TRADITIONAL AGROFORESTRY SYSTEMS AS A SAFE HAVEN FOR WOODY PLANT SPECIES: A CASE STUDY FROM A TOPO-CLIMATIC GRADIENT IN SOUTH CENTRAL ETHIOPIA

摘要

The deliberate maintenance of woody species in traditional agroforestry systems could partly compensate the high rate of deforestation in terms of conserving plant diversity. However, this role of traditional agroforestry is little documented. In this study we assessed the diversity of traditional agroforestry based production systems and their woody plant species across four agro-ecological zones (AEZs) near the central Rift Valley in Ethiopia. A total of 120 farms representing households of three wealth categories - poor, medium and rich - were assessed. A large variety of traditional agroforestry systems combinations existed. In total we identified 86 tree/shrub species belonging to 44 families, 71 of which were indigenous and the rest exotics. 95% of households retained trees while transforming natural forests into agricultural landscapes and 70% complemented with planting. There were variations in woody species richness between the AEZs and wealth classes. Similarly, some socio-economic attributes of the farm households such as land holding size, educational background of household head and off-farm activities were found to affect woody species composition in the agroforestry systems.