curvature 96.8 cm, the intensity gain factor is 13. The proposed SANS spectrometer could cover the neutron wavelength range from 2 A{sup {omicron}} up to 6 A{sup {omicron}} through small angles of scattering from 5 x 10{sup -3} rad. to 0.1 rad. i.e, the scattering wavevector transfer between 0.6 A{sup {omicron}-1} and 0.01 A{sup {omicron}-1}. The maximum neutron flux density on the specimen is 5 x 10{sup 5} n cm{sup -2} s{sup -1}. 8 figs.

  11. Index to Nuclear Safety: a technical progress review by chronology, permuted title, and author. Vol. 11(1)--Vol. 18(6)

    Energy Technology Data Exchange (ETDEWEB)

    Cottrell, W.B.; Klein, A.

    1978-04-11

    This index to Nuclear Safety covers articles published in Nuclear Safety, Vol. 11, No. 1 (January-February 1970), through Vol. 18, No. 6 (November-December 1977). It is divided into three sections: a chronological list of articles (including abstracts) followed by a permuted-title (KWIC) index and an author index. Nuclear Safety, a bimonthly technical progress review prepared by the Nuclear Safety Information Center (NSIC), covers all safety aspects of nuclear power reactors and associated facilities. Over 450 technical articles published in Nuclear Safety in the last eight years are listed in this index.

  12. Index to Nuclear Safety: a technical progress review by chronology, permuted title, and author. Vol. 11(1)--Vol. 18(6)

    International Nuclear Information System (INIS)

    Cottrell, W.B.; Klein, A.

    1978-01-01

    This index to Nuclear Safety covers articles published in Nuclear Safety, Vol. 11, No. 1 (January-February 1970), through Vol. 18, No. 6 (November-December 1977). It is divided into three sections: a chronological list of articles (including abstracts) followed by a permuted-title (KWIC) index and an author index. Nuclear Safety, a bimonthly technical progress review prepared by the Nuclear Safety Information Center (NSIC), covers all safety aspects of nuclear power reactors and associated facilities. Over 450 technical articles published in Nuclear Safety in the last eight years are listed in this index

  13. Adaptive value of phenological traits in stressful environments: predictions based on seed production and laboratory natural selection.

    Directory of Open Access Journals (Sweden)

    Benjamin Brachi

    Full Text Available Phenological traits often show variation within and among natural populations of annual plants. Nevertheless, the adaptive value of post-anthesis traits is seldom tested. In this study, we estimated the adaptive values of pre- and post-anthesis traits in two stressful environments (water stress and interspecific competition, using the selfing annual species Arabidopsis thaliana. By estimating seed production and by performing laboratory natural selection (LNS, we assessed the strength and nature (directional, disruptive and stabilizing of selection acting on phenological traits in A. thaliana under the two tested stress conditions, each with four intensities. Both the type of stress and its intensity affected the strength and nature of selection, as did genetic constraints among phenological traits. Under water stress, both experimental approaches demonstrated directional selection for a shorter life cycle, although bolting time imposes a genetic constraint on the length of the interval between bolting and anthesis. Under interspecific competition, results from the two experimental approaches showed discrepancies. Estimation of seed production predicted directional selection toward early pre-anthesis traits and long post-anthesis periods. In contrast, the LNS approach suggested neutrality for all phenological traits. This study opens questions on adaptation in complex natural environment where many selective pressures act simultaneously.

  14. Calling phenology of a diverse amphibian assemblage in response to meteorological conditions

    Science.gov (United States)

    Plenderleith, T. Lynette; Stratford, Danial; Lollback, Gregory W.; Chapple, David G.; Reina, Richard D.; Hero, Jean-Marc

    2017-12-01

    The strong association between amphibian activity, breeding and recruitment with local environmental conditions raises concerns regarding how changes in climate may affect the persistence of species populations into the future. Additionally, in a highly diverse assemblage of anurans, competition for breeding sites affects the time and duration of activity, as species compete for limited resources such as water. Meteorological conditions are strong drivers of amphibian activity, so we assessed whether temperature, rainfall, atmospheric pressure and humidity were associated with the calling phenology of an assemblage of anurans in South East Queensland, Australia. We performed calling surveys and collected digital recordings at 45 ponds in an area known for high anuran diversity. We performed detection analyses to investigate the influence of 10 meteorological variables in detection of calling activity in 19 amphibian species. Our results suggest four breeding strategies in the assemblage: explosive summer breeders, prolonged breeders, opportunistic breeders and a winter breeder. Classifying these species into associations provides a framework for understanding how species respond to environmental conditions. Explosive breeders (i.e. species demonstrating short and highly synchronised breeding periods) were particularly responsive to temperature. Our findings help elucidate the breeding phenology of frogs and provide valuable information on their mating systems in native Australian forests. This study highlights the difficulties of surveying even common anurans. We highlight the importance of predictability and stability in climate and the vulnerability of species for which reproduction appears to require highly specific environmental cues.

  15. Calling phenology of a diverse amphibian assemblage in response to meteorological conditions

    Science.gov (United States)

    Plenderleith, T. Lynette; Stratford, Danial; Lollback, Gregory W.; Chapple, David G.; Reina, Richard D.; Hero, Jean-Marc

    2018-05-01

    The strong association between amphibian activity, breeding and recruitment with local environmental conditions raises concerns regarding how changes in climate may affect the persistence of species populations into the future. Additionally, in a highly diverse assemblage of anurans, competition for breeding sites affects the time and duration of activity, as species compete for limited resources such as water. Meteorological conditions are strong drivers of amphibian activity, so we assessed whether temperature, rainfall, atmospheric pressure and humidity were associated with the calling phenology of an assemblage of anurans in South East Queensland, Australia. We performed calling surveys and collected digital recordings at 45 ponds in an area known for high anuran diversity. We performed detection analyses to investigate the influence of 10 meteorological variables in detection of calling activity in 19 amphibian species. Our results suggest four breeding strategies in the assemblage: explosive summer breeders, prolonged breeders, opportunistic breeders and a winter breeder. Classifying these species into associations provides a framework for understanding how species respond to environmental conditions. Explosive breeders (i.e. species demonstrating short and highly synchronised breeding periods) were particularly responsive to temperature. Our findings help elucidate the breeding phenology of frogs and provide valuable information on their mating systems in native Australian forests. This study highlights the difficulties of surveying even common anurans. We highlight the importance of predictability and stability in climate and the vulnerability of species for which reproduction appears to require highly specific environmental cues.

  16. A Passive Microwave L-Band Boreal Forest Freeze/Thaw and Vegetation Phenology Study

    Science.gov (United States)

    Roy, A.; Sonnentag, O.; Pappas, C.; Mavrovic, A.; Royer, A.; Berg, A. A.; Rowlandson, T. L.; Lemay, J.; Helgason, W.; Barr, A.; Black, T. A.; Derksen, C.; Toose, P.

