橡胶林的热量平衡

本文通过实测资料与理论计算,分析了我国主要橡胶产区(广东)不同类型橡胶园的热量平衡各分量的特征,并与热带次生杂木林、热带稀树草原及裸地作了对比。胶林的热量收入(净辐射)可观,晴天日总量最大可达15.95MJ/m~2,与次生林相仿,而大于空旷地。热量支出项中,蒸散耗热占60—70％,湍流热通量占25—35％,土壤热通量占5—10％。其比例随林型结构与林分而异,且胶林作用层与林地作用层之间、胶林(或纯茶林、次生林)与空旷地之间差异明显。

THE HEAT BALANCE OF RUBBER TREE STANDS IN GUANGDONG PROVINCE

Based on the observation data made in Mar. 1983 and Apr. 1984 and calculations, the characteristics of all components of heat balance for three types of rubber plantations in the principal rubber production area of China (Guangdong Province) were analysed and the comparison of the heat balance among rubber tree stands, tropical secondary forest, savanna and bare land has been made. It was shown that the heat income (net radiation) for rubber tree stands amounts to 15.95 MJ•m^-2 in clear days, which was similar to that of the secondary forest but greater than that of the open field. The heat consumed by evapotranspiration, turbulent heat flux and soil heat flux was 60-70%, 25-35% and 5-10%,respectively, the proportion varied with the structure and constitution of the forest. Moreover, heat balance differs considerably between the strata of rubber tree stands and forest floor, and between rubber tree stands (tea plantation, secondary forest) and open field.