Our understanding of the effects of drought on the
ecology of flowing waters is limited. Most knowledge
has come from studies of the effects of predictable
seasonal droughts rather than of supra-seasonal
droughts. At the levels of populations and communities,
some generalizations about the biotic responses to
the disturbance of drought may be made, but for
ecosystem processes more studies need to be carriedout.
With streams subject to seasonal droughts, both
descriptive and experimental studies can be planned
and carried out. For the impacts of supra-seasonal
droughts, it is obvious that long-term data sets need to
be compiled to allow assessment of the impacts of such
droughts (e.g. Wright et al., 2001). With global climate
change likely to increase the intensity and frequency of
droughts (Arnell et al., 1996), a comprehensive understanding
of the effects of drought on streams and their
biota becomes a basic requirement to forecast effects
and to aid resource management.