Ezcurra Exequiel
Department of Botany and Plant Sciences, University of California Riverside, Riverside, CA, USA.
Sci Adv. 2024 Aug 23;10(34):eadl1079. doi: 10.1126/sciadv.adl1079. Epub 2024 Aug 21.
Peaty sediments in coastal wetlands play an important role in the sequestration of atmospheric carbon dioxide and its belowground storage. Sediment cores are used to quantify organic matter (OM) density, estimated by multiplying the bulk density of a core segment by its OM fraction. This method can be imprecise, as repeated samples often differ widely. Recent studies have shown that sediment bulk density and OM fraction are not independent but tightly related by a function called the ideal-mixing model. Thus, the bulk density of the sediment can be directly estimated from its OM fraction. Statistical theory and simulations demonstrate that the high variance in the product estimation of OM density is the result of error propagation in the product of two functionally related variables with independent errors. Estimating OM density in wetland sediments using the ideal-mixing model is more precise than the traditionally used product estimate, especially in highly organic sediments.
沿海湿地的泥炭沉积物在大气二氧化碳的封存及其地下储存中发挥着重要作用。沉积物岩芯用于量化有机物质（OM）密度，通过将岩芯段的堆积密度乘以其OM分数来估算。这种方法可能不准确，因为重复采样的结果往往差异很大。最近的研究表明，沉积物堆积密度和OM分数并非相互独立，而是通过一种称为理想混合模型的函数紧密相关。因此，可以直接从其OM分数估算沉积物的堆积密度。统计理论和模拟表明，OM密度乘积估计中的高方差是两个具有独立误差的功能相关变量乘积中误差传播的结果。使用理想混合模型估算湿地沉积物中的OM密度比传统使用的乘积估计更精确，特别是在高有机沉积物中。
