نتایج جستجو برای: distance from rivers

تعداد نتایج: 5719811  

Journal: :Philosophical transactions of the Royal Society of London. Series B, Biological sciences 2013
Giselda Durigan Natalia Guerin José Nicola Martorano Neves da Costa

Over the past two decades, the headwaters of the Xingu Basin in the Amazon have been subjected to one of the highest deforestation rates in Brazil, with negative effects on both terrestrial and aquatic systems. The environmental consequences of forest land conversion have concerned the indigenous people living downstream, and this was the first motivation for the Y Ikatu Xingu campaign--'save t...

Journal: :The Journal of heredity 2013
Clinton W Epps Jessica A Castillo Anne Schmidt-Küntzel Pierre du Preez Greg Stuart-Hill Mark Jago Robin Naidoo

Population genetic structure is often used to infer population connectivity, but genetic structure may largely reflect historical rather than recent processes. We contrasted genetic structure with recent gene-flow estimates among 6 herds of African buffalo (Syncerus caffer) in the Caprivi Strip, Namibia, using 134 individuals genotyped at 10 microsatellite loci. We tested whether historical and...

2007
Sean F. Werle Norman A. Johnson Elizabeth R. Dumont Piotr Parasiewicz

We introduce an analysis method to demonstrate correlation between biota and the physical habitats that they occupy. Using the same calculations as does Nei’s genetic distance index, this method builds independent dissimilarity matrices for both habitat and fauna, which can then be compared in a common statistical framework. An important advantage of this method is that only frequency data are ...

Journal: :Frontiers in water 2021

Plastic accumulation in the marine environment is a major concern given harmful effects and longevity of plastics at sea. Although rivers are likely to significantly contribute flux plastic systems, behaviour debris fluvial systems remains poorly understood estimates riverine derived from field measurements modelling efforts highly uncertain. This paper presents new probabilistic model transpor...

Journal: :محیط زیست طبیعی 0
صیاد شیخی ئیلانلو دانشگاه علوم کشاورزی و منابع طبیعی گرگان مظاهر معین الدینی دانشگاه تهران مصطفی قلی پور دانشگاه علوم کشاورزی و منابع طبیعی گرگان علی شیخی دانشگاه حکیم سبزواری هادی کراچی دانشگاه حکیم سبزواری

habitat recognition and knowledge of habitat requirements are extremely important to the wildlife conservation, particularly for endangered and vulnerable species. the purpose of the study was to determine which ecological and habitat factors contribute the distribution of black billed sandgrous (pterocles orientalis) in shirahmad wildlife refuge. sampling was performed in two season (spring an...

Journal: :caspian journal of environmental sciences 2011
r. zarkami

in the present study, classification trees (cts-j48 algorithm) were used to study the occurrence of roach in rivers in flanders (belgium). the presence/absence of roach was modelled based on a set of river characteristics. the predictive performance of the cts models was assessed based on the percentage of correctly classified instances (cci) and cohen's kappa statistics. to find the best model...

2015
Gouthami Rao Joseph N. S. Eisenberg David G. Kleinbaum William Cevallos Gabriel Trueba Karen Levy

The use of contaminated surface water continues to be a pressing issue in areas of the world where people lack improved drinking water sources. In northern coastal Ecuador, many communities rely on untreated surface water as their primary source of drinking water. We undertook a study to explore how microscale river hydrodynamics affect microbial water quality at community water collection loca...

In the present study, classification trees (CTs-J48 algorithm) were used to study the occurrence of roach in rivers in Flanders (Belgium). The presence/absence of roach was modelled based on a set of river characteristics. The predictive performance of the CTs models was assessed based on the percentage of Correctly Classified Instances (CCI) and Cohen's kappa statistics. To find the best model...

Journal: :Environmental management 2005
Andrea J Radwell Thomas J Kwak

Preservation of extraordinary natural resources, protection of water quality, and restoration of impaired waters require a strategy to identify and protect least-disturbed streams and rivers. We applied two objective, quantitative methods to determine stream ecological integrity of headwater reaches of 10 Ozark rivers, 5 with Wild and Scenic River federal protective status. Thirty-four variable...

M. Norouzi, M. Pourkazemi

This study represents a large-scale population genetic analysis of the stellate sturgeon, Acipenser stellatus, in the Caspian Sea. In total, 192 samples of adult stellate sturgeon were collected from four commercial catch stations in the Northern (Volga and Ural Rivers) and Southern Caspian Sea (estuary of Sefidrud and Gorganrod Rivers-Iran). Fifteen sets of microsatellite primers developed fro...

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