نتایج جستجو برای: habitat parameters

تعداد نتایج: 630563  

2008
Rui Manuel Vitor Cortes Simone Varandas de Oliveira Samantha Jane Hughes Maria Teresa Ferreira

Combining habitat and biological characterization: ecological validation of the river habitat survey The River Habitat Survey (RHS) is a widespread technique used to characterize the habitats at the fluvial sector level and to quantify the magnitude of physical disturbances. In this study we tested the ability of this method to discriminate sites along a gradient of perturbation and to analyse ...

Journal: :محیط زیست طبیعی 0
سعیده ملکی نجف آبادی مربی دانشکده منابع طبیعی، دانشگاه زابل، ایران محمودرضا همامی استادیار دانشکده منابع طبیعی، دانشگاه صنعتی اصفهان، ایران وحید راهداری مربی پژوهشکده تالاب بین المللی هامون، دانشگاه زابل، ایران

ovis orientalis isphahanica has a restricted geographical range and is listed as vulnerable by iucn. however, there is not enough data on habitat associations of this taxon to be used as a base for conservation programmes. use of vegetation communities by isfahan mouflon in mouteh wildlife refuge was studied over a one-year period. habitat use was related to vegetation communities and habitat v...

Journal: :caspian journal of enviromental sciences 0

knowledge of habitat requirements of aquatic animals plays an important role in fisheries and protection programs of aquatic ecosystems. hence, this study was conducted to investigate the suitability indexes of habitat use and habitat suitability index (hsi) of barbus cyri in its distribution range in tootkabon river. a number of environmental variables, including elevation, water depth, river ...

2011
Kevin E. Omland MICHAEL D. MARTIN KEVIN E. OMLAND

—Environmental niche parameters of breeding ranges for two subspecies in the Orchard Oriole complex (Icterus spurius spurius and I. s. fuertesi) were characterized via ecological niche modeling. Niche models formulated from museum specimen collections largely agree with published breeding ranges of both taxa. Furthermore, our findings identify likely suitable habitat of migratory double breedin...

Journal: :Conservation biology : the journal of the Society for Conservation Biology 2008
Guozhen Shen Chaoyang Feng Zongqiang Xie Zhiyun Ouyang Junqing Li Marty Pascal

The giant panda (Ailuropoda melanoleuca), is one of the world's most endangered species. Habitat loss and fragmentation have reduced its numbers, shrunk its distribution, and separated the population into isolated subpopulations. Such isolated, small populations are in danger of extinction due to random demographic factors and inbreeding. We used least-cost modeling as a systematic approach to ...

2017
Dariusz Kubiak Piotr Osyczka

To date, the lichens Chrysothrix candelaris and Varicellaria hemisphaerica have been classified as accurate primeval lowland forest indicators. Both inhabit particularly valuable remnants of oak-hornbeam forests in Europe, but tend toward a specific kind of vicariance on a local scale. The present study was undertaken to determine habitat factors responsible for this phenomenon and verify the i...

Journal: :Journal of environmental quality 2007
Thomas Heatherly Matt R Whiles Todd V Royer Mark B David

The influence of specific stressors, such as nutrient enrichment and physical habitat degradation, on biotic integrity requires further attention in Midwestern streams. We sampled 53 streams throughout Illinois and examined relationships between macroinvertebrate community structure and numerous physicochemical parameters. Streams were clustered into four major groups based on taxa dissimilarit...

2003
ROBERT J. FLETCHER ROLF R. KOFORD

—Native tallgrass prairie and wetland habitat in the Prairie Pothole Region of the United States have declined over the past two centuries. Bird communities using these habitats have also experienced widespread declines that are often attributed to severe habitat loss and fragmentation. We estimated the change, or turnover, in bird populations in the Eagle Lake Wetland Complex, Iowa, with ongoi...

2007
Maria Drakaki Alkis A. Hatzopoulos Stylianos Siskos Dimitrios K. Papakostas

— Various model parameter calculation equations of RF CMOS inductors are compared. The calculation equations are using as variables either Y, Z-parameters or S-parameters. Results are based on on-wafer RF S-parameter measurements of a 3.75 turn spiral inductor fabricated in AMIS 0.7 μm CMOS DM1P n-well technology. Results obtained with calculation equations for a differentially driven inductor ...

2017
Lisa Winter Markus Berger Nikolay Minkov Matthias Finkbeiner

Background: Anthropogenic impacts on the environment often result in loss of biodiversity. However, the effects of different parameters (such as soil pH) on biodiversity, which can be influenced by human activities, are poorly investigated on a global scale. The paper at hand proposes an approach to examine the relationship between biodiversity and several parameters, which can be anthropogenic...

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