Linking Dissolved Organic Matter Composition to Landscape Properties in Wetlands Across the United States of America

作者：Martin R. Kurek, Kimberly P. Wickland, Natalie Nichols, Amy M. McKenna, Steven M. Anderson, M. Dornblaser, Nikaan Koupaei‐Abyazani, Brett A. Poulin, Sheel Bansal, Jason B. Fellman, Gregory K. Druschel, Emily S. Bernhardt, Robert G. M. Spencer · 发表于：Global Biogeochemical Cycles · 年份：2024 · DOI：10.1029/2023gb007917 · 被引用次数：28 · 研究领域：Peatlands and Wetlands Ecology、Soil and Water Nutrient Dynamics、Coastal wetland ecosystem dynamics

Abstract Wetlands are integral to the global carbon cycle, serving as both a source and a sink for organic carbon. Their potential for carbon storage will likely change in the coming decades in response to higher temperatures and variable precipitation patterns. We characterized the dissolved organic carbon (DOC) and dissolved organic matter (DOM) composition from 12 different wetland sites across the USA spanning gradients in climate, landcover, sampling depth, and hydroperiod for comparison to DOM in other inland waters. Using absorption spectroscopy, parallel factor analysis modeling, and ultra‐high resolution mass spectroscopy, we identified differences in DOM sourcing and processing by geographic site. Wetland DOM composition was driven primarily by differences in landcover where forested sites contained greater aromatic and oxygenated DOM content compared to grassland/herbaceous sites which were more aliphatic and enriched in N and S molecular formulae. Furthermore, surface and porewater DOM was also influenced by properties such as soil type, organic matter content, and precipitation. Surface water DOM was relatively enriched in oxygenated higher molecular weight formulae representing HUP High O/C compounds than porewaters, whose DOM composition suggests abiotic sulfurization from dissolved inorganic sulfide. Finally, we identified a group of persistent molecular formulae (3,489) present across all sites and sampling depths (i.e., the signature of wetland DOM) that are...