东亚季风区夏季陆地生态系统碳循环对东亚夏季风的响应

东亚地区陆地生态系统的时空变率表现出明显的对季风气候的响应特征。使用EOF（经验正交分解）方法分析了AVIM2动态植被陆面模式离线模拟试验模拟的1953～2004年东亚季风区夏季陆地生态系统总初级生产力（GPP）、生态系统净初级生产力（NPP）、净生态系统初级生产力（NEP）、植被呼吸以及土壤呼吸的时空分布特点，探讨了东亚夏季风对陆地生态系统碳循环影响机制。研究发现，在强季风年，江淮地区高温少雨的特点限制了光合作用，造成GPP偏低；而华南地区在强季风年气候温暖湿润，利于植被生长，GPP偏高。季风对于植被呼吸和土壤呼吸影响不明显，使得GPP和植被呼吸之差NPP的变化及NPP和土壤呼吸之差NEP的变化与GPP的变化保持一致。在强季风年江淮流域地区干热的气候条件使得NPP和NEP降低；但是在华南地区温度升高的同时降水增多使得在NPP偏高的基础上NEP也偏高。

Response of the Summer Terrestrial Carbon Cycle in the East Asian Monsoon Region to East Asian Monsoon

The temporal and spatial variability of the terrestrial ecosystem in the East Asia monsoon region reveals an obvious response characteristic to the monsoon climate. The Empirical Orthogonal Function (EOF) method is used to analyze the temporal and spatial distribution characteristics of Gross Primary Production (GPP), Net Primary Production (NPP), Net Ecosystem Production (NEP), and vegetation and soil respiration in the summer terrestrial ecosystem of the East Asian monsoon region obtained for the period 1953-2004 by off-line simulation of the Atmosphere Vegetation Interaction Model version 2 (AVIM2). In addition, the mechanism of influences of the East Asian monsoon on the terrestrial carbon cycle is discussed. Results show that during strong monsoon years with lower amounts of rainfall and higher temperatures in the Yangtze-Huaihe River basin, such restricted rainfall limits photosynthesis, which leads to lower GPP values. In southern China, however, rainfall amounts and temperatures are higher, which leads to stronger vegetation and, thus, higher GPP values. Because the East Asia summer monsoon does not significantly influence both plant and soil respiration, the changes in NPP, which marks the difference between GPP and vegetation respiration, and in NEP, which marks the difference between NPP and soil respiration, are consistent with that of GPP. During the strong summer monsoon years a hot and dry climate condition in the Yangtze-Huaihe River basin reduces NPP and NEP, whereas in Southern China the hot but wet climate increases NPP and NEP.