The spread of coarse grasses and changes in numbers of Lepidoptera in a woodland nature reserve.

摘要

Possible causes for the spread of coarse grasses (in particular Calamagrostis epigejos, Brachypodium sylvaticum and Deschampsia cespitosa) in ground vegetation and areas of Monks Wood, Cambridgeshire, UK (National Grid Reference TL28) during the last 15-20 years, are briefly discussed. Since the 1970s, butterflies [Rhopalocera] and moths [Heterocera] have been monitored in the wood as part of national monitoring schemes. Three butterfly species with larvae that feed on coarse grasses have become much more abundant in the wood, while most other butterfly species have declined in numbers relative to other sites in eastern England. Moths with grass-feeding larvae, as a group, have increased in abundance significantly more than other moths. There is evidence for butterflies that the trends recorded in Monks Wood have occurred elsewhere in eastern England, although less strongly than in the wood.