Impacts of participatory forest management on species composition and forest structure in Ethiopia

摘要

The present study assesses the impacts of decentralized forest management on forest conditions in Ethiopian Montane forests. We compared observed densities of different tree species and size categories in forests managed by local forest user groups (FUGs) and the government. We used forest inventory data from 23,046 ha of contiguous forest managed by 74 individual FUGs. Topographical variables, including altitude, slope and aspect, were retrieved from Digital Elevation Model data for each FUG polygon. Generalized additive models and matching models were employed to analyse the effects of management and eliminate confounding factors. Findings show that altitude and slope were the topographical variables that had the strongest influence on species distribution. The overall densities of mature trees ha-1 and four individual species {Afrocarpus falcatus, Schefflera abyssinica, Hypericum lanceolatum and Rapanea melanophloeos) were higher in forests under participatory management (p < 0.07). The three major commercial timber species Juniperus excelsa, Afrocarpus falcatus and Hagenia abyssinica constituted 49% of the total relative density and 39% the total relative frequency. In spite of the fact that inventories were carried out only 3-5 years after the forests had been handed over to FUGs, the observed patterns in vegetation density indicate that participatory management was more successful than government management in making forestry sustainable.