Plants are a powerful proxy for global tidal marsh methane fluxes

• 成果类型: Article
• 署名作者: Wilson, Emily M.; Balint, Sawyer J.; Fulweiler, Robinson W.
• 署名单位: Boston University; Boston University
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.2530848123
• 发表日期: 2026-07-21
• 页码: e2530848123
• 关键词: blue carbon; tidal marsh; methane; plants; spartina-alterniflora; GAS-TRANSPORT; emissions; carbon; AERENCHYMA; mechanisms; WETLAND

摘要

Methane (CH4) emissions can reduce the climate benefits of tidal marshes. Yet the drivers of tidal marsh CH4 emissions remain poorly quantified, and salinity, the most well-established proxy for tidal marsh CH4 fluxes, has low predictive performance. Here, we demonstrate that plant species out performs salinity as a single predictor of global tidal marsh CH4 fluxes, providing a powerful and simple predictor on its own. A multiproxy approach combining plant species with other predictors (i.e., latitude, salinity, season) further improves predictions of global CH4 fluxes. For our analysis, we compiled 87 studies with 2,094 mean measurements of CH4 fluxes and used random forest and generalized additive modeling to investigate the relationship among CH4 fluxes, salinity, and plants. We found that plant species was the most important predictor of CH4 fluxes globally. Our model of plant species alone explained 62% of the variability in CH4 fluxes and when including latitude, season, and soil salinity, explained 71%. We also developed a model with plant functional type for when plant species flux data are not available. We found that plant functional type alone explained 54% of the variability in CH4 fluxes, underscoring the influential role of plants. Previously, polyhaline marshes were thought to have low CH4 emissions. Here we show that CH4 fluxes from these marshes offset between 1% and 39% of carbon sequestration, depending on the plant species present and selected global warming potential value. This plant species-based approach significantly improves global CH4 flux estimates in tidal marshes and facilitates global carbon accounting.