福建省植被NPP时空格局及其驱动力分析

以福建省为研究区,以中等分辨率MODIS NDVI遥感数据、气象数据及其他辅助数据为数据源,基于植被净初级生产力(net primary productivity,NPP)光能利用率估算模型——CASA,定量研究了该区域历史序列(2001—2012年)NPP时空变化格局,探索其主要影响因素。结果表明:2001—2012年该区域NPP总体呈现下降趋势,2003年和2005年为历年变化下降率最大的两年;该区域NPP时空分布特征明显,在空间上表现为由南向北递减的空间分布格局,且沿海经济发达区域NPP普遍较低;时间上表现为春秋两季具有相同的空间分布,夏季具有最高的NPP,占全年NPP的56%,冬季平均NPP在120gC·m~(-2)·a~(-1)以下;降水和温度与NPP的线性相关性较小,且线性相关性随空间位置的不同而有所差异;福建省NPP对气候因子的响应随空间位置的变化而变化,在不同的区域,其主要的胁迫因子不同,NPP总体受到辐射量的驱动因素要比其他胁迫因子强。

Analysis of vegetation NPP spatiotemporal pattern and driving force in Fujian

In this paper,the satellite remote sensing products of med ium-resolution MODIS NDVI,meteorological data and other auxiliary data are implemented as the data source.Based on the vegetation net primary productivity (NPP) light energy utilization estimation model-CASA (Carnegie-Ames-Stanford Approach),the regional history sequence NPP spatiotemporal pattern and its main influence factors between 2001 and 2012 in Beijing were analyzed quantitatively with the support of remote sensing and GIS technology.The results indicated that:Generally,the NPP in Fujian from 2001 to 2012 had the tendency of decline.2003 and 2005 had the maximum downward rate.The NPP in Fujian shows significant spatiotemporal characteristics.Spatially,it has the distribution pattern of decreasing from South to North.Temporally,spring and autumn's NPP has the same spatial distribution;summer has the highest NPP which occupies 56％ of the total annual NPP,while winter has the least average NPP below 120gC · m-2 · a-1.The linear correlation of precipitation and temperature with the NPP is small and varied with the spatial location.The responds of NPP to meteorological stress factor was different in different regions and the main stress factor differs between locations.In general,it can be strongly influenced by solar radiation than other stress factors.