Diversity and dynamics in homegardens of southern Ethiopia

Abstract

Most homegarden studies have focused on Asia, where homegardens constitute a component of a spatially separated farming system consisting of cultivated fields with staple food and/or commercial crops away from homes complemented by the homegardens with supplementary crops such as fruits and vegetables surrounding residential houses. In the highlands of East and Central Africa, another type of homegarden is found in the form of an integrated farming system within itself and without additional cultivated fields. In these 'integral' homegardens, not only supplementary crops such as fruits and vegetables, but also staple food crops and cash crops are grown. The enset (Enset ventricosum) and coffee (Coffea arabica) homegarden system in southern Ethiopia is a typical example of such integral homegardens. An assessment of 144 of these homegardens was made to gain insights into their structure and vegetation composition and the relation between composition and geographic and socioeconomic factors. Four specific garden types are identified, which vary in commercial crop composition and diversity. These variations are related to farm size and access to roads and markets, and illustrate the dynamic character of homegardens. Overall, the diversity of the integral homegarden system seems to be somewhat lower than that of the 'complementary' homegarden systems in Asia, probably due to the inclusion of light demanding staple food crops and a relatively large number of commercial crops. The dynamic pathways of the integral homegarden systems because of commercialization appear similar to reported trends in the 'complementary' homegarden systems in Asia. Although the composition of the homegardens is influenced by socioeconomic dynamics, overall the Ethiopian homegardens can be characterized as being ecologically and socioeconomically sustainable. This can be attributed not only to species diversity but also to the presence of two keystone species-coffee and enset.