Water Loss and Canopy Resistance of a Young Sitka Spruce Plantation
Water Loss and Canopy Resistance of a Young Sitka Spruce Plantation
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西特卡云杉幼林的失水和树冠抵抗力
DOI：
10.1007/bf03335355
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发表时间：
1979
影响因子：
4.3
通讯作者：
R. Milne
中科院分区：
文献类型：
--
作者：
R. Milne
通过测量能量平衡中的净辐射、显热和地热通量，研究了 7 米高的斯提卡云杉林的蒸腾作用，以给出潜热通量，从而根据 Penman-Monteith 方程得出树冠阻力。感热通量是使用 Fluxatron 电路通过涡相关法测量的。在 7 月/8 月的连续六天测量中，冠层阻力通常呈下降趋势，从黎明时的高值 (约 150 s m−1) 到中午的 40 s m−1 左右，然后在日落时稳定返回到 >100 s m−1。在研究期间，蒸腾量平均为 3 mm day−1，一天内蒸腾速率的变化与净辐射的变化显着相关。与其他森林地点的已发表数据进行比较，得出的结论是，根据一两个地方收集的结果来概括不同地点不同物种的蒸腾速率和冠层抗力是不明智的。
Transpiration of a 7 m-high Stika spruce forest was investigated using measurments of net radiation, sensible heat and ground heat fluxes in an energy balance to give latent heat flux, and hence canopy resistance from the Penman-Monteith equation. Sensible heat flux was measured by the eddy-correlation method using a Fluxatron circuit.During six consecutive days of measurement in July/August, canopy resistance typically followed a decreasing trend from high values (≈150 s m−1) at dawn to around 40 s m−1 at midday and then returning steadily to >100 s m−1 at sunset. Transpiration was 3 mm day−1 on average over the period studied and changes in the rate within the day were significantly correlated with changes in net radiation.Comparisons are drawn with published data from other forest sites and the conclusion is reached that it is imprudent to generalise about transpiration rates and canopy resistances of different species at different sites from results gathered at one or two places.