Habitat transformation through land-use change threatens the persistence of many grassland ecosystems worldwide. Restoration is often applied successfully to restore the ecosystem functions after a major disturbance, but the plant diversity endpoint is difficult to predict as we have a poor understanding of the factors that lead to species losses per unit area of transformed grasslands. The aim of this study was to make use of untransformed benchmark sites in the ancient biodiverse grasslands of South Africa to determine how transformation influences the species richness of grassland ecosystems. Floristic data were sampled at 18 sites representing land-use changes with varying disturbance intensities (i.e. communal pastures, mine tailings, plantations, urban open spaces, home gardens, crop fields, and eroded areas). Floristic diversity of four plots was sampled within each of the 18 transformed grassland sites, paired with four plots in each adjacent untransformed benchmark site. Our results highlight that grassland endemic and threatened species are most affected, especially those growth forms are less tolerant to soil disturbance, such as geophytes. Long-lived, shade intolerant grassland forb species have evolved in open grassy habitats and contribute considerably to the phylogenetic and functional diversity of these ecosystems but are most at risk of being displaced by alien invasives in disturbed habitat. An understanding of which land-use disturbances filter out which groups of species and identifying indigenous disturbance-tolerant species that may potentially facilitate other more sensitive species could inform restoration strategies in South African grasslands.
Audio/Video, Conference Presentation, SER2019
Pre-approved for CECs under SER's CERP program
Society for Ecological Restoration