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Introduction
Extreme weather events, changes in precipitation, considerable variation in temperature and sea level rise provide evidence for global climate change (Dhillon & Wuenhlish 2013). Climate change, suggested to be largely a consequence of anthropogenic activities (Dhillon & Wuenhlish 2013), has impacted negatively on plant biodiversity in terms of both distribution and diversity (Trisurat, Shrestha & Kjelgren 2011).
Increasing temperatures, in particular, are likely to have a number of effects on plant communities globally (De Boeck et al. 2007). Global surface temperatures have risen by approximately 0.8 °C over the last century and are predicted to increase by 1.4-5.8 °C during the 21st century (Intergovernmental Panel on Climate Change [IPCC] 2007). In Africa, this increase in temperature is predicted to result in longer growing periods, higher fecundity, higher biomass allocation towards roots, and a possible shift towards tree-dominated biomes (Scheiter & Higgins 2009).
Predicting ecosystem responses to climate change is therefore becoming increasingly important, particularly in tropical regions, where species occupy narrow ranges owing to thermal specialisation (Laurance et al. 2011). These areas are likely to experience the greatest loss in biodiversity with an increase in temperature (Perez, Stroud & Feeley 2016). The effects of rising temperatures on grasslands is an important consideration given their high biodiversity (Boval & Dixon 2012), particularly in the tropics, where they occupy approximately 20% land cover (Parr et al. 2014). Grasslands play a particularly important role in carbon sequestration and nutrient recycling (Boval & Dixon 2012), and are threatened in many parts of the world by land-use change, poor management and climate change (Jewitt 2011; Parr et al. 2014; Sala et al. 2000).
The grassland biome in South Africa boasts high levels of endemic mammals, reptiles, butterflies, and very high levels of plant species diversity (Reyers et al. 2005). However, an estimated 35% of South African grassland has been either transformed or degraded (Egoh et al. 2011). An understanding of how grassland vegetation types will respond to, or be impacted on, by increased temperatures can inform their future conservation and management (Thuiller et al. 2008). Various climate change models and numerous in and ex situ experiments have attempted to predict and demonstrate the effects of rising temperatures within temperate...