Vegetation ecotones are rich in unique and endemic woody species and can be a focus of community-based conservation areas

Abstract

ABSTRACT Biodiversity is heterogeneously distributed across terrestrial landscapes. Although the impacts of habitat fragmentation on biodiversity were well studied, whether ecotones support biodiversity conservation or not is less understood, particularly in Sub-Saharan region. Hence, we compared woody species composition between ecotones and the adjoining vegetation types in Ethiopia. For this, firstly, four vegetation types, which are adjacent to each other at different sites, were selected from the vegetation map of Ethiopia. Secondly, a line transect (620 m in length) was laid out on ecotones at 50 m from the edges of the adjacent vegetation types on both sides. Moreover, transects that are equal in length to the ecotone transects were laid out on the adjoining vegetation types perpendicular to ecotone transects. Plots (size: 20 × 20 m each) were arranged on transects with 100 m interval. In total, from nine sites, 27 transect and 162 plots were used to collect data. The dissimilarity in woody species composition, differences in species richness and indicator species between ecotones and adjacent vegetation types were statistically analyzed. The results showed that woody species composition was dissimilar between ecotones and adjoining vegetation types. The species richness was significantly higher in ecotones when compared with the adjacent vegetation types. Moreover, the number of unique and endemic woody species was higher in ecotones than in adjoining vegetation types. The overall results suggest that ecotones promote plant diversity in Sub-Saharan Africa, as well as heterogeneity, and could be the focus of conservation in the face of continuing habitat fragmentation.