【摘要】 为分析土壤水分与气象因子对油松蒸腾作用的影响程度,提高造林成活率,并为林地水分管理提供科学依据。在2004年生长季典型晴天,采用盆栽试验,人为控制土壤水分,利用针叶Li-1600稳态气孔仪和BP-3400精密天平等仪器,对黄土半干旱区油松苗木的蒸腾特性及其影响因子的关系进行研究。结果表明:在不同的土壤水分条件下,油松蒸腾速率和气孔阻力的日变化曲线分别呈“双峰型”和“W”型;在典型晴天下,蒸腾速率与土壤含水量的关系呈三次曲线相关,7、8和10月份,油松叶片蒸腾速率达到最大值时所对应的土壤含水量分别为17.7%、19.8%和17.5%。蒸腾速率除自身生理特性的影响外,还受土壤水分和气象因子综合影响,当土壤水分充足时,蒸腾速率与气象因子相关性高;当土壤水分产生胁迫时,蒸腾速率与气象因子相关性降低。在严重土壤水分胁迫下,7和8月份气温对蒸腾作用的影响最大,10月份光合有效辐射的影响最大。在土壤充分供水的条件下,7月份空气相对湿度对蒸腾作用的影响最大,8月份是气温,10月份是叶温。更多还原

【Abstract】 Relationship between transpiration of forest tree and its influencing factors is closely.Through controlling soil moisture artificially,using portable steady porometer(Li-1600) and speedy weight method(BP-3400) etc.,Transpiration rate Tr of Pinus tabulaeformis and environmental factors were measured under the condition of representative fine day in growing season of 2004.The results indicated that the diurnal course of transpiration rate(Tr) and stomatal resistance(Rst) of Pinus tabulaeformis display a double-peak curve and a "W" curve respectively under different soil moisture.Under the condition of representative fine day,the transpiration rate presents a cubic relation with soil water content,the SWC which causing Tr of Pinus tabulaeformis highest was 17.7%,19.8% and 17.5% in July,August and October respectively.Tr was affected not only by its physiology characteristic but also by the SWC and meteorologic factors.Tr had significant correlation with meteorologic factors if the soil moisture was sufficient,but it will decrease in serious water stress condition;In serious water stress condition,air temperature is the mainly factor to affect Tr in July and August,and photo synthetically active radiation is the mainly factor in October.When the soil water is sufficient,the mainly factor to affect transpiration rate was relative humidity,air temperature and leaf temperature in July,August and October respectively.The result of this paper provided the scientific basis of increasing survival rate and managing soil water in forestland.更多还原