A comparative study of radiation balance above forest and grassland
A comparative study of radiation balance above forest and grassland
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森林与草地辐射平衡比较研究
DOI：
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发表时间：
1976
期刊：
影响因子：
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通讯作者：
C. J. Moore
中科院分区：
文献类型：
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作者：
C. J. Moore
辐射松种植园以上的日净辐射被发现超过附近的草地以上的测量约12%，在冬季和夏季的24%。这种差异与每种植被的地表温度相关的净长波辐射和净长波辐射的差异有关。整个冬季森林的蒸腾速率为0.11 ± 0.001，没有明显的日变化。结果表明，草地太阳辐射度具有正常的日变化趋势，冬季平均太阳辐射度为0.27 ± 0.03，夏季下降到0.24 ± 0.01，与太阳高度的增加相一致。
在白天的森林以上的净辐射Rn的每小时值被发现超过草地约15%，在冬季和夏季约25%。当森林湿润时，冠层热储量Q和地面热通量G的变化较小，这种差异也适用于蒸发可用能量（Rn-G-Q）。然而，当冠层干燥时，白天的Q值足够大，以减少森林的可用能量约草地。这种森林冠层的能量通常在夜间损失。
Daily net radiation above a Pinus radiata plantation was found to exceed that measured above nearby grassland by about 12% during the winter and 24% during the summer months. This difference was related to differences in the albedo and net longwave radiation associated with the surface temperature of each vegetation. Forest albedo was found to be 0.11 ± 0.001 throughout the winter and did not exhibit a significant diurnal variation. The grassland albedo was found to give the usual diurnal trend and a mean winter albedo of 0.27 ± 0.03 which decreased to 0.24 ± 0.01 in summer, consistent with increasing solar elevation.
Hourly values of net radiation Rn above the forest during daylight hours were found to exceed those for grassland by about 15% during the winter and about 25% during the summer. When the forest was wet and the change in canopy heat storage Q and ground heat flux G were small, such differences also applied to the energy (Rn—G—Q) available for evaporation. However, when the canopy was dry, values of Q during the day were sufficiently large to reduce the forest available energy to about that of the grassland. This forest canopy energy was generally lost during the night.