Epigaeic ant diversity and distribution in the sandstone sourveld in KwaZulu-Natal, South Africa.
Ants are sensitive to habitat change and may be affected by disturbances, such as alien plant invasion. Alien plant invasion is associated with negative effects on the functioning of ecosystems and may have adverse impacts on biodiversity. The aim of this study was to determine the diversity of ground-dwelling ants in Tanglewood and Giba Gorge Reserves in KwaZulu-Natal Province, South Africa. Ants were sampled in the wet and dry seasons. Pitfall trap sampling was carried out in an intact grassland, forest and a disturbed grassland. We collected 360 samples resulting in a total of 2,577 occurrences comprising of 54 species. We found that diversity of ants in the two sites was influenced by vegetation type. The intact grassland in the two reserves had greater diversity (40 ± 4.45) of ants compared with forest (22 ± 4.86) and disturbed grassland (27 ± 1.15); however, the disturbed grassland supported higher ant occurrences (50.03 ± 31.6). Opportunists represented the most diverse functional group with 17 species followed by specialist predators with 13 species and generalised Myrmicinae with 10 species. These results suggest that grassland disturbance by alien plant invasion provides suitable environmental conditions that may increase ant occurrences but decrease ant diversity.