Hydrologic balance, net primary productivity and water use efficiency of the introduced exotic Eucalyptus grandis × Eucalyptus urophylla plantation in south-western China  

作　　者：Yanting Hu Ping Zhao Yuqing Huang Liwei Zhu Guangyan Ni Xiuhua Zhao Zhihong Huang 

机构地区：[1]Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems,South China Botanical Garden,Chinese Academy of Sciences,723 Xingke Road,Tianhe District,Guangzhou 510650,China [2]Guangdong Provincial Key Laboratory of Applied Botany,South China Botanical Garden,Chinese Academy of Sciences,723 Xingke Road,Tianhe District,Guangzhou 510650,China [3]Key Laboratory of Beibu Gulf Environment Change and Resource Use,Ministry of Education and Guangxi Key Laboratory of Earth Surface Processes and Intelligent Simulation,Nanning Normal University,175 Mingxiu East Road,Nanning,Guangxi 530001,China [4]Department of Forest Ecology,College of Life Science and Technology,Central South University of Forestry and Technology,498 Shaoshan South Road,Changsha,Hunan 410004,China

出　　处：《Journal of Plant Ecology》2019年第6期982-992,共11页植物生态学报（英文版）

基　　金：National Natural Science Foundation of China(41630752,41030638 and 31800329);China Postdoctoral Science Foundation(2017M620392);Guangxi Major Science and Technology Project(AA17204087-9).

摘　　要：Aims Land cover changes can disrupt water balance and alter the partitioning of precipitation into surface runoff,evapotranspiration and groundwater recharge.The widely planted Eucalyptus trees in south-western China have the potential to bring about hydrologic impacts.Our research aims to elucidate the hydrologic balance characteristics of the introduced exotic Eucalyptus grandis×Eucalyptus urophylla plantation and to assess whether its high productivity results from high water use efficiency(WUE)or large water consumption.Methods A 400-m^(2) experimental plot was established in an E.grandis×E.urophylla plantation in south-western China.Water balance components,including stand transpiration(T_(r)),evapotranspiration(E_(t))and runoff(R)were obtained as follows:T_(r) was estimated based on sap flow measurements,E_(t) was estimated as the average of surface transpiration and evaporation weighted by the fractional green vegetation cover using a modeling approach,and R was collected using the installed metal frame.Net primary productivity(NPP)was obtained from allometric equation and annual diameter at breast height(DBH)increment determination.Important Findings Annual E_(t) and T_(r) were 430±31 and 239±17 mm,respectively.Annual T_(r) accounts for 56±8%of total evapotranspiration on average.WUE(NPP/T_(r))of the E.grandis×E.urophylla was estimated to be 3.3–3.9 mmol·mol^(−1).Based on the comparative analysis of T_(r) and WUE,E.grandis×E.urophylla had a high productivity due to its high WUE without exhibiting prodigal water use.Meteorological factors including vapor pressure deficit and global solar radiation(R_(s))were key factors regulating E_(t) and T_(r) in our research site.Annual surface runoff,E_(t) and canopy interception occupied 7%,27–30%and 16%of total precipitation,while the remaining 46–50%of precipitation was used for sustaining groundwater recharge and altering soil water storage.The higher runoff coefficient(7.1%)indicated the weaker capability of E.grandis×E.urophylla to reserve water

关 键 词：water balance EVAPOTRANSPIRATION water use efficiency sap flow runoff 

分 类 号：S71[农业科学—林学]