Browsing All Posts filed under »hydrology«

Springs – neglected ecosystems

March 26, 2022

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Springs can be defined as places on the Earth’s surface that are influenced by the exposure, and often the flow, of groundwater.  They support biodiverse ecosystems and have socioeconomic value as sources of water for drinking, agriculture, industry and recreation, , but they are often  highly vulnerable to human disturbance, such as groundwater depletion,  pollution, […]

How riparian trees  manage their water balance

March 26, 2022

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In riverine ecosystems, riparian vegetation supports aquatic and terrestrial biodiversity, stabilises river banks and modulates water flow between the stream and the floodplain.  However, stream channelisation has led to the widespread disconnection and loss of floodplain forests.  Successful riparian restoration schemes are those that create the conditions for plants to become established and survive fluctuating […]

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 […]

Aquatic plants regulate downstream nutrients

March 26, 2022

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Just as the processes of respiration and nutrient uptake by living cells affect the chemistry of the human body, the activities of all life-forms in a body of water influence its metabolism and carbon dynamics.  In freshwater streams, aquatic plants and algae are important agents of metabolism because they act as the stream’s internal source […]

Lake management gets harder as the climate changes

March 26, 2022

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Excessive inflows of nutrients, especially phosphorus in fertilisers, pesticides and sewage, reduce water quality in lakes and reservoirs and can encourage toxic algal blooms, often with serious implications for public health, food security and biodiversity.  Increases in nutrient inputs are partly due to increased rainfall associated with  climate change.  And the availability and residence times […]

A lesson from fish: don’t let stress ruin procreation

March 26, 2022

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Annual fishes live in temporary ponds that dry out completely in summer.  As a result they have the shortest life spans of all vertebrates: after a few months they perish and the next generation depends on the survival of their drought-proof eggs, which hatch when the pond is eventually flooded.  As the shallow ponds dry […]

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 […]

Water flow through the beds of streams

December 14, 2021

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The permeability of saturated sediments at the bottom of streams, where surface water and groundwater can mix, has a strong influence on the exchange of mass and energy across the sediment-water interface.  Streambed permeability depends mainly on sediment properties such as pore networks and the size and sorting of particles, and can vary greatly, even […]

Restoration of urban headwaters pays dividends

September 28, 2021

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Because urban streams are often ecologically degraded as a result of channelisation and pollution, restoration work is often attempted to improve ecosystem structure and function.  This usually involves remodelling of the stream channel.  Knowing that there are predictable shifts in ecosystem processes between headwater streams and the main body of the river, American ecologists investigated […]