Stand-replacing patches within a 'mixed severity' fire regime: quantitative characterization using recent fires in a long-established natural fire area
Stand-replacing patches within a 'mixed severity' fire regime: quantitative characterization using recent fires in a long-established natural fire area
复制标题
DOI：
10.1007/s10980-010-9470-5
复制
发表时间：
2010-07-01
影响因子：
5.2
通讯作者：
Stephens, Scott L.
中科院分区：
文献类型：
--
作者：
Collins, Brandon M.;Stephens, Scott L.
可变或混合严重程度的火情固有的复杂性使得重要火情属性（例如，不同严重程度烧毁的景观比例、林分替换斑块的大小和分布）的定量表征变得困难。因此，“混合严重性”一词存在歧义。我们通过对近期发生在高海拔混合针叶林中的两起荒地火灾进行空间分析来解决这一模糊性问题，这两次火灾发生在一个有 30 多年相对自由燃烧的自然火灾的地区。我们利用对火灾严重程度的可靠估计和详细的空间数据集来研究这些火灾中替换补丁的模式和控制。两场火灾之间，替代林地的斑块占总烧毁面积的 15%，其中包括许多小斑块（< 4 公顷）和少数大斑块（> 60 公顷）。较小的林分替代斑块通常与灌木为主（Arctostaphylos spp.和Ceanothus spp.）和松树为主的植被类型有关，而较大的林分替代斑块往往出现在更耐荫的、以冷杉为主的类型中。此外，在灌木为主的类型中，林分替换斑块通常仅限于下面的植被斑块，对于灌木类型来说，在两个火灾区域中，植被斑块比所有其他主要植被类型的植被斑块要小。对于白冷杉和红冷杉森林类型，我们几乎没有发现植被斑块对林分替代斑块范围的限制的证据。我们确定的斑块动态可用于为类似森林类型的景观管理策略提供信息。
The complexity inherent in variable, or mixed-severity fire regimes makes quantitative characterization of important fire regime attributes (e.g., proportion of landscape burned at different severities, size and distribution of stand-replacing patches) difficult. As a result, there is ambiguity associated with the term 'mixed-severity'. We address this ambiguity through spatial analysis of two recent wildland fires in upper elevation mixed-conifer forests that occurred in an area with over 30 years of relatively freely-burning natural fires. We take advantage of robust estimates of fire severity and detailed spatial datasets to investigate patterns and controls on stand-replacing patches within these fires. Stand-replacing patches made up 15% of the total burned area between the two fires, which consisted of many small patches (< 4 ha) and few large patches (> 60 ha). Smaller stand-replacing patches were generally associated with shrub-dominated (Arctostaphylos spp. and Ceanothus spp.) and pine-dominated vegetation types, while larger stand-replacing patches tended to occur in more shade-tolerant, fir-dominated types. Additionally, in shrub-dominated types stand-replacing patches were often constrained to the underlying patch of vegetation, which for the shrub type were smaller across the two fire areas than vegetation patches for all other dominant vegetation types. For white and red fir forest types we found little evidence of vegetation patch constraint on the extent of stand-replacing patches. The patch dynamics we identified can be used to inform management strategies for landscapes in similar forest types.