中国森林生态系统的植物碳贮量及其影响因子分析

利用中国第四次(1989~1993年)森林资源清查资料,指出中国森林植被的总碳贮量和碳密度分别为 3 778.1Tg(1Tg = 10¹² g)和41.321 Mg/hm²(1 Mg= 10⁶ g),其分布很不均衡,东北和西南各省的碳贮量和碳密度较大。中国森林碳贮量约占世界的1.1%,森林碳密度低于世界平均水平,但中国森林以中、幼龄林为主,占80%以上,表明中国森林植被具有巨大的固碳潜力,对全球碳循环具有重要作用。同时,采用多元线性回归模型、标准系数法定量分析了气候因子对森林植被碳贮量的影响程度,指出气温对森林植被碳贮量的贡献大于降水。

Carbon Storage of Forest Vegetation and Its Relationship with Climatic Factors

Forests are major vegetation types in terrestrial ecosystem and play a key role not only because they account for a greater part of the carbon exchange between the atmosphere and terrestrial biosphere than any other ecosystem type, but also because they can mitigate carbon dioxide emission under the background of global change, and accurately estimating forest carbon storage is increasingly gaining global attention. In terms of the fourth national forest inventory data (1989-1993), forest vegetation carbon storage and carbon density in China are estimated by the relationships between stand biomass and volume for different forest types. The results shows that total forest vegetation carbon storage and average carbon density in China are 3778.1Tg(1Tg = 10¹²g)and 41.32 Mg/hm²(1 Mg = 10⁶ g), respectively. Forest vegetation carbon is not distributed evenly among provinces in China: more than half of the carbon is stocked in northeastern and southwestern China. Carbon storage of forest vegetation in China is about 1.1% of the global vegetation, and forest carbon density is lower than the world's average, the major reason is that the area of pre-mature forests in China occupies more than 80% of Chinese forests. It suggests that Chinese forests have the large potential to fix carbon. In addition, based on linear multi-regression of forest carbon storage model and standard regressive coefficient methods, the relationship between carbon storage of forest vegetation in China and climatic factors including temperature and precipitation is developed:Y_c=2.004X_p-2.809X_t+1.805. The regressive coefficient of annual precipitation (X_p) and mean annual temperature (X_t) show that forest vegetation carbon storage will decrease with climate warming, but it will increase with the increase of precipitation. According to factor analysis method, the contribution of climatic factors to forest vegetation carbon storage is calculated, the contribution of annual precipitation is 2.363, and that of mean annual temperature 3.227, it indicates that the effect of temperature on forest carbon storage is larger than that of precipitation,and global warming may seriously affects the forest carbon storage in China. The study may be helpful not only to provide a method for estimating carbon storage of forest vegetation using systematic and continuously forest inventory data in China, but also to improve understanding the relationship between climatic factors and carbon storage of forest vegetation.