Effects of mammalian herbivores and termites on performance of native and exotic plantation tree seedlings

Invasion of exotic species is a global challenge and the potential for adverse effects on local biodiversity is particularly high in protected areas. Protected African savanna areas support globally important biodiversity. At the same time, forest plantations are widespread throughout Africa and exotic tree species frequently invade natural areas. To evaluate the potential invasiveness of plant species, it is pertinent to know to what extent, if at all, consumption by native herbivore assemblages differentially affects exotic and indigenous plants. We studied how two globally widespread exotic trees Eucalyptus grandis and Grevillea robusta and two common indigenous trees Milicia excelsa and Maesopsis eminii responded to natural herbivory by large herbivores and termites. We experimentally exposed 720 tree seedlings to: (i) no large herbivores or termites; (ii) termites only; (iii) large herbivores only; and (iv) both large herbivores and termites. When exposed to large herbivores and te...