    2016-12-01

    The boreal forest is the second largest land biome in the world and thus plays a major role in the global and regional climate systems. The extent, timing and duration of seasonal freeze/thaw (F/T) state influences vegetation developmental stages (phenology) and, consequently, constitute an important control on how boreal forest ecosystems exchange carbon, water and energy with the atmosphere. The effective retrieval of seasonal F/T state from L-Band radiometry was demonstrated using satellite mission. However, disentangling the seasonally differing contributions from forest overstory and understory vegetation, and the soil surface to the satellite signal remains challenging. Here we present initial results from a radiometer field campaign to improve our understanding of the L-Band derived boreal forest F/T signal and vegetation phenology. Two L-Band surface-based radiometers (SBR) are installed on a micrometeorological tower at the Southern Old Black Spruce site in central Saskatchewan over the 2016-2017 F/T season. One radiometer unit is installed on the flux tower so it views forest including all overstory and understory vegetation and the moss-covered ground surface. A second radiometer unit is installed within the boreal forest overstory, viewing the understory and the ground surface. The objectives of our study are (i) to disentangle the L-Band F/T signal contribution of boreal forest overstory from the understory and ground surface, (ii) to link the L-Band F/T signal to related boreal forest structural and functional characteristics, and (iii) to investigate the use of the L-Band signal to characterize boreal forest carbon, water and energy fluxes. The SBR observations above and within the forest canopy are used to retrieve the transmissivity (γ) and the scattering albedo (ω), two parameters that describe the emission of the forest canopy though the F/T season. These two forest parameters are compared with boreal forest structural and functional

  17. Data of evolutionary structure change: 1A96B-1VDMG [Confc[Archive

    Lifescience Database Archive (English)

    Full Text Available 1A96B-1VDMG 1A96 1VDM B G -EKYIVTWDMLQIHARKLASRLMPSEQWKGIIAVSRGGL...VPGALLARELGIRHVDTVCISSYDHD--NQRELKVLKRAEGDGEG--FIVIDDLVDTGGTAVAIREMYP-----KAHFVTIFAKPAGRPLVDDYVVDIPQDTWIEQPWDMG...7 LEU CA 198 1VDM G 1VDMG.../n14> 1VDM G 1VDMG2 1VDM G 1VDMG

  18. Spectral analysis of amazon canopy phenology during the dry season using a tower hyperspectral camera and modis observations

    Science.gov (United States)

    de Moura, Yhasmin Mendes; Galvão, Lênio Soares; Hilker, Thomas; Wu, Jin; Saleska, Scott; do Amaral, Cibele Hummel; Nelson, Bruce Walker; Lopes, Aline Pontes; Wiedeman, Kenia K.; Prohaska, Neill; de Oliveira, Raimundo Cosme; Machado, Carolyne Bueno; Aragão, Luiz E. O. C.

    2017-09-01

    The association between spectral reflectance and canopy processes remains challenging for quantifying large-scale canopy phenological cycles in tropical forests. In this study, we used a tower-mounted hyperspectral camera in an eastern Amazon forest to assess how canopy spectral signals of three species are linked with phenological processes in the 2012 dry season. We explored different approaches to disentangle the spectral components of canopy phenology processes and analyze their variations over time using 17 images acquired by the camera. The methods included linear spectral mixture analysis (SMA); principal component analysis (PCA); continuum removal (CR); and first-order derivative analysis. In addition, three vegetation indices potentially sensitive to leaf flushing, leaf loss and leaf area index (LAI) were calculated: the Enhanced Vegetation Index (EVI), Normalized Difference Vegetation Index (NDVI) and the entitled Green-Red Normalized Difference (GRND) index. We inspected also the consistency of the camera observations using Moderate Resolution Imaging Spectroradiometer (MODIS) and available phenological data on new leaf production and LAI of young, mature and old leaves simulated by a leaf demography-ontogeny model. The results showed a diversity of phenological responses during the 2012 dry season with related changes in canopy structure and greenness values. Because of the differences in timing and intensity of leaf flushing and leaf shedding, Erisma uncinatum, Manilkara huberi and Chamaecrista xinguensis presented different green vegetation (GV) and non-photosynthetic vegetation (NPV) SMA fractions; distinct PCA scores; changes in depth, width and area of the 681-nm chlorophyll absorption band; and variations over time in the EVI, GRND and NDVI. At the end of dry season, GV increased for Erisma uncinatum, while NPV increased for Chamaecrista xinguensis. For Manilkara huberi, the NPV first increased in the beginning of August and then decreased toward

  19. Phenological behaviour of early spring flowering trees in Spain in response to recent climate changes

    Science.gov (United States)

    Hidalgo-Galvez, M. D.; García-Mozo, H.; Oteros, J.; Mestre, A.; Botey, R.; Galán, C.

    2018-04-01

    This research reports the phenological trends of four early spring and late winter flowering trees in Spain (south Europe) from a recent period (1986-2012). The studied species were deciduous trees growing in different climatic areas: hazel ( Corylus avellana L.), willow ( Salix alba L.), ash ( Fraxinus angustifolia Vahl.) and white mulberry ( Morus alba L.). We analysed the response to climate and the trends of the following phenophases observed at the field: budburst, leaf unfolding, flowering, fruit ripening, fruit harvesting, leaf colour change and leaf-fall. The study was carried out in 17 sampling sites in the country with the aim of detecting the recent phenological response to the climate of these species, and the possible effect of climate change. We have observed differences in the phenological response to climate depending on each species. Sixty-one percent of studied sites suffered an advance of early spring phenophases, especially budburst on average by -0.67 days and flowering on average by -0.15 days during the studied period, and also in the subsequent fruit ripening and harvesting phases on average by -1.06 days. By contrast, it has been detected that 63% of sampling sites showed a delay in autumn vegetative phases, especially leaf-fall events on average by +1.15 days. The statistic correlation analysis shows in the 55% of the studied localities that phenological advances are the consequence of the increasing trend detected for temperature—being minimum temperature the most influential factor—and in the 52% of them, phenological advances occurred by rainfall variations. In general, leaf unfolding and flowering from these species showed negative correlations in relation to temperature and rainfall, whereas that leaf colour change and leaf-fall presented positive correlations. The results obtained have a great relevance due to the fact that they can be considered as reliable bio-indicators of the impact of the recent climate changes in southern

  20. Assessing the impact of extreme air temperature on fruit trees by modeling weather dependent phenology with variety-specific thermal requirements

    Science.gov (United States)

    Alfieri, Silvia Maria; De Lorenzi, Francesca; Missere, Daniele; Buscaroli, Claudio; Menenti, Massimo

    2013-04-01

    Extremely high and extremely low temperature may have a terminal impact on the productivity of fruit tree if occurring at critical phases of development. Notorious examples are frost during flowering or extremely high temperature during fruit setting. The dates of occurrence of such critical phenological stages depend on the weather history from the start of the yearly development cycle in late autumn, thus the impact of climate extremes can only be evaluated correctly if the phenological development is modeled taking into account the weather history of the specific year being evaluated. Climate change impact may lead to a shift in timing of phenological stages and change in the duration of vegetative and reproductive phases. A changing climate can also exhibit a greater climatic variability producing quite large changes in the frequency of extreme climatic events. We propose a two-stage approach to evaluate the impact of predicted future climate on the productivity of fruit trees. The phenological development is modeled using phase - specific thermal times and variety specific thermal requirements for several cultivars of pear, apricot and peach. These requirements were estimated using phenological observations over several years in Emilia Romagna region and scientific literature. We calculated the dates of start and end of rest completion, bud swell, flowering, fruit setting and ripening stages , from late autumn through late summer. Then phase-specific minimum and maximum cardinal temperature were evaluated for present and future climate to estimate how frequently they occur during any critically sensitive phenological phase. This analysis has been done for past climate (1961 - 1990) and fifty realizations of a year representative of future climate (2021 - 2050). A delay in rest completion of about 10-20 days has been predicted for future climate for most of the cultivars. On the other hand the predicted rise in air temperature causes an earlier development of

  1. Changes in phenology and frost risks of

    Directory of Open Access Journals (Sweden)

