油松栓皮栎混交林林地蒸散和水量平衡研究

20 0 1年 4— 1 0月 ,对北京西山地区一块 31年生的油松、栓皮栎混交林的林地蒸散和水量平衡进行了研究 .结果表明 ,通过标准木的标准比导率和树木胸径和边材面积的相关模型 ,可以比较准确地推算出林分的蒸腾耗水量 .油松和栓皮栎混交林的蒸腾耗水表现出明显的季节差异 ,栓皮栎的生长季标准比导率明显高于油松 ,是油松的 2 6倍 .就北京西部山区而言 ,林分存活与否的关键在于其是否能够经受住春季降雨少、气温高、湿度低、土壤残留水分少等干旱环境的考验

Forestland evapotranspiration and water balance of Pinus tabulaefor- mis and Quercus variabilis mixed stand

From April to October of 2001,a 31 year old Pinus tabulaeformis and Quercus variabilis mixed stand was studied on forestland evapotranspiration and water balance in western mountainous area of Beijing.The results show that the water consumption of transpiration can be reckoned through standard specific conductivity of standard tree and the relative model between breast height diameter of tree and sapwood area.The water consumption of transpiration of Pinus tabulaeformis and Quercus variabilis mixed stand has marked seasonal difference,and the standard specific conductivity of Quercus variabilis in the growing season is 2 6 times as high as that of Pinus tabulaeformis .As for western mountainous area of Beijing,the key factor of survival lies in whether it can stand the drought environment factors,such as less rainfall,higher air temperature,lower humidity and less soil water,etc.