我国亚热带毛竹林CO2通量的变异特征

2010年12月至2011年11月,利用涡度相关技术研究了我国亚热带(浙江)毛竹林生态系统的CO₂通量,分析了毛竹林净生态系统交换量(NEE)、生态系统呼吸量(RE)和生态系统总交换量(GEE)的变化.结果表明: 研究期间,毛竹林各月的NEE均为负值,7月最大,为-99.33 g C·m^-2,11月最小,仅-23.49 g C·m^-2,其变化曲线呈双峰型.各月CO₂通量平均日变化差异明显,9月最大,为-0.60 g CO₂·m^-2·s^-1,1月最小,为-0.30 g CO₂·m^-2·s^-1,且在NEE正负转换的时间点上呈明显的季节变化特征；全年RE呈单峰型变化,夏季最高、冬季最低,夜间RE与土壤温度呈极显著正相关.全年NEE、RE和GEE分别为-668.40、932.55和-1600.95 g C·m^-2·a^-1,NEE占GEE的41.8%.与其他生态系统相比,毛竹林的固碳能力极强.

Variation characteristics of CO2 flux in Phyllostachys edulis forest ecosystem in subtropical region of China

By using eddy covariance technique, this paper studied the CO2  flux in a Phyllostachys edulis forest ecosystem with high-efficiency management in Zhejiang Province of China from December, 2010 to November, 2011, and analyzed the variations of net ecosystem exchange (NEE), ecosystem respiration (RE), and gross ecosystem exchange (GEE). During the study period, the monthly NEE was always negative, with the maximum (-99.33 g C·m-2) in July and the minimum (-23.49 g C·m-2) in November, and the seasonal change showed a bimodal shape. The average diurnal change of the monthly CO2 flux varied greatly from -0.30 g CO2·m-2·s-1(January) to -0.60 g CO2·m-2·s-1(September). The NEE at the time point of positive and negative conversion had obvious seasonal characteristics. The yearly RE changed in unimodal shape, with the maximum in summer and the minimum in winter. The RE at nighttime had significant negative correlation with soil temperature. The yearly NEE, RE, and GEE were -668.40, 932.55, and -1600.95 g C·m-2·a-1, respectively, among which, the NEE occupied 41.8% of the GEE. As compared with other ecosystems, P. edulis forest ecosystem had a strong capability in carbon sequestration.