Browsing All Posts filed under »food webs«

Coarse, shallow and wooden… but useful nonetheless

June 19, 2017

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Coarse woody debris (CWD) derived from shoreline trees provides an important, spatially complex habitat and a food source for lake-dwelling organisms. Here are some interesting facts about lake CWD, taken from a recent review paper: In the absence of the physical action of flowing water, CWD breaks down more slowly in lakes than in streams. […]

Human impacts on ecological connectivity

June 19, 2017

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Ecological connectivity – the exchange of organisms between habitat patches or subpopulations – has an influence on many key processes, including population dynamics, nutrient flux, disease transmission, species invasions, food-web interactions, genetic isolation and the maintenance of biodiversity. A recent study reviewed ways in which graph theory has been used to investigate how human activities […]

How big is a food patch?

June 19, 2017

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Most studies of food patch choice by foraging animals have assumed that the patches in question are separate and well-defined. However, in many cases, predators feed in continuous habitats without obvious, discrete patches, and researchers are forced to choose an arbitrary spatial scale when calculating prey densities and interpreting the impacts of predators. An important […]

Herbivory is important in freshwater systems

March 27, 2017

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Until the 1990s it was believed that, in the main, freshwater and marine plants were connected to aquatic food webs only indirectly, through the breakdown of decaying vegetation by decomposers. However, over the last two decades there’s been a growing realisation that the activities of aquatic herbivores in consuming plants and channeling the derived nutrients […]

How fishing changes catchability

March 27, 2017

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The bolder members of a fish population – often defined as those most willing to continue to forage under the threat of predation – tend to be relatively exploratory, aggressive, territorial, and enjoy higher rates of food intake and specific growth than more timid individuals. However, their larger size makes bold fish more vulnerable to […]

Unravelling trends in stream nitrogen

March 27, 2017

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Oxides of nitrogen derived from agriculture, industry and emissions from the burning of fossil fuels fall out from the atmosphere and enter terrestrial and freshwater ecosystems. Over the last century the deposition of reactive nitrogen has increased three to five times, and this is reflected in a general global increase in stream nitrogen concentrations. However, at […]

How river transport affects dissolved organic matter

December 13, 2016

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In most rivers, the downstream transport of dissolved organic matter (DOM) makes large amounts of energy available to aquatic ecosystems. The River Continuum Concept (RCC) of Vannote et al. (1980) provided a useful framework for studying the influence of organic material from headwater streams on the structure and function of downstream ecosystems. The RCC hypothesized […]