Impacts of rattan cane harvesting on vegetation structure and tree diversity of Conservation Forest in Buton, Indonesia

Abstract

Lambusango Forest, Buton, Indonesia, is an example of the potential for conflict between forest conservation and long standing local extraction of Non-timber Forest Products (NTFPs), in this case rattan cane harvesting. This paper investigates the impacts of rattan harvesting on tree and understorey vegetation structure, species richness and diversity. Tree and understorey vegetation characteristics and soil and topographic variables were recorded in forest plots. Interviews with rattan harvesters recorded information on harvesting techniques and locations. The relationships between tree and understorey vegetation characteristics and soils, topography and rattan harvesting techniques were assessed with the multivariate ordination technique of Redundancy Analysis (RDA). Analysis of the relationships with rattan harvesting proximity and forest designation zone used Multivariate Analyses of Covariance (MANCOVA). Tree species richness and diversity are primarily affected by slope gradient and altitude, while tree size is affected mainly by soil chemical factors. Only a small part of the variation in tree structure measures can be attributed to the impacts of rattan cane harvesting. Stronger adverse effects on understorey vegetation density, including tree saplings and seedlings, were found. This is thought to be a case of rattan harvesting exacerbating the effects of competition between rattan plants and other understorey vegetation. Longer term monitoring of forest characteristics could provide stronger understanding of the impacts. However, rattan harvesting appears to have little effect on forest structure and diversity in Lambusango Forest, suggesting that relatively small scale NTFP extraction does not necessarily conflict with forest conservation.