Sources and fate of detritus in the shore zone of lakes

Abstract

The origin, distribution and decomposition of detritus are discussed in relation to the functioning of the lake littoral. Exemplary data from several years of study on the Masurian Lakes (northern Poland) are presented. Different sites (even within one lake) vary visibly as to the significance of autochthonous and allochthonous detritus. Terrestrial leaf litter and hydrophyte remains accumulate in great amounts and are important for the spatial structure of habitats. The decomposition rate of dead plants and animals and of their remains (up to their total disappearance) ranges from less than 10 days (algae, animal tissues) to over two years (leaf litter, reed shoots). The intensity of decomposition is greatly influenced by environmental conditions within the littoral zone. Animal activity is significant in the formation and processing of detritus (production of faeces and breaking down of large particles by shredders are the most important factors).