HR: 11:00h
AN: NB42A-03    [Abstracts]
TI: Leaf Litter Decomposition and its ETS (Electron Transport System) Activity in two Stream Ecosystems (Austria, Poland)
AU: * Leichtfried, M
EM: maria.leichtfried@oeaw.ac.at
AF: Institute of Limnology, Austrian Academy of Sciences, Mondseestr. 9,, Mondsee, A-3293 Austria
AU: Fleituch, T
EM: fleituch@iop.krakow.pl
AF: Institute of Nature Conservation,Polish Academy of Sciences, Al. Mickiewicza 33,, Cracow, PL-31120 Poland
AB: Biofilms are involved in decomposition of leaf litter, contributing to self-purification capacity of streams. Total community respiration was measured as ETS-activity (indicator of potential respiration). Objectives: to examine respiration rates in decomposing leaves in over-flown stream bottom, to trace the breakdown processes and to assess patterns of nutrient parameters in decomposing litter. Two 2nd order streams contrasting in geomorphology, hydrology, and climate regime were selected: an alpine stream (Oberer Seebach, Austria) and a submountain one (Goscibia, Poland). Alder leaves were exposed in coarse mesh bags in stream riffles and removed 5 times between November and March. The TOC content in leaf litter was lower in Oberer Seebach than in Goscibia. No significant differences were found in the decomposing time. The ETS activity was significantly higher in the Oberer Seebach than in the Goscibia, indicating higher density and activity of biofilms in the Austrian stream. The higher TON content also confirms it. Consequently, the leaf litter decomposition in Oberer Seebach was faster than in Goscibia. It can be explained by higher water temperature and velocity. In general, differences in decomposition of alder leaves and its ETS activity are caused by hydrological and thermal regimes in studied streams.
DE: 4239 Limnology
DE: 4804 Benthic processes/benthos
SC: North American Benthological Society [NB]
MN: 2005 Joint Assembly