Abstract Globally, prescribed fire, harvesting, and understory mastication, alone and in combination, are common forest management practices. Timber commodities, wildlife habitat, wildfire fuel reduction, soil conservation, and water quality are frequently targeted and assessed as these practices are utilized. In the 1960s, a study of paired, first-order watersheds was established in coastal South Carolina, USA, to evaluate the long-term impacts of forest management (i.e. prescribed fire, thinning, mastication of understory vegetation) on water quantity and quality. Following Hurricane Hugo in 1989, this included salvage logging on one watershed, but not the other. In 2015, these watersheds were comprehensively evaluated to determine differences in forest species composition, fuels, and soil chemistry. Softwood basal area was greater in the managed watershed than in the unmanaged watershed and hardwood basal area was greater in the unmanaged watershed than in the managed watershed. Total fuel mass did not differ between the two watersheds, but 1-hr and 1000-hr rotten fuel mass were greater on the unmanaged watershed. Ten-hr fuel mass was greater on the managed watershed. Calcium, nitrogen, magnesium, phosphorus, potassium, and pH differed between the litter (Oi horizon) and duff (Oe + Oa horizons) of both watersheds, but carbon only differed in the duff. Mineral soil (Ultisols, 0–10 and 10–20 cm depths) calcium and phosphorus differed between the watersheds, but pH and the other chemicals did not. Collectively, these results indicated that: (1) forest management and natural disturbance on these watersheds altered long-term forest structure; (2) different species compositions and the inclusion or exclusion of salvage logging after Hurricane Hugo produced different fuel compositions that may potentially impact potential wildfire hazard and fire behavior; (3) organisms as a primary soil-forming factor were impacted by long-term management, therefore, some soil chemical properties were affected. Collectively, these analyses highlighted the broad, long-term impacts to ecosystem properties and processes that might directly and indirectly result from active forest management and natural disturbance and the scale of site-specific assessment that might be considered when landowner objectives are targeted in forest management plans and practices.

中文翻译：

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美国东南沿海平原流域 50 年的森林管理和自然干扰导致的森林组成、燃料负荷和土壤化学

摘要 在全球范围内，规定的火灾、采伐和林下咀嚼，单独或结合使用，是常见的森林管理实践。木材商品、野生动物栖息地、减少野火燃料、土壤保护和水质在使用这些做法时经常成为目标和评估对象。在 1960 年代，在美国南卡罗来纳州沿海地区建立了成对一级流域的研究，以评估森林管理（即规定的火灾、间伐、林下植被的咀嚼）对水量和质量的长期影响。在 1989 年飓风雨果之后，这包括在一个流域而不是另一个流域进行抢救性伐木。2015 年，对这些流域进行了综合评估，以确定森林物种组成、燃料和土壤化学的差异。管理流域的软木基底面积大于未管理流域，而未管理流域的硬木基底面积大于管理流域。两个流域之间的总燃料质量没有差异，但 1 小时和 1000 小时的腐烂燃料质量在未管理的流域中更大。在管理的流​​域上，10 小时的燃料质量更大。钙、氮、镁、磷、钾和 pH 值在两个流域的枯枝落叶（Oi 层级）和低层（Oe + Oa 层）之间不同，但碳仅在低层层中不同。矿质土壤（Ultisol，0-10 和 10-20 厘米深度）钙和磷在流域之间不同，但 pH 值和其他化学物质没有。总的来说，这些结果表明：（1）这些流域的森林管理和自然干扰改变了长期的森林​​结构；(2) 在雨果飓风产生不同的燃料成分后，不同的物种组成以及包括或排除补救伐木，这可能会影响潜在的野火危害和火灾行为；(3) 生物作为主要的土壤形成因子受到长期管理的影响，因此，部分土壤化学性质受到影响。总的来说，这些分析强调了积极的森林管理和自然干扰可能直接或间接对生态系统特性和过程产生的广泛、长期影响，以及在森林管理中针对土地所有者目标时可能考虑的特定地点评估的规模计划和做法。