Ecological Grassland Restoration—A South African Perspective

Abstract

The principal drivers of Grassland Biome conversion and degradation in South Africa include agricultural intensification, plantation forestry, urban expansion and mining, together with invasive non-native plants and insidious rural sprawl. This biome is poorly conserved and in dire need of restoration, an ecologically centred practice gaining increasing traction given its wide application to people and biodiversity in this emerging culture of renewal. The pioneering proponent of restoration in South Africa is the mining industry, primarily to restore surface stability using vegetation cover. We noticed a historical progression from production-focussed non-native pastures to more diverse suites of native species and habitats in the restoration landscape. This paradigm shift towards the proactive “biodiversity approach” necessitates assisted natural regeneration, mainly through revegetation with grasses, using plugs, sods and/or seeds, together with long-lived perennial forbs. We discuss key management interventions such as ongoing control of invasive non-native plants, the merits of fire and grazing, and the deleterious impacts of fertilisers. We also highlight areas of research requiring further investigation. The “biodiversity approach” has limitations and is best suited to restoring ecological processes rather than attempting to match the original pristine state. We advocate conserving intact grassland ecosystems as the key strategy for protecting grassland biodiversity, including small patches with disproportionately high biodiversity conservation value.

Determining the critical recruitment needs for the declining population of Olea europaea subsp. africana (Mill.) P.S. Green in Free State, South Africa

“…While birds were partly migratory and resident in behavior, all mammals foraged at a central place, complemented by birds that disperse seeds over relatively longer distances in this study (Table 1). Our finding that 39% of the natural habitat has been transformed confirmed previous reports (e.g., Carbutt & Kirkman, 2022;Matsika, 2008;O'connor & Kuyler, 2009;Skowno et al, 2019) showing that agricultural production, human settlement, and mining activities have reduced the space available for O. europaea subsp. africana population in the Grassland Biome.…”

“…Grasslands are threatened by fragmentation, which involves the splitting of natural habitats into smaller isolated patches primarily by human disturbances such as land clearing for human settlement (Bredenkamp et al, 2006 ; Carbutt & Kirkman, 2022 ; Matsika, 2008 ; Neke & du Plessis, 2004 ; Skowno et al, 2019 ; Vukeya et al, 2023 ), agricultural activities (Matsika, 2008 ; Nkuekam et al, 2018 ; Turpie et al, 2007 ), and mining activities (Brown & du Preez, 2014 ; Olivier, 2020 ). Several studies have reported that 40% of the grassland biome has been irrevocably modified while 60% of remaining grassland areas are threatened as they are losing an important aspect of their composition, structure, and function (Little et al, 2015 ; Neke & du Plessis, 2004 ; SANBI, 2013 ; Skowno et al, 2019 ), which may need urgent restoration for biodiversity conservation.…”

Grassland cover declined in Southern Africa but increased in other African subcontinents in early 21st century

“…Our assessment of the magnitude of grassland cover changes at the subcontinent level revealed mixed findings. Carbutt et al, 2011;Brown and Bezuidenhout, 2020;Carbutt and Kirkman, 2022). There are possibilities that climate change also contributed to the reduction in the grassland biome in Southern Africa (Brown and Bezuidenhout, 2020).…”

“…Similarly, the increasing human activities, such as agricultural intensification (O'Connor and Kuyler, 2009), afforestation (Bond et al, 2019), urban sprawling (Yao et al, 2019;Puplampu and Boafo, 2021), mining (Carbutt and Kirkman, 2022), indiscriminate grazing (Wachiye et al, 2022) and burning activities in Africa (Tarimo et al, 2015;Bond, 2016;Dwomoh and Wimberly, 2017) could jointly or independently disrupt grassland ecosystems. The impacts of the recent and future climate changes and anthropogenic activities on grasslands are gradual processes that should be monitored through time and space for an in-depth understanding of the processes driving changes in African grasslands (Hobbie et al, 2003).…”

The key to temperate savanna restoration is to increase plant species richness reasonably

“…In terms of the functional attributes of each ecosystem, it is necessary to give consideration to both ecological protection and production practices (Bengtsson et al, 2019). However, although we know that restoration strategies for degraded grasslands should be tailored to local conditions (Liu et al, 2019;Carbutt and Kirkman, 2022;Lyu et al, 2022), human interventions for grassland restoration tend to consider the single ecological (diversity) or productive (biomass) functions of grasslands (Guo, 2007). Moreover, the functions of grasslands have also changed during different restoration stages, which requires us to adjust strategies in time and respond flexibly.…”