FIRE HISTORY ACROSS FOREST TYPES IN THE SOUTHERN BEARTOOTH MOUNTAINS, WYOMING
FIRE HISTORY ACROSS FOREST TYPES IN THE SOUTHERN BEARTOOTH MOUNTAINS, WYOMING
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DOI：
10.3959/trr2018-11
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发表时间：
2020-01
影响因子：
1.6
通讯作者：
Sabrina R. Brown;Ashley Baysinger;P. Brown;Justin L. Cheek;J. Diez;Christopher M. Gentry;T. A. Grant;Jeannine-Marie Jacques;D. Jordan;M. L. Leef;M. K. Rourke;J. Speer;Carrie E. Spradlin;J. T. Stevens;J. Stone;Brian Van Winkle;Nickolas E. Zeibig-Kichas
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文献类型：
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作者：
Sabrina R. Brown;Ashley Baysinger;P. Brown;Justin L. Cheek;J. Diez;Christopher M. Gentry;T. A. Grant;Jeannine-Marie Jacques;D. Jordan;M. L. Leef;M. K. Rourke;J. Speer;Carrie E. Spradlin;J. T. Stevens;J. Stone;Brian Van Winkle;Nickolas E. Zeibig-Kichas
摘要火是一个重要的生态系统过程，在形成怀俄明州西北部熊牙山的森林中起着关键作用。该地区的高度可变的地形提供了理想的条件，比较火制度相邻的森林类型，但在这方面的研究是有限的。我们重建火灾频率，树的年龄结构，火灾后的树木生长反应在克拉克福克游侠区的肖肖尼国家森林推断历史火灾行为和立场的影响变化。我们收集火灾疤痕的树木和地块为基础的树木年龄的地块范围为0.5-5平方公里的大小在两个森林类型分开2公里：低海拔的混合花旗松和黑松和较高海拔的林线森林为主的白皮松。1664年、1706年、1785年、1804年、1846年和1900年，低海拔森林发生火灾，平均火灾间隔为47年。1804年和1900年的火灾也记录在较高海拔的森林中，在1900年的火灾中，高海拔的树木死亡率很高。这两个森林是多年龄的树木队列的证据很少，以应对严重的，立场更换事件。平均而言，火灾后树木生长增加，平均年轮宽度火灾后39%，更广泛的花旗松和40%，更广泛的黑松比火灾前的平均水平，这表明一些树木死亡率可能发生在与低海拔森林火灾。烧伤更频繁，在低海拔的森林，偶尔能够蔓延到高海拔的白树皮station. Although我们怀疑的过渡发生在干燥的年份，从低到高海拔的火灾，我们没有发现任何关系火灾年份和可用的气候重建通过叠加的时代分析。更新在20世纪世纪在白树皮森林文件恢复后，这一森林1900年中度严重火灾事件。最后，特别是在海拔较低的花旗松森林，自最后一次记录火灾（1900年）以来的时间似乎比历史记录中的任何无火期都要长，这表明火灾排除可能会造成景观和斑块尺度林分结构的变化，这可能会影响未来的火灾行为，特别是树冠取代火灾的程度，在这些森林中。
ABSTRACT Fire is a critical ecosystem process that has played a key role in shaping forests throughout the Beartooth Mountains in northwestern Wyoming. The highly variable topography of the area provides ideal conditions to compare fire regimes across contiguous forest types, yet pyro-dendrochronological research in this area is limited. We reconstructed fire frequency, tree age structure, and post-fire tree growth response in the Clarks Fork Ranger District of the Shoshone National Forest to infer variations in historical fire behavior and stand effects. We collected fire-scarred trees and plot-based tree ages on plots ranging 0.5-5 km2 in size across two forest types separated by 2 km: a lower-elevation forest of mixed Douglas-fir and lodgepole pine and a higher elevation treeline forest dominated by whitebark pine. Fires occurred in the lower-elevation forest in 1664, 1706, 1785, 1804, 1846, and 1900 with a mean fire return interval of 47 years. The fires in 1804 and 1900 were also recorded in the higher elevation forest, with significant tree mortality at high elevation in the 1900 fire. Both forests were multi-aged with little evidence of tree cohorts in response to severe, stand-replacing events. On average, tree growth increased after fires, with mean ring widths after fire 39% wider in Douglas-fir and 40% wider in lodgepole pine than pre-fire averages, suggesting that some tree mortality likely occurred in association with lower-elevation forest fires. Burns were more frequent in the lower-elevation forest and were occasionally able to spread into the upper-elevation whitebark stand. Although we suspect the transition of fires from low-to high-elevation occurred during drier years, we did not find any relationship between fire years and available climatic reconstructions via superposed epoch analysis. Regeneration during the 20th Century in the whitebark forest documents recovery of this forest after the 1900 moderate-severity fire event. Finally, especially in the lower-elevation Douglas-fir forest, the period since the last recorded fire (1900) appears to be longer than any fire-free period in the historical record, suggesting that fire exclusion may be creating changes in landscape and patch-scale stand structures, which will likely impact future fire behavior, especially the extent of crown-replacing fire, in these forests.