    Thomas Kartschall

    2015-04-01

    Full Text Available For a retrospective period of 110 years between 1901 and 2010 (observed data, and for the subsequent future period between 2011 and 2100 we calculated the phenological development (bud burst, harvest ripeness, and in particular the spring frost risk (frost after bud burst, as one important derived variable for grapevine (Vitis vinifera L. cv Riesling for the whole of Germany. For the future climate we included two different scenarios (RCP8.5, RCP2.6 each of them containing a triple set with minimum, medium and maximum temperature increase. The time period between 1981 and 2010 as the last three decades in the observed data was chosen as reference. In general we found an acceleration of the phenological development (all main phases mainly beginning in the late 1980s. For the three-decade period between 2031 and 2060 this acceleration will reach 11±3$11\\pm3$ days in the RCP8.5-scenario. The acceleration for the other stages behaved similarly and results in an earlier harvest ripeness of 13±1$13\\pm1$ days. Since a warmer spring in general leads to earlier bud burst, but does not reduce the risk of frost events during this period in the same manner, changes in the risk of spring frost damage were relatively small. For the coming decades this risk will not decrease for all traditional German viticultural regions in the RCP8.5-scenarios; on the contrary, our results suggest it is likely to increase. The results showed an increasing spring frost risk not only for the debated “upcoming” potential viticultural areas in eastern Germany, an effect which will partly also reach the southernmost viticultural areas. This effect in northern and eastern Germany is due to earlier bud burst together with the stronger continental influence, but for the southern and western regions of Germany is mainly due to the even earlier bud burst. This could modify the regionally nuanced character of German wines.

  2. Why climate change will invariably alter selection pressures on phenology

    NARCIS (Netherlands)

    Gienapp, Phillip; Reed, Thomas E.; Visser, Marcel E.

    2014-01-01

    The seasonal timing of lifecycle events is closely linked to individual fitness and hence, maladaptation in phenological traits may impact population dynamics. However, few studies have analysed whether and why climate change will alter selection pressures and hence possibly induce maladaptation in

  3. Revisiting the Aluminum Trimesate-based MOF (MIL-96): from Structure Determination to the Processing of Mixed Matrix Membranes for CO2 Capture.

    KAUST Repository

    Benzaqui, Marvin; S. Pillai, Renjith; Sabetghadam, Anahid; Benoit, Virginie; Normand, Pé rine; Marrot, Jerome; Menguy, Nicolas; Montero, David; Shepard, William; Tissot, Antoine; Martineau-Corcos, Charlotte; Sicard, Clé mence; Mihaylov, Mihail; Carn, Florent; Beurroeis, Isabelle; Llewellyn, Philip L.; De Weireld, Guy; Hadjiivanov, Konstantin; Gascon, Jorge; Kapteijn, Freek; Maurin, Guillaume; Steunou, Nathalie; Serre, Christian

    2017-01-01

    A microporous Al trimesate-based metal-organic framework (MOF), denoted MIL-96-(Al), was selected as a porous hybrid filler for the processing of mixed matrix membranes (MMMs) for CO2/N-2 postcombustion separation. First, the structural model of MIL-96-(Al) initially reported was revisited using a combination of synchrotron-based single-crystal X-ray diffraction, solid-state nuclear magnetic resonance spectroscopy, and density functional theory (DFT) calculations. In a second step, pure MIL-96-(Al) crystals differing by their size and aspect ratio, including anisotropic hexagonal platelets and nanoparticles of about 70 nm in diameter, were prepared. Then, a combination of in situ IR spectroscopy, single-gas, and CO2/N-2 coadsorption experiments, calorimetry, and molecular simulations revealed that MIL-96-(Al) nanoparticles show a relatively high CO2 affinity over N-2 owing to strong interactions between CO2 molecules and several adsorption sites such as Al3+ Lewis centers, coordinated water, and hydroxyl groups. Finally, the high compatibility between MIL-96-(Al) nanoparticles and the 6FDA-DAM polymer allowed the processing of homogeneous and defect-free MMMs with a high MOF loading (up to 25 wt %) that outperform pure polymer membranes for CO2/N-2 separation.

  4. Revisiting the Aluminum Trimesate-based MOF (MIL-96): from Structure Determination to the Processing of Mixed Matrix Membranes for CO2 Capture.

    KAUST Repository

    Benzaqui, Marvin

    2017-11-08

    A microporous Al trimesate-based metal-organic framework (MOF), denoted MIL-96-(Al), was selected as a porous hybrid filler for the processing of mixed matrix membranes (MMMs) for CO2/N-2 postcombustion separation. First, the structural model of MIL-96-(Al) initially reported was revisited using a combination of synchrotron-based single-crystal X-ray diffraction, solid-state nuclear magnetic resonance spectroscopy, and density functional theory (DFT) calculations. In a second step, pure MIL-96-(Al) crystals differing by their size and aspect ratio, including anisotropic hexagonal platelets and nanoparticles of about 70 nm in diameter, were prepared. Then, a combination of in situ IR spectroscopy, single-gas, and CO2/N-2 coadsorption experiments, calorimetry, and molecular simulations revealed that MIL-96-(Al) nanoparticles show a relatively high CO2 affinity over N-2 owing to strong interactions between CO2 molecules and several adsorption sites such as Al3+ Lewis centers, coordinated water, and hydroxyl groups. Finally, the high compatibility between MIL-96-(Al) nanoparticles and the 6FDA-DAM polymer allowed the processing of homogeneous and defect-free MMMs with a high MOF loading (up to 25 wt %) that outperform pure polymer membranes for CO2/N-2 separation.

  5. 40 CFR 96.340 - State trading budgets.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false State trading budgets. 96.340 Section...) NOX BUDGET TRADING PROGRAM AND CAIR NOX AND SO2 TRADING PROGRAMS FOR STATE IMPLEMENTATION PLANS CAIR NOX Ozone Season Allowance Allocations § 96.340 State trading budgets. (a) Except as provided in...

  6. Effects of an accidental dry-season fire on the reproductive phenology of two Neotropical savanna shrubs.

    Science.gov (United States)

    Dodonov, P; Zanelli, C B; Silva-Matos, D M

    2017-10-30

    Fire is a recurrent disturbance in savanna vegetation and savanna species are adapted to it. Even so, fire may affect various aspects of plant ecology, including phenology. We studied the effects of a spatially heterogeneous fire on the reproductive phenology of two dominant woody plant species, Miconia albicans (Melastomataceae) and Schefflera vinosa (Araliaceae), in a savanna area in South-eastern Brazil. The study site was partially burnt by a dry-season accidental fire in August 2006, and we monitored the phenolology of 30 burnt and 30 unburnt individuals of each species between September 2007 and September 2008. We used restricted randomizations to assess phenological differences between the burnt and unburnt individuals. Fire had negative effects on the phenology of M. albicans, with a smaller production of reproductive structures in general and of floral buds, total fruits, and ripe fruits in burnt plants. All unburnt but only 16% of the burnt M. albicans plants produced ripe fruits during the study. Fire effects on S. vinosa were smaller, but there was a greater production of floral buds and fruits (but not ripe fruits) by burnt plants; approximately 90% of the individuals of S. vinosa produced ripe fruits during the study, regardless of having been burnt or not. The differences between the two species may be related to S. vinosa's faster growth and absence from the seed bank at the study site, whereas M. albicans grows more slowly and is dominant in the seed bank.

