稳态气孔计法和整株称重法测定蒸腾速率的比较研究

Comparison on the Transpiration Values Measured with Portable Steady Porometer Method and Whole-tree Weighing Method

在黄土半干旱区,2004年生长季典型天气,采用盆栽试验,人为控制土壤水分,利用稳定气孔计法（Li-1600）与整株称重法（BP-3400精密天平）,对侧柏、油松、刺槐和沙棘叶片蒸腾速率进行了测定。结果表明,随着土壤含水量的升高,叶片蒸腾速率上升;稳定气孔计测值恒大于整株称重的测值,两种方法测值的比值随土壤含水量的增加而升高,当土壤含水量达到田间持水量时,两种方法测定值的比值反而减小。7月,气孔计测值与整株称重测值之比,刺槐平均为2.50,沙棘为2.57;8月,侧柏为2.48,油松为2.28;10月,侧柏为1.19,油松为1.86,刺槐为1.53,沙棘为1.97,本研究可作为黄土半干旱区利用稳定气孔计研究林木蒸腾耗水的参考。

Transpiration rate of Platycladus orientalis, Pinus tabulaeformis, Robinia pseudoacacia and Hippophae rhamnoides were measured by portable steady porometer （Li-1600） and whole-tree weighing method （BP-3400） in growing season of 2004, artificially controlling water amount in pot experiment, in semi-arid region of the Loess Plateaus. It indicated that transpiration rate of leaves rose when soil water content increased; measured value of portable steady porometer were always higher than measured value of whole-tree weighing , the ratios of measured value of two methods rose with increasing soil water content, but reduced when soil water content reached field moisture capacity; the ratios of measured value of portable steady porometer and whole-tree weighing of Robinia pseudoacacia and Hippophae rhamnoides was 2.50 and 2. 57 respectively in July, the ratios of measured value of portable steady porometer and whole-tree weighing of Platycladus orientalis and Pinus tabulaeformis was 2.48 and 2.28 respectively in August, the ratios of measured value of portable steady porometer and wholetree weighing method of Platycladus orientalis , Pinus tabulae f ormis , Robinia pseudoacacia and Hi ppophae rhamnoides was 1.19, 1. 86, 1. 53 and 1. 97 respectively in October. The conclusion would be regarded as the reference of forest tree transpiration in semi-arid region of Loess Plateau.