长白山阔叶红松林生长季热量平衡变化特征

根据长白山阔叶红松林2001年5月下旬至10月上旬微气象梯度观测资料和辐射、土壤热通量资料，用波文比-能量平衡方法(BREB方法)计算了森林的显热通量和感热通量，并计算了森林大气和植被体的储热量，分析了阔叶红松林热量平衡各项的日变化和季节变化，结果发现，热量平衡(净辐射)与太阳总辐射呈线性关系；热量平衡各项都与净辐射有相同的日变化特征，为昼正夜负的曲线．各项的绝对值一般表现为净辐射>潜热通量>感热通量>储热变化．受日照时间的影响，6～10月各分量正值的日持续时间逐渐缩短．月平均结果，白天净辐射6月份最大，10月上旬最小，变化于0～527W·m^-2，夜间的净辐射在0～-121W·m^-2．潜热通量白天和夜间分别在0～441、0～-81W·m^-2，感热通量昼夜分别在0～80、0～-26W·m^-2．储热变化则为0～44、0～-26W·m^-2．白天潜热通量占净辐射的比例8～10月逐渐下降，而感热通量和储热变化的比例9～10月明显上升，特别在严霜后2～3d，出现潜热通量比例突减、感热通量比例突增的现象．文中还对通量观测仪器、方法进行了简要分析．

Dynamics of heat balance during growing season of broadleaved Korean pine forest in Changbai Mountains

Based on the gradient measurement of microclimate factors, radiation and soil heat flux from late May to early October, 2001 and by the method of Bowen ratio-energy balance (BREB), this paper estimated the latent heat and sensible heat above the broadleaved Korean pine forest in Changbai Mountains. The energy storage of forest air and vegetative was calculated, and the seasonal variations of heat balance components of the forest were analyzed. The results showed that the net radiation of the forest and the solar radiation were linearly correlated. All the heat balance components had the similar characteristics of diurnal variation to the net radiation, showing curves positive at daytime and negative at night, and the terms ranged as net radiation > latent heat > sensible heat > storage. The time of keeping positive terms in a day became shorter from June to October as influenced by shinning time. The highest net radiation was in June and the lowest in October. The monthly averaged net radiation was 0-527 and 0-(-)121 W x m(-2), and the latent heat was 0-441 and 0-(-)81 W x m(-2) for day and night, respectively. Sensible heat was 0-80 and 0-(-)26 W x m(-2), and energy storage was 0-44 and 0-(-)26 W x m(-2) for day and night, respectively. The ratio of latent heat to net radiation at daytime decreased gradually from August to October, and the ratio of sensible heat and energy storage increased correspondingly. Especially 2-3 days after the first severe frost, a sudden drop of latent heat and a sudden bounce of sensible heat appeared. The instruments and measurement methods of heat flux were also concisely discussed in this paper.