  7. Ecosystem Responses To Plant Phenology Across Scales And Trophic Levels

    Science.gov (United States)

    Stoner, D.; Sexton, J. O.; Nagol, J. R.; Ironside, K.; Choate, D.; Longshore, K.; Edwards, T., Jr.

    2015-12-01

    Plant phenology in arid and semi-arid ecoregions is constrained by water availability and governs the life history characteristics of primary and secondary consumers. We related the behavior, demography, and distribution of mammalian herbivores and their principal predator to remotely sensed vegetation and climatological indices across the western United States for the period 2000-2014. Across scales, terrain and topographic position moderates the effects of climatological drought on primary productivity, resulting in differential susceptibility among plant functional types to water stress. At broad scales, herbivores tie parturition to moist sites during the period of maximum increase in local forage production. Consequently, juvenile mortality is highest in regions of extreme phenological variability. Although decoupled from primary production by one or more trophic levels, carnivore home range size and density is negatively correlated to plant productivity and growing season length. At the finest scales, predation influences the behavior of herbivore prey through compromised habitat selection, in which maternal females trade nutritional benefits of high plant biomass for reduced mortality risk associated with increased visibility. Climate projections for the western United States predict warming combined with shifts in the timing and form of precipitation. Our analyses suggest that these changes will propagate through trophic levels as increased phenological variability and shifts in plant distributions, larger consumer home ranges, altered migration behavior, and generally higher volatility in wildlife populations. Combined with expansion and intensification of human land use across the region, these changes will likely have economic implications stemming from increased human-wildlife conflict (e.g., crop damage, vehicle collisions) and changes in wildlife-related tourism.

  8. Combining satellite derived phenology with climate data for climate change impact assessment

    Science.gov (United States)

    Ivits, E.; Cherlet, M.; Tóth, G.; Sommer, S.; Mehl, W.; Vogt, J.; Micale, F.

    2012-05-01

    The projected influence of climate change on the timing and volume of phytomass production is expected to affect a number of ecosystem services. In order to develop coherent and locally effective adaptation and mitigation strategies, spatially explicit information on the observed changes is needed. Long-term variations of the vegetative growing season in different environmental zones of Europe for 1982-2006 have been derived by analysing time series of GIMMS NDVI data. The associations of phenologically homogenous spatial clusters to time series of temperature and precipitation data were evaluated. North-east Europe showed a trend to an earlier and longer growing season, particularly in the northern Baltic areas. Despite the earlier greening up large areas of Europe exhibited rather stable season length indicating the shift of the entire growing season to an earlier period. The northern Mediterranean displayed a growing season shift towards later dates while some agglomerations of earlier and shorter growing season were also seen. The correlation of phenological time series with climate data shows a cause-and-effect relationship over the semi natural areas consistent with results in literature. Managed ecosystems however appear to have heterogeneous change pattern with less or no correlation to climatic trends. Over these areas climatic trends seemed to overlap in a complex manner with more pronounced effects of local biophysical conditions and/or land management practices. Our results underline the importance of satellite derived phenological observations to explain local nonconformities to climatic trends for climate change impact assessment.

  9. Climatic effects on the phenology of geophytes

    OpenAIRE

    Eppich, Boglárka; Dede, Lilla; Ferenczy, Antal; Garamvölgyi , Ágnes; Horváth , Levente; Isépy , István; Priszter , Szaniszló; Hufnagel, Levente

    2009-01-01

    Nowadays, the scientific and social significance of the research of climatic effects has become outstanding. In order to be able to predict the ecological effects of the global climate change, it is necessary to study monitoring databases of the past and explore connections. For the case study mentioned in the title, historical weather data series from the Hungarian Meteorological Service and Szaniszló Priszter’s monitoring data on the phenology of geophytes have been used. These ...

  10. Search for the β decay of 96Zr

    Science.gov (United States)

    Finch, S. W.; Tornow, W.

    2016-01-01

    96Zr and 48Ca are unique among double-β decay candidate nuclides in that they may also undergo single-β decay. In the case of 96Zr, the single-β decay mode is dominated by the fourth-forbidden β decay with a 119 keV Q value. A search was conducted for the β decay of 96Zr by observing the decay of the daughter 96Nb nucleus. Two coaxial high-purity germanium detectors were used in coincidence to detect the γ-ray cascade produced by the daughter nucleus as it de-excited to the ground state. The experiment was carried out at the Kimballton Underground Research Facility and produced 685.7 days of data with a 17.91 g enriched sample. No counts were seen above background, producing a limit of T1/2 > 2.4 ×1019 year. This is the first experimental search that is able to discern between the β decay and the double-β decay to an excited state of 96Zr.

  11. Environmental effects on growth phenology of co-occurring Eucalyptus species.

    Science.gov (United States)

    Rawal, Deepa S; Kasel, Sabine; Keatley, Marie R; Aponte, Cristina; Nitschke, Craig R

    2014-05-01

    Growth is one of the most important phenological cycles in a plant's life. Higher growth rates increase the competitive ability, survival and recruitment and can provide a measure of a plant's adaptive capacity to climate variability and change. This study identified the growth relationship of six Eucalyptus species to variations in temperature, soil moisture availability, photoperiod length and air humidity over 12 months. The six species represent two naturally co-occurring groups of three species each representing warm-dry and the cool-moist sclerophyll forests, respectively. Warm-dry eucalypts were found to be more tolerant of higher temperatures and lower air humidity than the cool-moist eucalypts. Within groups, species-specific responses were detected with Eucalyptus microcarpa having the widest phenological niche of the warm-dry species, exhibiting greater resistance to high temperature and lower air humidity. Temperature dependent photoperiodic responses were exhibited by all the species except Eucalyptus tricarpa and Eucalyptus sieberi, which were able to maintain growth as photoperiod shortened but temperature requirements were fulfilled. Eucalyptus obliqua exhibited a flexible growth rate and tolerance to moisture limitation which enables it to maintain its growth rate as water availability changes. The wider temperature niche exhibited by E. sieberi compared with E. obliqua and Eucalyptus radiata may improve its competitive ability over these species where winters are warm and moisture does not limit growth. With climate change expected to result in warmer and drier conditions in south-east Australia, the findings of this study suggest all cool-moist species will likely suffer negative effects on growth while the warm-dry species may still maintain current growth rates. Our findings highlight that climate driven shifts in growth phenology will likely occur as climate changes and this may facilitate changes in tree communities by altering inter

  12. Investigating the Relationship between the Inter-Annual Variability of Satellite-Derived Vegetation Phenology and a Proxy of Biomass Production in the Sahel

    Directory of Open Access Journals (Sweden)

    Michele Meroni

    2014-06-01

    Full Text Available In the Sahel region, moderate to coarse spatial resolution remote sensing time series are used in early warning monitoring systems with the aim of detecting unfavorable crop and pasture conditions and informing stakeholders about impending food security risks. Despite growing evidence that vegetation productivity is directly related to phenology, most approaches to estimate such risks do not explicitly take into account the actual timing of vegetation growth and development. The date of the start of the season (SOS or of the peak canopy density can be assessed by remote sensing techniques in a timely manner during the growing season. However, there is limited knowledge about the relationship between vegetation biomass production and these variables at the regional scale. This study describes the first attempt to increase our understanding of such a relationship through the analysis of phenological variables retrieved from SPOT-VEGETATION time series of the Fraction of Absorbed Photosynthetically Active Radiation (FAPAR. Two key phenological variables (growing season length (GSL; timing of SOS and the maximum value of FAPAR attained during the growing season (Peak are analyzed as potentially related to a proxy of biomass production (CFAPAR, the cumulative value of FAPAR during the growing season. GSL, SOS and Peak all show different spatial patterns of correlation with CFAPAR. In particular, GSL shows a high and positive correlation with CFAPAR over the whole Sahel (mean r = 0.78. The negative correlation between delays in SOS and CFAPAR is stronger (mean r = −0.71 in the southern agricultural band of the Sahel, while the positive correlation between Peak FAPAR and CFAPAR is higher in the northern and more arid grassland region (mean r = 0.75. The consistency of the results and the actual link between remote sensing-derived phenological parameters and biomass production were evaluated using field measurements of aboveground herbaceous biomass

  13. Journal of Development and Communication Studies Vol. 4. No. 2 ...

    African Journals Online (AJOL)

    Thomas Gill

    Journal of Development and Communication Studies, 2016 ... adoption of nutrition and environment-related technologies/information (N&E) ..... Decision Nutrition ... followed by WIA (109.46), RTEP (96.38) and Non-WIA/RTEP (65.96). Post.

