Assessment of the diversity and distribution of the threatened tree species in a logged forest in Vietnam

Conservation of biodiversity and of endangered tree species in tropical forests represents a challenge in the era of deforestation and overlogging. Assessments of biodiversity and of conservation species are essential to estimating the conservation value of ecosystems in order to develop appropriate management measures. This paper discusses the floristic composition, the diversity, and the regeneration of the conservation species in a logged forest in southern Vietnam. Twenty five one hectare plots have been set up using circular sub-plots of 8 metres diameter and at a distance of 10m from the centre point of other sub-plots. The sampling is approximately 50% in each plot. Ten years after the last logging, the species richness appears low, when compared with the close protected area, but the diversity is quite high and conservation species still occur. Twelve conservation species have been studied from the point of view of their distribution and regeneration. Some are close to extinction but some others show promise in terms of regeneration. Six floristic groups have been identified and, among them, two are of interest from a conservation point of view. This logged forest still has a high conservation value, and the process that aims at developing protection measures is clearly relevant.