نتایج جستجو برای: trophic states

تعداد نتایج: 465825  

2006
Clark V. Pearson Lee A. Dyer

The roles of consumers (top-down forces) versus resources (bottom-up forces) as determinants of alpha diversity in a community are not well studied. Numerous community ecology models and empirical studies have provided a framework for understanding how density at various trophic levels responds to variation in the relative strength of top-down and bottom-up forces. The resulting trophic theory ...

2008
Teresa Mathews Nicholas S. Fisher

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...

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...

Journal: :Global change biology 2014
Guillem Chust J Icarus Allen Laurent Bopp Corinna Schrum Jason Holt Kostas Tsiaras Marco Zavatarelli Marina Chifflet Heather Cannaby Isabelle Dadou Ute Daewel Sarah L Wakelin Eric Machu Dhanya Pushpadas Momme Butenschon Yuri Artioli George Petihakis Chris Smith Veronique Garçon Katerina Goubanova Briac Le Vu Bettina A Fach Baris Salihoglu Emanuela Clementi Xabier Irigoien

Ocean warming can modify the ecophysiology and distribution of marine organisms, and relationships between species, with nonlinear interactions between ecosystem components potentially resulting in trophic amplification. Trophic amplification (or attenuation) describe the propagation of a hydroclimatic signal up the food web, causing magnification (or depression) of biomass values along one or ...

2005
LUCIANE O. CROSSETTI CARLOS E. DE M. BICUDO

(Effects of nutrient impoverishment on phytoplankton biomass: a mesocosms experimental approach in a shallow eutrophic reservoir (Garças Pond), São Paulo, southeast Brazil). Nutrient impoverishment in mesocosms was carried out in a shallow eutrophic reservoir aiming to evaluate the nutrient removal technique as a method for eutrophication reduction. Garças Pond is located in the Parque Estadual...

Journal: :Ecological Indicators 2022

Microbial communities are an important component of aquatic ecosystems. They play active roles in the biogeochemical cycles organic matter and nutrients to maintain health stability In present study, shifts microbial overlying water 15 shallow lakes with different trophic states Hubei Province (China) were assessed using Illumina MiSeq sequencing technology. The results revealed that proteobact...

2013
ANDREA R. LITT

Non-native plant invasions can change communities and ecosystems by altering the structure and composition of native vegetation. Changes in native plant communities caused by non-native plants can influence native wildlife species in diverse ways, but the outcomes and underlying mechanisms are poorly understood. Here, we review and synthesize current information for the Intermountain West of th...

Journal: :The International journal of developmental biology 2002
Glen B Banks Peter G Noakes

Approximately half of the motoneurons generated during normal embryonic development undergo programmed cell death. Most of this death occurs during the time when synaptic connections are being formed between motoneurons and their target, skeletal muscle. Subsequent muscle activity stemming from this connection helps determine the final number of surviving motoneurons. These observations have gi...

Journal: :Ecological applications : a publication of the Ecological Society of America 2015
Mireia Bartrons Claudio Gratton Brian J Spiesman M Jake Vander Zanden

Ecosystems can be linked by the movement of matter and nutrients across habitat boundaries via aquatic insect emergence. Aquatic organisms tend to have higher concentrations of certain toxic contaminants such as methylmercury (MeHg) compared to their terrestrial counterparts. If aquatic organisms come to land, terrestrial organisms that consume them are expected to have elevated MeHg concentrat...

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