نتایج جستجو برای: trophic indices

تعداد نتایج: 97826  

2011
Yaoyang Xu Meiling Shao Xinqin Han Qinghua Cai

Limnologists have regarded temporal coherence (synchrony) as a powerful tool for identifying the relative importance of local-scale regulators and regional climatic drivers on lake ecosystems. Limnological studies on Asian reservoirs have emphasized that climate and hydrology under the influences of monsoon are dominant factors regulating seasonal patterns of lake trophic status; yet, little is...

2017
Vincent Pellissier Anne Mimet Colin Fontaine Jens-Christian Svenning Denis Couvet

Humans are changing the biosphere by exerting pressure on land via different land uses with variable intensities. Quantifying the relative importance of the land-use composition and intensity for communities may provide valuable insights for understanding community dynamics in human-dominated landscapes. Here, we evaluate the relative importance of the land-use composition versus land-use inten...

2014
E Kathryn Morris Tancredi Caruso François Buscot Markus Fischer Christine Hancock Tanja S Maier Torsten Meiners Caroline Müller Elisabeth Obermaier Daniel Prati Stephanie A Socher Ilja Sonnemann Nicole Wäschke Tesfaye Wubet Susanne Wurst Matthias C Rillig

Biodiversity, a multidimensional property of natural systems, is difficult to quantify partly because of the multitude of indices proposed for this purpose. Indices aim to describe general properties of communities that allow us to compare different regions, taxa, and trophic levels. Therefore, they are of fundamental importance for environmental monitoring and conservation, although there is n...

2008
Cecelia C. S. Hannides Brian N. Popp Michael R. Landry Brittany S. Graham

We quantify the trophic positions of subtropical open-ocean zooplankton species using amino acid–specific (AA) stable nitrogen isotopic compositions. We model animal trophic position by computing trophic 15N enrichment of glutamic acid relative to phenylalanine, and find that trophic position for primary copepod consumers (Oithona spp., Neocalanus robustior) and secondary copepod consumers (Ple...

2005
H. Y. Wu

In order to elucidate the distribution of soil nematodes in coastal wetlands and the effect of different distance from the sea line on soil nematode communities, we investigated the community structure of soil nematodes in one wetland perpendicularly oriented from Bohai sea coastline. In June 2006, soil samples were collected from the Yellow River Delta wetlands, in Dongying city of Shandong Pr...

Journal: :Environmental science and pollution research international 2013
Xiang Tan Fran Sheldon Stuart E Bunn Quanfa Zhang

Diatoms have been regularly used as bioindicators to assess water quality of surface waters. However, diatom-based indices developed for a specific geographic region may not be appropriate elsewhere. We sampled benthic diatom assemblages in the upper Han River, a subtropical river in China, to evaluate applicability of 14 diatom-based indices used worldwide for water quality assessment. A total...

A.G.M. Osman, M.M. Farrag, S.F. Mehanna, Y.A. Osman,

This work highlights the role of otolithic morphometrics, shape indices and ultrastructure in the identification of three Mullidae species from the Red Sea. Differences in otolithic measurements were detectable in all three-goatfish species. The statistical analysis of otolithic morphometric parameters showed that otolithic measurements are good indicators of fish size. For all three species, t...

Journal: :The Journal of trauma 2003
David G Jacobs Brian Ray Plaisier Philip S Barie Jeffrey S Hammond Michele R Holevar Karlene E Sinclair Thomas M Scalea Wendy Wahl

Journal: :Water Practice & Technology 2023

Abstract This study aims to analyse the spatio-temporal trends in water quality, trophic state, and organic contamination of an alpine lake Darjeeling Himalaya through field investigations portray a comprehensive picture using multivariate analysis. Analysed parameters have shown notable seasonal variations were within acceptable range for inland surface water. Water quality index (WQI) polluti...

Journal: :international journal of environmental research 2014
f. abdolahpur monikh m. hosseini j. kazemzadeh khoei a.f. ghasemi

in this study, three stations of the north persian gulf were analyzed in order to determinethe effect of trophic levels on the concentration of harmful pahs in fish and sediment. in all cases,similar distributions were observed in which benzo(a)pyrene largely predominated andbenzo(b)fluoranthene and pyrene were the second major compounds in fish tissues. the predominantcomponents of pahs in sed...

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