The Experimental Management of Vegetation at Wicken Fen, Cambridgeshire

Abstract

(1) Recent evidence for changes in the time of cutting of the 'litter' communities of Wicken Fen, Cambridgeshire in the past suggests that early-season cutting may have been the traditional regime, as opposed to the autumn cutting undertaken now. These herbaceous communities are very rich in plant species and support an interesting assemblage of insect species. (2) The effects of mowing in May, July or September on the richness and composition of the two types of 'litter' communities found at Wicken Fen were assessed over three growing seasons (1980-82) in a large-scale field experiment. (3) In Molinia 'litter', differences between treatments were relatively small, though changes in botanical composition were noticeably greatest under July cutting. The richness of dicotyledonous species increased under all treatments. (4) In Calamagrostis 'litter', differences between treatments were more marked. In particular, September cutting seemed to cause relatively small changes in species composition, and in the richness of dicotyledonous species, from year to year. Again, July cutting caused the largest changes. (5) The findings reported here do not contradict the contention that the decrease in the richness of dicotyledonous species in litter on the site may be linked with changes in cutting practice. This study has influenced the recent decision to switch back to the summer cutting of litter at Wicken Fen.