Selecting species for active and passive restoration of Kibale National Park

Abstract

The use of native species in forest restoration has been increasingly recognized as an effective means of restoring ecosystem functions and biodiversity to degraded areas across the world. However, successful selection of species adapted to local conditions requires specific knowledge which is often lacking, especially in developing countries. In order to scale up forest restoration, experimental data on the responses of native species to propagation and restoration treatments across a range of local conditions are required. In this study, species that can be passively restored by natural regeneration were distinguished from those requiring active restoration. Tree species dominance was quantified (measured by an importance value index, IVIi) and used abundance–size correlations to select those species suitable for passive and/or active restoration of disturbed riparian vegetation in Kibale National Park. We sampled riparian vegetation in a 50×10–m plot in each of the sixty two sample plots in the digraded ecosystems. All the species which were regenerating and had a diameter of atleast 5cm were selected, and Pearson’s rank correlation between abundance and diameter classes was calculated. For thirteen species, it was determined that passive restoration could be sufficient for their establishment. The remaining fifty two species could be transplanted by means of active restoration. The high number of tree species found in the degraded ecosystem suggests that the species pool for ecological restoration is large. However, sampling in the degraded ecosysem helped to reduce the number of species that requires active restoration. Restoration objectives must guide the selection of which methods to implement; in different conditions, other criteria such as dispersal syndrome or social value could be considered in the species selection.