Browsing All Posts filed under »ecosystems«

Restoration and invertebrates: Build it and at least some of them will come

September 25, 2017

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It’s commonly assumed that the biodiversity of a disturbed ecosystem can be improved by restoring its original physical and chemical conditions. According to this “Field of Dreams” view (“build it and they will come”), ecosystem recovery occurs through the recolonization activities of lost species.  While a lot of river restoration is founded on Field of […]

Restoration and invertebrates: Reappraising stream condition indicators

September 25, 2017

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In degraded rivers and stream systems, the replanting of riparian vegetation is a common restoration activity, partly because increases in shading, nutrient interception and litter fall are expected to provide food and habitat benefits for aquatic communities. Changed habitat conditions should be reflected in indices of stream condition, such as those based on macroinvertebrate richness. […]

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 to predict water temperatures

March 27, 2017

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Because temperature is a key variable affecting a myriad of ecological processes, there’s a need for reliable ways of predicting the temperature of water bodies. Such temperatures can be influenced by both natural factors (e.g., air temperature, local topography, stream discharge, groundwater interactions) and anthropogenic factors (e.g., deforestation, thermal pollution, flow alteration, and runoff from […]

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 […]