海南岛橡胶林通量足迹与源区分布研究

为分析影响橡胶林通量观测数据质量的因素，利用农业部儋州热带农业资源与生态环境重点野外试验站50m高通量观测塔2010年12个月连续的通量观测资料，应用Schmid的FSAM（Flux．Source Area Model）模式，分析不同大气条件下橡胶林通量足迹与源区分布特征。结果表明：（1）在大气不稳定状态时，通量各传感器测得的信息源区比大气稳定状态时源区面积相对较小；在相同贡献率水平下，大气稳定状态生长季节观测到的通量信息源区面积比非生长季节的信息源区面积大，大气不稳定状态非生长季节的通量信息源区面积比生长季节的信息源区面积大。（2）盛行风方向在110°-250°时，生长季大气不稳定情况下，通量测量的信息源区（P=80％）迎风方向范围在100—758m之间，垂直于迎风方向范围在-251—251m之间，非生长季大气不稳定情况下，迎风方向和垂直迎风方向的范围较均值略大些；生长季稳定条件下，迎风方向和垂直迎风方向的范围分别为173—1858m和-534—534m，非生长季稳定条件下，迎风方向和垂直迎风方向的范围较均值略小些。（3）风向在0°-110°，250°-360°时，与盛行风方向上的通量信息源区面积相比，橡胶林大气处于稳定状态，其通量信息源区面积范围明显要高，但在非稳定大气状态时，二者相差不大。

Distribution of footprint and fluxes source area of rubber plantation in Hainan Island

In order to analyze and control the quality of the rubber plantation flux observation data, the FSAM model （Flux-source Area Model） was used to calculate flux footprint and source areas according to the continuous flux measurement with the open-path eddy covarianee system on the 50 m tower of the Ministry of Agriculture Danzhou Key Field Station of Observation and Research for Tropical Agricultural Resources and Environments from Jan. 1 to Dec. 31,2010. The spatial representative of flux measurement of the rubber plantations in Hain- an Island, the south of China, was explained. Source areas of rubber plantation were found smaller under the unstable than under the stable atmospheric stratification. The source areas were larger in the growing season than in the dormant season at the same contribution level for the stable stratification, but they were smaller under the unstable stratification. In the main wind direction of 110°-250°, the upwind range of source areas of the rubber plantation was 100--758 m, and the vertical upwind range was -251--251 m at a 80% contribution level under the unstable stratification in the growing season, whereas the upwind and vertical upwind ranges were slightly larger than those under the unstable stratification in the dormant season. The upwind and vertical upwind ranges of the source areas were 173--1858 m and -534--534 m, respectively under the stable stratification in the growing season, and they were slightly smaller than those under the stable stratification in the dormant season. In the wind directions of 0°-110° and 250°--360°, the upwind range of the source areas was larger under the stable stratification of the rubber plantation than but similar to those in the prevailing wind direction under the unstable stratification.