Non-crop and crop plant diversity and determinants in homegardens of Abay Chomen District, Western Ethiopia

Homegarden is one of the potential landuse practices in an agricultural landscape where trees and shrubs are deliberately grown in association with crop production and animal husbandry. The general plant diversity and species composition have been well studied in tropical homegardens. However, the explicit study of plant diversity in terms of different functional groups such as crops and non-crops was poorly addressed. Moreover, how these diversities are mediated by the socio-ecological factors was less understood. Here, we examined the plant diversity in homegardens at three levels, (1) pooled diversity, (2) non-crop diversity and (3) crop diversity. A semi-structured questionnaire was also used to collect data on age, household size and household plant use types in 36 homegardens in June 2017. Along with this data, we have also measured the size of the homegardens and undertook complete plant inventory in these homegardens. The generalized linear model (GLM) was used to analyze the effect of age, household size and households’ plant use types on species richness in homegardens. Moreover, one-way ANOVA was employed to test the effect of these factors on the Shannon diversity index of the plant species. The result of the generalized linear model analysis showed that the pooled plant species richness in homegardens increased with increasing the plant use types. The number of non-crop species in homegardens was significantly varied by the households’ use types of the plants and the homegarden area. Moreover, the crop species richness increased with increasing households’ use types of plants and household family size. Our overall results showed that the diversities of different functional groups were mediated by different socio-ecological factors. In general, our study suggests that explicit examining of plant diversity and the factors that determine these diversities of different functional groups is vital in understanding the role of homegardens in biodiversity conservation.