天目山柳杉树干液流的昼夜及季节变化

Diurnal and seasonal variation of stem sap flow for Cryptomeria fortunei in Mount Tianmu

利用热扩散式液流探针,连续观测天目山古柳杉生长季树干液流速率,同步测定环境因子,测定柳杉液流昼夜变化、晴雨天气液流通量及不同月份的日均液流量变化特征,分析树干液流与环境因子的响应关系。结果表明:(1)柳杉树干液流量日变化幅度显著,日最大值和最小值分别为194.0 kg/d和5.4 kg/d;(2)晴天树干液流变化幅度比雨天要大,不同月份日均液流量最高为6月(66.85 kg),最低为8月(46.12 kg);(3)柳杉树干液流与空气温度、辐射强度呈极显著正相关,与空气湿度呈负相关。

A thermal dissipation probe（TDP） was used to measure the variation of stem sap flow for an old tree Cryptomeria fortunei in Mount Tianmu,the environmental factors were also measured simultaneously.Based on the data from May to October in 2009,this paper analyzed the day and night variation of sap flow,sap flux in sunny or rainy day,and daily sap flow average per month and response of sap flow to environmental factors.Results showed that daily sap flux varied larger during the growth period,its maximum and minimum was 194.0 kg/d and 5.4 kg/d respectively.The change extent of sap flow was lager in sunny day than in rainy day,the highest daily sap flow average per month was 66.85 kg in June and the lowest was 46.12 kg in August.Sap flow was positively correlated with solar radiation,air temperature significantly,however negatively with relative humidity.