Browsing All Posts filed under »production«

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. […]

Low biodiversity in productive lakes

December 13, 2016

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The over-supply of nutrients to lakes (through pollution, for example) stimulates the growth of plant plankton, which blocks light from reaching bottom-dwelling algae and higher plants. Therefore, nutrient excess has the potential to reduce habitat diversity and the associated biodiversity of animal plankton, macroinvertebrates and fish. An international team of biologists looked at the relationship […]

Restoration ecology: are we forgetting top-down control?

June 1, 2016

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Authors of a recent review article argue that restoration ecologists rely heavily on the assumption that natural communities are controlled by bottom-up processes (i.e., the upward transfer of nutrients and energy from plants to animals), but tend to ignore the complementary effects of top-down control by animals on nutrient cycling and the abundance and diversity […]

Remote surveillance: assessing water quality

June 1, 2016

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Remote sensing technology gives natural resource managers and landowners the ability to monitor environmental conditions in new and powerful ways. However, the remote assessment of water quality in lakes and ponds is complicated by wide variations in the inorganic and organic composition of suspended particles, which affect the optical environment, and the moderate- and medium-resolution […]

Counter-productive perspectives

March 23, 2016

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A central aim of freshwater research is to understand the processes that regulate biological productivity. However, while lake-based investigations have focussed heavily on controls on primary production, river-based researchers have tended to concentrate more on production limits imposed by physical habitat requirements. If lake and river researchers think about production in different ways, and concentrate […]

Adding wood to streams: when is it worthwhile?

March 23, 2016

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Placing woody material into waterways with the aim of improving habitat quality is a common stream restoration technique. However, debate continues around the extent to which wood placement actually leads to significant increases in fish abundance. In a wide-ranging literature review, American ecologists note that many researchers reported that the installation of instream structures was […]

Waterbird numbers & fertilizer use

March 23, 2016

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Nutrients applied as fertiliser to farmland leach into rivers and streams and are transported to coastal waters, where concentrations of nitrogen and phosphorus are now respectively ten and three times higher than in pre-industrial times. While moderate rises in nutrient availability can have beneficial impacts on aquatic production, excessive nutrient levels lead to the eutrophication […]