Original paper

Produktionsbiologische Untersuchungen an der Loisach anhand von Aufwuchsmessungen

[Ecological studies on the periphyton productivity in the River Loisach]

Wachs, Bodo

Abstract

The periphyton is a component of the primary aquatic production. Most of the periphyton species do not occur in the plankton. In the years 1979 to 1981 ecological studies on the periphyton productivity have been made in the middle course of the River Loisach, which is an alpine tributary of the River Isar. In this ecosystem three biotopes were investigated: the Loisach as inflow to Lake Kochel, the lake near the point of entry of the river and the Loisach as outflow of this lake. The biomass on exposed large (30 x 30 cm) plastic plates was analysed monthly. Because the Loisach is not strongly polluted by organic wastes, transmittance of light and stream velocity are discussed as factors influencing population growth of the periphyton community. These investigations were made as research work within the scope of the Sonderforschungsbereich 81 from the TU Munich, Teilprojekt A5. The aim of this whole research project is to study the flow rate and the system of nutrients in Lake Kochel, situated in the Lower Alps and flowed through by the River Loisach.

Keywords

ecological studiesperiphytonplanktonRiver LoisachGermany