نتایج جستجو برای: trophic transfer
تعداد نتایج: 304989 فیلتر نتایج به سال:
The application of stable isotope analysis (SIA) has become a standard scientific approach in Agricultural and Ecological researches and, more in general, in several disciplines such as biology, botany, zoology, organic chemistry, climatology, and nutrition. The main objectives of this paper are (1) to provide a simple definition of stable isotopes and (2) to illustrate analytical measurement m...
Body size exerts multiple effects on plankton food-web interactions. However, the influence of size structure on trophic transfer remains poorly quantified in the field. Here, we examine how the size diversity of prey (nano-microplankton) and predators (mesozooplankton) influence trophic transfer efficiency (using biomass ratio as a proxy) in natural marine ecosystems. Our results support previ...
Abstract Trophic transfer efficiency (TTE) is usually calculated as the ratio of production rates between two consecutive trophic levels. Although seemingly simple, TTE estimates from lakes are rare. In our review, we explore processes and structures that must be understood for a proper lake estimate. We briefly discuss measurements positions mention how ecological efficiencies, nutrients (N, P...
The bioaccumulation of trace elements in aquatic organisms can be described with a kinetic model that includes linear expressions for uptake and elimination from dissolved and dietary sources. Within this model, trace element trophic transfer is described by four parameters: the weight-specific ingestion rate (IR); the assimilation efficiency (AE); the physiological loss rate constant (ke); and...
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...
Studies of trophic-level material and energy transfers are central to ecology. The use of isotopic tracers has now made it possible to measure trophic transfer efficiencies of important nutrients and to better understand how these materials move through food webs. We analyzed data from thirteen 15 N-ammonium tracer addition experiments to quantify N transfer from basal resources to animals in h...
Plankton play a key role in oceanic carbon flux as the primary biological mechanism for the sequestration of carbon out of the atmosphere into surface waters. The transfer of energy between phytoplankton and zooplankton can be inferred from regular patterns in population size structure, where plots of abundance within size classes typically show a power-law dependence on size. Here we analyze s...
Factors constraining the structure of food webs can be investigated by comparing classes of ecosystems. We find that pelagic ecosystems, those based on one-celled primary producers, have longer food chains than terrestrial ecosystems. Yet pelagic ecosystems have lower primary productivity, contrary to the hypothesis that greater energy flows permit higher trophic levels. We hypothesize that lon...
Microscopic plastic debris is emerging as a global conservation issue. Ingestion of microplastics has been demonstrated in a range of marine animals both in the laboratory and in the oceans, but we know little of how microplastics may be transferred across trophic levels. Here, we used mussels (Mytilus edulis) and crabs (Carcinus maenas) to investigate the bioaccumulation and trophic transfer o...
There is increasing recognition of the importance of dietary pathways in determining metal body burdens in marine organisms. With a simple kinetic model that requires information about the ingestion rate of an animal and the assimilation efficiency (AE) and efflux rate constant (ke) of a metal following dietary exposure, it is possible to quantitatively predict the trophic transfer and biomagni...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید