Complex Relationships of the Effects of Topographic Characteristics and Susceptible Tree Cover on Burn Severity
Complex Relationships of the Effects of Topographic Characteristics and Susceptible Tree Cover on Burn Severity
复制标题
地形特征和易感树木覆盖度对烧伤严重程度影响的复杂关系
DOI：
10.3390/su10020295
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发表时间：
2018
期刊：
影响因子：
3.9
通讯作者：
Sang Woo Lee
中科院分区：
文献类型：
--
作者：
Hyunjoo Lee;Y. Choi;Sang Woo Lee
森林火灾和燃烧严重程度马赛克对森林生态系统的火灾后动态和复杂性有着深远的影响。许多研究已经调查了地形变量和易受影响的树木覆盖与烧伤严重程度之间的关系。然而，这些关系还没有被完全阐明，因为大多数研究都假设这些关系是线性的。因此，我们通过比较线性和非线性模型，检验了地形变量和感病树种盖度与烧伤严重程度之间的线性和非线性关系。韩国有记录以来最大的森林火灾Samcheok火灾现场被用作研究区域。我们生成了802个分辨率为500米的网格单元，覆盖了整个研究区域，并收集了一个数据集，其中包括地形变量和红松树的百分比，这是韩国最敏感的树木覆盖类型。利用传统的线性模型和广义加性模型对基于地形变量的线性模型和基于日本红松树的非线性模型进行了估计。结果表明，红松树的比例与烧伤严重程度呈线性关系，强调了营林和森林管理对降低烧伤严重程度的重要性。同时，地形变量对烧伤严重程度具有非线性影响。在地形变量中，海拔对烧伤严重程度的非线性影响最大，可能是通过盖过敏感燃料对海拔影响的影响，或者是由于地形特征对火前燃料条件的非线性影响，包括易受影响的树木覆盖的空间分布和可用性。为了验证和推广海拔和其他地形变量的非线性影响，需要在不同地理位置具有不同树木覆盖类型的不同火灾现场进行额外的研究。
Forest fires and burn severity mosaics have profound impacts on the post-fire dynamics and complexity of forest ecosystems. Numerous studies have investigated the relationship between topographic variables and susceptible tree covers with regard to burn severity. However, these relationships have not been fully elucidated, because most studies have assumed linearity in these relationships. Therefore, we examined the linearity and the nonlinearity in the relationships between topographic variables and susceptible tree covers with burn severity by comparing linear and nonlinear models. The site of the Samcheok fire, the largest recorded forest fire in Korea, was used as the study area. We generated 802 grid cells with a 500-m resolution that encompassed the entire study area and collected a dataset that included the topographic variables and percentage of red pine trees, which are the most susceptible tree cover types in Korea. We used conventional linear models and generalized additive models to estimate the linear and the nonlinear models based on topographic variables and Japanese red pine trees. The results revealed that the percentage of red pine trees had linear effects on burn severity, reinforcing the importance of silviculture and forest management to lower burn severity. Meanwhile, the topographic variables had nonlinear effects on burn severity. Among the topographic variables, elevation had the strongest nonlinear effect on burn severity, possibly by overriding the effects of susceptible fuels over elevation effects or due to the nonlinear effects of topographic characteristics on pre-fire fuel conditions, including the spatial distribution and availability of susceptible tree cover. To validate and generalize the nonlinear effects of elevation and other topographic variables, additional research is required at different fire sites with different tree cover types in different geographic locations.