【摘要】 通过对毛乌素沙地几种主要植物的枝条在剪断前后的蒸腾速率的研究 ,发现这些植物枝条的蒸腾速率在剪离母株后一般会发生较大的变化 ,说明用快速称重法测定得到的剪断枝条的蒸腾速率与剪断前植物的实际蒸腾速率也存在较大的偏差。由于这类变化与植物的生物学特性、生长环境的水分条件、测定时叶片的水分状况、剪断的部位和测定的时间等多种因素都有密切关系 ,定量地预测某个植物剪断枝条的蒸腾速率的变化一般也比较困难。用快速称重法测定植物的蒸腾速率需要有同步的校正措施 ,否则结果不可靠。气孔计在测定植物枝条剪断前后蒸腾速率的相对变化率时比较准确。因而 ,用快速称重法测定植物的蒸腾速率 ,用气孔计来校正其偏差 ,这种二合一的方法是测定植物蒸腾速率比较准确而理想的方法更多还原

【Abstract】 Porometric analysis of transpiration variance of plant cuttings of 8 species in Maowusu Sandland, Inner Mongolia was carried out.Transpiration rate of a plant part changed immediately after cutting.Quantitation and prediction of such a change were different as the nature of the change was relevant to the leaf water status of the plant which,in turn,was species,habitat and cutting time specific. Therefore, average transpiration rate of a plant cutting measured in a certain time interval was not a representive transpiration rate of the plant without any correction. Based on the present result, the author’s suggest that porometry is applicable when a correction is made by a coefficient expressing the difference in transpiration rate between before and after cutting, which can be used to estimate the transpiration rate of the plant.更多还原