基于涡度相关法的森林生态系统碳交换及其控制机制  

Carbon Exchange Between Forest Ecosystems and the Atmosphere and Its Control Mechanisms Based on the Eddy Covariance Method

作　　者：同小娟[1] 张劲松[2] 孟平[2] TONG Xiao-juan;ZHANG Jin-song;MENG Ping(College of Forestry,Beijing Forestry University,Beijing 100083,China;Research Institute of Forestry,Chinese Academy of Forestry,Beijing 100091,China)

机构地区：[1]北京林业大学林学院,北京100083 [2]中国林业科学研究院林业研究所,北京100091

出　　处：《温带林业研究》2018年第2期1-9,14,共10页Journal of Temperate Forestry Research

基　　金：国家自然科学基金(31100322)

摘　　要：森林生态系统在全球碳循环中起着重要作用。涡度相关法被认为是研究森林生态系统碳交换的可靠方法之一。在全球范围内,基于涡度相关法对森林生态系统碳交换已经开展了大量的研究。这些研究结果为解释森林碳吸收、碳平衡组分(净生态系统碳交换NEE、总初级生产力GPP、生态系统呼吸Rec)的季节和年际变化提供了方便。不同纬度森林生态系统碳交换具有显著的差异。森林生态系统碳交换的季节、年和年际变化受环境因子(如太阳辐射、气温、降水、土壤温湿度)影响。由于植被类型和立地条件存在差异,不同森林生态系统碳交换变化的主要驱动因子存在一定的差异。极端区域气候事件(如干旱)在气候变化背景下发生的频率会增加。这些极端气候事件可能会抵消森林生态系统碳汇或甚至造成净碳排放。除了环境因子,干扰(如火灾、收获)会使生态系统在短时间内由碳汇变为碳源。因此,研究环境因子和干扰对森林生态系统碳交换的影响,有助于提高人们对森林碳吸收过程的理解。多数森林站点开展的碳收支研究时间尺度比较短(10年以下)。虽然以上研究解释了碳收支在季节和年上的差异,但不能得出生态系统的平均状态,也不能给出极端气候事件对碳收支的影响。在生态系统尺度上研究碳收支需要超过10年以上的数据,长时间序列数据可以让人们直接了解景观如何对气候波动、干扰等做出响应。为降低森林生态系统碳收支评估的不确定性,今后还需要长期监测生态系统碳通量对气候因子的响应,采用多变量模型数据融合方法估算森林生态系统碳收支,并对站点上所得的碳通量数据进行尺度上推。Forest ecosystems make a considerable contribution to the global carbon cycle.The eddy covariance is considered as one of reliable methods measuring carbon exchange between forest ecosystems and the atmosphere.Based on the eddy covariance method,extensively investigations have been conducting on carbon exchange between forest ecosystems and the atmosphere.These investigations are highly beneficial in answering the critical research questions of carbon uptake,the variation of carbon budget components(net ecosystem carbon exchange,gross primary productivity,ecosystem respiration).The difference of carbon exchange in forest ecosystems among latitudes was significant.The seasonal,annual and interannual variability in carbon exchange was controlled by environmental variables(e.g.solar radiation,air temperature,precipitation and soil moisture and temperature).The main factors controlling the temporal variation of carbon exchange over forest ecosystems were not the same since forest types and stand conditions were different.The extreme climate events,such as drought,will be more frequent under a changing climate,and it will offset or even lead to net carbon loss,thus releasing CO2 to the atmosphere.In addition to environmental factors,carbon exchange was affected by severe disturbances(e.g.fire,harvest)and forest ecosystem shifted from CO2 sink to source in short term.Therefore,it is vital tostudy on the response of carbon exchange to environmental factors and disturbance to help us understand the process of carbon uptake.Up to date,short term(less than 10 years)investigations on carbon exchange have been conducting in some sites.Although the differences of the seasonal and annual carbon exchange can be explained by the above studies,the average state of the ecosystems under consideration and the effect of anomalous climatic events on CO2 budgets were not obtained.At the ecosystem time scale,study on carbon budget needs the data more than 10 years.Long term series can help us understand how forest ecosystems response to

关 键 词：森林生态系统 涡度相关 碳交换 气候因子 干扰 

分 类 号：S718.554[农业科学—林学]