吴志祥等

摘 要 以位于海南岛西北部儋州地区的橡胶林为研究对象，采用涡度相关技术进行长期CO2通量观测，获得海南岛橡胶林生态系统碳通量的动态特征，并分析其对各影响因子的响应情况。结果表明：（1）橡胶林生态系统净碳交换量（NEE）日动态均为“U”型曲线，白天均为碳吸收（NEE为负值），夜间均为碳排放（NEE为正值）；全年各月除2月外，NEE月总值均为负值，吸收碳，雨季4～10月各月NEE值均较大，旱季1～3月、11～12月，各月NEE值均较小；橡胶林年固碳能力强大，超过11.0 t C/（hm2·a）。（2）橡胶林生态系统NEE与光合有效辐射（PAR）、冠层内大气平均温度（Ta）、地下5 cm土壤温度（T_-5 cm）和饱和水汽压差（VPD）及地下5 cm土壤含水量（VWC_-5 cm）等均负相关，但影响强度不同，其中PAR影响最为显著；另外NEE还与橡胶林本身林分状况及周围大气环境CO2浓度等相关。

关键词 碳通量；影响因子；橡胶林生态系统；海南岛

中图分类号 P422.4；Q948；S718 文献标识码 A

Abstract The rubber plantation in the northwest of Danzhou，Hainan area was used as the study object with the eddy covariance technique for long-term CO2 flux observations， Hainan rubber forest ecosystem carbon flux dynamic characteristics were obtained， and the responses on the environmental factors were analyzed in the research. The results showed as follows：（1）The daily dynamic of net ecosystem carbon exchange（NEE）of rubber plantation ecosystem was an“U”shaped curve； and rubber trees absorbed carbon during the daytime（NEE negative）， released carbon nighttime（NEE positive）. All the monthly NEE values throughout the year except February were negative（rubber trees absorb carbon）； and the NEE values from April to October during the rainy season were large， from January to March， November to December during the dry season little. Rubber plantation ecosystem had the strong carbon sequestration capability， and the yearly NEE values were more than 11.0 t C/（hm2·a）.（2）The NEE of rubber plantation ecosystem and all the environmental factors such as photosynthetically active radiation（PAR）， the average atmosphere temperature within the canopy（Ta）， -5 cm soil temperature（T_-5 cm）， vapor pressure deficit（VPD）and -5 cm soil volume water content（VWC_-5 cm）were negatively correlated with different intensity， and PAR was the most significantly related factor. NEE was also associated with the rubber plantation itself stand conditions and ambient atmospheric CO2 concentration. The results could provide a reference for tropical plantation ecosystems carbon estimates and offer basic data reduction for the government trade negotiations.

Key words Carbon fluxes； Factors； Rubber plantation ecosystem； Hainan Island

doi 10.3969/j.issn.1000-2561.2014.11.001

巴西橡胶树（Hevea brasiliensis Müll. Arg.）人工林（本文简称为橡胶林）是我国热带地区最重要的森林生态系统，在我国海南、云南、广东等地的种植面积已超过1×106 hm2。多年种植橡胶树的生产实践和研究证明，橡胶人工林是世界上热带地区开发、在旱地建立的最好的生态系统之一，在我国热区及东南亚种植橡胶树，是应用生态学原理开发热区获得成功的一个范例[1]。在热带次生林、稀树草原和草地灌丛等基础上开发种植的橡胶林（林下间种绿肥覆盖），其结构与热带雨林、热带季风性雨林相近似[2-4]。但另一方面，因近10年来天然橡胶干胶价格上涨，橡胶树种……