A multiple-site comparison of woodpecker communities in Bornean lowland and hill forests

LAMMERTINK, M.

CONSERVATION BIOLOGY

WILEY-BLACKWELL PUBLISHING, INC

Año: 2004 vol. 18 p. 746 - 757

0888-8892

Logging in the Sunda region of Southeast Asia has affected nearly all lowland forests. Despite numerous studies on the effects of this logging, its impact on vertebrate communities remains unclear because few researchers have compared more than two independent study sites. I assessed whether a community of 14 woodpecker species in West Kalimantan, Indonesian Borneo, has been affected by logging in lowlands and whether hill-forest reserves are a suitable alternative for woodpecker conservation. Eight study sites in lowland plains ( 70 m elevation) occurred in unlogged forest and forests with a range of increasing logging intensities. In addition, two sites were sampled in unlogged hill forest (120-400 m elevation). Woodpecker species richness and composition in lowlands remained unchanged over the range of increasing logging disturbance. Over this range, however, significant reductions occurred in total woodpecker biomass (61% reduction), total woodpecker density (41% reduction), and densities of Checker-throated Woodpecker (Picus mentalis) and Great Slaty Woodpecker (Mulleripicus pulverulentus), which were reduced 85% and 83%, respectively. The quantity of timber removed (cut basal area) was a better predictor of woodpecker density than the proportion of an area remaining as unlogged patches. Time since logging, which varied from 3 to 22 years, had little predictive value. Within home ranges in logged areas, woodpeckers foraged preferentially in unlogged patches but preferred logged patches for other activities. Hill forest, although unlogged, had woodpecker densities, biomass, and species richness even lower than heavily logged lowland sites. Notably, the Great Slaty Woodpecker was absent from hill sites, which implies that hill reserves are not an option for conservation of this logging-sensitive species. The responses of this species in population density may serve as an indicator in forest management. Protection of logged lowland forest should be preferred over that of unlogged hill forests, but emphasis in conservation effort in the Sunda region is currently on hill forests. Safeguarding the few remaining areas of unlogged lowland forest on Borneo must be a top priority because those forests are of vital importance as reference sites in biodiversity studies.