RESTORATION OF BUTTERFLIES IN <em>ACACIA</em> <em>MANGIUM</em> PLANTATIONS ESTABLISHED ON DEGRADED GRASSLANDS IN EAST KALIMANTAN

Abstract

The biodiversity status of insects in plantations in the tropics is little known. To evaluate the biodiversity restoration function of the plantation, we compared the species richness and species composition of butterfly assemblages in three plantations of Acacia mangium, two ex-forest grasslands and a native forest in East Kalimantan based on repeated 45-min sampling sessions in December 2004, May 2005 and December 2005. Higher species richness was recorded in plantation than in grassland, indicating that the plantation could support more butterfly species. Even higher species richness was found in the native forest. The species accumulation trend indicated by a rarefaction curve suggested that there were many more undiscovered species in the native forest. The butterflies found in the native forest included many range-restricted species, which were not found in the plantation and grassland. These range-restricted species were thought to be specific to the interior of the native forest and unlikely to colonise the plantations. Artificial plantations established on degraded grasslands can enrich butterfly assemblage, but this enrichment is mainly due to the increase in species with moderate or wide distribution ranges, rather than the recovery of range-restricted native forest species.