Browsing All Posts filed under »dispersal«

Dams challenge platypus populations

March 26, 2022

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The construction of dams has many adverse effects on river hydrology and ecology.  Dams limit animal movements and reduce the cover of riparian vegetation, which leads to bank erosion and the filling of stream pools with sediment.  Dam-related impacts have been documented for many types of riverine animals, including macroinvertebrates, amphibians and waterbirds.  However, the […]

To be continued: the legacy of the River Continuum Concept

December 14, 2021

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A recent review examined the historical importance of the River Continuum Concept (RCC), which was introduced by Robin Vannote and co-workers in 1980.  This concept revolutionised stream ecology research by prompting a shift from a descriptive to a predictive approach and encouraging multidisciplinary collaboration between biologists, geomorphologists and geochemists.  The RCC became a key framework […]

Gene flow in complex river systems

December 14, 2021

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Understanding how variations in habitat connectivity affect gene flow and possible genetic isolation in river systems is tricky because of the unique structural features of stream ecosystems, which are notoriously difficult to model: unlike terrestrial landscapes, they are linear branching networks, which means that overland distance is often a poor indicator of the correlation between […]

Guidelines for conserving groundwater ecosystems

December 14, 2021

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Aquatic groundwater-dependent ecosystems include subsurface aquifers, springs, seepage wetlands and other groundwater-fed surface waters.  Their biodiversity is high: for example, in Europe around 13% of all freshwater animal species are found only in groundwater.  Many of these species are rare, with limited distributions, and some are “living fossils”.  Groundwater species deliver ecosystem services by recycling […]

Land use patterns can aggravate toxic plankton blooms

September 28, 2021

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An understanding of how environmental factors affect the composition of biological communities is a crucial prerequisite for managing challenges due to climate change, land use practices and invasive species.  However, establishing the significance of interacting local and regional factors that vary widely across space and time is a challenge in itself.   Canadian biologists set out […]

Aquatic insects on the decline

September 28, 2021

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Although there’s growing evidence that species in many animal groups, including insects, amphibians, aquatic invertebrates and birds, are experiencing dramatic and widespread declines in abundance, identifying the factors driving these changes is a major challenge because most ecosystems are affected by several stressors at the same time.  In addition, long-term data sets on species abundance […]

When bold individuals stay put

December 17, 2020

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Although ecological studies often assume that all members of an animal population have similar responses to environmental conditions, it’s now clear that members of the same species can display consistent behavioural differences, and that such personality traits are often correlated.  For example, boldness, aggression and sociability have been linked to dispersal behaviour, with bolder, more […]

River resilience and the three Rs

June 25, 2020

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River ecosystems are impacted by a wide range of disturbances.  Floods and droughts are the most important types of natural disruption, while human-induced impacts include pollution, habitat degradation and climate change.   An ecosystem’s ability to recover from disturbance – its resilience – is a key concern in river management.  A multinational research team has developed […]

Coming to grips with community complexity

June 25, 2020

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Although it’s well known that the mix of species in natural communities is influenced by environmental factors and the geography of habitat patchiness, it’s unclear how these factors create the spatial and temporal patterns observed in nature.  Brazilian ecologists tested the hypothesis that the structure of freshwater plankton communities can be explained, at least in part, […]

River junctions can be ecological hotspots

March 31, 2020

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Sudden hydrodynamic, sedimentary and ecological changes have often been recorded at the junction points where river tributaries from different drainage areas meet, but do similar changes occur at the confluences of anabranch rivers, where the water is largely sourced from the same area?  Anabranch rivers consist of multiple channels separated by vegetated islands which have […]