Abstract: In order to study the heat transfer characteristics of plant layer, this paper selected ten species of common landscape plants on the campus, and determined the thermal conductivity of their leaves, convective heat transfer coefficient between leaves and surrounding air, conducts several experimental measurements and analyses, fit the approximate relationship between thermal conductivity and leaf water content, compare the experimentally determined convective heat transfer coefficient with the convective heat transfer coefficient obtained through theoretical calculation of empirical formula, and compare the relative humidity of air before and after contact with leaves. The results showed that there was a cooling and humidifying effect of the leaves; the thermal conductivity of the blade changed less with temperature at 5 to 25 ℃; When the leaf temperature was 20 ℃, the thermal conductivity of the blade decreased with the reduction of leaf water content; the convective heat transfer coefficient of the experimental test was in high agreement with the theoretical calculation.

Key words: leaf thermal conductivity convective , heat transfer coefficient , vegetation layer thermal resistance , leaf water content , cooling and humidification

摘要： 为研究植物层传热特性，选取校园内十种常见园林植物测定其叶片导热系数、叶片与周边空气对流换热系数，拟合导热系数与叶片含水量的近似关系式，对比实验测定对流换热系数与通过经验公式理论计算所得对流换热系数，比较与叶片接触前后空气的相对湿度。结果表明，叶片存在降温增湿作用，在5～25 ℃下叶片导热系数随温度变化较小；叶温20 ℃时，叶片导热系数随叶片含水量降低而减小；实验测试对流换热系数与理论计算结果吻合度较高。

关键词: 叶片导热系数 , 对流换热系数 , 植被层热阻 , 叶片含水量 , 降温增湿