Transect-survey of the impact of elephant on black rhinoceros browse availability

The study quantified potential browsing opportunities for black rhinoceros along a gradient of elephant utilization in the Main camp-section of the Addo Elephant National Park. Fifty-five 30m line-transects were distributed across five sites exposed to elephant and three Control sites with no elephant. An additional 8 transects were placed within 300m of Hapoor water point to contextualise the gradient of elephant utilization. Variables recorded along each transect included: (1) total browse biomass, (2) preferred browse biomass, and (3) the number of available bites. To explain the pattern of browsing opportunities, data on the number and area of elephant pathways and maximum canopy height were also recorded at each transect.

本研究针对阿多大象国家公园（Addo Elephant National Park）主营区域，量化了黑犀牛（black rhinoceros）沿大象利用强度梯度分布的潜在觅食机会。研究共布设55条30米长的样线（line-transect），分布于5个受大象活动影响的样地，以及3个无大象活动的对照样地。另在哈普尔水源点（Hapoor water point）周边300米范围内增设8条样线，以明确大象利用强度的梯度特征。每条样线需记录的变量包括：(1) 总采食生物量、(2) 偏好采食生物量，以及(3) 可采食口数。为阐释觅食机会的分布格局，研究还在每条样线处记录了大象通道的数量与面积，以及最高冠层高度数据。