5 Conclusion
We found that GE had caused significant soil acidification across
China’s grasslands. Surface soil pH showed greatest decline rates in GE
grasslands, while deeper soil pH showed limited responses to GE. In
general, the largest decrease in soil pH occurred after medium-term
periods (5–15 years) of GE, whereas soil pH exhibited a smaller
response in long-term periods (≥15 years) of GE. Of the environmental
factors examined, MAP, biomass accumulation and soil C and N dynamics
were the important factors influencing the RPC following GE. Grassland
dominated by sedge species had a higher pH decrease rate in surface
soil, whereas forbs and shrubs had the lowest RPC in deeper soil. Our
results provide an important reference for future grassland management
in China.