The impact of elephant herbivory in Kruger National Park

17 Jul 2020 - 16:45

Most savanna plant species are strong resprouters after damage by fire or elephants; they are highly persistent.  This makes it difficult to know how much damage inflicted by elephants, is too much because these plants do not die after even excessive elephant damage. Prof Jeremy Midgley and colleagues investigated a common palm in Kruger National Park both inside and outside a large elephant exclosure. Outside the exclosure almost all individuals of the lala palm (Hyphaene petersiana) were too short to have fruits (A in the Figure); they were effectively sterile. Inside the exclosure, individuals were tall and had many fruits (C). However, because this species needs elephants to disperse the large fruits (B), there was no recruitment inside the exclosure despite an abundance of fruits on trees and on the ground.  H. petersiana is between a rock and a hard place in Kruger National Park. The lack of mature individuals where elephants have access to them suggests the present level of elephant damage is too high for this species; it cannot evolve nor disperse. Also, the flowers, fruits and tall stems produced by mature individuals are used by other animal species; so other animals are disadvantaged by excessive elephant herbivory.  A suggestion from this work is for managers to use the reproductive status of trees as a guideline as to whether herbivory is too intense or not. (Mass sterilization of a common palm species by elephants in Kruger National Park, South Africa. Scientific Reports (2020) 10:11719).