Division of Plant Industry, CSIRO, Canberra.
Planta. 1969 Sep;88(3):261-73. doi: 10.1007/BF00385069.
Two experiments were conducted to determine the transpiration rates of tropical and temperate grasses under a range of environmental conditions. In dense populations, three temperate grasses lost considerably more water per unit leaf area than did four tropical grasses, though tropical grasses tended to produce more dry matter per unit leaf area. The efficiency of production in relation to water use was thus greater in tropical than in temperate grasses. Wheat, a temperate grass, lost water at an average rate 2.25 times that of sorghum, a tropical grass, on a unit leaf area basis when single leaves were exposed to temperatures from 17 to 32° and light intensities from 1.7 to 4.4×10(4) ergs cm(-2) sec(-1) at 0.55 μ (1,100 to 2,800 ft.-c.). The measurement of transpiration and leaf temperature indicated that latent heat loss was much more important in wheat, and sensible heat loss was more important in sorghum as means of dissipating excess energy absorbed. These findings were attributed to the greater resistance to gas diffusion offered by sorghum than by wheat stomata in each environment.
进行了两项实验，以确定在一系列环境条件下热带和温带草的蒸腾速率。在密集的种群中，三种温带草每单位叶面积失去的水分比四种热带草多得多，尽管热带草每单位叶面积往往产生更多的干物质。因此，与水的利用相比，热带草的生产效率更高。当单叶暴露在 17 到 32°C 的温度和 1.7 到 4.4×10(4)ergs cm(-2) sec(-1)的光强度下时，以单位叶面积为基础，温带草小麦的水分流失速度平均是热带草高粱的 2.25 倍。蒸腾和叶片温度的测量表明，在小麦中，潜热损失更为重要，而在高粱中，感热损失更为重要，这是消耗过多吸收能量的两种方式。这些发现归因于高粱的气孔比小麦的气孔在每种环境中对气体扩散的阻力更大。
