HR: 1330h
AN: B33E-14    [Abstracts]
TI: Riparian Vegetation Control of In-Stream Temperature
AU: * Davies, P M
EM: pdavies@cyllene.uwa.edu.au
AF: Centre of Excellence in Natural Resource Management, University of Western Australia, 444 Albany Highway, Albany, WA 6330 Australia
AB: Stream temperature is an important physical characteristic that can control the structure of aquatic fauna and influence key ecological processes. The response of in-stream temperature to topographic and vegetative shade can be predicted with reasonable accuracy at the sub-catchment scale. A more difficult task is to determine the biotic response to thermal stress and therefore set guideline values. A series of LD₅₀ experiments supported extensive worldwide literature on temperature tolerances of aquatic fauna. Temperature modelling was applied at different biogeographic zones of Australia. In Mediterranean climates where low flow corresponded with high summer air temperatures, in-stream thermal stress was highly seasonal. In the tropics the situation was reversed such that high air temperatures, during summer, corresponded with high stream flows that moderated the magnitude of seasonal variation. When combined with the estimated thermal tolerance of selected taxa, model analyses identified critical bottlenecks, in space and time, and enabled prioritisation of riparian restoration efforts.
DE: 0400 Biogeosciences
DE: 1803 Anthropogenic effects
SC: Biogeosciences [B]
MN: 2005 Joint Assembly