Leaf litter breakdown processing in the functional monitoring of a mountain stream

This research is a contribution to an integrated overview of the alpine low-order river ecosystem. We associated the results obtained from colonization and breakdown processes (functional aspects, i.e. colonization of natural and artificial leaf packs and of artificial inorganic substrates), with the morphohydrological features of the river bed, with density and biomass of benthic invertebrates and with banks quality. We studied the Ausor stream, North-East Italy, a natural alpine stream with a narrow steep gradient channel. The applied monitoring methods allowed us to point out the total biodiversity, the seasonal. and regional heterogeneity of macrobenthos and of habitats and the efficiency of breakdown and colonization processes. The integrated overview, achieved from the comparison of results, showed that diversity and variability of habitats are connected with the natural morphological development of the river bed and of riparian areas. Furthermore, heterogeneity and variability of habitats are essential in supporting biodiversity and the functional processes occurring in a natural environment.