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  • Carbon Emissions From Low‐Order Streams in a Tropical, High‐Elevation, Peatland Ecosystem Are Mediated by Catchment Morphology
Title: Carbon Emissions From Low‐Order Streams in a Tropical, High‐Elevation, Peatland Ecosystem Are Mediated by Catchment Morphology
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 CO2concentrations and fluxes occurring within these systems, particularly as a function of catchment morphology. Here we evaluated spatial patterns of CO2in three tropical, headwater catchments in relation to the river network and stream geomorphology. We measured dissolved carbon dioxide (pCO2), aquatic CO2emissions, 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 CO2to the atmosphere. More notably, we found marked, predictable spatial organization in aquatic carbon fluxes as a function of landscape position. For example,pCO2was 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 ofpCO2and gas transfer velocity (k) in mountainous streams, and as such they should be considered in catchment‐scale assessments of CO2emissions. Furthermore, our work suggests that accurate estimation of CO2emissions requires understanding of dynamics across the entire stream network, from the smallest seeps to larger streams.  more » « less
Award ID(s):
2317854
PAR ID:
10615068
Author(s) / Creator(s):
; ; ; ; ;
Publisher / Repository:
American Geophysical Union
Date Published:
Journal Name:
Water Resources Research
Volume:
61
Issue:
4
ISSN:
0043-1397
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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