Forest impacts on snow accumulation and ablation across an elevation gradient in a temperate montane environment
Forest impacts on snow accumulation and ablation across an elevation gradient in a temperate montane environment
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温带山地环境中森林对海拔梯度积雪和消融的影响
DOI：
10.5194/hess-21-5427-2017
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发表时间：
2016
影响因子：
6.3
通讯作者：
A. Nolin
中科院分区：
文献类型：
--
作者：
T. Roth;A. Nolin
森林覆盖通过冠层拦截和亚冠层能量平衡过程的变化改变积雪积累和消融速率。然而，积雪受森林冠层过程影响的方式因气候、地形和森林特征而异。在这里，我们展示了一项为期4年的研究结果，该研究是对俄勒冈瀑布地区雪林相互作用的研究。我们连续监测了研究区低、中、高三个海拔的成对森林和开放站点的雪和气象变量。在每月或每两周的基础上，我们调查了连接森林和开放场地的900米横断面的雪深和雪水当量。研究结果表明，低、中立地的茂密、相对温暖的森林通过增加冠层截雪量和增加亚冠层积雪的能量输入来阻碍积雪的积累。与森林样地相比，低地和中部开放样地积雪深度更深，持续时间更长（分别为4 ~ 26天和11 ~ 33天）。然而，在相对寒冷的高海拔地区，我们看到相反的关系，森林地区的积雪持续时间比附近的开放地区长15 - 29天。在一项为期4年的研究中，低森林和中森林的冠层拦截效率（cie）值分别占总降雪量的79%和76%，而低密度高森林的cie值为31%。在所有海拔高度，由于海洋性气候和森林的存在，森林环境中的长波辐射似乎是主要的能量成分，分别占低、中、高林场积雪总能量输入的82%、88%和59%。高开点的高风速显著增加了湍流能量交换和雪升华。在高森林地区，较低的风速创造了有利的降雪沉积。这些结果显示了了解森林覆盖对亚冠积雪演变的影响的重要性，并强调了改进森林覆盖模型表示以准确预测海洋森林水资源的必要性。
Forest cover modifies snow accumulation and ablation rates via canopy interception and changes in sub-canopy energy balance processes. However, the ways in which snowpacks are affected by forest canopy processes vary depending on climatic, topographic and forest characteristics. Here we present results from a 4 year study of snow-forest interactions in the Oregon Cascades. We continuously monitored snow and meteorological variables at paired forested and open sites at three elevations representing the Low, Mid, and High seasonal snow zones in the study region. On a monthly to bi-weekly basis, we surveyed snow depth and snow water equivalent across 900 m transects connecting the forested and open pairs of sites. Our results show that the dense, relatively warm on forests at Low and Mid sites impede snow accumulation through increased canopy snow interception and increase energy inputs to the sub-canopy snowpack. Compared with the Forest sites, snowpacks are deeper and last longer in the Open site at the Low and Mid sites (4 – 26 days and 11 – 33 days, respectively). However, we see the opposite relationship at the relatively colder High sites with the Forest site maintaining snow longer into the spring by 15 – 29 days relative to the nearby Open site. Over a 4 year study, canopy interception efficiency ( C IE ) values in the Low- and Mid-Forest sites, were 79 % and 76 % of the total event snowfall, whereas C IE was 31 % at the lower density High-Forest site. At all elevations, longwave radiation in forested environments appears to be the primary energy component due to the maritime climate and forest presence, accounting for 82 %, 88 %, and 59 % of total energy inputs to the snowpack at the Low-, Mid-, and High-Forest sites, respectively. Higher wind speeds in the High-Open site significantly increase turbulent energy exchanges and snow sublimation. Lower wind speeds in the High-Forest site create preferential snowfall deposition. These results show the importance of understanding the effects of forest cover on sub-canopy snowpack evolution and highlight the need for improved forest cover model representation to accurately predict water resources in maritime forests.
中纬度山区环境中雨雪和晴天融雪期间观测到的能量通量的变化
影响因子：
3.8
作者：
Garvelmann J;Pohl S;Weiler M
通讯作者：
Weiler M