Accurately modeling the effects of variable forest structure and change on snow distribution and persistence is critical to water resource management. The resolution of many snow models is too coarse to represent heterogeneous canopy structure in forests, and therefore, most models simplify forest effects on snowpack mass and energy budgets. To quantify the loss of snowpack prediction from simplifications of forest canopy-mediated processes, we applied a high-resolution energy balance snowpack model at two forested sites at a fine (1 m²) and coarse (100 m²) spatial resolution. Simulating open and forested areas separately, as is done in many land surface models (LSMs), leads to biases between the coarse and fine-scale simulations because there is no representation of areas that are near (e.g., <15 m from) trees but with no overhead canopy, which are common in forests of low to medium tree density. Consistent with previous LSM intercomparisons, the coarser simulations predict greater under-canopy radiation (by 30%–80% at our sites), faster snow ablation (by almost 2×), and earlier snow disappearance (by 1–22 days). Many of these biases are reduced dramatically or eliminated when canopy edge environments are considered in the coarser simulations. Furthermore, remaining disagreement between the 100-m and 1-m models can be partially explained by using a combination of tree height, canopy cover, and canopy edginess (which together can explain 46%–96% of remaining model biases). The lack of information about canopy edges and other fine-scale forest structure characteristics in many current LSMs may limit their reliability for simulating forest disturbance.

中文翻译：

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考虑精细森林结构对于模拟山地森林的积雪质量和能源预算是必要的

准确模拟可变森林结构和变化对雪分布和持续性的影响对于水资源管理至关重要。许多雪模型的分辨率太粗糙，无法表示森林中的异质冠层结构，因此，大多数模型简化了森林对积雪质量和能量收支的影响。为了量化简化森林冠层介导过程造成的积雪预测损失，我们在细 (1 m ² ) 和粗 (100 m ²) 空间分辨率。像在许多陆地表面模型 (LSM) 中所做的那样，分别模拟开阔和森林地区会导致粗略模拟和精细模拟之间存在偏差，因为没有表示靠近（例如，距离）树木但距离树木 <15 m 的区域没有高架树冠，这在中低树木密度的森林中很常见。与之前的 LSM 比对一致，较粗略的模拟预测更大的冠层下辐射（在我们的站点上增加 30%–80%）、更快的雪消融（几乎 2 倍）和更早的雪消失（1–22 天）。当在较粗略的模拟中考虑冠层边缘环境时，许多这些偏差会显着减少或消除。此外，100 米和 1 米模型之间的剩余差异可以通过使用树高、冠层覆盖、和冠层边缘（它们一起可以解释剩余模型偏差的 46%–96%）。许多当前 LSM 中缺乏关于冠层边缘和其他精细森林结构特征的信息可能会限制它们模拟森林干扰的可靠性。