How might intensification of farming influence dung beetle diversity (Coleoptera: Scarabaeidae) in Maputo Special Reserve (Mozambique)?

Abstract

There are concerns over the increasing encroachment of humans, domestic livestock, and farming onto Maputo Special Reserve because of the potential for habitat modification. Therefore, differences between an undisturbed area of the reserve and a neighbouring farming area are assessed using dung beetle as indicators. In each of the two areas, pig-dung-baited pitfall traps were used to sample dung beetle assemblages in two contrasting habitats, grassland and forest. Distributional analysis of the 57 species and 36 942 individuals that were captured, showed that species richness, species turnover, relative abundance patterns, and biogeographical composition differed strongly between both habitats and areas under different land usage. However, in analyses that apportion variation, the greatest amounts were related to habitat rather than land usage. Even so, in both habitats, the total and mean number of species per trap was higher in the farmed area than in the reserve although this was a significant trend only in grassland. Furthermore, in grassland, widespread species were better represented in the farmed area than in the reserve whereas in forest, widespread species were poorly represented compared to grassland. Also in forest, Maputaland endemics were better represented in the reserve than in the farmed area. Further work is necessary to separate the different geographical, ecological, and land usage factors responsible for the patterns detected in this preliminary study. Even so, there are clearly differences between the Maputo Special Reserve and the farmed area.