<正>采用ICT 2000TE树干液流测定系统,研究了密度为1020株/hm2的11年生火炬松秋季树干液流特征及其与环境因子的关系。结果表明:火炬松树干液流表现为单峰曲线,日出后,树干液流迅速上升,峰值出现在中午前后,日落后至次日日出前液流微弱或几近无上升液流;树干液流速度白天10时至17时平均约26cm/h,最大达到54cm/h;不同径阶火炬松树干液流流量差异极显著。4株样木的胸径分别为13.5,10.2,15.7,16.6cm,秋季耗水量分别为13.28,13.27,36.33,49.80kg/d。环境因子对树干液流的影响次序由大到小依次为:气温、相对湿度、光合有效辐射、土壤温度、土壤水分;逐步回归建立的方程达到极显著水平。

The stem sap flow determining system "ICT2000TE" was used to study the characteristics of stem sap flow of 11yearold Pinus taeda with the spacing of 1 020 plants/hm2 in the autumn and the correlation to environmental factors.The results show that the stem sap flow behaves as a singlepeaked curve:it increases sharply after the sun rises and reaches its peak around noon,and the sap flows weakly or almost stops from sunset to sunrise.The average flow speed is 26 cm/h from 10∶00～17∶00 with the maximum of roughly 54 cm/h.The stem sap of trees with different DBH is significantly different.The 4 sample trees with DBH of 10.2,13.5,15.7 and 16.6 cm consume 13.27,13.28,36.33 and 49.8 kg of water respectively per day.The sequence of the environmental factors influencing the stem sap flow is:air temperature>relative humidity>effective photosynthetic radiation>soil temperature>soil moisture.The equation set up with stepwise regression shows it reaches an extremely significant level.