气候变化对秦岭南北植被净初级生产力的影响（Ⅱ）——近52年秦岭南北植被净初级生产力

根据秦岭南北54个气象站1960—2011年逐日数据,采用周广胜—张新时模型、Penman-Monteith模型、气候倾向率、相关分析和Spline插值等方法分析近52 a气象要素的时空变化特征及其对植被净初级生产力的影响。结果表明：1）秦岭南北多年平均植被净初级生产力由北向南逐步上升,排序为巴巫谷地〉汉水流域〉秦岭南坡〉秦岭以北,各子区植被净初级生产力变化趋势不一,植被净初级生产力上升的站点占本区站点总数的比例顺序为汉水流域〉秦岭南坡〉巴巫谷地〉秦岭以北,秦岭以南地区增加更为明显,生态区23个站点中植被净初级生产力年际波动并不大,介于1.34～1.89之间;2）植被净初级生产力与湿润指数、降水量和相对湿度呈显著水平（P〈0.01）的正相关关系,相关系数排序为降水量〉湿润指数〉相对湿度,降水的增多会促进植被净初级生产力的累积,水分是主要制约因素;3）植被水分利用效率由南向北递减,排序为巴巫谷地〉汉水流域〉秦岭南坡〉秦岭北坡,绝大部分地区呈现不显著的上升趋势,近52 a来,水分利用效率普遍呈上升趋势,但并不显著,整体上维持相对稳定水平。

Effects of climate change on net primary productivity of vegetation in the northern and southern regions of the Qinling Mountains(Ⅱ) :Net primary productivity of vegetation in recent 52 a

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 52 a 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 52 a,water use efficiency increased insignificantly and maintained at stable level.