基于通量观测的温带森林碳交换变化特征及影响因素研究

The Study on Temporal Variation and Impact Factors of Carbon Exchange in Temperate Forest Based on Eddy Flux

摘要: 随着全球经济的高速发展，二氧化碳总排放量越来越高，在这个环境问题日益严重的紧要关头，森林在植物光合固碳这一过程中扮演着关键的角色；中国温带森林面积大、蓄积量高，因此作为我国研究森林固碳的重要对象。本论文研究对象为长白山阔叶红松林，利用公式GPP = −(Fc − Re)拆分为呼吸作用与光合作用两种不同通量，并在不同时间尺度上分析其变化特征，从而得出生态系统净二氧化碳交换量(Fc)在不同时间尺度上的变化趋势，可得知Fc日平均尺度与月尺度基本保持一致。日尺度上森林生态系统在日间由于光合作用多表现为碳汇，夜晚因呼吸作用表现为碳源；月尺度上，Fc的季节尺度变化总体呈负值，则表示除了程度区分之外所有月份都处于吸收CO₂，及碳汇的状态；提取环境因子数据与Re、GPP做相关性分析，检测相关性是否显著；结果表明：太阳辐射及土壤温度为主要相关因子，达到显著相关水平。2007年长白山阔叶红松林处于吸收二氧化碳的“碳汇”状态。

Abstract: With the rapid development of the global economy, the total carbon dioxide emissions are getting higher and higher, at this critical moment when the environmental problem is becoming more and more serious. Forests play a key role in the process of plant photosynthesis carbon sequestration, and China’s temperate forests have a large area and high accumulation, so they are important objects for the study of forest carbon sequestration in China. The object of this paper is the broad-leaved red pine forest of Changbai Mountain, which is divided into two different fluxes of respiratory action and photosynthesis by using the formula GPP-Re, and analyzing its change characteristics on different time scales so as to obtain the net carbon dioxide of the ecosystem. The changing trend of exchange quantity (Fc) on different time scales shows that the average scale of Fc day is basically consistent with the monthly scale, and those forest ecosystems on the daily scale are represented as carbon sinks during the day due to photosynthesis, and nighttime as carbon sources due to respiratory action. On the monthly scale, Fc’s seasonal scale change was negative overall, indicating that all months except the degree distinction were in the state of absorbing CO₂ and carbon sinks. The correlation between the extraction of environmental factor data and Re and GPP was analyzed to detect whether the correlation was significant, and the results showed that solar radiation and soil temperature were the main correlation factors. In 2007, Changbaishan broad-leaved red pine forest was in the “carbon sink” state of absorbing carbon dioxide.