中国主要灌丛植被碳储量

 在广泛收集资料的基础上，利用植被平均碳密度方法，估算了我国6种主要灌丛植被的碳储量，并分析了其区域分布特征。主要结果如下：1) 6种灌丛植被总面积为15 462.64 ×10⁴ hm²，总碳储量为1.68±0.12 Pg C(1 Pg=10¹⁵g)，灌丛植被平均碳密度为10.88±0.77 Mg C?hm^-2(1 Mg=10⁶ g)，不同植被类型差异较大，在5.92～17Mg C?hm^-2之间波动。2) 从区域分布来看，西南3省(云南、贵州、四川)既是我国灌丛主要的分布地区之一，分布面积占6种灌丛总面积的23.5%，又是我国灌丛碳储量的主要储库，碳储量占整个6种灌丛碳储量的1/3（32.6%），适宜的水热条件决定了该地区的植被平均碳密度要高于全国平均水平。3) 与我国森林和草地的植被碳储量相比，这些灌丛碳储量相当于我国森林和草 地碳储量的27%～40%和36%～55%。

VEGETATION CARBON STORAGE OF MAJOR SHRUBLANDS IN CHINA

Background and Aims Shrublands is one of the major types of terrestrial ecosystems, which widely distributes from tropical to polar regions. Due to their largely distributional area in China, it is very important for us to exactly estimate their carbon storages and spatial distributions. Answers to the following questions were sought: (a) How much is the vegetation carbon storage of major shrublands in China? (b) How are their spatial distributions in China? Methods Based on published biomass data in shrublands and 1∶4 000 000 digital vegetation map of China, carbon storage of major shrublands in China was estimated using the method of mean biomass carbon density for different shrublands types. Key Results The carbon storage of six shrublands in China is 1.68±0.12 Pg C(1 Pg = 10¹⁵ g) with an total area of 15 462.64×10⁴ hm². The average vegetation carbon density is 10.88±0.77 Mg C?hm^-2, varying from 5.92 to 17.00 Mg C?hm^-2 for different shrubland types. The distribution of shrublands is spatially heterogeneous in the country. Shrublands in three provinces (Yunnan, Guizhou and Sichuan) in Southwest China occupies 23.5% of the total area and contributes to approximately one_third (32.6%) of the total carbon storage of six shrubland types in China due to favorable climeste and soil conditions. The area of six shrubland types in Inner Mongolia is the second largest among all the provinces. However, the vegetation carbon storage in Inner Mongolia shrublands is only 84.81 Tg C (1 Tg = 10¹² g), following that of Yunnan, Guizhou, Sichuan, Jiangxi, and Hunan. The probable reason is ascribed to its arid or semiarid climatic conditions. Although shrublands hold about 1.5 times the area of forests in China, the carbon storage of shrublands corresponds 27%－40% of forests because carbon density of shrublands accounts for only one_fifth of forests. Similarly, the proportion of vegetation carbon storage of shrublands to that of grasslands in China varies from 36% to 55% due to the different areas of grasslands used in previous studies. Conclusion This study draw the following conclusions: (a) As important ecos ystem types in China, shrublands hold large vegetation carbon storage, which is main component of China’s vegetation carbon storage. (b) Because of different climatic and soil conditions, their distributions are spatially heterogeneous in China and The average vegetation carbon density varies greatly for different shrubland types.