Role of exclosure on woody species diversity in comparison to adjacent open grazing land: The case of wenago district, Southern Ethiopia

Abstract

Ethiopia has suffered from degradation of forests and loss of biodiversity as a result of anthropogenic activities mainly for the purpose of expanding farm lands, construction materials, fuel wood and charcoal production. The objective of the study was to assess the status of exclosure comparing with adjacent open grazing land. In each area exclosure and open grazing land uses, a plot of 20 m x 20 m, 10 m x 10 m and 2 m x 2 m area size for trees, shrubs and herbs, respectively, was drawn using systematic method. A total of 66 plots in 10 hectare area were sampled along the transect line. Diameter at breast height (DBH) was measured using caliper, and tree height was measured using clinometer and Woody species data were analyzed through Shannon–Wiener diversity index (H1) and Sorensen similarity coefficient indices (Is) using SPSS version 20, excel software and the linear relationship between diversity mean value and land uses were compared using chi-square. A total of 35 plant species belonging to 25 families were identified and recorded. Shannon’s species diversity index (H') in exclosure and adjacent open grazing was 2.591 and 0.889, respectively. Exclosure had a significantly higher number of woody species diversity compared to adjacent open grazing land. Herbs were not influenced by both compared land uses. In order to keep the present progress and rehabilitation status of woody diversity, sustainable management of area exclosure is very necessary and planners, policy makers and stakeholders need coordination and participatory based plant species conservation strategies.