Hutto Richard L
Avian Science Center, Division of Biological Sciences, University of Montana, Missoula, Montana 59812, USA.
Ecol Appl. 2008 Dec;18(8):1827-34. doi: 10.1890/08-0895.1.
Many scientists and forest land managers concur that past fire suppression, grazing, and timber harvesting practices have created unnatural and unhealthy conditions in the dry, ponderosa pine forests of the western United States. Specifically, such forests are said to carry higher fuel loads and experience fires that are more severe than those that occurred historically. It remains unclear, however, how far these generalizations can be extrapolated in time and space, and how well they apply to the more mesic ponderosa pine systems and to other forest systems within the western United States. I use data on the pattern of distribution of one bird species (Black-backed Woodpecker, Picoides arcticus) as derived from 16465 sample locations to show that, in western Montana, this bird species is extremely specialized on severely burned forests. Such specialization has profound implications because it suggests that the severe fires we see burning in many forests in the Intermountain West are not entirely "unnatural" or "unhealthy." Instead, severely burned forest conditions have probably occurred naturally across a broad range of forest types for millennia. These findings highlight the fact that severe fire provides an important ecological backdrop for fire specialists like the Black-backed Woodpecker, and that the presence and importance of severe fire may be much broader than commonly appreciated.
许多科学家和林地管理者一致认为,过去的火灾抑制、放牧和木材采伐做法在美国西部干燥的黄松林中造成了不自然和不健康的状况。具体而言,据说这类森林的燃料负荷更高,火灾也比历史上发生的火灾更为严重。然而,目前尚不清楚这些普遍情况在时间和空间上能外推多远,以及它们在多大程度上适用于美国西部更为湿润的黄松系统和其他森林系统。我利用来自16465个采样点得出的一种鸟类(黑背啄木鸟,Picoides arcticus)的分布模式数据,表明在蒙大拿州西部,这种鸟类极度依赖于遭受严重火灾的森林。这种特殊化具有深远的意义,因为它表明我们在山间西部许多森林中看到的严重火灾并非完全“不自然”或“不健康”。相反,严重烧毁的森林状况可能在数千年来在广泛的森林类型中自然发生。这些发现凸显了这样一个事实,即严重火灾为像黑背啄木鸟这样的火灾专家提供了重要的生态背景,而且严重火灾的存在和重要性可能比通常认为的要广泛得多。