Interspecific variation in the reproductive response of acacia species to protection from large mammalian herbivores

We quantified the fruit set of four Acacia spp. inside and outside of long-term experimental exclosures in order to examine the fitness consequences of herbivory by large mammals. We found a considerable interspecific variation in the reproductive fitness costs of herbivory in four African Acacia spp. Acacia nilotica and A. brevispica respond to protection from large mammalian herbivores by, greatly increasing their seed set. In contrast, there was little or no increase in seed set in A. mellifera and A. etbaica. The reasons for these differences are not known, but may be related to armament morphologies.