  14. Water SA - Vol 30, No 3 (2004)

    African Journals Online (AJOL)

    Application of a residential end-use model for estimating cold and hot water demand ... of multistage filtration using different filter media against conventional water ... (Germs et al., 2004), published in the April 2004 (Vol 30 No 2) issue of Water ...

  15. Large hadron collider workshop. Proceedings. Vol. 3

    International Nuclear Information System (INIS)

    Jarlskog, G.; Rein, D.

    1990-01-01

    The aim of the LHC workshop at Aachen was to discuss the 'discovery potential' of a high-luminosity hadron collider (the Large Hadron Collider) and to define the requirements of the detectors. Of central interest was whether a Higgs particle with mass below 1 TeV could be seen using detectors potentially available within a few years from now. Other topics included supersymmetry, heavy quarks, excited gauge bosons, and exotica in proton-proton collisions, as well as physics to be observed in electron-proton and heavy-ion collisions. A large part of the workshop was devoted to the discussion of instrumental and detector concepts, including simulation, signal processing, data acquisition, tracking, calorimetry, lepton identification and radiation hardness. The workshop began with parallel sessions of working groups on physics and instrumentaiton and continued, in the second half, with plenary talks giving overviews of the LHC project and the SSC, RHIC, and HERA programmes, summaries of the working groups, presentations from industry, and conclusions. Vol. 1 of these proceedings contains the papers presented at the plenary sessions, Vol. 2 the individual contributions to the physics sessions, and Vol. 3 those to the instrumentation sessions. (orig.)

  16. Large hadron collider workshop. Proceedings. Vol. 1

    International Nuclear Information System (INIS)

    Jarlskog, G.; Rein, D.

    1990-01-01

    The aim of the LCH workshop at Aachen was to discuss the 'discovery potential' of a high-luminosity hadron collider (the Large Hadron Collider) and to define the requirements of the detectors. Of central interest was whether a Higgs particle with mass below 1 TeV could be seen using detectors potentially available within a few years from now. Other topics included supersymmetry, heavy quarks, excited gauge bosons, and exotica in proton-proton collisions, as well as physics to be observed in electron-proton and heavy-ion collisions. A large part of the workshop was devoted to the discussion of instrumental and detector concepts, including simulation, signal processing, data acquisition, tracking, calorimetry, lepton identification and radiation hardness. The workshop began with parallel sessions of working groups on physics and instrumentation and continued, in the second half, with plenary talks giving overviews of the LHC project and the SSC, RHIC, and HERA programmes, summaries of the working groups, presentations from industry, and conclusions. Vol. 1 of these proceedings contains the papers presented at the plenary sessions, Vol. 2 the individual contributions to the physics sessions, and Vol. 3 those to the instrumentation sessions. (orig.)

  17. Effects of the urban heat island on the phenology of Odonata in London, UK

    Science.gov (United States)

    Villalobos-Jiménez, Giovanna; Hassall, Christopher

    2017-07-01

    Urbanisation is one of the major drivers of ecosystem change and includes increased temperatures in cities leading to an urban heat island (UHI). This study quantified the phenological response of odonates across London, UK, from 1990 to 2012, using a database of 1,031,277 historical sightings. The ordinal flight dates of each species were used to calculate the leading edge, middle and trailing edge of the flight period (P5, P50 and P95, respectively). The results suggest that the phenology of odonates is affected by the UHI only at a community level: no significant changes in the P5 or P50 of the flight period were found, although the P95 shows a mean advance of 4.13 days compared to rural areas, thus suggesting a contraction of the flight period in urban areas. However, only one individual species ( Sympetrum striolatum) exhibited an advance in the P95 of the flight period in urban areas compared to rural areas. On the other hand, climate change (minimum temperature) had a much stronger impact on the phenology of odonates at the community level with a significant advance of 6.9 days °C-1 in the P5 of the flight period, 3.1 days °C-1 in the P50 and 3.3 days °C-1 in the P95 flight date. Similarly, a significant advance in P5 was found in 7 of the 15 species tested in response to minimum temperature, and 2 species showed a significant advance in P50 in response to minimum temperature, but no species showed a shift in the P95 flight date due to minimum temperature. As shown in previous studies, life history influences the phenological response of odonates, with spring species and those species lacking an egg diapause being the most responsive to increased temperatures, although summer species and species with obligate egg diapause also respond to the UHI by advancing the P95 by 3.8 and 4.5 days, respectively, compared to rural areas, thus contracting the flight period. The present study shows that the UHI has negligible impacts on emergence patterns of odonates

  18. Phenology of Lymantria monacha (Lepidoptera:Lymantriidae) laboratory reared on spruce foliage or a newly developed artificial diet

    Science.gov (United States)

    Melody A. Keena; Alice Vandel; Oldrich. Pultar

    2010-01-01

    Lymantria monacha (L.) (Lepidoptera: Lymantriidae) is a Eurasian pest of conifers that has potential for accidental introduction into North America. The phenology over the entire life cycle for L. monacha individuals from the Czech Republic was compared on Picea glauca (Moench) Voss (white spruce) and a newly...

  19. Z Physics at LEP 1. Vol. 3

    International Nuclear Information System (INIS)

    Altarelli, G.; Kleiss, R.; Verzegnassi, C.

    1989-01-01

    The contents of this final report from the Workshop on Z Physics at LEP can be divided into two parts. The first part, comprising Vols. 1 and 2, is a relatively concise but fairly complete handbook on the physics of e + e - annihilation near the Z peak (with normal LEP luminosity and unpolarized beams, appropriate for the first phase of LEP operation). The second part (Vol. 3) is devoted to a review of the existing Monte Carlo event generators for LEP physics. A special effort has been made to co-ordinate the different parts of this report, with the aim of achieving a systematic and balanced review of the subject, rather than having simply a collection of separate contributions. (orig.)

  20. Z physics at LEP 1. Vol. 1

    International Nuclear Information System (INIS)

    Altarelli, G.; Kleiss, R.; Verzegnassi, C.

    1989-01-01

    The contents of this final report from the Workshop on Z Physics at LEP can be divided into two parts. The first part, comprising Vols. 1 and 2, is a relatively concise but fairly complete handbook on the physics of e + e - annihilation near the Z peak (with normal LEP luminosity and unpolarized beams, appropriate for the first phase of LEP operation). The second part (Vol. 3) is devoted to a review of the existing Monte Carlo event generators for LEP physics. A special effort has been made to co-ordinate the different parts of this report, with the aim of achieving a systematic and balanced review of the subject, rather than having simply a collection of separate contributions. (orig.)

