Climate change effects on the community aboveground biomass in semiarid grassland of China

摘要

Climate change has affected the inter-annual variation in grassland aboveground biomass, but direct, long-term ground observations are rare.We evaluated the annual and monthly variations of temperature and precipitation m typical semiarid grassland of the Loess Plateau m China during 1992-2011.Long-term biomass data were related with daily temperature and rainfall, respectively, using Partial Least Squares regression, to explore the effects of climate change on grassland biomass.Results indicated that during the past 20 years, annual and monthly temperature has increased.Precipitation showed a decreased trend, mainly occurred in the middle of the growing season.Variations m biomass can well be explained by the changes of temperature and precipitation.Increased temperatures between April and May have a positive effect on the biomass increase, while hot June and July reduced the biomass.Increasing rainfall in May and decreased precipitation from June to August further depressed the aboveground biomass.