Effects of selective logging on the butterflies of a Bornean rainforest

Selective logging has been the main cause of disturbance to tropical forest s in Southeast Asia, so the extent to which biodiversity is maintained in s electively logged forest is of prime conservation importance. We compared t he butterfly assemblages of Bornean primary rainforest to those of rainfore st selectively logged 6 years previously. We sampled by means of replicated transects stratified into riverine and ridge forests and we included roads in the logged forest. There was a three-fold variation in species richness and abundance over the 8-month sampling period. More species and individua ls were observed in the logged forest, although between-replicate variabili ty was high. Rarefied species richness was positively correlated with canop y openness within the range of disturbance levels encountered at our forest sites. Within families, there was no significant difference in the number of species between primary and logged forest. There was a significant diffe rence in the relative abundance of species, but this was due largely to the abundance of one or two species. Community ordination separated the sites along a gradient of disturbance and revealed strong differences between riv erine and ridge-forest butterfly assemblages in primary forest that were ob scured in logged forest. There was no evidence that logging has resulted in a change in the composition of the butterfly assemblages from species with a local distribution to more widespread species. We conclude that at a log ged forest site in close proximity to primary forest, low intensities of lo gging do not necessarily reduce the species richness or abundance of butter flies, although assemblage composition is changed.