Effects of climate change on net primary productivity of vegetation in the northern and southern regions of the Qinling Mountains（Ⅱ）：Effects of climate change on net primary productivity of vegetation
JIANG Chong, WANG Fei, MU Xin-Min, LI Rui
（1.College of Resources and Environment, Northwest A&F University, 712100, Yangling, Shaanxi；2.Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resources, 712100, Yangling, Shaanxi：China）
Abstract：Based on the daily data from 54 meteorological stations in Northern and Southern Regions of the Qinling Mountains between 1960 and 2011, with the help of Zhou Guangsheng-Zhang Xinshi Model, Penman-Monteith Model, climate trend rate, correlation analysis and Spline interpolation method, the climate change in the northern and southern region of the Qinling Mountains during last 52a and its effect on Net Primary Productivity (NPP) as well as the variation of NPP in different scenarios were analyzed. The results showed that: 1）According to the size of NPP, NPP increased from north to south gradually. and the order was given as Ba-Wu Valley, Han River Basin, the southern slope and northern region of Qinling Mountains. According to the percent of NPP increasing stations accounted for the total stations, the sub regions had different change trend with the order of Han River Basin, Ba-Wu Valley, southern slope and northern region of Qinling Mountains. The extreme ratio of inter-annual variability of NPP in ecological regions were not very big, ranging from 1.34 to 1.89. 2）Humid index, precipitation and humid index correlated positively with NPP, which reached 0.01 significant level. According to the size of correlation coefficient, the order was given as humid index, precipitation and relative humid. The increase of precipitation would promote accumulation of NPP, which indicated that water was the main restricting factors. 3）Water use efficiency of vegetation decreased from south to north with the order Ba-Wu Valley, Han River Basin, southern slope and northern region of Qinling Mountains. Most of the area had insignificant upward trend, and in last 52a, water use efficiency increased insignificantly and maintained at stable level.
2012, Vol. 10 
