全球植被与大气之间碳通量的模式估计

用大气植被相互作用模式(AⅥM)模拟了全球陆地植被的净初级生产力(NPP)。AⅥM由相互耦合的两部分组成：物理过程，包括陆地表面水分和能量在土壤、植被与大气之间的传输；以及生理生态过程，如：光合、呼吸、干物质分配、凋落和物候等。全球的植被分为13类，土壤按质地分为6类。用EMDI提供的全球1637个包括不同植被类型的NPP观测点数据对模型进行了检验。NPP模拟的结果表明：全球陆地植被的平均NPP为405.13 g C m-2yr-1，不同植被类型的平均NPP变化范围在99.58 g C m-2yr-l(苔原)到996.2 g C m-2yr-l(热带雨林)之间。全球年总NPP为60.72 Gt C yr-l，其中最大的部分为热带雨林，15.84 Gt C yr-1，占全球的26.09％。最大的碳汇是在北半球的温带。模式模拟的NPP在全球的空间和季节分布是合理的。

Model Estimates of Global Carbon Flux between Vegetation and the Atmosphere

The net primary productivity (NPP) of global terrestrial vegetation is estimated by an Atmosphere-Vegetation Interaction Model (AVIM). AVIM consists of two intercoupled components: phys ical processes, involving water and energy transfer among soil, vegetation and the atmosphere at the land surface and eco-physiological processes, ie. photosynthesis, respiration, dry matter allocation, littering, phenology. Globally vegetation is classified into 13 types and soil texture is classified into 6 types. The esti mated NPP for different vegetation types at 1637 sites are validated with the observed data provided by EMDI. The main results of NPP estimation show that global averaged NPP is 405.13 g C m-2yr-1 varying from 99.58 g C m-2yr-1 (tundra) to 996.2 g m-2yr-1 (rainforest). Global total annual NPP is about 60.72Gt Cyr-1, in which the maximum part, about 15.84 Gt C yr-1, accounting for 26.09% of the total is contributed by tropical rainforest. The maximum carbon sink occurs in the temperate region of the Northern Hemi sphere. The global spatial and seasonal distribution of terrestrial NPP is estimated reasonably.