Conservation of biodiversity is a major environmental challenge today. Homegarden agroforestry (HGAF) have large potential for biodiversity conservation. However, little attention has been paid to the relative importance of HGAF in terms of biodiversity conservation. Hence, this study was conducted to estimate and compare the woody species diversity and structure of HGAF, and adjacent natural forest (NF). Three sites were purposively selected based on the presence of HGAF and NF adjacent to each other. Stratified sampling system was used to select representative home gardens from different wealth categories (rich, medium and poor) to account for differences in woody species diversity. In NF, a systematic transect sampling technique was employed on the topography parallel to the slope of the stand. A total of 90 plots (10 m × 20 m) were used to collect vegetation data in both land uses. 32 species representing 26 genera and 20 families were identified, of which 30 woody species belonging to 24 genera and 20 families in HGAF and 11 species belonging to 9 genera and 8 families in NF were recorded. Of all woody species, 66% were indigenous. Density, richness and diversities of woody species were significantly higher in HGAF than in NF (p<0.05), whereas at the community level, trees and shrubs had significantly smallest stem diameters, height and basal area in HGAF than in adjacent NF (p<0.05). The results show that HGAF complements the NF for biodiversity conservation and helps to counteract the loss of woody species from the NF.

Keywords: Biodiversity, indigenous species, South Tigray, low land.