南京紫金山风景林碳密度空间动态变化分析

Spatial dynamic analysis of scenic forest carbon density in Zijinshan mountain in Nanjing city

以南京市东郊紫金山国家森林公园风景林为研究对象，利用1988年、2002年、2006年3期森林资源二类调查数据，采用林木蓄积量一生物量的转换公式，将风景林地上部分蓄积量转换成生物量和碳密度。在此基础上，对研究区的碳密度进行趋势面分析、冷热点探测、地理加权回归分析、空间格局分析。研究结果表明：（1）紫金山碳密度在空间分布上呈现出一种由东西部显著差异到同心圆状分布的变化趋势，1998～2006年，碳密度峰值由西往中，再往中北转移。（2）1998～2006年，紫金山风景林碳密度热点主要分布在海拔较高，坡度较大，NDVI植被指数较高，距离道路较远的地方；冷点反之。（3）2006年紫金山风景林碳密度大小与NDVI植被指数、海拔、坡度、距道路距离呈正相关。

Scenic forest in Zijinshan Mountain National Forest Park in east suburb of Nanjing city was taken as the research objects, and the forest resource survey data from three periods in 1988, 2002 and 2006 were gathered as the main information sources. On this basis, by using the conversion formula from forest volume to biomass, the volume factor of scenic forest above ground was converted into the factors of carbon stocks and carbon density. Then the carbon density in the studied region was probed by using cold/hot spot detection, and was analyzed by employing the methods of trend surface analysis, geographically weighted regression analysis and spatial pattern analysis. The results show that （1） the carbon density spatial distribution in Zijingshan mountain area presented a changing variation tendency that from having a marked difference between the western and eastern to becoming a concentric distribution, from in1998 to 2006, the position of carbon density peak value transferred from west to the middle and then to the farther north; （2） the hot spots of carbon density of scenic forest in Zijinshan mountain were mainly distributed in positions with high altitude, high slope, high NDVI and far away from the roads. For the cold spots, the situation was on the contrary; （3） the carbon density of scenic forest in Zijinshan mountain were positively correlated with NDVI, altitude, slope and distance from roads.