Breithaupt Joshua L, Steinmuller Havalend E, Rovai Andre S, Engelbert Kevin M, Smoak Joseph M, Chambers Lisa G, Radabaugh Kara R, Moyer Ryan P, Chappel Amanda, Vaughn Derrick R, Bianchi Thomas S, Twilley Robert R, Pagliosa Paulo, Cifuentes-Jara Miguel, Torres Danilo
Florida State University Coastal & Marine Lab, St Teresa, FL USA.
Dauphin Island Sea Lab, Dauphin, AL Island.
Wetlands (Wilmington). 2023;43(6):57. doi: 10.1007/s13157-023-01698-z. Epub 2023 Jun 22.
The use of loss on ignition (LOI) measurements of soil organic matter (SOM) to estimate soil organic carbon (OC) content is a decades-old practice. While there are limitations and uncertainties to this approach, it continues to be necessary for many coastal wetlands researchers and conservation practitioners without access to an elemental analyzer. Multiple measurement, reporting, and verification (MRV) standards recognize the need (and uncertainty) for using this method. However, no framework exists to explain the substantial differences among equations that relate SOM to OC; consequently, equation selection can be a haphazard process leading to widely divergent and inaccurate estimates. To address this lack of clarity, we used a dataset of 1,246 soil samples from 17 mangrove regions in North, Central, and South America, and calculated SOM to OC conversion equations for six unique types of coastal environmental setting. A framework is provided for understanding differences and selecting an equation based on a study region's SOM content and whether mineral sediments are primarily terrigenous or carbonate in origin. This approach identifies the positive dependence of conversion equation slopes on regional mean SOM content and indicates a distinction between carbonate settings with mean (± 1 S.E.) OC:SOM of 0.47 (0.002) and terrigenous settings with mean OC:SOM of 0.32 (0.018). This framework, focusing on unique coastal environmental settings, is a reminder of the global variability in mangrove soil OC content and encourages continued investigation of broadscale factors that contribute to soil formation and change in blue carbon settings.
The online version contains supplementary material available at 10.1007/s13157-023-01698-z.
利用土壤有机质（SOM）的烧失量（LOI）测量值来估算土壤有机碳（OC）含量是一种已有数十年历史的做法。尽管这种方法存在局限性和不确定性，但对于许多无法使用元素分析仪的沿海湿地研究人员和保护从业者来说，它仍然是必要的。多重测量、报告和验证（MRV）标准认识到使用这种方法的必要性（以及不确定性）。然而，目前还没有一个框架来解释将SOM与OC联系起来的各种方程之间的巨大差异；因此，方程的选择可能是一个随意的过程，导致估计结果差异很大且不准确。为了解决这种不清晰的情况，我们使用了来自北美洲、中美洲和南美洲17个红树林地区的1246个土壤样本数据集，计算了六种独特类型沿海环境设置下的SOM到OC的转换方程。提供了一个框架，用于理解差异并根据研究区域的SOM含量以及矿物沉积物主要是陆源还是碳酸盐源来选择方程。这种方法确定了转换方程斜率对区域平均SOM含量的正相关性，并表明碳酸盐环境（平均（±1标准误差）OC:SOM为0.47（0.002））和陆源环境（平均OC:SOM为0.32（0.018））之间的区别。这个关注独特沿海环境设置的框架提醒人们红树林土壤OC含量存在全球变异性，并鼓励继续研究导致蓝碳环境中土壤形成和变化的广泛因素。
在线版本包含可在10.1007/s13157-023-01698-z获取的补充材料。
