Post-burn study of herbaceous understory plots at Jacobs Branch and Devils Den burn sites, 1992

Establishment and maintenance of pitch pine/hardwood ecosystems in the southern Appalachians depends on intense wildfire. These ecosystems typically have a substantial evergreen shrub component (Kalmia latifolia) which limits regeneration of future overstory species. Wildfires provide microsite conditions conducive to pine regeneration and reduce Kalmia competition. Recent droughts in the region have resulted in significant acreages of southern pine beetle killed pine/hardwood stands. Site conditions are amenable to the high intensity fires needed to regenerate pine; however, fire suppression limits the role of wildfire in these ecosystems. Research shows that pines will not regenerate in the absence of severe disturbance, such as a high intensity fire, and mixed pine/hardwood ecosystem will not be maintained. On three sites in the southern Appalachians, stands characterized by sparse overstories and dense Kalmia latifolia L. shrub layers were felled in early summer and burned in early fall. Amounts of aboveground vegetation and forest floor mass, nitrogen (N), and carbon (C) were measured before and after treatment by sampling wood, foliage, herbs, grasses, and forest floor (Oi and Oe + Oa layers). This data set constitutes the post-burn study of herbaceous understory plots at Jacobs Branch and Devil's Den burn sites, 1992.

阿巴拉契亚南部地区的北美油松/硬木混交林生态系统的建立与维持，依赖高强度野火。这类生态系统通常拥有丰富的常绿灌木组分——山月桂（Kalmia latifolia），其会抑制后续林冠层树种的天然更新。野火可为油松更新提供适宜的微生境条件，并削弱山月桂的竞争优势。近期该区域发生的干旱，导致大片林分被南方松小蠹（southern pine beetle）致死的油松/硬木林所覆盖。当前立地条件满足油松更新所需的高强度火烧需求，但林火防控限制了野火在这类生态系统中的作用。研究表明，若缺乏高强度火烧这类剧烈扰动，油松将无法完成天然更新，混交油松/硬木林生态系统也将难以维持。研究人员在阿巴拉契亚南部的三个试验样地中，于初夏砍伐了林冠层稀疏、山月桂（Kalmia latifolia L.）灌丛致密的林分，并于初秋实施火烧处理。在处理前后，通过对木材、叶片、草本植物、禾草以及森林枯落物层（Oi层与Oe+Oa层）进行取样，测定了地上生物量、森林枯落物质量以及氮（N）、碳（C）的含量。本数据集为1992年Jacobs Branch与Devil's Den火烧样地的林下草本样地火烧后研究数据。