Browsing All Posts filed under »biodiversity«

How the food web affects river restoration

October 8, 2018

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River restoration commonly  concentrates on improving habitat quality for threatened fish populations.  However, because stream fish are strongly influenced by food availability, competition and predation, a case can be made for also incorporating food web modelling into the restoration process.  A group of environmental scientists developed an ecosystem model and applied it to a river-floodplain […]

Research on insect emergence warms up

October 8, 2018

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Long-term data show that climate change affects ecosystem functioning and the body size distributions of animal species, but more information is needed to understand the mechanisms underlying these changes.  There’s a need for experimental studies that take account of linkages between the aquatic and terrestrial environment and that simulate changes in the intensity and frequency […]

Small fish species are more at risk

October 8, 2018

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Large-bodied animal species tend to have relatively low fecundity, long generation times and slow growth rates, which makes for low population turnover and a heightened risk of extinction.  This trend seems to be true for vertebrates such as mammals and marine fish, but not, it seems, for freshwater fish.  Australian ecologists explored the relationship between […]

How does disturbance affect biodiversity?

October 8, 2018

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In freshwater systems, drying events are ramp disturbances that reduce habitat availability and connectivity, while floods are sudden pulse disturbances.  The relationship between disturbance and biodiversity is complex, and although some studies indicate that perennial rivers, which often flood, are more biodiverse than intermittent rivers, which periodically stop flowing and dry out, other work suggests […]

The magical diatom diet

July 5, 2018

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In forested headwater streams, detritus derived from decaying plant material is the primary source of energy driving the aquatic ecosystem, and most studies of such systems have focussed on the fate of leaf litter, the main resource.   However, because the food quality of detritus is extremely low it’s unclear how headwater streams support their  biological […]

Surveying river birds

July 5, 2018

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River birds are effective ecological indicators because they’re linked to river and riparian food webs in many  ways and are easily observed.  Boat-based surveys of river birds pose disturbance issues and can be difficult during periods of high or low flow, while transect-based surveys can be compromised by lack of access to private land.  Researchers […]

Why are there so many crocodiles in tropical waterholes?

March 26, 2018

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Transfers of organic material from one aquatic environment to another (for example, through flood pulses or animal migrations) allow productive donor ecosystems to subsidise less productive habitats. However, there are big variations in the extent to which different animal species depend on production subsidies.  To explore such differences, Australian researchers collected a wide array of […]