Spatial-temporal Dynamics of Vegetation in the Newly Created Water-level-fluctuation Zone of Three Gorges Reservoir:a Case Study in Baijia Stream, Kaixian County, China

"AfterimpoundentoftheThreeGorgesReservoir,alargepermanentsampleplotwasplacedinitswater-level-fluctuationzonebesideBaijiaStream,KaixianCounty,China.Vegetationintheplotwasinvestigatedinthesummerof2008,2009and2010.Theresultindicatedthatcommunity’scomponent,biodiversityandabovegroundbiomassshowedobviousspatial-temporaldynamics.Totalspieciesnumberofvascularflorainsidedecreasedyearly,from52speciesin2008to41speciesin2009andto35speciesin2010.Theareabelow156minelevationwasdominatedbyPaspalumpaspaloidesandXanthiumsibiricumin2008.However,PaspalumpaspaloideswasrapidreplacedbyCynodondactyloin2009andX.sibiricumexpandeditsdistributioninupperareaoftheplot.In2010,X.sibiricumdepresseditspopulationinlowerareasoftheplotastheThreeGorgesReservoirstartedtoimpoundhalfmonthearlierinthewinterof2009anddecreasedseedbankforitsgermination.Shannon-WienerIndexincreasedaselevationaccordingtothedataof2009and2010,whichreflectedtheinflu-enceofsubmergedgradient.Abovegroundbiomassofvegetationineachelevationzoneoftheplotindicatedgreatvariation.KeywordsThreeGorgesReservoir;water-level-fluctuationzone;vegetation;spatial-temporaldynamics;biodiversity"