Impact of African elephants on baobab (Adansonia digitata L.) population structure in northern Gonarezhou National Park, Zimbabwe

Abstract

The impact of African elephant (Loxodonta africana) on population structure of baobab trees (Adansonia digitata L.) was assessed in northern Gonarezhou National Park (GNP), southeast Zimbabwe. Baobabs were sampled in March 2008 and September 2012 using 11 randomly laid belt transects of variable length within 1 km of the eastern and western sections of the Runde River and also away (> 1 km) from the water sources. A total of 223 baobabs, 130 near permanent water sources and 93 away from permanent water sources, were sampled. Baobab density did not significantly differ across the two study sites. Furthermore, there were no significant differences in girth at breast height between the two study sites. Results of the present study suggest that elephants target large baobabs (girth ≥ 5 m). In contrast, significant difference in baobab damage was recorded between the two sites. A single dead baobab tree was encountered at a site away from water sources. A larger proportion of elephant damaged baobabs was located closer to permanent water sources. However, baobab recruitment and regeneration was higher in areas close to permanent water sources than in distant areas. Management should come up with strategies to monitor vegetation changes in order to avoid loss of baobabs and other tree species.