The Effects of Landscape Change on Plant Diversity and Structure in the Bale Mountains National Park, Southeastern Ethiopia

Abstract

Bale Mountains National Park is one of the protected areas in Ethiopia that holds the largest area of Afroalpine habitat in Africa and the second largest stand of moist tropical forest. Nevertheless, human settlements, overgrazing, and recurrent fire are the main problems in the park. This study aimed to determine the effects of human-induced landscape change in floristic composition and structure in the park. The vegetation data were collected systematically from 96 sample plots laid along 24 line transects in the edge and interior habitats of the six land cover types. Vegetation composition and landscape structural analysis were made using R software version 3.5.2 and FRAGSTATS version 4.2.1, respectively. Patch number was strong and positively affected species richness (r = −0.90, $p<0.05$ ), diversity (r = −0.96, $p<0.01$ ), and basal area (r = −0.96, $p<0.001$ ), whereas mean patch size was strong and negatively influenced species richness (r = 0.95, $p<0.05$ ), diversity (r = 0.87, $p<0.05$ ), and basal area (r = 0.82, $p<0.05$ ). The overall species richness, Shannon diversity index, and Margalef index were significantly higher in the edge habitat; however, the mean basal area of woody species was significantly higher in the interior habitat at $p<0.05$ . This study uncovered that the park is floristically rich and diverse, and it provides a variety of ecological and economic benefits to the surrounding community and to the nation at large. However, these benefits are gradually declining due to the high level of anthropogenic activities in the park. Thus, integrated environmental management strategy that blends with sustainable use of natural resources should be implemented to minimize the threats.