Paying to restore urban streams

March 25, 2018

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Rivers and streams provide many ecosystem services, including the supply and purification of water, climate regulation, flood protection, fisheries, aesthetic values and recreation.  In urban settings, the loss of stream ecosystem services as a result of pollution, erosion and habitat degradation has prompted widespread attempts at environmental repair. However, although levels of investment in urban […]

Serious streambank erosion in farming catchments

March 25, 2018

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Streambank erosion is influenced by a number of factors, including water movement, freeze-thaw cycles, bank drying, vegetative cover, animal trampling and agricultural practices. Studies show that bank erosion can be  responsible for a significant fraction of the sediment exported by streams and rivers.  In western Europe, where many areas of grassland have been converted to […]

Aquatic plants help animal plankton to disperse

March 25, 2018

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Freshwater bodies containing aquatic plants generally support a wide range of animal plankton. If the dormant stages of zooplankton are attached to roots and the submerged parts of plants, the dislodgement and displacement of aquatic vegetation during floods could play a role in plankton dispersal. To assess this possibility, Argentinian researchers collected specimens of free-floating […]

A mature approach to growth data

March 25, 2018

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The age at which an animal matures is a key life history trait with implications for ecology, evolution and population dynamics, but data on maturation can be costly to collect. However, in many animals growth occurs in two phases, with a change-point at maturity, which means that it’s sometimes possible to estimate the maturation age […]

Riparian roots help streams breathe

December 21, 2017

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In aquatic systems, especially those with abundant plants, dissolved oxygen concentrations often show strong daily fluctuations because there’s a net input of oxygen from photosynthesis during the day but a net loss of oxygen due to   respiration at night.  When researchers working on a small tropical stream in São Paulo State, Brazil recorded this pattern […]

Benefits and costs of habitat complexity

December 21, 2017

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The fact that biodiversity tends to be higher in structurally complex habitats suggests that, on balance, the fitness-related advantages of habitat complexity outweigh the disadvantages.  Possible advantages include a greater supply of locations where animals can hide from predators and conserve their energy, and higher abundances of potential prey.  Also, in complex habitats less energy […]

Size and survival in tadpoles  

December 21, 2017

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  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 […]