摘要
通过涡度相关设备监测湖南岳阳长江外滩地杨树人工林生态系统与大气间的碳、水交换,研究生态系统水分利用效率(WUE=FCO2/FH2O)的规律及其与环境因子的响应变化关系。测定了杨树林生态系统WUE不同季节10个晴朗日09:0016:00时半小时平均值的日变化,不同季节,WUE的变化不同。生态系统WUE受环境因子的影响较大,4 9月份,WUE随着温度升高有减小的趋势;10月到翌年3月份,系统WUE随着气温升高而升高。汛期林地土壤淹水的情况下,系统WUE随土壤体积含水量(SWC)增加而增大;林地没淹水情况下,生态系统WUE随着含水量的增加变化不规律。非讯期土壤热通量5d平均值与系统WUE的关系,随着土壤热通量的增加,WUE也增加。生态系统WUE与系统饱和水汽压差呈负相关。经主成分分析,土壤含水量与大气温度在杨树林生态系统WUE影响因子中占较大的特征比例。
The regularity of Water use efficiency（WUE） of the variation in response to changes of environmental factors in popular（including P.deltoides cv.‘2KEN8’,P.deltoides cv.‘55 /65’and P.× euramiercana cv.‘Nl-80121’） ecosystem were studied by the eddy-covariance that has monitored the carbon and water flux between atmosphere and poplar ecosystem in bottomland of Yangtze River.The WUE of the ecosystem had regular diurnal variation decided by ecophysiological characteristics in different seasons.And environmental factors also affected the WUE obviously.（1） The WUE had a razor-thin decrease with the temperature increasing from April to September and increased from October to March in next year as the temperature increasing.（2） In the flood season,WUE increased in case of soil ponded,and changed irregularly under the non-ponded situation as the rising of SWC.（3） In non-flood season,the average of soil heat flux showed an positive correction with the average five-days WUE.（4） WUE and VPD significantly correlated negatively.By the principle analyze,SWC and air temperature had larger impact on the WUE in popular ecosystem.
出处
《生态学报》
CAS
CSCD
北大核心
2010年第11期2933-2939,共7页
Acta Ecologica Sinica
基金
国家林业局948资助项目(2006-4-16)
