Parallel responses of species and genetic diversities of Indonesian butterflies to disturbance in tropical rainforests

Cécile Fauvelot1,2, Daniel F.R Cleary2,3, and Steph B.J Menken2. Parallel responses of species and genetic diversities of Indonesian butterflies to disturbance in tropical rainforests. 1Environmental Science, University of Bologna at Ravenna, Via S. Alberto 163, I-48100 Ravenna, Italia; 2Institute for Biodiversity and Ecosystem Dynamics (IBED), University of Amsterdam, PO Box 94766, 1090 GT Amsterdam, the Netherlands; 3National Museum of Natural History, ‘Naturalis’, P.O. Box 9517, 2300 RA Leiden, the Netherlands.

Species diversity within communities and genetic diversity within species are two fundamental levels of biodiversity. We investigated the short term impact of disturbance on butterfly species diversity, as well as on the genetic diversity and structure of two Lycaenidae species. Forest fragments were sampled from five landscapes in East Kalimantan (Borneo, Indonesia) differentially disturbed by selective logging and the 1997/98 El Niño Southern Oscillation-(ENSO) induced fires. Sampling occurred before (in 1997) and after the forest fires (in 1998, 1999, 2000, and 2004). Both targeted species underwent serious population size reductions following 1997/98 ENSO-induced drought and fires, like most of butterfly species. We found that both strong spatial and temporal correlations exist between species- and allelic-richness across affected rainforest habitats. Our results suggest that the 1997/98 ENSO-induced drought and fires caused massive reductions in both species diversity and species genetic diversity. Observed genetic rescues were linked to population location relative to patches of unburned forest (and thus to source populations). Coupled with evidence that changes in species richness are a direct result of local extirpation, these data further suggest that forces governing variation at the two levels operate over parallel and short timescales, with serious implications for biodiversity recovery following disturbance.