北京山区典型树种树干液流特征及其对环境因子的响应研究

Characteristic of Stem Sap Flux Velocity of Individual Trees and Its Response to Environmental Factors in the Beijing Mountain Area

2010年6—9月在妙峰山林场,运用SF-L树干液流仪分别研究分析了典型晴天和生长季侧柏、栓皮栎、油松、刺槐的树干液流速率变化特征及树干液流速率对环境因子的响应。结果表明:4种树种的树干液流速率变化规律呈单峰型,其中侧柏的平均树干液流速率最大,为0.079 3cm/min,刺槐最小,为0.048cm/min。4种树种在各个月份的平均液流速率变化较大,但均在8月份达到最大值。对环境因子影响树干液流速率的相关分析表明:气温、太阳辐射、VDP、土壤含水率和土壤水势与树干液流速率呈正相关,而相对湿度与树干液流速率呈负相关关系,风速、土壤温度与树干液流速率的相关性不明确。太阳辐射对树干液流速率的影响最大,其中对阔叶树种刺槐和栓皮栎的影响比对针叶树种油松和侧柏更大。环境因子对阔叶树影响较大,对针叶树影响较小。运用多元线性回归方法,得出了4种不同树种的树干液流速率和环境因子的多元线性回归方程。

The sap flow velocity and its response to the meteorological factors of Platycladus orientalis,Quercus variabilis,Pinus tabulaeformis and Robinia pseudoacacia were studied by heat dissipation probe technique from June to September in 2010.The study site was in Miaofengshang Forest.The results indicated that the stem sap flow velocity of all the trees in the typical clear day changed with a single peak type curve,the highest sap flow velocity was 0.079 3 cm/min for Platycladus orientalis,while the smallest one was 0.048 cm/min for Robinia pseudoacacia.The variation between each month has great differences,but they all reached the maximum value in August.Combined with the correlation analysis,the sap flow velocity was positively correlated with the solar radiation,the temperature,VDP,the soil moisture and soil water potential,whereas the relative humidity was negative correlation and the correlation with wind speed and soil temperature was uncertain.The most important environmental factor was solar radiation,while the influence on Quercus variabilis and Robinia pseudoacacia was greater than it on Platycladus orientalis,Quercus variabilis.The environmental factors had more effects on broadleaved trees than coniferous trees.Multiple linear regression analysis was employed to establish the liner model of four different trees stem sap flow velocity.