Impacts of conventional logging and portable sawmill logging operations on tree diversity in east new britain, papua new guinea

Portable sawmill logging in Papua New Guinea is widely advocated by ecoforestry organisations as an ecologically improved method of rainforest exploitation because of its reduced impact on biodiversity. Here the impacts of conventional high impact/intensity conventional logging, and low impact/intensity portable sawmill logging on tree diversity six years after harvest are compared based on current operational practices. Tree diversity was significantly lower after high impact/intensity logging in comparison to low impact/intensity logging and unlogged forest. Low impact logging resulted in a reduction in tree diversity of 5 % and 25 % for the Shannon Wiener index (H') and Simpson's index (D) of diversity, respectively, in comparison to unlogged forest. Conventional logging resulted in a reduction in diversity of 25 % (H') and 48 % (D) in comparison to unlogged forest. Based on comparisons with other studies high reductions in tree diversity after conventional high impact logging are attributed to initial losses from high harvesting intensities, high post harvest mortality, and low diversity of new recruitment. The implications of these results for sustainable forest management and forest conservation in Papua New Guinea are discussed.