Impacts of alien vegetation on animal diversity in South Africa: a synthesis
Susana Clusella-Trullas1, Raquel A. Garcia1
1Centre for Invasion Biology, Dept Botany and Zoology, Stellenbosch University, Private Bag X1, Matieland 7602, South Africa
Increasing numbers of invasive alien plant (IAP) species are establishing around the globe and can have negative effects on resident species diversity. These impacts depend on a variety of factors, including the extent of the plant invasion, the region and taxonomic group affected. These context dependencies make extrapolations of the effects of IAPs on resident biota from region to region a substantial challenge.
Here, we aim to synthesize studies that have examined the effects of IAPs on animal diversity in South Africa. We focus on ectothermic organisms (reptiles, amphibians and arthropods) as the environment more directly influences their energy budgets, they generally have smaller dispersal distances than mammals and birds, and they make a large contribution to overall animal diversity. Relevant articles were sourced using a combination of key words relating to i. the effects of IAPs on species diversity (richness, abundance and composition), ii. the invasive plant and iii. the native ectotherm. We also extracted information on mechanisms driving the impacts such as changes in habitat structure, thermal opportunities, prey and predator data, and refuge/nest site availability and explore if these are related to the growth form, stand age and spatial coverage of the IAP.