2.6 Climatic data
The gridded daily dataset (CN05.1) with a spatial resolution of 0.25°×0.25° constructed by the “anomaly approach” during the interpolation with more 2400 station observations in China was employed to obtain the meteorological data for the study sites during 1997-2016 (New et al. , 2000; Xu et al. , 2009). In the “anomaly approach”, we derived the final dataset by calculating a gridded climatology, and then adding a gridded daily anomaly to the climatology. The air temperature for each elevation on each site was derived through topographic correction with the lapse rate of air temperature set at 0.65C (100 m)-1 (Zhao et al. , 2008). The same value of precipitation was assumed along the elevational gradient on each site. The temperature variables included the mean annual temperature (MAT), the mean temperature in the growing season (Tg), the annual mean maximum air temperature (Tmax), and the annual mean maximum air temperature (Tmin); the precipitation variables included the mean annual precipitation (MAP) and the mean precipitation in the growing season (Pg).