2000～2015年江汉平原区域植被NPP时空特征及其对气候变化的响应

植被NPP对气候变化的响应是全球变化与陆地生态系统碳循环研究的重要核心内容之一。利用CASA模型估算了2000~2015年江汉平原植被NPP，并利用线性回归与逐像元相关性分析方法定量研究了江汉平原植被NPP的时空变化特征及其与气候因素的相关性。结果表明：（1）16年来江汉平原植被NPP的年总量在25.43~29.76 TgC之间，呈波动增加趋势；（2）江汉平原NPP的空间分布格局具有明显的不均匀特征，形成一系列的高值中心和低值中心，符合“丘陵-平原-河流-城市”的衰减趋势；（3）江汉平原NPP与年降水量、年均温的相关系数分别为0.183 7和0.498 5；经显著性检验可知，江汉平原NPP的产量与年降水量相关性较弱，而与年均温则呈较强的正相关关系；（4）植被NPP与年降水量、年均温呈正相关的像元面积分别占总面积的69.19%和83.41%，主要分布在江汉平原腹部的农耕区域，说明江汉平原农耕区NPP的产量对年降水量与年均温的依赖性较强。

Spatial-temporal Variation of Vegetation Net Primary Productivity and Its Response to Climate Change in Jianghan Plain from 2000 to 2015

Response of vegetation NPP to climate change is one of the key issues in the study of global change and terrestrial ecosystem carbon cycle. In this paper, vegetation NPP was estimated by CASA model in Jianghan Plain from 2000 to 2015, and the spatial-temporal variation characteristics of vegetation NPP and its relativities with climatic factors were quantitatively studied by linear regression and pixel correlation analysis. Results are summarized as follows: (1) Total annual NPP ranged from 25.43 to 29.76 TgC in Jianghan Plain from 2000 to 2015, and showing an increasing trend of fluctuation. (2) The spatial distribution pattern of NPP in Jianghan Plain is obviously uneven, forming a series of high value and low value centers, which was consistent with the attenuation trend of “hills-plain-river-city”. (3) The correlation coefficients between NPP and annual precipitation, and annual mean temperature were 0.183 7 and 0.498 5, respectively; and the significant test of correlation coefficient indicated that the yield of NPP in Jianghan Plain has a weak correlation with annual precipitation, but a positive correlation with annual mean temperature. (4) The area with positive correlation between NPP and annual precipitation and annual mean temperature accounted for 69.19% and 83.41% of the total area, respectively, mainly distributed in the agricultural region in the abdomen of Jianghan Plain, which indicated that the yield of NPP in the agricultural region of Jianghan Plain was strongly dependent on the annual precipitation and annual mean temperature.