Abstract:
This study was about the impact of cattle grazing on recently rehabilitated site at a former opencast coal mine in Mpumalanga, Witbank coalfield. The area has been rehabilitated by backfilling and levelling of spoil material, subsoil material, placement of approximately 400-mm topsoil layer and grassing. For the purpose of this study, ten (5 x 5 m2) exclosures were erected and cattle was allowed to graze outside the exclosures. Two benchmark sites were identified and vegetation surveys were done in two wet seasons in 2017 and 2018. Soil samples were collected and analysed for pH, Ca, Na, Mg, K, P, NO3, NH4 and textural classes. Most soil parameters were in an acceptable range when compared to the grassland soil fertility index. The effect of grazing in block I based on individual plant species showed some effects in terms of plant diversity, biomass and ground cover. There was a decrease in plant diversity over the study period. For a significant effect of grazing on species composition, more time is needed for sampling, one year is not enough to see changes, and to conclude if the change was positive or negative. However, in terms of species composition, there was an increase in forb species from 12% to 17 % and disappearance of grass species such as Digitaria eriantha and Chloris virgata in and around exclosures. Rainfall data was considered from the past 30 years, and it was found that during the study period the rainfall in the area was just above the normal range (650-700 mm/year). In other studies, it took more than six year to see the effects of cattle grazing on vegetation in disturbed areas, and also to determine the progress on vegetation development when comparing to other areas.
