An Evaluation of downland turf re-creation, using invertebrates as indicators.

Abstract

Seven study sites within the South Wessex Downs Environmentally Sensitive Area (SWD ESA) were used to evaluate re-created downland turf, a habitat created under one of the scheme management options. The novel habitat was compared to adjacent areas of established downland and to the edges of arable fields, by collecting vegetation data, and using invertebrates as indicators of habitat quality. The recreated downland sites were re-seeded 1 to 3 years before the study. The new habitat was influenced by adjacent established downland and calcicolous species were found colonising the: edges of the re-created downland. The edges of established downland were degraded in terms of plant species richness, probably by previous arable use in adjacent fields. It was found that the re-created downland was being used by several butterfly species for breeding as well as for nectaring and that these activities were concentrated around the edges of the habitat. A second indicator group, the Homoptera, were also found on the re-created downland and, although no evidence of breeding was gathered, some of the species found on the habitat were characteristic of established downland. A third aspect of the study focused on the effect on associated herbivores of the nonnative varieties of downland species which are sown into the re-created downland. It was found that these were not as easily digested as a native variety and that although the larvae gained more weight they pupated later, thus increasing their chances of predation. This has not previously been demonstrated and it is hoped that they will help improve the management of the SWD ESA in future years.