Carbon Emissions From Low‐Order Streams in a Tropical, High‐Elevation, Peatland Ecosystem Are Mediated by Catchment Morphology

作者：Keridwen M. Whitmore, Amanda Delvecchia, Elizabeth Farquhar, Gerard Rocher‐Ros, Esteban Suárez, Diego Riveros‐Iregui · 发表于：Water Resources Research · 年份：2025 · DOI：10.1029/2024wr038036 · 被引用次数：4 · 研究领域：Peatlands and Wetlands Ecology、Coastal wetland ecosystem dynamics、Integrated Water Resources Management

Abstract Inland waters emit large amounts of carbon and are key players in the global carbon budget. Particularly high rates of carbon emissions have been reported in streams draining mountains, tropical regions, and peatlands. However, few studies have examined the spatial variability of CO 2 concentrations and fluxes occurring within these systems, particularly as a function of catchment morphology. Here we evaluated spatial patterns of CO 2 in three tropical, headwater catchments in relation to the river network and stream geomorphology. We measured dissolved carbon dioxide ( p CO 2 ), aquatic CO 2 emissions, discharge, and stream depth and width at high spatial resolutions along multiple stream reaches. Confirming previous studies, we found that tropical headwater streams are an important source of CO 2 to the atmosphere. More notably, we found marked, predictable spatial organization in aquatic carbon fluxes as a function of landscape position. For example, p CO 2 was consistently high (>10,000 ppm) at locations close to groundwater sources and just downstream of hydrologically connected wetlands, but consistently low (<1,000 ppm) in high gradient locations or river segments with larger drainage areas. Taken together, our findings suggest that catchment area and stream slope are important drivers of p CO 2 and gas transfer velocity ( k ) in mountainous streams, and as such they should be considered in catchment‐scale assessments of CO 2 emissions. Furthermore, our ...