Browsing All Posts filed under »temperature«

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 […]

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 […]

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 […]

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 […]

Costs of laissez-faire stewardship

June 7, 2021

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Stream pollution and the degradation of freshwater ecosystems have often been linked to waste discharges from coal mines.  Pollution often continues to occur for many years after a mine is closed because the mine gradually fills with groundwater and eventually releases contaminant flows at the surface.  In Australia there are over 50,000 abandoned mines (coal […]

Restoring overheated rivers

March 13, 2021

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One of the features of the so-called “urban stream syndrome” is thermal pollution caused by warm  environments in built-up areas, which can increase stream temperatures above the tolerance threshold for aquatic organisms.  The good news is that urban stream temperatures can be reduced by re-naturalisation measures designed to improve flood control, water quality and habitats.  […]

Assessing plankton communities: coarse classification works well

March 13, 2021

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Information on the responses of ecological communities to environmental factors plays a significant role in the management of natural resources.  However, assessing the responses of some important groups, such as lake plankton, is often difficult because of a lack of taxonomic expertise.  A possible solution to this problem is to classify organisms by functional physiological, […]