Summertime Radiation Balances of Clearcut and Shelterwood Slopes in Southwest Oregon
Summertime Radiation Balances of Clearcut and Shelterwood Slopes in Southwest Oregon
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俄勒冈州西南部净伐和庇护木斜坡的夏季辐射平衡
DOI：
10.1093/forestscience/33.2.504
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发表时间：
1987
期刊：
影响因子：
1.4
通讯作者：
S. Childs
中科院分区：
文献类型：
--
作者：
H. R. Holbo;S. Childs
在俄勒冈州西南部的三个阔叶林和三个防护林树冠下，对入射太阳辐射、反射太阳辐射、净辐射和出射长波辐射进行了测量。这个数据集被用来描述重新造林地点的辐射平衡。所有研究地点的入射太阳能量(K↓)产生近地表小气候(即净辐射Q*)的比例为0.5±0.0 6。这个值明显低于未砍伐森林的通常测量值(Q*/K↓=0.7至0.9.)。虽然阔叶林和防护林的Q*/K↓是相同的，但防护林下层的净辐射较小，因为覆盖层部分拦截了传入的太阳辐射。谢尔特伍德的数据也显示出夜间长波辐射损失的预期减少。影响防护林和采伐林地反照率的主要因素是砍伐，与未焚烧的0.21相比，砍伐使反照率降至0.13。用地面净辐射和防护林冠层净辐射之和的简单模型估算了整个站点的净辐射。模型计算表明，与未采伐的林地相比，采伐地点的总净辐射平均减少了36%。谢特伍德林下环境没有砍伐环境那么恶劣，因为大部分站点的净辐射都消散在覆盖层的树冠上。该模型还用于估算冠层密度对冠层下净辐射的影响。为。SCI。32(2)：504-516。
Measurements of incoming solar radiation, reflected solar radiation, net radiation, and outgoing longwave radiation were made on three clearcuts and below three shelterwood canopies in southwest Oregon. This dataset was used to characterize the radiation balance of reforestation sites. The fraction of incoming solar energy (K ↓) producing the near surface microclimate (i.e., the net radiation, Q*) was 0.5 ± 0.06 for all sites studied. This value is appreciably lower than commonly measured values of uncut forest (Q*/K ↓ = 0.7 to 0.9). Although Q*/K ↓ is the same for clearcuts and shelterwoods, shelterwood understories have smaller net radiation because the overstory partially intercepts incoming solar radiation. Shelterwood data also exhibit the expected decrease in longwave radiation loss at night. The major factor affecting site albedo in both shelterwoods and clearcuts was slashburning, which decreased albedo to 0.13 as compared to 0.21 for unburned sites. Net radiation for entire sites was estimated with a simple model to sum ground surface net radiation and shelterwood canopy net radiation. Model calculations suggest that harvested sites average a 36% reduction in total net radiation when compared to unharvested stands. Shelterwood understory environments are less harsh than clearcut environments because much of the total site net radiation is dissipated in the overstory canopy. The model is also used to estimate the effect of canopy density on net radiation below the canopy. For. Sci. 32(2):504-516.