Tree Colonisation under Native and Exotic Restoration Plantings in Navugulu Central Forest Reserve, in Central Uganda

Abstract

Forest restoration by planting trees often accelerates succession, but the characteristics of trees that regenerate under the restoration plantings have rarely been evaluated. The current study assessed ecological guilds, growth form, habitat types, dispersal mechanisms, species composition, diversity and structure of trees regenerating under the six restoration plantings in Navugulu forest reserve. Data were collected by laying 10 plots of 50×10 m with a 20 m distance between plots. All trees planted and regenerating in the established plots were measured for height and Diameter at breast height and were recorded. The ecological guilds, growth form, habitat types and dispersal mechanism were obtained from literature. The results showed that most regenerating trees were animal dispersed. Celtis africana, Maesopsis eminii, Terminalia superba and Trichilia drageana supported regenerating trees belonging to all the ecological guilds. Restoration plantings supported regeneration of trees belonging to two growth forms and all restoration plantings supported at least three habitat type. The contribution of restoration plantings to regeneration could be attributed to their capacity to modify soils and atmosphere that enhance growth of a number of species under their crowns. Native tree species i.e. Celtis africana, Maesopsis eminii and Trichilia drageana maybe adopted even in other restoration programmes because these species have proved to create suitable environments for tree regeneration.Non-native tree species like Terminalia superb may also be incorporated in restoration plantings since it can also facilitate tree regeneration. On the whole, restoration plantings have potential to replenish degraded forest areas. Thus, more research needs to be carried out to ascertain the potential of other native and non-native tree species used in restoration programs.