Impact of African elephants on Baikiaea plurijuga woodland around natural and artificial watering points in northern Hwange National Park, Zimbabwe

Abstract

The extent of African elephant ( Loxodonta africana ) induced damage on shrub and mature Baikiaea plurijuga trees was investigated around artificial and natural watering points in northern Hwange National Park, Zimbabwe. Damage was assessed in three zones of elephant occupancy during the dry season i.e. high elephant occupancy zone (≤ 1 km from water points), moderate elephant occupancy zone (> 1–2 km from water points) and low elephant occupancy zone (> 2 km from water points). A total of 48 plots along baseline transects were sampled among four artificial watering points and four natural watering points at increasing distance from the watering points. Damage to recruits, mature B. plurijuga and overall woody vegetation decreased with distance from artificial watering points. In addition, damage to mature B. plurijuga and overall woody vegetation decreased with distance from natural watering points, whereas damage to recruits did not change with distance from water points. Our results show that artificial watering points are associated with higher damage to B. plurijuga recruits and overall woody vegetation within ≤ 1 km radius from water points compared to natural watering points. Other changes associated with increasing distance from artificial watering points were increase in canopy cover and decrease in woody species diversity. In the natural watering points, we recorded an increase in canopy cover, mean basal area of B. plurijuga shrubs and height B. plurijuga shrubs, and a decrease in species diversity with distance from watering points. Overall, woody species diversity was higher around natural watering points than around artificial watering points. Our findings suggest that browsing by large herbivores near watering points leads to the degradation of vegetation.