A. Meyer et Ei. Meyer, Discharge regime and the effect of drying on macroinvertebrate communitiesin a temporary karst stream in East Westphalia (Germany), AQUAT SCI, 62(3), 2000, pp. 216-231
The special hydrological situation of temporary streams has a great influen
ce on the abiotic processes and other habitat conditions for organisms. To
monitor possible impacts of stream drying on the composition of lotic commu
nities, streamflow measurements and collections of the macrozoobenthos were
conducted in a temporary and an adjacent upstream permanent section of the
karat stream Sauer (East Westphalia, Germany) in 1996. The Sauer has a sum
mer-dry temporary now regime. The seasonal dry phase: can last from spring
to early autumn, so the duration of the dry phase varies from one to severa
l months, increasing with distance downstream from the upstream permanent s
ection. The number of invertebrate taxa and individuals decreases with incr
easing duration of the dry phase. The permanent section is characterized by
taxa typical of montane and submontane streams, whereas the fauna of the t
emporary section is quite different, composed of representatives of various
zonal areas. Limnephilid caddisflies are particularly characteristic of th
is section. Life cycle strategies and specific adaptations with respect to
habitat drying are discussed for several species. It can be concluded that
the temporary discharge regime of the karst stream Sauer has a clear effect
on the invertebrate communities. They mainly consist of species which can
be seen as characteristic faunal elements of temporary streams.