南疆植被总初级生产力对区域降水的响应规律

为研究总初级生产力(Gross primary productivity,GPP)对区域降水的响应规律,本研究通过对南疆地区喀什、阿克苏、和田3个市2000—2014年的GPP进行分析,得出GPP的时空分布规律,进而与2000—2011年同期的降水进行耦合分析,以探寻植被GPP与降水之间的响应关系,从而为南疆地区植被生态保持和可持续发展提供依据。结果表明:1)从时间尺度来看,GPP呈现出与季节相关的波动性,年均GPP的极值点基本出现在每年的7月;2)在空间分布上,和田地区的GPP在空间上呈现北低南高的空间格局,阿克苏地区的GPP呈现北高南低的空间格局,并且在数值上存在较大的差异性,喀什地区的GPP呈现北高南低的空间格局,西北部GPP分布比较集中并有较高的值;3)变化趋势上,和田地区呈现上升趋势、阿克苏地区整体比较稳定、喀什地区呈现上升的趋势;4)研究区域内GPP与降水之间均为正相关关系。当降水滞后1个月时,和田及喀什GPP与降水之间的相关系数显著提高,但是阿克苏地区没有表现出时滞性,说明响应关系更加明显。

Response of gross primary production in Southern Xinjiang to regional precipitation

In order to study the response of gross primary productivity(GPP)to regional precipitation, this study analyzed the GPP of Kashgar, Aksu and Hotan in Southern Xinjiang from 2000 to 2014. The spatial and temporal distribution of GPP were obtained and coupled with the precipitation over the same period to explore the responses of GPP to precipitation in order to provide a basis for the ecological maintenance and sustainable development of vegetation in Southern Xinjiang. The results showed that: 1)GPP presented seasonal fluctuations. The annual average GPP peak point basically appeared in July of each year. 2)In terms of spatial distribution, GPP in Hotan presented low value in north and high value in south, while GPP in Aksu presented high value in north and low value in south where there was a large difference in numerical values. GPP in Kashgar was the same as that of Aksu, but the distribution of GPP in the northwest was relatively concentrated and had a relatively high value. 3)As for the trend, GPP in Hotan displayed an increasing trend, GPP in Aksu was relatively stable, and GPP in Kashgar was on the rise. 4)There was a positive correlation between GPP and precipitation in the study area. When the precipitation lagged behind for one month, the correlation coefficient in Hotan and Kashgar was significantly improved, but the Aksu region didn''t show the lagging effects, indicating that the response relationship was more obvious.