BIOMASS STUDIES IN SEMINATURAL ECOSYSTEMS INFLUENCED BY SCYTHING AT THE SOLENDET-NATURE-RESERVE, CENTRAL NORWAY .1. RICH FEN COMMUNITY

The results of studies are presented of the above- and below-ground bi omass in permanent plots in a rich fen community at Solendet in 1992 a nd 1993. The biomass decreases with increasing scything frequency, as shown by comparing plots not scythed since 1950, plots scythed biennia lly, and plots scythed annually. The biomass of below-ground roots and rhizomes always exceeds that of above-ground shoots. The ratio betwee n the above- and below-ground biomass is lowest for the community that has remained unscythed for more than 40 years. There are considerable differences in the number of shoots and the biomass between the compa red years perhaps partly because of fluctuations in climatic condition s.