Large wood drives physical and ecological processes in river systems, but the relative roles of continuous individual tree mortality versus episodes of mass mortality in wood recruitment are not well understood. Here, the 2016 Chimney Tops 2 wildfire, a rare severe wildfire in the eastern United States, was used as a case study for examining the role of mass tree mortality in wood loads of streams in Great Smoky Mountains National Park (GSMNP), Tennessee. Wood surveys were conducted on four reaches in two drainage systems affected by the fire to ascertain the total frequency and volume of burned and unburned wood pieces and jams. Relative to unburned wood, the Chimney Tops 2 fire resulted in a major influx of burned wood to the study reaches, with large percentages of individual pieces (average of 47% by frequency, 48% by volume) and jams (average of 72% by frequency, 93% by volume) exhibiting burn marks. Burned wood pieces had a larger diameter than unburned pieces (p = .065). Results suggest that rare mass‐mortality events like the Chimney Tops 2 wildfire could play a major role in wood dynamics of mountain streams in humid forested regions.

中文翻译：

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继2016年烟囱Tops 2野火之后的溪流木材装载：美国田纳西州大烟山国家公园

大型木材推动了河流系统中的物理和生态过程，但人们对连续不断的个体树木死亡率与大规模死亡率事件在木材募集中的相对作用尚不十分了解。在此，以2016年烟囱Tops 2野火（美国东部罕见的严重野火）为例，研究了田纳西州大烟山国家公园（GSMNP）树木死亡在溪流木材负载中的作用。在受火灾影响的两个排水系统的四个河段进行了木材调查，以确定已燃烧和未燃烧的木块和果酱的总频率和体积。相对于未燃烧的木材，烟囱Tops 2火灾导致大量燃烧的木材涌入研究范围，其中单个碎片所占的百分比较高（按频率平均为47％，48％（体积）和果酱（平均72％（频率），93％（体积））显示出燃烧痕迹。燃烧过的木块的直径比未燃烧过的木块大（p = .065）。结果表明，罕见的大规模死亡事件，如“烟囱顶部2号”野火，可能在潮湿森林地区的山流木材动力学中起主要作用。