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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 […]
July 5, 2018
Comments Off on The magical diatom diet
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 […]
March 26, 2018
Comments Off on Why are there so many crocodiles in tropical waterholes?
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 […]
March 25, 2018
Comments Off on How sedimentation affects the food web
In rivers and streams, high predator densities are predicted to boost algal biomass by reducing the number of grazing animals. However, in disturbed systems the smothering of stream bed surfaces by sediment is expected to have an opposite, negative effect on algal biomass. Studies that investigate interactions between sedimentation (an abiotic stress factor) and predation […]
December 21, 2017
Comments Off on Size and survival in tadpoles
Because interactions between predator and prey species are usually size-dependent, their ecological impacts are affected by variations in body size within predator and /or prey populations. However, there’s been little research on the ways that such variation affects animal communities. Using tadpoles of the brown frog (Rana pirica) as model prey and larvae of […]
December 21, 2017
Comments Off on Once more from the top
Top-down trophic cascades are population-level effects transmitted along food chains, from consumers down to primary producers. In a typical three-level food chain the loss of top predators (for example, as a result of human exploitation) allows herbivore populations to increase, which in turn reduces populations of algae or higher plants. However, few studies have considered […]
October 8, 2018
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