نتایج جستجو برای: trophic indices

تعداد نتایج: 97826  

Journal: :Brazilian journal of biology = Revista brasleira de biologia 2007
F C Ferreira M Petrere

The effect of anthropic alterations such as drain discharge on a fish community was studied in the Ribeirão Claro River, municipality of Rio Claro, State of São Paulo, southeastern Brazil. Samples were made monthly in three different points along the river (headwaters, mid course, and confluence) between December, 2003 and March, 2004, which is the reproductive period for the majority of the sp...

2014
Taurai Bere

Aquatic ecosystem biomonitoring tools are largely lacking for many developing countries, resulting in adoption of tools developed from other countries/regions. In many instances, however, the applicability of adopted tools to the new system has not been explicitly evaluated. The objective of this study was to test the applicability of foreign diatom-based water quality assessment indices to urb...

1999
D. L. Porazinska L. W. Duncan R. McSorley J. H. Graham

Nematode communities were monitored for three years in a citrus soil ecosystem in Central Florida under various agricultural regimes comparing standard vs. reduced-input practices. Differences in agricultural regimes consisted of two fertilization levels, two irrigation levels, and two types of ground cover under the tree (herbicide vs. mulch). While some nematodes were affected sporadically by...

2015
AUDREY VALLS MARTA COLL VILLY CHRISTENSEN

Various definitions and indices have been proposed in the literature to identify keystone species. In this study, we intended to make the concept of keystone species operational for marine biodiversity conservation. We used an exclusive definition of keystone species, based on the original concept of keystone predator, and derived a new functional index of keystoneness (KS) from an ecosystem-mo...

Journal: :Current Biology 2017
Nicholas A.J. Graham Tim R. McClanahan M. Aaron MacNeil Shaun K. Wilson Joshua E. Cinner Cindy Huchery Thomas H. Holmes

The distribution of biomass among trophic levels provides a theoretical basis for understanding energy flow and the hierarchical structure of animal communities. In the absence of energy subsidies [1], bottom-heavy trophic pyramids are expected to predominate, based on energy transfer efficiency [2] and empirical evidence from multiple ecosystems [3]. However, the predicted pyramid of biomass d...

Journal: :Frontiers in Environmental Science 2022

In the Anthropocene, man has imposed his activities above natural processes of ecosystems. Rivers have undergone major changes associated with urban centers, so monitoring them is important to determine their status and suitability provide environmental services. Studies applying community ecology approach, such as energy flow in aquatic macroinvertebrate assemblages, may be appropriate functio...

Journal: :Ekologia 2022

Abstract This work concerns the inventory of invertebrates in apple tree plot Dorset golden variety Tizi-Ouzou area by using four methods trapping (Barber traps, coloured sweep net and butterflies net) during study period from July 2015 until June 2016. allowed us to collect 214 species belonging 96 families, 18 orders five classes invertebrates. Ecological indices make it possible account for ...

2014
Sara Vieira Samir Martins Lucy A. Hawkes Adolfo Marco M. Alexandra Teodósio

The loggerhead turtle (Caretta caretta) is an endangered marine reptile for whom assessing population health requires knowledge of demographic parameters such as individual growth rate. In Cape Verde, as within several populations, adult female loggerhead sea turtles show a size-related behavioral and trophic dichotomy. While smaller females are associated with oceanic habitats, larger females ...

Journal: :Revista de biologia tropical 2002
Matthias Wolff

The present article gives an overview on the leading concepts and modelling approaches for marine ecosystems' research including (1) The trophodynamic theory of pelagic ecosystems, (2) Compartment/network models, (3) Mesocosm experiments and (4) Individual based modelling approaches and virtual ecosystems (VE). The main research questions addressed, as well as the potential and limits of each a...

Journal: :Journal of special operations medicine : a peer reviewed journal for SOF medical professionals 2011
D W Callaway E R Smith J Cain G Shapiro W T Burnett S D McKay R Mabry

105 inTroducTion Civilian Tactical Emergency Medical Support (TEMS) has a long history in the United States. Enormous progress has been made during the past ten years in developing professional and operational standards within the field. However, to date, there still exists no standard of care within TEMS specifically, and more broadly for high threat pre-hospital trauma care. Current civilian ...

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