title: Landscape functionality of plant communities in the Impala Platinum mining area, Rustenburg.
abstract: The tremendous growth of the platinum mining industry in South Africa has affected the natural environment adversely. The waste produced by platinum mineral processing is alkaline, biologically sterile and has a low water-holding capacity. These properties in the environment may constitute dysfunctional areas that will create 'leaky' and dysfunctional landscapes, limiting biological development. Landscape Function Analysis (LFA) is a monitoring procedure that assesses the degradation of landscapes, as brought about by human, animal and natural activities, through rapidly assessing certain soil surface indicators which indicate the biophysical functionality of the system. The "Trigger-Transfer-Reserve-Pulse" (TTRP) conceptual framework forms the foundation for assessing landscape function when using LFA. The two main aspects of this framework are the loss of resources from the system and the utilisation of resources by the system. After a survey of landscape heterogeneity to reflect the spatial organisation of the landscape, soil surface indicators are assessed within different patch types (identifiable units that retains resources that pass through the system) and interpatches (units between patches where vital resources are not retained, but lost) to assess the capacity of patches with various physical properties in regulating the effectiveness of resource control in the landscape. Indices describing landscape organisation are computed by a spreadsheet analysis, as well as soil surface quality indices. When assembled in different combinations, three indices emerge that reflect soil productive potential, namely: the (1) surface stability, (2) infiltration capacity, and (3) the nutrient cycling potential of the landscape. In this study we compared the landscape functionality of natural thornveld areas, rehabilitated opencast mines and rehabilitated slopes of tailings dams in the area leased for mining in the Rustenburg area. Our results show that the rehabilitated areas had a higher total SSA functionality due to higher infiltration and nutrient cycling indices than the natural thornveld landscapes. The length of interpatches and the width of patches greatly influenced the landscape function of the studied areas. The natural thornveld areas had a marginally higher total patch area than the rehabilitated areas. Vegetated patches (grass-, sparse grass-, grassy forb-, and grassy shrub-patches) generally scored the highest functionality indices, whilst bare soil interpatches contributed to the landscape functionality of the various plant communities the least.
authors.affiliation: School of Environmental Sciences and Development, North-West University, Potchefstroom Campus, Potchefstroom 2531, South Africa. 20480628@nwu.ac.za
authors.forename: L
authors.initials: L
authors.lastname: van der Walt
authors.forename: S S
authors.initials: SS
authors.lastname: Cilliers
authors.forename: K
authors.initials: K
authors.lastname: Kellner
authors.forename: D
authors.initials: D
authors.lastname: Tongway
authors.forename: L
authors.initials: L
authors.lastname: van Rensburg
mesh_terms: D003247:Conservation of Natural Resources; D004784:Environmental Monitoring / Q000379:methods*; D008906:Mining; D010984:Platinum; D012987:Soil / Q000032:analysis
chemical_list: D012987:Soil; D010984:Platinum