毛乌素沙地主要建群植物蒸腾耗水特性的研究

摘要

在植物生长旺季初期(7月份),采用LI-1600型气孔针对毛乌素沙地主要建群植物油蒿(Artemisia ordosica)、中间锦鸡儿(Caragana intermedia)、沙柳(Salix psammoph yla)和旱柳(Salix matsudana)的蒸腾耗水进行了测定.结果表明:供试植物的蒸腾速率日动态曲线均为单峰型,无午休现象,其中固定沙地油蒿和半固定沙地油蒿的蒸腾速率在中午13:00出现峰值.气孔扩散阻力是所有供试植物蒸腾速率的主要影响因子.对供试植物的蒸腾耗 水进行的评估表明,不同植物的日最大蒸腾速率和日平均蒸腾速率大小为固定沙地油蒿＞半固定沙地油蒿＞沙柳＞旱柳＞中间锦鸡儿；植物单株月累计蒸腾耗水量大小为旱柳＞沙柳＞固定沙地油蒿＞半固定沙地油蒿＞中间锦鸡儿；植物种群单位面积单位时间内的蒸腾耗水量大小顺序为固定沙地油蒿＞半固定沙地油蒿＞沙柳＞旱柳＞中间锦鸡儿.%Water consumption of Artemisia ordosica , Caragana intermedia , Salix psammophyla and Salix matsudana by transpiration were measured under natural conditions by using a portable LI-1600 sto-ma meter in the mid July when plants grow vigorously. The results indicated that the diurnal changes of transpiration rate of all the plants showed single-peak curves; the transpiration rate of Artemisia ordosica (both in fixed sandy land and in semi-fixed sandy land) had a peak value at 13 :00. For all the plants stomatal diffusive resistance was the main factor impacting transpiration rate. Through assessment of water consumption by plants, the order of daily mean values and daily maximum values of transpiration rates was Artemisia ordosica in fixed sandy land>Artemisia ordosica in semi-fixed sandy land>Salix psammo-phyla> Salix matsudana > Caragana intermedia, the order of monthly water consumption of individual plant by transpiration was Salix matsudana>Salix psammophyla> Artemisia ordosica in fixed sandy land >Artemisia ordosica in semi-fixed sandy land>Caragana intermedia and the order of water consumption of plant population of per unit area and per unit time by transpiration was Artemisia ordosica in fixed sand-y land>Artemisia ordosica in semi-fixed sandy land>Sa/tx psammophyla>Salix matsudana>Caragana intermedia.