LEAF TEMPERATURES
LEAF TEMPERATURES
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DOI：
10.2307/2439126
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发表时间：
1959-01-01
影响因子：
3
通讯作者：
LOOMIS, WE
中科院分区：
文献类型：
--
作者：
ANSARI, AQ;LOOMIS, WE
用热电偶和电位计测量叶片温度。在不同的环境和植物条件下，以及在阳光和阴影下交替加热和冷却循环期间，对不同厚度的叶子进行了读数。叶子倾向于承担空气温度。阳光加热薄叶6-10[degree]C以上的空气中约1分钟。将非常厚的叶子在20-30分钟内加热到高于空气20[degree]C。在阴凉处的静止空气中冷却与在阳光下加热的速率相同，并且对于所有测试的叶子，该速率乘以以g/cm 2计的叶子质量的乘积是恒定的。5分钟/小时的风将阳光下的叶温降低到空气温度的一半。这种冷却效应可导致风蒸腾作用的减少。蒸腾作用对叶温的影响较小。萎蔫叶片表现出几乎相同的温度反应肿胀的。干燥的叶子在阴凉处比蒸腾的叶子加热得少，冷却得快。凡士林叶比蒸腾叶温暖1-3[degree]C，但表现出相似的加热和冷却曲线。
Leaf temperatures were measured with a thermocouple and potentiometer. Readings were taken on leaves of varying thickness, under varying environmental and plant conditions, and during alternating heating and cooling cycles in sun and shade. Leaves tended to assume air temperature. Sunshine heated thin leaves 6-10[degree]C above the air in about 1 minute. Very thick leaves were heated 20[degree]C above air in 20-30 minutes. Cooling in still air in shade was at the same rate as heating in sunshine, and the product of this rate times leaf mass in g/cm2 was constant for all leaves tested. Wind at 5 minutes/hour lowered leaf temperature in the sun about half way to air temperature. This cooling effect can result in a reduction of transpiration by wind. Transpiration had a minor effect on leaf temperature. Wilted leaves showed nearly the same temperature response as turgid ones. Dried leaves heated less and cooled faster in shade than transpiring leaves. Vaselined leaves were 1-3[degree]C warmer than transpiring leaves but showed similar heating and cooling curves.