نتایج جستجو برای: trophic structure

تعداد نتایج: 1579737  

Journal: :Marine pollution bulletin 2015
E Punzo P Strafella G Scarcella A Spagnolo A M De Biasi G Fabi

The distribution of polychaetes associated with an offshore gas platform built on a muddy-sandy bottom in the northern Adriatic Sea was investigated with emphasis on their feeding structure. Polychaete species were collected at different distances from the rig using a Van Veen grab. Assessment of the polychaete community and trophic groups for impacts related to the presence of the platform dem...

2015
Michaela Holá Miloš Ježek Tomáš Kušta Michaela Košatová

Stable isotope measurements are increasingly being used to gain insights into the nutritional ecology of many wildlife species and their role in ecosystem structure and function. Such studies require estimations of trophic discrimination factors (i.e. differences in the isotopic ratio between the consumer and its diet). Although trophic discrimination factors are tissue- and species-specific, r...

Journal: :Brazilian journal of biology = Revista brasleira de biologia 2001
M Callisto P Moreno F A Barbosa

The assessment of the diversity of habitats and the characterisation of the functional trophic groups of benthic macroinvertebrate communities of some rivers of Serra do Cipó (MG) were the main objectives of this study. The available trophic resources and the types of substrata were characterised along with the structure and composition of their using functional trophic groups. Serra do Cipó is...

Journal: :The Science of the total environment 2017
David E Powell Noriyuki Suganuma Keiji Kobayashi Tsutomu Nakamura Kouzo Ninomiya Kozaburo Matsumura Naoki Omura Satoshi Ushioka

Bioaccumulation and trophic transfer of cyclic volatile methylsiloxanes (cVMS), specifically octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), and dodecamethylcyclohexasiloxane (D6), were evaluated in the pelagic marine food web of Tokyo Bay, Japan. Polychlorinated biphenyl (PCB) congeners that are "legacy" chemicals known to bioaccumulate in aquatic organisms and biomagnify...

2005
Robert R. Christian Daniel Baird Joseph Luczkovich Jeffrey C. Johnson Ursula M. Scharler Robert E. Ulanowicz

Assessments of trophic structure through ecological network analysis (ENA) have been done in a wide variety of estuarine and coastal environments. For example, some have used it to compare trophic structures within ecosystems focusing on temporal conditions (Baird and Ulanowicz 1989; Baird et al. 1998) and among ecosystems focusing on spatial conditions (e.g. Baird and Ulanowicz 1993; Christens...

Journal: :Ecology 2015
Adam T Ford Jacob R Goheen David J Augustine Margaret F Kinnaird Timothy G O'Brien Todd M Palmer Robert M Pringle Rosie Woodroffe

Increasingly, the restoration of large carnivores is proposed as a means through which to restore community structure and ecosystem function via trophic cascades. After a decades-long absence, African wild dogs (Lycaon pictus) recolonized the Laikipia Plateau in central Kenya, which we hypothesized would trigger a trophic cascade via suppression of their primary prey (dik-dik, Madoqua guentheri...

2009
Anna Eklöf

Eklöf, A. 2009. Species extinctions in food webs – local and regional processes. Doctoral thesis. SUMMARY Loss of biodiversity is one of the most severe threats to the ecosystems of the world. The major causes behind the high population and species extinction rates are anthropogenic activities such as overharvesting of natural populations, pollution, climate change and destruction and fragmenta...

A.H. Hamidian, A.R. Mirzajani M. Karami

The bioaccumulations of metals Cu, Cd, Ni, Cr, Co, Mn, Zn and Fe were measured in bivalves, Cerastoderma glucaum, and four species of fishes including Alburnus chalcoides, Liza aurata, Rutilus frisii and Sander lucioperca from various trophic levels of the Caspian food web. The concentrations of Cd, Cr, Co and Ni in most samples of fish were below the detection limits; while the concentrations ...

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