矮嵩草草甸主要植物气孔分布及开闭规律与蒸腾强度的关系

 本文研究了高寒矮嵩草草甸6种植物叶片气孔的分布、密度和开闭日变化规律与蒸腾强度的关系。结果表明：多数植物上下表皮均有气孔分布，而矮嵩草的气孔集中分布在下表皮，羊茅的气孔集中分布在上表皮。同一植物类群中，叶片气孔密度大者，植物蒸腾强度也相对较高。气孔日变化是在日出后，随气温和大气湿度的变化而变化，在9时和午后3时气孔几乎全部张开，然后逐渐关闭。植物蒸腾强度随气孔开闭而发生变化，矮嵩草的蒸腾强度在11时左右达到峰值；垂穗披碱草和美丽风毛菊是在午后1时达到峰值，植物没有“午睡” 现象。

THE RELATION OF DISTRIBUTION CHARACTER AND DIURNAL CHANGES OF STOMATA OPENING AND CLOSURE WITH TRANSPIRATION INTENSITY OF MAIN PLANTS IN KOBRESIA HUMILIS MEADOW

The relation of distribution, density and diurnal changes of stomatal opening and closure in six plants of alpine Kobresia humilis meadow were studied during May–September in 1986. The results indicate that the leaf stomata of most plants are distributed in both the upper and lower epidermis, but with the K. humilis they are distributed in the lower epidermis, and with the Festuca ovina, they are all distributed in the upper epidermis. The leaf stomata open at 9 am until 3pm and then close gradually. Transpiration intensity of plants varies with the stomata’s opening and closure. The transpiration intensity of K. humilis achieved peak at about 11 am, but Elymus nutans and Saussurea superba at about 1 pm, after which it falls gradually until stops completely sunset. The changes of stomatal opening and closure as well as the transpiration intensity of plants are affected by both air temperture and the relative ambient humidity.