Diversity in Homegarden Agroforestry Systems of Southern Ethiopia

The agroforestry homegardens of the Southern Ethiopian highlands are dominated by the native perennial crops enset and coffee, and additionally include a large variety of staple food crops, vegetables and tree crops. This traditional subsistence agriculture is changing into a market-oriented agriculture with decreased diversity.In this dissertation the diversity, species composition and productivity of these homegardens are characterized, the factors that affect their dynamics are identified and the implications of these changes for agricultural sustainability are assessed.Each homegarden had on average 16 crop and 21 tree species with enset, coffee and maize being the most common crops. Four homegarden prototypes were distinguished. They differed not only in the share of crops, but also in composition of tree species.Variation among sites in both prototypes and crop species is large and is largely explained by geographical location and altitudinal differences. Also access to market and major roads was very important. Increasing commercialization and land pressure have lead to the decline in the areas of the perennials enset, coffee and trees and an increase of annual crops. This could adversely affect the ecological benefits derived from these integrated and complex systems and threaten their long- term sustainability. Research and development efforts should aim at developing techniques on how to integrate high value crops into the systems without affecting their integrity.