Post-burn study of woody plants at Jacobs Branch West burn site, 1991-1992

Recent declines in the yellow pine component of pine-hardwood stands in the southern Appalachian Mountains has prompted managers to increase the use of fire as a silviculture tool. The fell and burn treatment is designed to remove competing vegetation (hardwoods and mountain laurel [Kalmia latifolia]) to ensure successful establishment of planted eastern white pine (Pinus strobus). Two years after burning, mountain laurel had accumulated more biomass than any other species and accounted for 43% of total biomass in year 1 and 20% in year 2. By year 4, mountain laurel ranked fifth (8.9% of total) in total biomass among hardwood species behind Allegheny serviceberry (Amalanchier arborea, 14.3%), chestnut oak (Quercus prinus, 13.7%), red maple (Acer rubrum, 12.4%), and scarlet oak (Q. coccinea, 9.3%). Across sites, woody species richness ranged from 19-24 in year 1 and 14-22 in year 4. Species richness varied across sites and years, and there were substantial changes in the distribution of biomass among species. The introduction of fire allowed the once dominant pitch pine (P. rigida) to successfully reestablish. On sites, pine accounted for 25% of pretreatment stem density, but <1% and 2% in the first and fourth growing seasons after burning, respectively. However; in year 1, pines had increased in density 20-fold compared to pretreatment levels, and by year 4, had maintained a 17-fold increase compared to pretreatment. The use of fire in forest management has been the subject of considerable criticism. In light of current public concerns over the loss of critical or unique habitats, fire may gain public support for use as a restoration tool.

阿巴拉契亚山脉南部的松硬木林中黄松组分的持续衰退，促使森林管理者增加将火作为营林工具的使用频次。采伐火烧处理旨在清除竞争性植被（硬木树种与山月桂（Kalmia latifolia）），以保障人工栽植的东部白松（Pinus strobus）成功定植。火烧后两年的观测结果显示，山月桂的生物量积累量高于其他所有物种，其生物量占总生物量的比例在火烧后第1年为43%，第2年为20%。至实验第4年时，在硬木树种的总生物量排序中，山月桂位列第5（占总生物量的8.9%），其占比低于阿勒格尼唐棣（Amalanchier arborea，14.3%）、栗栎（Quercus prinus，13.7%）、红枫（Acer rubrum，12.4%）以及猩红栎（Q. coccinea，9.3%）。各试验样地的木本物种丰富度在实验第1年介于19至24之间，第4年则介于14至22之间。物种丰富度随样地与实验年份存在显著差异，各物种间的生物量分布也发生了显著变化。火烧干预使得曾经占据优势的脂松（P. rigida）得以成功恢复定植。试验样地中，火烧前松树的茎秆密度占总茎秆密度的比例为25%，但火烧后的第1个和第4个生长季，该占比分别降至不足1%和2%。不过，与火烧前的密度水平相比，实验第1年松树的种群密度增长了20倍；到实验第4年时，其密度仍较火烧前维持了17倍的增长幅度。森林经营中的火烧手段长期以来饱受大量批评。鉴于当前公众对关键或独特生境丧失的担忧，火烧作为生态修复工具或可获得公众的支持。