  1. Influence of physiological phenology on the seasonal pattern of ecosystem respiration in deciduous forests.

    Science.gov (United States)

    Migliavacca, Mirco; Reichstein, Markus; Richardson, Andrew D; Mahecha, Miguel D; Cremonese, Edoardo; Delpierre, Nicolas; Galvagno, Marta; Law, Beverly E; Wohlfahrt, Georg; Black, T Andrew; Carvalhais, Nuno; Ceccherini, Guido; Chen, Jiquan; Gobron, Nadine; Koffi, Ernest; Munger, J William; Perez-Priego, Oscar; Robustelli, Monica; Tomelleri, Enrico; Cescatti, Alessandro

    2015-01-01

    Understanding the environmental and biotic drivers of respiration at the ecosystem level is a prerequisite to further improve scenarios of the global carbon cycle. In this study we investigated the relevance of physiological phenology, defined as seasonal changes in plant physiological properties, for explaining the temporal dynamics of ecosystem respiration (RECO) in deciduous forests. Previous studies showed that empirical RECO models can be substantially improved by considering the biotic dependency of RECO on the short-term productivity (e.g., daily gross primary production, GPP) in addition to the well-known environmental controls of temperature and water availability. Here, we use a model-data integration approach to investigate the added value of physiological phenology, represented by the first temporal derivative of GPP, or alternatively of the fraction of absorbed photosynthetically active radiation, for modeling RECO at 19 deciduous broadleaved forests in the FLUXNET La Thuile database. The new data-oriented semiempirical model leads to an 8% decrease in root mean square error (RMSE) and a 6% increase in the modeling efficiency (EF) of modeled RECO when compared to a version of the model that does not consider the physiological phenology. The reduction of the model-observation bias occurred mainly at the monthly time scale, and in spring and summer, while a smaller reduction was observed at the annual time scale. The proposed approach did not improve the model performance at several sites, and we identified as potential causes the plant canopy heterogeneity and the use of air temperature as a driver of ecosystem respiration instead of soil temperature. However, in the majority of sites the model-error remained unchanged regardless of the driving temperature. Overall, our results point toward the potential for improving current approaches for modeling RECO in deciduous forests by including the phenological cycle of the canopy. © 2014 John Wiley & Sons

  2. STECH VOL5 (1) FEBRUARY, 2016

    African Journals Online (AJOL)

    Copyright 1AARR 2012-2016: www.afrrevjo.net

    STECH VOL 5 (1) FEBRUARY, 2016. Vol. 5 (1), S/No11, February, 2016: 1-13 ..... Knowledge produce is an act of discovery which involves exploring, analyzing .... Architectural Research, Elsevier: Higher Education Press Limited Company.

  3. Snowmelt timing, phenology, and growing season length in conifer forests of Crater Lake National Park, USA

    Science.gov (United States)

    O'Leary, Donal S.; Kellermann, Jherime L.; Wayne, Chris

    2018-02-01

    Anthropogenic climate change is having significant impacts on montane and high-elevation areas globally. Warmer winter temperatures are driving reduced snowpack in the western USA with broad potential impacts on ecosystem dynamics of particular concern for protected areas. Vegetation phenology is a sensitive indicator of ecological response to climate change and is associated with snowmelt timing. Human monitoring of climate impacts can be resource prohibitive for land management agencies, whereas remotely sensed phenology observations are freely available at a range of spatiotemporal scales. Little work has been done in regions dominated by evergreen conifer cover, which represents many mountain regions at temperate latitudes. We used moderate resolution imaging spectroradiometer (MODIS) data to assess the influence of snowmelt timing and elevation on five phenology metrics (green up, maximum greenness, senescence, dormancy, and growing season length) within Crater Lake National Park, Oregon, USA from 2001 to 2012. Earlier annual mean snowmelt timing was significantly correlated with earlier onset of green up at the landscape scale. Snowmelt timing and elevation have significant explanatory power for phenology, though with high variability. Elevation has a moderate control on early season indicators such as snowmelt timing and green up and less on late-season variables such as senescence and growing season length. PCA results show that early season indicators and late season indicators vary independently. These results have important implications for ecosystem dynamics, management, and conservation, particularly of species such as whitebark pine ( Pinus albicaulis) in alpine and subalpine areas.

  4. Long-term temporal changes in central European tree phenology (1946-2010) confirm the recent extension of growing seasons

    Science.gov (United States)

    Kolářová, Eva; Nekovář, Jiří; Adamík, Peter

    2014-10-01

    One of the ways to assess the impacts of climate change on plants is analysing their long-term phenological data. We studied phenological records of 18 common tree species and their 8 phenological phases, spanning 65 years (1946-2010) and covering the area of the Czech Republic. For each species and phenophase, we assessed the changes in its annual means (for detecting shifts in the timing of the event) and standard deviations (for detecting changes in duration of the phenophases). The prevailing pattern across tree species was that since around the year 1976, there has been a consistent advancement of the onset of spring phenophases (leaf unfolding and flowering) and subsequent acceleration of fruit ripening, and a delay of autumn phenophases (leaf colouring and leaf falling). The most considerable shifts in the timing of spring phenophases were displayed by early-successional short-lived tree species. The most pronounced temporal shifts were found for the beginning of seed ripening in conifers with an advancement in this phenophase of up to 2.2 days year-1 in Scots Pine ( Pinus sylvestris). With regards to the change in duration of the phenophases, no consistent patterns were revealed. The growing season has extended on average by 23.8 days during the last 35 years. The most considerable prolongation was found in Pedunculate Oak ( Quercus robur): 31.6 days (1976-2010). Extended growing season lengths do have the potential to increase growth and seed productivity, but unequal shifts among species might alter competitive relationships within ecosystems.

  5. Morpho-phenological and Antibacterial Characteristics of Aconitum spp.

    Directory of Open Access Journals (Sweden)

    Yoirentomba Meetei SINAM

    2013-05-01

    Full Text Available Aconitum species have been traditionally used as ethnomedicine to cure various ailments. The present study reveals the morpho-phenology and antibacterial property of alkaloid extracts of the two Aconitum species. The morpho-phenological characteristics will be helpful for determining the resource availability. Aconitum nagarum is erect type, whereas, Aconitum elwesii is a climber. Aconitum elwesii grows in advance of A. nagarum in terms of growth, flowering and senescence. Towards the end of the year, when the fruits have ripened, the parent tuber dies off. As a result, the daughter tuber becomes independent and in the following spring, takes over the function of the parent tuber. Aconitum nagarum and A. elwesii were found to contain 4-5 aconitine equivalent (AE mg/g of alkaloid. These alkaloids showed antibacterial activity against different bacterial species including human pathogens, namely, Staphylococcus aureus, Salmonella typhimurium, Bordetella bronchiseptica, Escherichia coli, Bacillus subtilis, Pseudomonas putida, Pseudomonas fluorescence and Xanthomonas campestris. However, the extent of antibacterial activity varied among different bacterial species. The antibacterial activity against S. aureus, B. bronchiseptica, and B. subtilis was bactericidal in nature, whereas, against other tested bacterial species was bacteriostatic. Efficacy of the antibacterial activity of these alkaloids was evaluated by comparing with that of standard antibiotics. Differential localization of the antibacterial principle was observed among the Aconitum species studied.

