Restoration of degraded secondary forest with native species: a case study in the highland of Ethiopia. (Special Issue: Innovation and new horizons in tree nursery stock production and forest restoration - from research to business.)

摘要

Ethiopia is losing a significant cover of natural forest every day owing to deforestation, yet surprisingly little field-based information exists on the ecological requirements and silvicultural strategies for the majority of the native species, which could be translated into plans for conservation and restoration. Munessa Dry afromontane forest is heavily degraded and characterized by many gaps. It has been disturbed by illegal logging and expansion for subsistence farming. What remains is a fragmented and overlogged forest. A study was conducted in Munessa Dry afromontane forest to evaluate the contribution of silvicultural options for sustainable management and conservation of forest resources in the highlands of Ethiopia. Under the project, the growth and photosynthesis response of four native tree species seedlings under a variable light environment in a gap were analyzed. The different species exhibited different survival strategies in forest understorey and open environment. Planting in the gap centre resulted in high light intensities, allowing a significantly higher increase in root collar diameter and height. Water use efficiency differs among species, the highest being Podocarpus falcatus, followed by Prunus africana, Cordia africana and Juniperus procera. Therefore, by strategically planting native tree species on suitable target areas with desired spatial configuration, the maximum potential of natural conditions could be captured and secondary forests could be restored.