4.3 Implications of GE for grassland management
Following the implementation of the comprehensive ‘Returning Grazing Land to Grassland’ project, GE has had a negative effect on soil pH in China’s grassland ecosystems. In addition, soil acidification also had lasted for decades and could be maintained for a long periods because of the deposition of atmospheric N and sulfur across China’s grasslands (Yang et al. , 2012). These two factors may be variably superimposed. Sustained soil acidification could enhance the leaching loss of base cations (e.g., Ca2+, K+, Mg2+ and Na+), and the release of mobile forms of Al3+ and Mn2+, which influences plant physiological activities (e.g., toxicity) for grassland species (Kochian, 1995; Poschenrieder et al. , 2008). Long-term soil acidification could also change structure and function at ecosystem scale, such as C–N transformation processes and plant and microbial diversities (Liu et al. , 2011). Similar management recommendations might be applied in other grassland ecosystems with similar histories and patterns of ecological degradation, such as the African savannas (Talore et al. , 2015), temperate grassland of north America (Anderson et al. , 2008) and Pampas of South America (Piñeiro et al. , 2009).