梭梭群落碳交换的尺度转换研究:从叶片到群落  

Scale Transformation of Carbon Exchange over Haloxylon ammodendron Community: From Leaf to Community

作　　者：李守娟[1,2,3] 马杰[1,2] 唐立松[1,2] 李彦[1,2] 刘冉[1,2] 

机构地区：[1]中国科学院新疆生态与地理研究所荒漠与绿洲国家重点实验室,新疆乌鲁木齐830011 [2]中国科学院阜康荒漠生态系统国家站,新疆阜康831505 [3]中国科学院大学,北京100049

出　　处：《干旱区研究》2016年第2期362-370,共9页Arid Zone Research

基　　金：国家自然科学基金项目(41201041;41301279;41171049);"西部之光"西部博士项目(XBBS201204)

摘　　要：以古尔班通古特沙漠南缘梭梭群落为研究对象,利用LI-COR 6400光合仪、大型同化箱及涡度相关系统,从叶片、个体及群落尺度,于2013年4—9月对不同生长阶段的梭梭净光合速率与呼吸速率进行测定。根据个体生物量与叶面积指数(LAI)进行叶片尺度向个体尺度以及个体尺度向群落尺度的转换。结果表明:1从叶片尺度向个体尺度转换。采用个体尺度的碳交换量推导值,与同化箱测量的个体碳交换量进行对比,二者的变化趋势基本一致,包括数量级和峰值出现的时间,二者差异不显著(P<0.05),相关系数为0.934。2从个体尺度向群落尺度转换。通过累加得到群落尺度碳交换量的累加值,与涡度相关系统观测的碳交换量进行比较。二者的变化趋势基本相同,量级也相同,相关系数为0.849。3由叶片尺度向个体尺度转换及个体尺度向群落尺度转换时,夜间推导值与实测值的差异显著,二者相关性较低。其原因可能是夜间温度低,造成细胞内酶活性降低;夜间CO2浓度增加抑制叶片呼吸,及涡度相关系统呼吸数据有效性低等因素,具体原因还需进一步加以证明。Haloxylon ammodendron,a constructive species growing in the southern part of the Gurbantonggut Desert,was chosen as the study object,and the net photosynthetic rate and respiration rate of H. ammodendron during the period from April to September 2013 were measured using the LI-COR 6400 Protable Photosynthesis system,big assimilation box and eddy covariance system. According to the individual biomass and leaf area index（ LAI）,the transformations from the leaf scale to the individual scale and from the individual scale to the community scale were carried out. The results are as follows： ① Transformation from the leaf scale to the individual scale： the derived value of carbon exchange at individual scale and the measured value of individual carbon exchange were compared,the change trends,orders of magnitudes and occurring time of peak values were basically similar,the difference between these two was not significant（ P〈0. 05）,and the correlation coefficient between the two results was0. 934; ② Transformation from the individual scale to the community scale： the accumulated value of carbon exchange at community scale and the carbon exchange value measured with eddy covariance system were compared,the change trends of the two results and the orders of magnitudes were basically the same,and the correlation coefficient between the two results was 0. 849; ③ When the leaf scale was transformed to the individual scale or the individual scale was transformed to the community scale,the difference between the nocturnal derived value and the measured values was significant,and their correlation was low. Such situation was possibly caused by the reduction of intracellular enzymic activity due to the low temperature at night,restriction of leaf respiration due to the increase of CO2 concentration at night,or low effectiveness of the respiration data from eddy covariance system. The very specific reasons need to be further proved.

关 键 词：生态系统 碳交换 梭梭群落 叶片尺度 个体尺度 群落尺度 涡度相关法 

分 类 号：S718.54[农业科学—林学]