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Summary: Annu. Rev. Ecol. Evol. Syst. 2004. 35:25784
doi: 10.1146/annurev.ecolsys.35.120202.110122
Copyright c 2004 by Annual Reviews. All rights reserved
First published online as a Review in Advance on June 22, 2004
LANDSCAPES AND RIVERSCAPES: The Influence
of Land Use on Stream Ecosystems
J. David Allan
School of Natural Resources and Environment, University of Michigan,
Ann Arbor, Michigan 48109; email: dallan@umich.edu
Key Words catchment, disturbance, stressor response, stream health, river
Abstract Local habitat and biological diversity of streams and rivers are strongly
influenced by landform and land use within the surrounding valley at multiple scales.
However, empirical associations between land use and stream response only varyingly
succeed in implicating pathways of influence. This is the case for a number of reasons,
including (a) covariation of anthropogenic and natural gradients in the landscape;
(b) the existence of multiple, scale-dependent mechanisms; (c) nonlinear responses;
and (d) the difficulties of separating present-day from historical influences. Further
research is needed that examines responses to land use under different management
strategies and that employs response variables that have greater diagnostic value than
many of the aggregated measures in current use.
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