ChangesinWaterUseEfficiencyCausedbyClimateChange,CO2Fertilization,andLandUseChangesontheTibetanPlateauBinghaoJIA1,2,XinLUO1,LonghuanWANG*1,3,4,andXinLAI51StateKeyLaboratoryofNumericalModelingforAtmosphericSciencesandGeophysicalFluidDynamics(LASG),InstituteofAtmosphericPhysics,ChineseAcademyofSciences,Beijing100029,China2CollaborativeInnovationCenteronForecastandEvaluationofMeteorologicalDisasters(CIC-FEMD),NanjingUniversityofInformationScience&Technology,Nanjing210044,China3KeyLabofVirtualGeographicEnvironment(NanjingNormalUniversity),MinistryofEducation,Nanjing210023,China4JiangsuCenterforCollaborativeInnovationinGeographicalInformationResourceDevelopmentandApplication,Nanjing210023,China5PlateauAtmosphereandEnvironmentKeyLaboratoryofSichuanProvince,ChengduUniversityofInformationTechnology,Chengdu610225,China(Received22June2022;revised18August2022;accepted24August2022)ABSTRACTTerrestrialecosystemwateruseefficiency(WUE)isanimportantindicatorforcouplingplantphotosynthesisandtranspiration,andisalsoakeyfactorlinkingthecarbonandwatercyclesbetweenthelandandatmosphere.However,underthecombinationofclimatechangeandhumanintervention,thechangeinWUEisstillunclear,especiallyontheTibetanPlateau(TP).Therefore,satelliteremotesensingdataandprocess-basedterrestrialbiospheremodels(TBMs)areusedinthisstudytoinvestigatethespatiotemporalvariationsofWUEovertheTPfrom2001to2010.Then,theeffectsoflanduseandlandcoverchange(LULCC)andCO2fertilizationonWUEfrom1981–2010areassessedusingTBMs.ResultsshowthatclimatechangeistheleadingcontributortothechangeinWUEontheTP,andtemperatureisthemostimportantfactor.LULCCmakesanegativecontributiontoWUE(–20.63%),whichisgreaterthanthepositivecontributionofCO2fertilization(11.65%).Inaddition,CO2fertilizationcaneffectivelyimproveecosystemresilienceontheTP.Onthenorthwestplateau,theeffectsofLULCCandCO2fertilizationonWUEaremorepronouncedduringthedriestyearsthantheannualaverage.ThesefindingscanhelpresearchersunderstandtheresponseofWUEtoclimatechangeandhumanactivity...
