Assessment of fire severity and species diversity in the southern Appalachians using Landsat TM and ETM+ imagery
Assessment of fire severity and species diversity in the southern Appalachians using Landsat TM and ETM+ imagery
复制标题
DOI：
10.1016/j.rse.2006.03.019
复制
发表时间：
2007-05
影响因子：
13.5
通讯作者：
M. Wimberly;M. Reilly
中科院分区：
文献类型：
--
作者：
M. Wimberly;M. Reilly
对阿巴拉契亚山脉南部大规模野火的干扰生态学知之甚少。在北卡罗来纳州西部的林维尔峡谷荒野地区发生了一场4000公顷的野火，这为研究一系列严重程度的大火提供了一个难得的机会。本研究的目的是：1）评估使用多时相陆地卫星图像来绘制阿巴拉契亚山脉南部火灾严重程度的潜力，2）研究地形和森林群落类型对火灾严重程度空间格局的影响; 3）研究预测火灾严重程度与物种丰富度变化之间的关系。非线性回归方程预测了基于现场的复合燃烧指数（CBI）作为标准化燃烧比（dNBR）变化的函数，R2为0.71。火灾的严重程度是最高的干燥的地形位于上山坡，山脊，和西南方面，并在松树社区比其他森林类型。预测的CBI与物种丰富度的变化呈正相关，并与火灾后覆盖的松树幼苗（弗吉尼亚松，P.刚，和P. pungens），这表明烧伤严重程度地图可用于预测社区级火灾的影响，在大型景观。尽管这场火灾的规模相对较大的阿巴拉契亚山脉南部，严重程度与地形变异和火灾前植被，火灾严重程度的空间变化与物种丰富度的变化密切相关。因此，林维尔峡谷火灾似乎普遍加强了潜在的环境梯度所施加的生态约束。
Relatively little is known about the disturbance ecology of large wildfires in the southern Appalachians. The occurrence of a 4000-ha wildfire in the Linville Gorge Wilderness area in western North Carolina has provided a rare opportunity to study a large fire with a range of severities. The objectives of this study were to 1) assess the potential for using multi-temporal Landsat imagery to map fire severity in the southern Appalachians, 2) examine the influences of topography and forest community type on the spatial pattern of fire severity; and 3) examine the relationship between predicted fire severity and changes in species richness. A non-linear regression equation predicted a field-based composite burn index (CBI) as a function of change in the Normalized Burn Ratio (dNBR) with an R2of 0.71. Fire severity was highest on drier landforms located on upper hillslopes, ridges, and on southwest aspects, and was higher in pine communities than in other forest types. Predicted CBI was positively correlated with changes in species richness and with the post-fire cover of pine seedlings (Pinus virginiana, P. rigida, and P. pungens), suggesting that burn severity maps can be used to predict community-level fire effects across large landscapes. Despite the relatively large size of this fire for the southern Appalachians, severity was strongly linked to topographic variability and pre-fire vegetation, and spatial variation in fire severity was correlated with changes in species richness. Thus, the Linville Gorge fire appears to have generally reinforced the ecological constraints imposed by underlying environmental gradients.