Character istics of Sap F lux Den sity andW a ter Use of P inus ca ribaeaP lan ta tion in Dry Sea son on the L eizhou Peninsula A Study on the Stem Sap Flow of Ind ividualTrees of Populus simonii underD ifferentWeather Conditions in Rainy Season in Guanting Reservoir Stock Sap Flow Characters of Juglans reg ia and Relationship withM eteorological Factors in Dry Season