USDA-FS, Pacific Northwest Research Station, 1133 N. Western Avenue, Wenatchee, Washington, 98801, USA.
College of the Environment-SEFS, University of Washington, Seattle, Washington, 98195, USA.
Ecol Appl. 2021 Dec;31(8):e02432. doi: 10.1002/eap.2432. Epub 2021 Aug 25.
Forest landscapes across western North America (wNA) have experienced extensive changes over the last two centuries, while climatic warming has become a global reality over the last four decades. Resulting interactions between historical increases in forested area and density and recent rapid warming, increasing insect mortality, and wildfire burned areas, are now leading to substantial abrupt landscape alterations. These outcomes are forcing forest planners and managers to identify strategies that can modify future outcomes that are ecologically and/or socially undesirable. Past forest management, including widespread harvest of fire- and climate-tolerant large old trees and old forests, fire exclusion (both Indigenous and lightning ignitions), and highly effective wildfire suppression have contributed to the current state of wNA forests. These practices were successful at meeting short-term demands, but they match poorly to modern realities. Hagmann et al. review a century of observations and multi-scale, multi-proxy, research evidence that details widespread changes in forested landscapes and wildfire regimes since the influx of European colonists. Over the preceding 10 millennia, large areas of wNA were already settled and proactively managed with intentional burning by Indigenous tribes. Prichard et al. then review the research on management practices historically applied by Indigenous tribes and currently applied by some managers to intentionally manage forests for resilient conditions. They address 10 questions surrounding the application and relevance of these management practices. Here, we highlight the main findings of both papers and offer recommendations for management. We discuss progress paralysis that often occurs with strict adherence to the precautionary principle; offer insights for dealing with the common problem of irreducible uncertainty and suggestions for reframing management and policy direction; and identify key knowledge gaps and research needs.
过去两个世纪以来，北美西部（wNA）的森林景观发生了广泛的变化，而在过去四十年中，气候变暖已成为一个全球性现实。历史上森林面积和密度的增加以及最近快速变暖、昆虫死亡率增加和野火燃烧区之间的相互作用，现在正在导致大规模的突然景观变化。这些结果迫使森林规划者和管理者确定能够改变未来生态和/或社会不可取结果的策略。过去的森林管理，包括广泛采伐耐火和耐气候的大老树和老林、火灾排除（包括原住民和闪电引发的火灾）以及高效的野火抑制，都促成了目前 wNA 森林的状况。这些做法在满足短期需求方面取得了成功，但与现代现实相差甚远。Hagmann 等人回顾了一个世纪以来的观察结果和多尺度、多探针的研究证据，这些证据详细说明了自欧洲殖民者涌入以来森林景观和野火模式的广泛变化。在过去的一万年中，大片的 wNA 已经被欧洲殖民者定居，并通过原住民部落有计划的燃烧得到了积极的管理。Prichard 等人随后回顾了历史上原住民部落应用的管理实践以及目前一些管理者为实现森林弹性条件而有意管理森林的应用研究。他们围绕这些管理实践的应用和相关性提出了 10 个问题。在这里，我们强调了这两篇论文的主要发现，并为管理提供了建议。我们讨论了在严格遵守预防原则时经常出现的进展瘫痪问题；为处理常见的不可减少的不确定性问题提供了一些见解，并对管理和政策方向的重新制定提出了建议；并确定了关键的知识差距和研究需求。
