Dung and carrion beetle diversity in small forest patches versus large continuous forest in the southern Cape, South Africa

Abstract

Naturally fragmented indigenous forests in the southern Cape of South Africa are particularly understudied in terms of beetle diversity. This study therefore aimed to determine whether southern Afrotemperate forest dung and carrion beetle diversity differs between continuous forest and naturally occurring forest patches. Beetles were sampled from sixteen sites: eight within a continuous forest and eight within forest patches using three baited pitfall trap types (carrion, pig dung, and carrion plus pig dung). A total of 500 individual beetles were sampled from forest patches and 272 individual beetles from continuous forests. Forest patches supported a richer diversity of dung and carrion beetles (8 spp.) compared to continuous forests (3 spp.), and also supported a higher abundance of generalist species. More individuals and species were collected with a combination of carrion and pig dung while no species exclusively preferred the carrion bait. Body size of two beetle species differed between forest patches and continuous forests, though the pattern was contradictory. The intermediate disturbance hypothesis may explain these results, as forest patches often have human- or animal-made paths that traverse them, increasing their permeability. Predictably, the provision of ecosystem services is thus maintained, or even enhanced, in forest patches, highlighting their conservation significance.