Water distribution at local and landscape scales affects tree utilization by elephants in Chobe National Park, Botswana

作者：Fullman Timothy Jon^*; Child Brian

来源：African Journal of Ecology, 2013, 51(2): 235-243.

DOI：10.1111/aje.12026

• African elephant
• Chobe National Park
• herbivory
• Loxodonta africana
• piosphere
• vegetation utilization

African elephant distribution and impacts are influenced by water availability. This study investigates the formation of piospheres gradients of vegetation degradation with increasing proximity to water at local and landscape scales in Chobe National Park, Botswana. Thirty-four plots record elephant impact on trees in a transect extending over 60km from the Chobe River, differentiating between debarking and browsing on branches. Elephant utilization exhibits local patterns nested within a landscape-level context. At a local scale, branch herbivory decreases with distance from water, while debarking first decreases and then increases again. At a landscape scale, regression and canonical correlation analyses show decreasing debarking with distance from the river. Surprisingly, branch herbivory increases with distance from river, except within the first 10km where previous studies have focused. Elephant impact on vegetation is both more complex and extensive than previously assumed. Piosphere predictions are upheld at the local scale, with utilization decreasing with distance from water. This does not hold at the landscape scale, however, likely due to seasonal shifts in elephant distribution, diet and the presence of water in ephemeral pans. These findings have important implications for elephant management and emphasize the importance of looking across scales when assessing elephant impact.

• 出版日期2013-6