我国主要森林生态系统碳贮量和碳平衡

CARBON STORAGE AND BUDGET OF MAJOR CHINESE FOREST TYPES

在广泛收集资料的基础上，估算了我国主要森林生态系统的碳贮量和碳平衡通量，分析了它们的区域特征。主要结果如下：１）我国森林生态系统的平均碳密度是２５８．８３ ｔ·ｈｍ^(－２)，基本趋势是随纬度的增加而增加；其中植被的平均碳密度是５７． ０７ ｔ·ｈｍ^(－２)，随纬度的增加而减小；土壤碳密度约是植被碳密度的３． ４倍，其区域特点与植被碳密度呈相反趋势，随纬度升高而增加；凋落物层平均碳密度是８． ２１ｔ·ｈｍ^(－２)，随水热因子的改善而减小。２）森林生态系统有机碳库包括植被、土壤和凋落物层３个部分，采用林业部调查规划设计院１９８９～１９９３年最新统计的我国森林资源清查资料，估算我国主要森林生态系统碳贮量为２８１．１６×１０~８ｔ，其中植被碳库、土壤碳库、凋落物层碳库分别为６２．００×１０~８ｔ、２１０．２３×１０~８ｔ、８．９２×１０~８ｔ。落叶阔叶林、暖性针叶林、常绿落叶阔叶林、云冷杉（Ｐｉｃｅａ－Ａｂｉｅｓ）林、落叶松（Ｌａｒｉｘ）林占森林总碳贮量的８７％，是我国森林主要的碳库。３）我国森林生态系统在与大气的气体交换中表现为碳汇，年通量为４．８０×１０~８ｔ·ａ^(－１)，基本规律是从热带向寒带，碳汇功能下降，这取决于系统碳?

The regional characteristics of carbon storage and carbon dioxide fluxes of major Chinese forest ecosystems were studied from the points of internal biological cycle, based on published data regarding forest biomass, productivity, the organic carbon content of soil profile, stand and annual weight of the litter, soil respiration etc. The results are as follows: the average carbon density of Chinese forest ecosystem is 258. 83 t .hm-2, showing a generally increasing trend with increasing latitude; carbon density of the vegetation, soil and litter is 57. 07 t ·hm-2, 193. 55 t .hm-2, and 8. 21 t.hm-2, respectively ; the characteristics of the carbon density of these three fractions (vegetation, soil, lit-ter) were also analyzed ; from the recent areal data provided by the Ministry of Forestry of China in 1989-1993 the total carbon storage of Chinese forests was estimated to be 281. 16 X 108 t, in which the vegetation, soil and litter were 62. 00X 108 t, 210. 23 X 108 t, 8. 92 X 108 t, making up 22. 2%, 74. 6%, 3. 2%, respectively of the total, the carbon storage of deciduous broad-leaved forests, warmer temperate coniferous forests, evergreen / evergreen- deciduous broad-leaved forests, Picea-Abies forests, and Larix forests were the major carbon pool of the forest, making up 87 % of the total; in China the net flux between the forest ecosystem and the atmosphere is 4. 80 X 108 t .a-1, and the forest ecosystem acts as a carbon sink when exchanged with the atmosphere, absorbing 48. 7% of the carbon dioxide from burning of biomass, fossil fuel and human respiration (9. 87 X 108 t .a-1 ). Generally, the carbon dioxide fixing capacity of the deciduous forest is higher than the coniferous forests, decreasing with increasing latitude.