An investigation into the ground-living spider communities of Hamsterley forest

Abstract

A study was made of the ground-living spider communities of a commercial forest, using sites at various stages of the management cycle to represent different stages of succession. Clear-felling resulted in an increase in the abundance of large polyphagous cursorial hunters associated with open habitats, and a corresponding reduction in the numbers of small web-building litter species, with a more limited prey range, which characterised the later stages of succession. The most important factor in this change appeared to be the removal of the canopy, resulting in a modification of microclimatic conditions, and degradation of the litter layer. In the first nine years after clear-felling, there were clear and relatively rapid changes in community structure associated with successional age. The observed changes were considered to be mainly due to the increasing vegetation density in this period, which provided both particular structures and a more favourable microclimate for certain species. Associated changes were also found in species richness, abundance, diversity and eveness, which increased during this period. These attributes decreased into late succession, though the pattern was less clear for species abundance, and the oldest sites were less species rich, diverse and even than those of early succession. In late succession, the rate of community change slowed, the most mature sites being very similar in terms of their communities. In general, the differences that did exist were not related to the position of the site on the successional gradient. It was considered that these differences were not due to a single factor, but rather reflected the importance of different factors at each site.