Organic Matter Dynamics and Invertebrate Functional Groups in a Mountain Stream in the West Tatra Mountains, Poland

Abstract

AbstractInvestigations were carried out at two sites on a low order mountain stream in order to characterise the role of macroinvertebrates in organic matter decomposition. Total benthic organic matter content ranged from 6 to 1304 g AFDM m−2. The fine fraction constituted more than 50% of the total POM at both sites in all seasons, except for autumn. In transported POM the coarse fraction dominated and its highest values were noted in May, after the snow melt season. The density of bottom fauna was five times higher on the sandy‐gravel bottom than on the stony bottom. In both habitats, gathering collectors and scrapers were most abundant; shredders constituted only a few percent of the benthic community in the stony habitat. Our results indicate that the role of shredders is small, and mechanical fragmentation and microbial activity are mainly responsible for fine particle formation.