Habitat modification by grazing lawns reduces soil mite diversity in a South African National Park

Abstract

Soil mesofauna are an integral part of the functioning of an ecosystem. They are relatively small in body size, occur in varying habitats and operate in a range of ecological niches. Soil mites are quite sensitive to changes in their environment and contribute to several important ecosystem services in their environments. This investigation aimed to determine how soil mite communities change in and around lawns in the Bontebok National Park (BNP). Sites that were sampled were categorised into lawns, ecotones and natural vegetation. Soils were collected to analyse physio-chemical parameters and to evaluate species composition of soil dwelling mites. Shannon and Simpson indices were used to determine species diversity of the different zones sampled and soil properties were used to generate PCAs and boxplots. There were changes in mite populations and community structure that were noticed in and around grazing lawns in the park, with a great reduction in diversity in lawns and the highest diversity seen in the ecotones. Lawns had higher proportions of macro and micronutrients, in addition to higher heavy metal content, which affected the oribatid mite populations inhabiting those areas. The establishment of lawns in the BNP had a negative impact on the mite populations in the park. This can be a major concern to soil mite communities in the park as they act as a vital component of the ecosystem, and contribute importantly to the overall functioning of their environment.