Browsing All Posts filed under »habitat diversity«

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. […]

Plankton migration is system-dependent

June 19, 2017

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Lake zooplankton commonly switch microhabitats on a regular day-night basis by migrating horizontally between stands of vegetation and open waters, or by migrating vertically between deep and surface waters. These movements have been explained in terms of the need to avoid predators (especially fish) and excessive ultraviolet radiation.  However, although zooplankton are known to seek […]

Erasing the boundaries

June 19, 2017

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The new discipline of ecohydraulics considers the effects of water movement in aquatic ecosystems and blends ideas and techniques from aquatic ecology and engineering hydraulics. A central challenge for ecohydraulics is to reconcile differences between hydraulic engineers and ecologists in terms of the spatial and/or temporal scale of the processes that they tend to deal […]

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 […]

Dealing with river complexity

March 27, 2017

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Hydromorphology is a relatively new field that deals with the structure of hydrological systems and changes in their form over time. Many such changes are influenced by human-induced pressures. Realistic attempts to conceptualize hydromorphological forms and processes reflect the fact that rivers are complex multidimensional systems with longitudinal, lateral, vertical and temporal components, as well […]

Tree cover makes for lower fish diversity

March 27, 2017

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A pervasive feature of lowland streams, especially in areas where land has been cleared for agriculture or urban development, is a decrease in forested cover from the headwaters to the mouth. The presence or absence of streamside tree cover has a profound influence on stream ecology. Streams running through undisturbed forests typically contain large woody […]

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 […]