Setting a reference for wetland carbon: the importance of accounting for hydrology, topography, and natural variability
Setting a reference for wetland carbon: the importance of accounting for hydrology, topography, and natural variability
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DOI：
10.1088/1748-9326/acd26a
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发表时间：
2023-05
影响因子：
6.7
通讯作者：
G. Stewart;A. Kottkamp;Michael Williams;M. Palmer
中科院分区：
文献类型：
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作者：
G. Stewart;A. Kottkamp;Michael Williams;M. Palmer
湿地土壤是全球有机碳（C）的重要汇，也是C管理和核算工作的重点。湿地恢复的持续推动为气候减缓提供了机会，但由于缺乏参考信息和对湿地自然变化的不完全理解，C储存预期定义不清。我们试图解决这些不足之处，（1）量化的范围内的变化，湿地土壤有机碳（SOC）股票的抑郁景观（Delmarva半岛，美国）和（2）调查的作用，水文和相对地形在解释湿地之间的变化。我们发现，在个别湿地和类似的植被和水文地貌特征的湿地之间的高度变异。这表明，不确定性，应明确提出从湿地类型或土地覆盖类推断生态系统过程。水文制度的差异，特别是水位下降的速度，解释了一些湿地之间的变异，但SOC股票和一些水文指标之间的关系黯然失色与单独的研究地点的因素。相对地形占了类似的一部分SOC储量变化的水文，表明它可以是一个有效的替代在大规模的分析。随着世界各地湿地的恢复和重点增加量化碳效益，适当定义和评估参考系统的重要性是至关重要的。我们的研究结果强调了目前在这一过程中的不确定性，但建议将景观异质性和自然变异的驱动因素纳入参考信息可能会改善湿地恢复的实施和评估。
Wetland soils are a key global sink for organic carbon (C) and a focal point for C management and accounting efforts. The ongoing push for wetland restoration presents an opportunity for climate mitigation, but C storage expectations are poorly defined due to a lack of reference information and an incomplete understanding of what drives natural variability among wetlands. We sought to address these shortcomings by (1) quantifying the range of variability in wetland soil organic C (SOC) stocks on a depressional landscape (Delmarva Peninsula, USA) and (2) investigating the role of hydrology and relative topography in explaining variability among wetlands. We found a high degree of variability within individual wetlands and among wetlands with similar vegetation and hydrogeomorphic characteristics. This suggests that uncertainty should be presented explicitly when inferring ecosystem processes from wetland types or land cover classes. Differences in hydrologic regimes, particularly the rate of water level recession, explained some of the variability among wetlands, but relationships between SOC stocks and some hydrologic metrics were eclipsed by factors associated with separate study sites. Relative topography accounted for a similar portion of SOC stock variability as hydrology, indicating that it could be an effective substitute in large-scale analyses. As wetlands worldwide are restored and focus increases on quantifying C benefits, the importance of appropriately defining and assessing reference systems is paramount. Our results highlight the current uncertainty in this process, but suggest that incorporating landscape heterogeneity and drivers of natural variability into reference information may improve how wetland restoration is implemented and evaluated.