Soil carbon in the South Atlantic United States: Land use change, forest management, and physiographic context
Soil carbon in the South Atlantic United States: Land use change, forest management, and physiographic context
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美国南大西洋土壤碳：土地利用变化、森林管理和地理学环境
DOI：
10.1016/j.foreco.2022.120410
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发表时间：
2022
影响因子：
3.7
通讯作者：
Swanston, Christopher W.
中科院分区：
文献类型：
--
作者：
Nave, Lucas E.;DeLyser, Kendall;Domke, Grant M.;Holub, Scott M.;Janowiak, Maria K.;Ontl, Todd A.;Sprague, Eric;Viau, Nickolas R.;Walters, Brian F.;Swanston, Christopher W.
基于证据的森林碳(C)管理需要在与土地所有者和资源专业人员相关的尺度上，确定土壤有机碳（SOC）储量的基线模式和驱动因素，以及它们对土地利用变化和管理的响应。有机碳是最大的陆地碳库，其相关数据集的增长有助于利用综合技术在管理相关尺度上评估有机碳储量及其变化。我们报告了综合使用已发表研究和两个大型数据库的荟萃分析的结果，其中我们确定了基线模式和驱动因素，量化了土地利用变化和森林管理的影响，并为不同的管理制度及其SOC影响提供了生态背景。我们对南大西洋各州进行了一系列生态区域有机碳评估，这是第四次评估。在生态区域层面上，基线有机碳储量随气候、地形和土壤物理因素（如温度和降水、坡度和坡向以及土壤质地）而变化。南大西洋各州对美国国家尺度的森林碳汇和林产品产业尤为重要。土地利用变化和森林管理对有机碳储量影响不大。在以前开垦过的土地上重新造林增加了SOC储量，而砍伐森林进行耕作则产生相反的效果；对于连片林地，采伐与有机碳增加有关，而规定的火灾与有机碳下降有关。再造林对上层矿质土壤（+30%）的影响很大，而且是积极的，但在下层矿质土壤中没有检测到。规定火灾的负面影响是由于有机层的大量碳损失（-46%）；火灾和收获对上层矿质土壤没有影响，但都增加了下层矿质土壤的有机碳（分别为+8.2和+46%，后者的不确定性较高）。初始土壤通常比最终土壤更容易受到规定的火灾或收获的负面影响，固有因素（包括土壤分类）和管理影响之间的协方差表明，内陆与沿海地理区域在管理制度和有机碳趋势方面存在差异。在较冷、较湿、地形崎岖的阔叶林中，有较大的基线SOC储量，规定的火灾甚至光采伐通常会降低SOC；相比之下，集约化管理的沿海平原松林最初的有机碳储量很小，但即使是一次轮作也能迅速增加。地点（地形）和实践（管理制度）之间的这种协方差表明，当作为更广泛的（例如国家一级的）森林C或气候政策的一部分实施时，森林C管理的不同方法可能与其他生态或生产目标相辅相成。
Evidence-based forest carbon (C) management requires identifying baseline patterns and drivers of soil organic carbon (SOC) stocks, and their responses to land use change and management, at scales relevant to landowners and resource professionals. The growth of datasets related to SOC, which is the largest terrestrial C pool, facilitates use of synthesis techniques to assess SOC stocks and changes at management-relevant scales. We report results from a synthesis usingmeta-analysis of published studies, as well as two large databases, in which we identify baseline patterns and drivers, quantify influences of land use change and forest management, and provide ecological context for distinct management regimes and their SOC impacts. We conducted this, the fourth in a series of ecoregional SOC assessments, for the South Atlantic States, which are disproportionately important to the national-scale forest C sink and forest products industry in the U.S. At the ecoregional level, baseline SOC stocks vary with climatic, topographic, and soil physical factors such as temperature and precipitation, slope gradient and aspect, and soil texture. Land use change and forest management modestly influence SOC stocks. Reforestation on previously cultivated lands increases SOC stocks, while deforestation for cultivation has the opposite effect; for continuously forested lands, harvesting is associated with SOC increases and prescribed fire with SOC declines. Effects of reforestation are large and positive for upper mineral soils (+30%) but not detectable in lower mineral soils. Negative effects of prescribed fire are due to significant C losses from organic horizons (-46%); fire and harvest have no impacts on upper mineral soils but both increase SOC in lower mineral soils (+8.2 and +46%, respectively, with high uncertainty in the latter). Inceptisols are generally more negatively impacted by prescribed fire or harvest than Ultisols, and covariance between inherent factors (including soil taxonomy) and management impacts indicates how interior vs. coastal physiographic sections differ in their management regimes and SOC trends. In the cooler, wetter, topographically rugged interior hardwood forests, which have larger baseline SOC stocks, prescribed fire and even light harvesting generally decrease SOC; in contrast, intensively managed coastal plain pine plantations begin with small initial SOC stocks, but exhibit rapid gains over even a single rotation. This covariance between place (physiography) and practice (management regime) suggests that distinct approaches to forest C management may be complementary to other ecological or production goals, when implemented as part of wider (e.g., state-level) forest C or climate policy.