"Research on Net Primary Productivity and Its Spatio-temporal Characteristics in the Three Gorges Reservoir Area (Chongqing Section) During 1998 to 2007"

"BasedontheCASAmodel,wereportaremotesensingestimationofnetprimaryproductivity(NPP)during1998to2007,usingSPOT/VGTNDVIdata,vegetation-typecoverage,aswellasmeteorologicalandotherdata,andweanalyzeitsspatiotemporalcharacteristics.Resultsshowthat1)thevolatilityofNPPduring1998to2007dropsonthewhole.2)SeasonalvariationofNPPduring1998to2007showsthefollowingregularitysummer(675.705gC？m-2)>spring(368.2gC？m-2)>autumn(207.944gC？m-2)>winter(49.495gC？m-2).Insummer,themaximumvalueofNPP(1022.173gC？m-2)occurredin2000;theminimumvalueofNPP(318.321gC？m-2)occurredin2006.3)NPPvaluesintheresearchregionvariedbetween184.8and515.548gC？m-2during1998to2007.HighvaluesweremainlydistributedinnortheastChongqing,suchasWuxi,Wushan,Fengjie,andinsoutheastChongqing,suchasShizhu,Wulongandothers.LowvaluesweredistributedinZhongxian,Fulingandmostofthemainurbanareas.4)Thehighestproductivityperunitareawasfoundinregionsofbroad-leavedforests.Productivitywasprogressivelylowerinthefollowingvegetationclassificationsbushfallowandirrigatedgrassvegetation,coniferousforestvegetation,grassymarshland,aquaticvegetation,andwaterarea."