半干旱黄土地区幼龄侧柏叶蒸腾的数学模型  

A Study on Mathematical Model of Chinese Arborvitae Leaf Transpiration in the Semi-arid Region of the Loess Plateau

作　　者：王百田[1] 郭江红[1] 杨雪松[1] 

机构地区：[1]北京林业大学水土保持学院教育部水土保持与荒漠化防治重点实验室,北京100083

出　　处：《中国水土保持科学》2003年第3期15-20,共6页Science of Soil and Water Conservation

基　　金：国家自然科学基金项目(3007063);国家科技攻关项目(2001BA510B0304)

摘　　要：通过人工控制水分,形成单株幼龄侧柏的不同土壤水分梯度环境。在自然环境下对侧柏叶片定时、定位进行蒸腾速率及林冠层的光照、空气温度、空气湿度、叶水势和土壤水分等因子的同步观测。蒸腾速率与各个因子的相关分析表明:黄土半干旱地区侧柏蒸腾速率η_t/(μg·cm^(-2)·s^(-1))与光照强度E/(μmol·m^(-2)·s^(-1))、空气饱和差p_v/kPa、叶水势Ψ/kPa、气温t/℃的关系可以分别表示为:η_t=αE^b,η_t=αp_v^b,η_t=αψ~b,η_t=αt^2+bt+c;侧柏的蒸腾速率η_t与气孔阻力Rs/(s·cm^(-1))和土壤含水量W/％有密切关系,可以分别表示为:η_t=α+bW+cW^2+dW^3,Rs=α+bW+cW^2+dW^3。用气温、空气饱和差、叶水势3个因素建立了半干旱黄土地区幼龄单株侧柏蒸腾速率的非线性指数预测模型:η_t=0.695 0exp(0.031 58t-14.249 2/Pv+0.760 6/Ψ),经检验获得了满意的数值模拟结果。Soil moisture gradations of single Chinese arborvitae tree were established through artificial control of water amount, then the transpiration rate of leaf was observed under the natural conditions with a steady-state porometer in a fixed time interval, and the environmental factors, such as E, temperature and atmosphere humidity in canopy layer, water potential of leaf, soil water moisture, were observed synchronously. After a correlation analysis, the relationships of transpiration rate of Chinese arborvitae in semi-arid regions of loess plateau with the factors of physiological absorbed radiation ( E) , vapour pressure deficit (pv) , water potential of leaf (?) , and air temperature ( t) is respectively obtained as follows: ηt = aEb, ηt = apb, ηt = a?b , ηt = at2 + bt + c . Meanwhile, the relationship of transpiration rate and stomatal resistance (Rs) with soil water content (W) is given as follows: ηt = a + bW + cW2 + dW3, Rs = a + bW + cW2 + dW3. Based on the above analysis on the relationship between transpiration rate and various factors, the leaf transpiration model of Chinese arborvitae is developed, reasonable forecast result has been achieved using three factors including air temperature and vapour pressure deficit as well as water potential of leaf. The model is as follows: ηt = 0.6950exp(0.03158t- 14.249 2/pv + 0.7606/?).

关 键 词：半干旱地区 黄土高原 侧柏 幼龄树 叶片 蒸腾速率 数学模型 土壤-植物-大气连续体 

分 类 号：S154.4[农业科学—土壤学]