摘要
1966年,Philip提出了比较完整的SPAC系统后,能够用统一的能量指标——“水势”来定量地研究整个系统中各个环节能量水平的变化,而且已经用来解决生产中比较综合、复杂的问题。本文拟从力和阻力两个方面研究7种树木蒸腾的水分关系。一、材料和方法本研究是在内蒙古林科院树木园内进行,海拔1056m左右;属温带大陆性气候;土壤为冲积土,生长季内,土壤剖面2m深内的平均土壤水势变动在-0.04—-0.20MPa之间,地下水深11m。
Transpiration rate (Tr), stomatal resistence (Dr), leaf water patential (Lp) and its corresponding environmental factors of seven tree species have been measured with LI-1600 steady state prometer and pressure chamber. When the soil water potential in 2m depth is-0.04—-0.20MPa, the light intensity is the main factor to influence Tr, which is mainly influened by Dr. The relationship between Li and Dr can be expressed by following formula: Dr=ae^(b/Li), thus light intensity according to its influence on Tr can be divided into three regions: Weak light region, Tr=K/Dr, Transition region, Tr=K·ψ_(L-A)/Dr; light saturation region, Tr=a·ψ_(L-A)+b where a, b and K are coefficients, ψ_(L-A) is the difference of leaf-air water potential.
出处
《林业科学》
EI
CAS
CSCD
北大核心
1991年第5期545-549,共5页
Scientia Silvae Sinicae
关键词
树木
蒸腾速率
阻力
叶内外水势
Transpiration rate
Stomatal resistance
Difference of leaf-air water potential
Light intensity
