A Continental‐Scale Estimate of Soil Organic Carbon Change at NEON Sites and Their Environmental and Edaphic Controls
A Continental‐Scale Estimate of Soil Organic Carbon Change at NEON Sites and Their Environmental and Edaphic Controls
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DOI：
10.1029/2022jg006981
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发表时间：
2023-05
期刊：
影响因子：
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通讯作者：
Jie Hu;A. Hartemink;A. Desai;P. Townsend;R. Abramoff;Zhe Zhu;D. Sihi;Jingyi Huang
中科院分区：
文献类型：
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作者：
Jie Hu;A. Hartemink;A. Desai;P. Townsend;R. Abramoff;Zhe Zhu;D. Sihi;Jingyi Huang
目前的碳循环模型侧重于气候和土地利用变化对初级生产力和表土中微生物矿物依赖的碳周转的影响，而很少关注垂直土壤过程和沿剖面土地利用变化的土壤依赖性响应。在这项研究中，采用时空分析来估计美国国家生态观测站网络 (NEON) 站点表层土/A 层和底土/B 层的土壤有机碳 (SOC) 30 年来的变化。为了区分土地利用、环境和土壤因素对 SOC 变化的影响，将时空替换与连续变化检测和分类算法以及结构方程建模结合使用。结果表明，（a）在自然植被下，东部NEON站点发现的Spodosols和Inceptisols具有大量表土SOC积累（+0.4至+1.2 Mg C ha−1year−1），而西部的Inceptisols和Andisols具有相当程度的表土SOC损失（-0.5至-1.8 Mg C ha−1year−1）； (b) 中原地区的软土和腐烂土在耕作和放牧过程中容易遭受严重的有机碳损失； (c) 径流/侵蚀和淋滤潜力、垂直移位和矿物质吸附是控制 NEON 站点 SOC 变化的最重要因素。我们的工作可用于参数化模拟 SOC 变化的生态系统模型。
Current carbon cycle models focus on the effects of climate and land‐use change on primary productivity and microbial‐mineral dependent carbon turnover in the topsoil, while less attention has been paid to vertical soil processes and soil‐dependent response to land‐use change along the profile. In this study, a spatial‐temporal analysis was used to estimate soil organic carbon (SOC) change in topsoil/A horizon and subsoil/B horizon at National Ecological Observatory Network (NEON) sites, USA over 30 years. To separate the effects of land‐use, environmental, and edaphic factors on SOC change, space‐for‐time substitution was used in combination with the Continuous Change Detection and Classification algorithm and Structural Equation Modeling. Results showed that (a) under natural vegetation, Spodosols and Inceptisols found in the eastern NEON sites had substantial topsoil SOC accumulation (+0.4 to +1.2 Mg C ha−1 year−1), while Inceptisols and Andisols in the west had a comparable magnitude of topsoil SOC loss (−0.5 to −1.8 Mg C ha−1 year−1); (b) Mollisols and Alfisols in the Central Plains sites were susceptible to significant SOC loss under farming and grazing; (c) Runoff/erosion and leaching potential, vertical translocation, and mineral sorption were the most important factors controlling SOC variation across the NEON sites. Our work could be used to parameterize ecosystem models simulating SOC change.