A Study on water consumption characteristics of Phyllostachys edulis,a typical afforestation species in Southern Jiangsu Province of China

In order to study water consumption characteristics of Phyllostachys edulis,this paper conducts a continuous observation from September 2012 to August 2013 of the leaf transpiration rate,the sap flow rate and environmental factors by using LI-6400,sap flow meter and mini weather station in Nanjing Dongshanqiao Forest. The results indicate that:( 1) the change of the transpiration rate( Tr) takes on a single-peak curve in all seasons. So does the net photosynthetic rate( Pn) in spring,autumn and winter.The Trand Pnare at its highest in summer. Stomatal conductance has a prominent influence on the transpiration rate.( 2) The sap flow rate of Phyllostachys edulis showes distinct diurnal changing rhythms both in sunny and cloudy days in different seasons. The crest values of the sap flow rate in spring,summer,autumn and winter are 2. 207 kg /h,4. 380 kg /h,2. 062 kg /h,and 0. 300 kg /h respectively.( 3) The dominant environmental factors in spring,summer are solar radiation,but VPD in autumn and winter. Soil temperature and VPD have a significant impact on the average daily sap flow rate of Phyllostachys edulis.( 4)The models which relate the transpiration rate,sap flow rate,daily sap flow with impact factors can explicitly reflect the water consumption characteristics of Phyllostachys edulis.