Tropical wetlands are important in the global carbon (C) cycle and climate system. To elaborate government policies that protect wetland ecosystem services, spatially explicit data on the existing C stocks are needed. This study quantified above and below ground C stocks in mangrove, swamp forests, marshes, and grazed wetlands in three different regions in Mexico (Veracruz, Tabasco/Campeche, and Chiapas states), using a combination of remote sensing techniques and field data collection. We report a 0.688 Gt C stock in the areas investigated showing that these wetlands hold important C stocks. The total C stock of Mexico’s wetlands is expected to be considerably larger as our study is not a complete survey of Mexico’s total wetland area. Across the three regions, the currently unprotected swamp forests and marshes had substantial peat deposits storing ≈ 0.232 and 0.375 Pg C, respectively. The high C stocks found in swamp forests (1801 ± 283 Mg C ha⁻¹) and marshes (1100 ± 376 Mg C ha⁻¹) are likely to be vulnerable to human interventions such as drainage. Flooded grasslands, used for grazing, had substantially lower C storage (271 ± 122 Mg C ha⁻¹), showing that grazed areas are less effective as C stores. Across sites the belowground C pool that was two orders of magnitude greater than the aboveground biomass C stocks. Carbon storage in wetland vegetation types differed among the three study regions, indicating the need for developing government policies considering a specific regional approach to protect the C stocks of coastal wetlands. Given that freshwater swamps had the greatest C stocks and freshwater marshes stored most C, these wetland peat deposits should be prioritized for conservation, via new legislation or inclusion in payment for ecosystem services schemes.

热带湿地在全球碳（C）循环和气候系统中很重要。为了制定保护湿地生态系统服务的政府政策，需要有关现有碳库的空间明确数据。这项研究结合了遥感技术和现场数据收集，对墨西哥三个不同地区（韦拉克鲁斯州，塔巴斯科州/坎佩切州和恰帕斯州）的红树林，沼泽森林，沼泽地和放牧湿地中的地面C和地下碳库进行了量化。我们在调查的区域报告了0.688 Gt的C储量，表明这些湿地拥有重要的C储量。由于我们的研究不是对墨西哥湿地总面积的完整调查，因此墨西哥湿地的总碳储量预计将大大增加。在这三个地区，当前未受保护的沼泽森林和沼泽地的泥炭沉积量分别约为≈0.232和0.375 PgC。在沼泽森林中发现高碳储量（1801±283 Mg C ha^-1）和沼泽（1100±376 Mg C ha ^-1）可能容易受到人为干预（例如排水）的影响。用于放牧的水淹草原的碳储存量低得多（271±122 Mg C ha ^-1），表明放牧区域的效果不如C店。在地下站点中，地下碳库比地下生物量碳库大两个数量级。在三个研究区域之间，湿地植被类型中的碳储量有所不同，这表明需要制定政府政策，同时考虑一种特定的区域方法来保护沿海湿地的碳储量。鉴于淡水沼泽中的碳储量最多，而淡水沼泽中的碳储量最多，因此应优先考虑通过新立法或将其纳入生态系统服务计划的支付范围，优先考虑对这些湿地泥炭沉积进行保护。