Post-burn study of woody vegetation at Jacobs Branch East, 1994

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（Southern Appalachian Mountains）松硬木林分中黄松组分的近年衰退，促使林务管理者增加将火作为营林（silviculture）工具的使用频次。本研究采用的伐除焚烧处理，旨在清除竞争植被（硬木植物与山月桂（Kalmia latifolia）），以保障人工栽植的东部白松（Pinus strobus）成功定植。焚烧后第1年与第2年，山月桂的总生物量占比分别为43%与20%；且在焚烧满两年时，其生物积累量已超过其余所有物种。至第4年，在硬木物种的总生物量排序中，山月桂位列第5（占总生物量的8.9%），依次落后于阿勒格尼唐棣（Amalanchier arborea，14.3%）、栗栎（Quercus prinus，13.7%）、红枫（Acer rubrum，12.4%）与猩红栎（Q. coccinea，9.3%）。各研究样地的木本物种丰富度在焚烧后第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年份的不同存在显著差异，各物种间的生物量分布也发生了显著变化。火干预使得曾为林分优势种的刚松（P. rigida）得以成功恢复定植。所有样地中，松树在处理前的株数密度（stem density）占比达25%，但在焚烧后的第1和第4个生长季，该占比分别降至不足1%与2%。不过，与处理前相比，焚烧后第1年松树的株数密度增长了20倍；至第4年，其株数密度仍较处理前提升了17倍。森林经营中用火的做法一直饱受大量批评。鉴于当前公众对关键或独特生境丧失的担忧，火作为生境修复工具的应用或可获得公众支持。