  6. Combined impact of climate change, cultivar shift, and sowing date on spring wheat phenology in Northern China

    Science.gov (United States)

    Xiao, Dengpan; Tao, Fulu; Shen, Yanjun; Qi, Yongqing

    2016-08-01

    Distinct climate changes since the end of the 1980s have led to clear responses in crop phenology in many parts of the world. This study investigated the trends in the dates of spring wheat phenology in relation to mean temperature for different growth stages. It also analyzed the impacts of climate change, cultivar shift, and sowing date adjustments on phenological events/phases of spring wheat in northern China (NC). The results showed that significant changes have occurred in spring wheat phenology in NC due to climate warming in the past 30 years. Specifically, the dates of anthesis and maturity of spring wheat advanced on average by 1.8 and 1.7 day (10 yr)-1. Moreover, while the vegetative growth period (VGP) shortened at most stations, the reproductive growth period (RGP) prolonged slightly at half of the investigated stations. As a result, the whole growth period (WGP) of spring wheat shortened at most stations. The findings from the Agricultural Production Systems Simulator (APSIM)-Wheat model simulated results for six representative stations further suggested that temperature rise generally shortened the spring wheat growth period in NC. Although the warming trend shortened the lengths of VGP, RGP, and WGP, the shift of new cultivars with high accumulated temperature requirements, to some extent, mitigated and adapted to the ongoing climate change. Furthermore, shifts in sowing date exerted significant impacts on the phenology of spring wheat. Generally, an advanced sowing date was able to lower the rise in mean temperature during the different growth stages (i.e., VGP, RGP, and WGP) of spring wheat. As a result, the lengths of the growth stages should be prolonged. Both measures (cultivar shift and sowing date adjustments) could be vital adaptation strategies of spring wheat to a warming climate, with potentially beneficial effects in terms of productivity.

  7. Index to Nuclear Safety. A technical progress review by chronology, permuted title, and author. Vol. 11, No. 1 through Vol. 15, No. 6

    International Nuclear Information System (INIS)

    Cottrell, W.B.; Klein, A.

    1975-04-01

    This issue of the Index to Nuclear Safety covers only articles included in Nuclear Safety, Vol. 11, No. 1, through Vol. 15, No. 6. This index is presented in three sections as follows: Chronological List of Articles by Volume; Permuted Title (KWIC) Index; and Author Index. (U.S.)

  8. Multidecadal trends in the nesting phenology of Pacific and Atlantic leatherback turtles are associated with population demography

    OpenAIRE

    Robinson, Nathan J.; Valentine, Sara E.; Santidrián Tomillo, Pilar; Saba, Vincent S.; Spotila, James R.; Paladino, Frank V.

    2013-01-01

    Knowledge of the mechanisms influencing phenology can provide insights into the adaptability of species to climate change. Here, we investigated the factors influencing multidecadal trends in the nesting phenology of the leatherback turtle Dermochelys coriacea at Playa Grande, Costa Rica, in the eastern Pacific Ocean and at Sandy Point, US Virgin Islands, in the western Atlantic Ocean. Between 1993 and 2013, the median nesting date (MND) at Playa Grande occurred later, at a rate of ~0.3 d yr-...

  9. ECONOMICS OF ALEXANDER THE GREAT (15 vols + 4 cdroms) by Gregory Zorzos

    OpenAIRE

    Gregory Zorzos

    2002-01-01

    Research contains many ancient texts (Ancient Greek, Hebrews, Hieroglyphs, Assyrian, Sumerian, Babylonian, Latin, etc.). 1. (MICRO-MACRO ECONOMICS OF ALEXANDER THE GREAT (5 vols + cdrom). Microeconomics and macroeconomics of Alexander the Great. Economic theories, feasibilities, economic plannings, general description of the campaign's business plan etc. 2. BANKS OF ALEXANDER THE GREAT (2 vols + cdrom) Describes banking system, economists, financiers, investors, accountants, bookkeepers, etc,...

  10. Phenological monitoring of fruit trees in the Czech republic

    Science.gov (United States)

    Hajkova, L.; Striz, M.; Nekovar, J.

    2010-09-01

    Phenological observations at CHMI has a long tradition. Aside from several short-term series in 18th and 19th century the general phenology network has been started in 1923.In 1987 the network has been divided into tree observation types (field crops, fruit trees and wild plants) with separate methodology instructions. The period 1991 - 2010 has been selected. We have statistically evaluated results of fruit trees phenophase onset (bud burst - BBCH07, inflorescence emergence - BBCH57, beginning of flowering - BBCH61, end of flowering - BBCH69) in above mentioned period (apple, pear, cherry, morello, apricot). The second step has been evaluation of interval duration with meteorological characteristics (air temperature, sunshine duration, number of days with precipitation above 1 mm).In selected period 1991 - 2009 were observed subsequent average phenophase onset: BBCH 07 - 25th March, BBCH 57 - 14th April, BBCH61 - 26th April, BBCH69 - 12th May (Malus domestica Borkh. - species Idared). Prunus armeniaca L. - species Velkopavlovická shows these results in period 1991 - 2009: BBCH07 - 27th March, BBCH57 - 5th April, BBCH61 - 7th April, BBCH69 - 19th April.

  11. Spatio-Temporal Changes of Net Primary Productivity and its Response to Phenology in Northeast China during 2000-2015

    Science.gov (United States)

    Qiu, Y.; Zhang, L.; Fan, D.

    2018-04-01

    The relationship between net primary productivity (NPP) and phenological changes is of great significance to the study of regional ecosystem processes. In this study, firstly, NPP was estimated with the remote sensing model based on the SPOT-VGT NDVI dataset (2000-2015), meteorological data and the vegetation map in Northeast China. Then, using NDVI time series data which was reconstructed by polynomial fitting, phenology was extracted with the dynamic threshold method. Finally, the relationship between NPP and phenology was analyzed. The results showed that NPP mainly increased in the cropland, grassland, forestland and shrubland; however, vegetation NPP decreased in the ecotone among cropland, grassland and forestland. Correlation analysis suggested that the relationships between NPP and phenological metrics (i.e., the start of the growing season (SOS), the end of the growing season (EOS), the length of the growing season (LOS)) were different due to geographical location. On the whole, there was a positive correlation between NPP and the LOS in the forestland, and negative in the cropland and grassland, indicating that extended LOS can promote the accumulation of forestland NPP. By analyzing the monthly NDVI data during the vigorous growth period, the increase of NPP in the grassland and cropland was mainly due to the better growth from June to August, and shortened LOS did not lead to reduce the NPP. Generally, the response of NPP to phenology in Northeast China were more complex, showing obvious difference of vegetation types and spatial variability, we need to consider topography, community structure and other factors in the further studies.

  12. 40 CFR 96.3 - Measurements, abbreviations, and acronyms.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Measurements, abbreviations, and acronyms. 96.3 Section 96.3 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... pounds. CO2—carbon dioxide. NOX—nitrogen oxides. O2—oxygen. ...

  13. Author Details

    African Journals Online (AJOL)

    Matthews, LS. Vol 96, No 9 (2006): Part 2 - Articles Four decades of conjoined twins at Red Cross Children's Hospital - lessons learned. Abstract PDF · Vol 96, No 9 (2006) - Articles Four decades of conjoined twins at Red Cross Children's Hospital-lessons learned. Abstract PDF. ISSN: 0256-95749. AJOL African Journals ...

