黄河小浪底人工混交林冠层CO2储存通量变化特征  

Variation characteristics of carbon storage flux over a mixed plantation of the Xiaolangdi area

作　　者：同小娟[1] 张劲松[2] 孟平[2] 李俊[3] 

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,国家林业局林木培育重点实验室,北京100091 [3]中国科学院地理科学与资源研究所陆地水循环及地表过程重点实验室,北京100101

出　　处：《生态学报》2015年第7期2076-2084,共9页Acta Ecologica Sinica

基　　金：国家自然科学基金(31100322);国家林业局公益性行业项目(GYHY20110400904)

摘　　要：基于黄河小浪底人工混交林2008年的CO2浓度和碳通量数据,分析了不同天气条件下CO2浓度在时间和空间上的变化特征,对比了CO2浓度廓线法和涡度相关法估算的CO2储存通量,研究了CO2储存通量的日、季变化特征。结果表明:人工混交林冠层上方月平均CO2浓度具有明显的季节变化规律。月平均CO2浓度最大值出现在3月(370μmol/mol),最低值出现在8月(347μmol/mol)。涡度相关法估算的CO2储存通量比廓线法所得结果偏低9%。生长季,冠层CO2储存通量和净生态系统碳交换量(NEE)日平均值分别为-0.0004和-0.091 mg CO2m-2s-1,冠层CO2储存通量在NEE中仅占0.4%。2008年CO2储存通量和NEE分别为-46.1、-1133 g CO2m-2a-1。在年尺度上,CO2储存通量占NEE的4.1%。因此,在日和年尺度上计算黄河小浪底人工混交林NEE时,CO2储存通量可以忽略。Forest plays an important role in carbon cycle and global climate change. To estimate accurately net ecosystem carbon exchange （NEE） between forest ecosystem and the atmosphere and understand the ecophysical factors influencing NEE, it is necessary to study the variation characteristics of CO2 storage flux. In this study, the eddy covariance method and the profile method were used to measure COz flux and CO2 concentration over a warm-temperate mixed plantation in the Xiaolangdi area in 2008, respectively. The temporal and spatial variations of CO2 concentration under sunny and cloudy sky conditions above the forest canopy were analyzed. CO2 storage flux obtained by the eddy covariance was compared with those derived from the profile method and the diurnal and seasonal variations of CO2 storage flux were investigated. The results showed that the diurnal and seasonal variations in CO2 concentration were obvious. In the sunny days of the growing season, CO2 concentrations above the plantation canopy decreased continuously and the minimal CO2 concentration appeared at 12：00. After 12：30, CO2 concentration increased slowly. However, in the cloudy days, the maximal and minimal CO2 concentrations occurred in the early morning and at about 14：30, respectively. At the annual scale, CO2 concentration peaked in March, with a value of 370μmol/mol. The minimal CO2 concentration occurred in August, with a value of 347μmol/mol. CO2 storage flux estimated by the eddy covarianee method was 9% lower than that obtained by the profile method. During the growing season of 2008, monthly mean CO2 storage flux was -0.0004 mg CO2 m-2 s-1 and NEE was -0. 091 mg CO2 m-2 s-1. At the daily scale, the proportion of CO2 storage flux to NEE was only 0.4%. In 2008, CO2 storage flux and NEE were -46.1 and -1133 g CO2 m-1 a-1, respectively. On an annual scale, CO2 storage flux only accounted for 4.1% of NEE. Therefore, at the longer time （daily or annual） scale, CO2 storage flux could be neglected when NEE is estimated in the mixed

关 键 词：人工混交林 涡度相关法 CO2浓度廓线法 CO2储存通量 净生态系统碳交换 

分 类 号：S718.5[农业科学—林学]