Dispersionsdynamik des Zoobenthos in den Bettsedimenten eines Gebirgsbaches / einger. von Karl Ludwig Josef Panek

• VerfasserIn: Panek, Karl L.
• Place / Publishing House: 1991
• Year of Publication: 1991
• Language: German
• Physical Description: III, 190 Bl.; Ill., graph. Darst.

eng: The aim of the study was to investigate the dispersal dynamic of the zoobenthos within the bedsediments of an alpine brook. The study was done in the Oberer Seebach, a flashy second-order stream in the northern limestone formation of the alps between the Mittersee (766 m a.s.l) and the Untersee (608 m a.s.l.) near Lunz/See, Lower Austria. Accordingly to the objective, a new sampler, the cage-pipe, was specially designed. It allows sampling in different sediment depths as well as in all horizontal directions without disturbance. The interstitial waterflow and the transport of fine sediment through the interstices was therefore recorded together with the animals. The mean quantity of interstitial sediment, which was carried into the cages, is about 170 mg/3d for the fine (; 1 mm) and 200 mg/3d for the coarse fraction (= 1 mm). To describe the dispersal activity of the zoobenthos, an activity rate was calculated by dividing the relative abundance of different taxa infreeze-core-samples by the relative abundance in cage-pipe-samples. The activity rate is influenced by the interstitial waterflow as well as by the transport of fine interstitial sediment. Decreasing waterflow and/or increasing amount of transported fine sediment cause increasing activity rates. This correlation explains the depth boundary of the bedsediments. Over the whole sampling period no significant differences were found between the four immigration directions, upstream, downstream, laterally left and right.