The diversity of epigeal insects after the application of the brush packing restoration method following bush-encroachment control in South Africa

Abstract

Evidently, bush encroachment caused by factors, such as overgrazing, results in a change in savanna ecosystems. This shift in vegetation structure can affect many factors, including insect fauna. Epigeal arthropods occupy smaller habitat patches and therefore respond to the effects of bush encroachment at finer scales. Different restoration efforts to combat bush encroachment have been implemented. A low-intensity management method is brush packing, which involves the use of removed woody branches to cover the soil surface. This study investigates whether the application of brush packing is effective in the restoration of insect communities. Total insect richness and the tendency towards diversity were higher on bush-controlled plots, irrespective of brush packing. This trend was found for all tested insect orders, except for Hymenoptera. However, non-metric multidimensional scaling ordination clustered distinctive insect communities in areas where brush packing was applied. The results indicate that the application of brush packing results in higher habitat heterogeneity and, consequently, more diversified insect communities on a small scale. We argue that brush packing application does not only benefit vegetation structure, but can also improve insect community composition, thereby increasing overall ecosystem health and stability, making this restoration method suitable for highly degraded areas.

Keywords:

• bush-packing
• ecosystem restoration
• insect diversity
• management
• savanna restoration