  14. A Modified Spatiotemporal Fusion Algorithm Using Phenological Information for Predicting Reflectance of Paddy Rice in Southern China

    Directory of Open Access Journals (Sweden)

    Mengxue Liu

    2018-05-01

    Full Text Available Satellite data for studying surface dynamics in heterogeneous landscapes are missing due to frequent cloud contamination, low temporal resolution, and technological difficulties in developing satellites. A modified spatiotemporal fusion algorithm for predicting the reflectance of paddy rice is presented in this paper. The algorithm uses phenological information extracted from a moderate-resolution imaging spectroradiometer enhanced vegetation index time series to improve the enhanced spatial and temporal adaptive reflectance fusion model (ESTARFM. The algorithm is tested with satellite data on Yueyang City, China. The main contribution of the modified algorithm is the selection of similar neighborhood pixels by using phenological information to improve accuracy. Results show that the modified algorithm performs better than ESTARFM in visual inspection and quantitative metrics, especially for paddy rice. This modified algorithm provides not only new ideas for the improvement of spatiotemporal data fusion method, but also technical support for the generation of remote sensing data with high spatial and temporal resolution.

  15. Population dynamics and flight phenology model of codling moth differ between commercial and abandoned apple orchard ecosystems

    Directory of Open Access Journals (Sweden)

    Neelendra K Joshi

    2016-09-01

    Full Text Available Apple orchard management practices may affect development and phenology of arthropod pests, such as the codling moth (CM, Cydia pomonella (L. (Lepidoptera: Tortricidae, which is a serious internal fruit-feeding pest of apples worldwide. Estimating population dynamics and accurately predicting the timing of CM development and phenology events (for instance, adult flight and egg-hatch allows growers to understand and control local populations of CM. Studies were conducted to compare the CM flight phenology in commercial and abandoned apple orchard ecosystems using a logistic function model based on degree-days accumulation. The flight models for these orchards were derived from the cumulative percent moth capture using two types of commercially available CM lure baited traps. Models from both types of orchards were also compared to another model known as PETE (prediction extension timing estimator that was developed in 1970s to predict life cycle events for many fruit pests including CM across different fruit growing regions of the United States. We found that the flight phenology of CM was significantly different in commercial and abandoned orchards. CM male flight patterns for first and second generations as predicted by the constrained and unconstrained PCM (Pennsylvania Codling Moth models in commercial and abandoned orchards were different than the flight patterns predicted by the currently used CM model (i.e.,1970’s model. In commercial orchards, during the first and second generations, the PCM unconstrained model predicted delays in moth emergence compared to current model. In addition, the flight patterns of females were different between commercial and abandoned orchards. Such differences in CM flight phenology between commercial and abandoned orchard ecosystems suggest potential impact of orchard environment and crop management practices on CM biology.

  16. Effect of phenology on agonistic competitive interactions between invasive and native sheet-web spiders

    Science.gov (United States)

    Houser, Jeremy D.; Porter, Adam H.; Ginsberg, Howard; Jakob, Elizabeth M.

    2016-01-01

    The phenologies of introduced relative to native species can greatly influence the degree and symmetry of competition between them. The European spider Linyphia triangularis (Clerck, 1757) (Linyphiidae) reaches very high densities in coastal Maine (USA). Previous studies suggest thatL. triangularis negatively affects native linyphiid species, with competition for webs as one mechanism. We documented phenological differences between L. triangularis and three native species that illustrate the potential for the reversal of size-based competitive advantage over the course of the year. To test whether relative size influences interaction outcome, we allowed a resident spider to build a web and then introduced an intruder. We examined whether the outcomes of agonistic interactions over the webs were influenced by the species of the resident (invasive or native), the relative size of the contestants, and the species × size interaction. We found that the importance of relative size differed among species. In interactions between L. triangularis and each of two native species, size played a greater role than resident species on the outcome of interactions, suggesting that competitive advantage reverses over the season based on phenology-related size differences. Linyphia triangularis had a negative impact on the third species regardless of relative size.

  17. Improvement of Management of Rhagoletis Cerasi in Bosnia and Herzegovina Based on a Phenological Model

    Directory of Open Access Journals (Sweden)

    Nježić Branimir

    2017-06-01

    Full Text Available European cherry fruit fly (Rhagoletis cerasi is the key pest of sweet and sour cherry throughout Europe. Pest management is usually based on pesticide application. The key of successful management is knowing the proper time of pesticide application, based on the phenological model. To develop a phenological model, a local population of the pest from the northern part of Bosnia and Herzegovina was studied. First adult appearance and population densities were monitored by yellow sticky traps. Soil and air temperatures were compared at two thermal thresholds, 5 °C and 7 °C. Air temperature was applied in the model since it is more suitable for farmers and is related to soil temperature. Both thermal thresholds can be used. The first adult flies were captured after 435 degree-days (dd and the first cumulative 5% of the catch after 605 dd. These two times should be considered for time of application of pesticides. Regarding time for first egg hatch, the first larva burrowed into fruits at 730 dd. Cultivars that can be harvested beginning on the 730 dd calculate from 1 March are considered to have low risk of cherry fruit fly damage.

  18. Spring and Autumn Phenological Variability across Environmental Gradients of Great Smoky Mountains National Park, USA

    Directory of Open Access Journals (Sweden)

    Steven P. Norman

    2017-04-01

    Full Text Available Mountainous regions experience complex phenological behavior along climatic, vegetational and topographic gradients. In this paper, we use a MODIS time series of the Normalized Difference Vegetation Index (NDVI to understand the causes of variations in spring and autumn timing from 2000 to 2015, for a landscape renowned for its biological diversity. By filtering for cover type, topography and disturbance history, we achieved an improved understanding of the effects of seasonal weather variation on land surface phenology (LSP. Elevational effects were greatest in spring and were more important than site moisture effects. The spring and autumn NDVI of deciduous forests were found to increase in response to antecedent warm temperatures, with evidence of possible cross-seasonal lag effects, including possible accelerated green-up after cold Januarys and early brown-down following warm springs. Areas that were disturbed by the hemlock woolly adelgid and a severe tornado showed a weaker sensitivity to cross-year temperature and precipitation variation, while low severity wildland fire had no discernable effect. Use of ancillary datasets to filter for disturbance and vegetation type improves our understanding of vegetation’s phenological responsiveness to climate dynamics across complex environmental gradients.

  19. Index to Nuclear Safety. A technical progress review by chronology, permuted title, and author. Vol. 11, No. 1--Vol. 17, No. 6

    International Nuclear Information System (INIS)

    Cottrell, W.B.; Klein, A.

    1977-01-01

    This index to Nuclear Safety covers articles in Nuclear Safety Vol. 11, No. 1 (Jan.-Feb. 1970), through Vol. 17, No. 6 (Nov.-Dec. 1976). The index includes a chronological list of articles (including abstract) followed by KWIC and Author Indexes. Nuclear Safety, a bimonthly technical progress review prepared by the Nuclear Safety Information Center, covers all safety aspects of nuclear power reactors and associated facilities. The index lists over 350 technical articles in the last six years of publication

  20. Index to Nuclear Safety. A technical progress review by chronology, permuted title, and author. Vol. 11, No. 1--Vol. 17, No. 6

    Energy Technology Data Exchange (ETDEWEB)

    Cottrell, W.B.; Klein, A.

    1977-02-23

    This index to Nuclear Safety covers articles in Nuclear Safety Vol. 11, No. 1 (Jan.-Feb. 1970), through Vol. 17, No. 6 (Nov.-Dec. 1976). The index includes a chronological list of articles (including abstract) followed by KWIC and Author Indexes. Nuclear Safety, a bimonthly technical progress review prepared by the Nuclear Safety Information Center, covers all safety aspects of nuclear power reactors and associated facilities. The index lists over 350 technical articles in the last six years of publication.