نتایج جستجو برای: trophic index

تعداد نتایج: 410552  

Journal: :Proceedings. Biological sciences 2016
Dirk Sanders Andrea Moser Jason Newton F J Frank van Veen

Trophic assimilation efficiency (conversion of resource biomass into consumer biomass) is thought to be a limiting factor for food chain length in natural communities. In host-parasitoid systems, which account for the majority of terrestrial consumer interactions, a high trophic assimilation efficiency may be expected at higher trophic levels because of the close match of resource composition o...

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: :Journal of nematology 2012
Shabeg S Briar Corinne Barker Mario Tenuta Martin H Entz

Soil nematode community response to treatments of three, four-year crop rotations (spring wheat-pea-spring wheat-flax, spring wheat-green manure-spring wheat-flax, and spring wheat-alfalfa-alfalfa-flax) under conventional and organic management, and native tall grass restoration (restored prairie) were assessed in June 2003, and July and August 2004. The research site was the Glenlea Long-term ...

M.H. Abolhasani, R. Ghorbani S.A. Hosseini S.A.A. Hedayati S.A.R. Hashemi

Measurement of chlorophyll-a can be considered important to investigate the primary production of an ecosystem. This study aimed to investigate chlorophyll-a concentration, primary production and the factors affecting them in Shadegan Wetland located in Khouzestan Province - Iran. Sampling for measuring (NO3, PO4, BOD5, DO, pH, EC, salinity, temperature) was performed seasonally at five samplin...

Journal: :Archives of disease in childhood 1968
R D Creery M A Voyce A W Preece A R Evason

The patient, a 7-year-old girl, with no previous history of circulatory disorder, developed rubella, and a week later a discoloration of her fingers was noted. The index finger of the right hand became purple and cold and then the index finger of her left hand became similarly affected. Other fingers were soon involved (see Fig.) and by the third week some discoloration of the toes was noticed....

2002
Rainer Froese Stefan Garthe Uwe Piatkowski Daniel Pauly

We compared several large marine ecosystems in terms of species numbers of fishes, sea birds, marine mammals, and cephalopods. We examined how these numbers were distributed by trophic level, from herbivores to top predators. We created group-specific trophic signatures as plots of number of species by trophic level, and used these to identify similarities and discrepancies between taxonomic gr...

Journal: :Revista de biologia tropical 2011
Camilo B García Cristian Camilo Contreras

Ecological studies on commercial important fish species are of great value to support resource management issues. This study calculated trophic levels of those Colombian Caribbean fish species whose diet has been locally described. Usable diet data of 119 species resulted in 164 trophic level estimates. An ordinary regression model relating trophic level and fish size was formulated. The regres...

2016
Stephanie Brodie Matthew D. Taylor James A. Smith Iain M. Suthers Charles A. Gray Nicholas L. Payne

Consumption is the basis of metabolic and trophic ecology and is used to assess an animal's trophic impact. The contribution of activity to an animal's energy budget is an important parameter when estimating consumption, yet activity is usually measured in captive animals. Developments in telemetry have allowed the energetic costs of activity to be measured for wild animals; however, wild activ...

2014
Michael Manton

The term green infrastructure addresses the spatial structure of anthropogenic, seminatural and natural areas, as well as other environmental features which enable society to benefit from ecosystems’ multiple services. Focusing on two green infrastructures, anthropogenic wet meadows and natural forest successions, this thesis applies a macroecological approach based on comparisons of multiple l...

2013
Paul Woodcock David P. Edwards Rob J. Newton Chey Vun Khen Simon H. Bottrell Keith C. Hamer

Trophic organisation defines the flow of energy through ecosystems and is a key component of community structure. Widespread and intensifying anthropogenic disturbance threatens to disrupt trophic organisation by altering species composition and relative abundances and by driving shifts in the trophic ecology of species that persist in disturbed ecosystems. We examined how intensive disturbance...

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