叶片温度对水汽扩散阻力测量的影响。
Leaf temperature effects on measurements of diffusive resistance to water vapor transfer.
作者信息
Morrow P A, Slatyer R O
机构信息
Department of Biological Sciences, Stanford University, Stanford, California 94305.
出版信息
Plant Physiol. 1971 Apr;47(4):559-61. doi: 10.1104/pp.47.4.559.
Substantial errors can be introduced to estimates of leaf resistance (r(l)) obtained from diffusion porometers unless precautions are taken to reduce the leaf-cup temperature difference (T(leaf) - T(cup)) to acceptable levels prior to measurement. When T(leaf) > T(cup), underestimation of leaf resistance occurs; the reverse applies when T(leaf) < T(cup).The effect is most pronounced under open-stomata conditions and declines as stomatal resistance increases. Under typical measurement conditions, T(leaf) - T(cup) values of the order of 1 C induce a reduction in the ratio of the apparent to true leaf resistance to about 0.8 when the leaf resistance is low (r(l) = 1-2 sec cm(-1)). When T(leaf) - T(cup) = 5 C, the ratio drops below 0.5. Under high leaf resistance conditions (r(l) = 10-50 sec cm(-1)) the comparable ratios are approximately 0.9 and 0.7, respectively.
除非采取措施在测量前将叶室温差（T(leaf) - T(cup)）降低到可接受水平，否则用扩散气孔计获得的叶片阻力（r(l)）估计值可能会出现重大误差。当T(leaf) > T(cup)时，会出现叶片阻力估计值偏低的情况；当T(leaf) < T(cup)时则相反。这种影响在气孔开放条件下最为明显，并随着气孔阻力增加而减小。在典型测量条件下，当叶片阻力较低（r(l) = 1 - 2秒厘米(-1)）时，T(leaf) - T(cup)值约为1℃会导致表观叶片阻力与真实叶片阻力之比降至约0.8。当T(leaf) - T(cup) = 5℃时，该比值降至0.5以下。在高叶片阻力条件下（r(l) = 10 - 50秒厘米(-1)），相应的比值分别约为0.9和0.7。
Zotero 插件