The Effects of Bark Beetle Outbreaks on Forest Development, Fuel Loads and Potential Fire Behavior in Salvage Logged and Untreated Lodgepole Pine Forests
The Effects of Bark Beetle Outbreaks on Forest Development, Fuel Loads and Potential Fire Behavior in Salvage Logged and Untreated Lodgepole Pine Forests
复制标题
树皮甲虫爆发对抢救采伐和未经处理的黑松林的森林发育、燃料负荷和潜在火灾行为的影响
DOI：
10.1016/j.foreco.2012.07.027
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发表时间：
2012
影响因子：
3.7
通讯作者：
R. Hubbard
中科院分区：
文献类型：
--
作者：
Byron J. Collins;C. Rhoades;M. Battaglia;R. Hubbard
最近山松甲虫的侵扰导致了落基山脉地区树木的广泛死亡和木质燃料的堆积，引起了人们对未来林分状况和火灾行为的担忧。我们量化了采伐对树木再生和燃料负荷的影响，相对于附近未采伐的24个科罗拉多州中北部的lodgepole松林，这些松林经历了高山松甲虫造成的70%的上层死亡率。我们使用实地测量来预测在爆发和相关采伐之后的一个世纪里森林中燃料负荷和潜在火灾行为的变化。我们的实地测量和林分发展预测表明，通过创造促进黑松和白杨（而不是亚高山冷杉）再生的条件，挽救性采伐将改变未来林分林冠火灾行为的潜力。大量的亚高山冷杉在未经处理的、被甲虫杀死的林分上再生，预计会形成一层阶梯燃料，更有可能使表面燃烧的火焰蔓延到森林冠层。与未经处理的林分相比，采伐增加了3倍以上的木质表面燃料；然而，在甲虫入侵后的30年内，随着枯树倒下，未经处理的林分中粗燃料将大幅增加（约55Mgha−1），并且燃料负荷的增加将持续一个多世纪。尽管回收性采伐只能处理一小部分甲虫出没的科罗拉多州森林，但在这些地区，采伐将影响林分发展和燃料负荷，并将在一个多世纪内改变潜在的火灾行为。
Recent mountain pine beetle infestations have resulted in widespread tree mortality and the accumulation of dead woody fuels across the Rocky Mountain region, creating concerns over future forest stand conditions and fire behavior. We quantified how salvage logging influenced tree regeneration and fuel loads relative to nearby, uncut stands for 24 lodgepole pine forests in north-central Colorado that had experienced >70% overstory mortality from mountain pine beetles. We used our field measurements to predict changes in fuel loads and potential fire behavior in the forests that develop over the century following the outbreak and associated harvesting. Our field measurements and stand development projections suggest that salvage logging will alter the potential for canopy fire behavior in future stands by creating conditions that promote regeneration of lodgepole pine and quaking aspen as opposed to subalpine fir. The abundant subalpine fir that has regenerated in untreated, beetle-killed stands is predicted to form a stratum of ladder fuels more likely to allow fires burning on the surface to spread into the forest canopy. Harvesting increased woody surface fuels more than 3-fold compared to untreated stands immediately after treatments; however, coarse fuels will increase substantially (by ∼55Mgha−1) in untreated stands within three decades of the beetle infestation as dead trees topple, and the elevated fuel loads will persist for more than a century. Though salvage logging will treat a small fraction of beetle-infested Colorado forests, in those areas treatment will affect stand development and fuel loads and will alter potential fire behavior for more than a century.