Biomass and production of two vascular plants in a boreal mesotrophic fen

The vertical distribution of biomass and production was measured using indirect C-14 isotope techniques in a boreal mesotrophic fen dominated by Carex rostrata and Potentilla palustris. The biomass of C. rostrata was high (2290 g . m(-2)), 78% of which was fine-root biomass. Even with a low turnover rate (0.59 yr(-1)), fine roots also accounted for 74% of the total production of 1424 g . m(-2). yr(-1). The majority of the belowground biomass was found in the uppermost 30 cm. However, living roots of C. rostrata were found down to a depth of 230 cm. In fen ecosystems, the direct input of carbon through deep-penetrating roots to slowly decomposing layers may considerably affect the accumulation of peat.