Mowing as a tool for wet meadows restoration: Effect of long-term management on species richness and composition of sedge-dominated wetland

This paper presents the results of a 16-year mowing experiment performed in fluviogenous wetland of the Narewka River valley, NE Poland. The main objective of the study was to evaluate whether the floristic composition of an abandoned wet meadow can be restored by the reestablishment of mowing once species richness has declined following the encroachment of rushes. We found that management in the form of annual mowing at the turn of June and July had a strong effect on wetland vegetation and led to substantial increase in species diversity and richness and supported development of many meadow species. This favorable reaction was observed only in first initial years after implementation of management – in the long run influence of mowing was modified by hydrological factors. These results confirmed a link between the species richness and the habitat conditions of the wetland, which varied in response to the water input from snowmelt and precipitation. Mowing failed to eliminate the most expansive tall fast-growing generalist species and despite many years of management vegetation still resembled a rush community dominated by tall grasses: Calamagrostis canescens and Phragmites australis. We hypothesize that mowing alone is not adequate to suppress rush species. It is highly probable that management must be accompanied by appropriate hydrological conditions, among which long-lasting flooding (in late summer) is of great importance.

► We carried out a 16-year mowing experiment in sedge dominated wetland.
► Effect of annual mowing on restoration of wet meadow was evaluated.
► Mowing supported development of meadow species but failed to eliminate rush species.
► In the long run influence of mowing was modified by hydrological factors.