Is microclimate-driven turnover of dung beetle assemblage structure in regenerating coastal vegetation a precursor to re-establishment of a forest fauna?

• Published in: Journal of insect conservation Vol. 17; no. 3; pp. 565 - 576
• Main Authors: Davis, Adrian L. V., van Aarde, Rudi J., Scholtz, Clarke H., Guldemond, Robert A. R., Fourie, Johan, Deschodt, Christian M.
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01-06-2013; Springer; Springer Nature B.V
• Subjects: Acacia; Animal Ecology; Animal, plant and microbial ecology; Applied ecology; Biodiversity; Biological and medical sciences; Biomedical and Life Sciences; Conservation biology; Conservation Biology/Ecology; Conservation, protection and management of environment and wildlife; Dung; Ecological succession; Endemism; Entomology; Environmental degradation: ecosystems survey and restoration; Environmental restoration; Fauna; Forests; Fundamental and applied biological sciences. Psychology; Insects; Life Sciences; Microclimate; Original Paper; Vegetation; Woodlands; South Africa; Dune forest; Chronosequence; Succession; Dung beetle; Restoration; woodland; Patchiness; Scarabaeinae; Richards Bay; Acacia karroo woodland; Coleoptera; Insecta; Environmental factor; Microclimate; Precursor; Woodland; Dicotyledones; Angiospermae; Turnover; Ecological recovery; Community structure; Forest zone; Fauna; Woody plant; Leguminosae; Arthropoda; Scarabaeidae; Acacia; Vegetation; Spermatophyta; Bay; Invertebrata; Dunes
• ISSN: 1366-638X; 1572-9753
• DOI: 10.1007/s10841-012-9542-8

We questioned the capability of post-mining rehabilitation and successional changes in coastal vegetation to achieve restoration of dune forest, dung beetle assemblages in the Maputaland Centre of Endemism, South Africa. A repeat 2010 study of structural turnover between dung beetle assemblages across a 33 year successional sere of rehabilitating vegetation and old-growth forest (>73 years) produced comparable results to an earlier study across the 23 year chronosequence of 2000. Despite overlap, three structural patterns along the 33 year chronosequence were associated with specific stages of vegetation succession and their characteristic microclimates as in 2000. Although species biased to unshaded habitat dominated the earliest succession, there was rapid re-establishment of dominance by shade-associated forest species. In concert with progression from unshaded, post-mining vegetation to strongly shaded, early successional,
Acacia
shrub-woodland, there was an initial increase in similarity of the dung beetle fauna (species-poor, low abundance) to that in strongly-shaded forest (also species-poor, low abundance). However, in concert with decreasing shade cover in late successional woodland, the dung beetle fauna became species-rich with high abundance so that the early successional trajectory of increasing similarity to forest fauna either levelled off to a plateau (species in 2000; abundance in 2010) or declined (species in 2010, abundance in 2000). It remains to be seen if gaps forming in the oldest
Acacia
woodland permit forest tree saplings of the exposed understorey to recreate a forest canopy that would be tracked by dung beetles to re-establish a typically species-poor, deep shade, forest assemblage with low abundance.