Andean headwater and piedmont streams are hot spots of carbon dioxide and methane emissions in the Amazon basin

[en] Rivers substantially contribute to global greenhouse gas emissions, yet emissions from headwater streams are poorly constrained. Here, we report dissolved concentrations of carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) in Andean headwater and piedmont streams in the Napo River basin in Ecuador, part of the Amazon River catchment. Concentrations increased exponentially with elevation decrease between 3990 and 175 m above sea level. Concentration changes scaled with catchment slope, and were attributed to variations in gas transfer velocity, forest cover, inundation extent, and water temperature. We estimate river emissions across the whole Amazon basin using existing data for the lowland Central Amazon. We find that Andean mountainous headwater and piedmont streams are hotspots of CO2 and CH4 emission, with respective areal fluxes being 1.7 and 4.5 higher in headwater streams, and 1.2 and 6.6 higher in piedmont streams than in lowland streams. Together, Andean mountainous headwater and piedmont streams and rivers represented 35% CO2 and 72% CH4 of basin scale integrated fluvial diffusive emissions. Conversely, N2O emissions from headwater and piedmont streams were low compared to lowland streams.

Research Center/Unit :

FOCUS - Freshwater and OCeanic science Unit of reSearch - ULiège

Disciplines :

Aquatic sciences & oceanology

Author, co-author :

Chiriboga Gavidia, Washington Gonzalo ; Université de Liège - ULiège > Freshwater and OCeanic science Unit of reSearch (FOCUS)

Borges, Alberto ; Université de Liège - ULiège > Département d'astrophysique, géophysique et océanographie (AGO) > Chemical Oceanography Unit (COU)

Language :

English

Title :

Andean headwater and piedmont streams are hot spots of carbon dioxide and methane emissions in the Amazon basin

Publication date :

16 March 2023

Journal title :

Communications Earth and Environment

eISSN :

2662-4435

Publisher :

Nature Publishing, London, United Kingdom

Volume :

Issue :

Pages :

1-13

Peer reviewed :

Peer Reviewed verified by ORBi

Additional URL :

https://www.nature.com/articles/s43247-023-00745-1

Funders :

ARES CCD - Académie de Recherche et d'Enseignement Supérieur. Coopération au Développement

Data Set :

https://zenodo.org/record/7495193

Available on ORBi :

since 17 March 2023

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Bibliography

Raymond, P. A. et al. Global carbon dioxide emissions from inland waters. Nature 503, 355–359 (2013). DOI: 10.1038/nature12760
Stanley, E. H. et al. The ecology of methane in streams and rivers: patterns, controls, and global significance. Ecol. Mon. 86, 146–171 (2016). DOI: 10.1890/15-1027
Maavara, T. et al. Nitrous oxide emissions from inland waters: Are IPCC estimates too high? Glob. Change Biol. 25, 473–488 (2018). DOI: 10.1111/gcb.14504
Lauerwald, R. et al. Spatial patterns in CO2 evasion from the global river network. Global Biogeochem. Cycles 29, 534–554 (2015). DOI: 10.1002/2014GB004941
Liu, S. et al. The importance of hydrology in routing terrestrial carbon to the atmosphere via global streams and rivers. Proc. Natl. Acad. Sci. USA 119, e2106322119 (2022). DOI: 10.1073/pnas.2106322119
Sawakuchi, H. O. et al. Carbon dioxide emissions along the lower Amazon River. Front. Mar. Sci. 4, 76 (2017). DOI: 10.3389/fmars.2017.00076
Friedlingstein, P. et al. Global Carbon Budget 2020. Earth Syst. Sci. Data 12, 3269–3340 (2020). DOI: 10.5194/essd-12-3269-2020
Rosentreter, J. A. et al. Half of global methane emissions come from highly variable aquatic ecosystem sources. Nature Geosci. 14, 225–230 (2021). DOI: 10.1038/s41561-021-00715-2
Saunois, M. et al. The Global Methane Budget 2000–2017. Earth Syst. Sci. Data 12, 1561–1623 (2020). DOI: 10.5194/essd-12-1561-2020
Kroeze, C., Dumont, E. & Seitzinger, S. P. Future trends in emissions of N2O from rivers and estuaries. J. Integr. Environ. Sci. 7, 71–78 (2010). DOI: 10.1080/1943815X.2010.496789
Hu, M., Chen, D. & Dahlgren, R. A. Modeling nitrous oxide emission from rivers: a global assessment. Glob. Change Biol. 22, 3566–3582 (2016). DOI: 10.1111/gcb.13351
Clough, T. J., Bertram, J. E., Sherlock, R. R., Leonard, R. L. & Nowicki, B. L. Comparison of measured and EF5-r-derived N2O fluxes from a spring-fed river. Glob. Change Biol. 12, 477–488 (2006). DOI: 10.1111/j.1365-2486.2005.01092.x
Webb, J. R., Clough, T. J. & Quayle, W. C. A review of indirect N2O emission factors from artificial agricultural waters. Environ. Res. Lett. 16, 043005 (2021). DOI: 10.1088/1748-9326/abed00
Borges, A. V. et al. Globally significant greenhouse gas emissions from African inland waters. Nat. Geosci. 8, 637–642 (2015a). DOI: 10.1038/ngeo2486
Borges, A. V. et al. Divergent biophysical controls of aquatic CO2 and CH4 in the World’s two largest rivers. Sci. Rep. 5, 15614 (2015). DOI: 10.1038/srep15614
Sawakuchi, H. O. et al. Methane emissions from Amazonian Rivers and their contribution to the global methane budget. Glob. Change Biol. 20, 2829–2840 (2014). DOI: 10.1111/gcb.12646
Pan, Y. et al. A Large and persistent carbon sink in the World’s forests. Science 333, 988–993 (2011). DOI: 10.1126/science.1201609
Fluet-Chouinard, E., Lehner, B., Rebelo, L. M., Papa, F., & Hamilton, S. K. Development of a global inundation map at high spatial resolution from topographic downscaling of coarse-scale remote sensing data. Remote Sens. Environ. 158, 348–361 (2015). DOI: 10.1016/j.rse.2014.10.015
Marx, A. et al. A review of CO2 and associated carbon dynamics in headwater streams: A global perspective. Rev. Geophys. 55, 560–585 (2017). DOI: 10.1002/2016RG000547
Horgby, Å. et al. Unexpected large evasion fluxes of carbon dioxide from turbulent streams draining the world’s mountains. Nat. Commun. 10, 4888 (2019). DOI: 10.1038/s41467-019-12905-z
Borges, A. V. et al. Variations in dissolved greenhouse gases (CO2, CH4, N2O) in the Congo River network overwhelmingly driven by fluvial-wetland connectivity. Biogeosciences 16, 3801–3834 (2019). DOI: 10.5194/bg-16-3801-2019
Duvert, C., Butman, D. E., Marx, A., Ribolzi, O. & Hutley, L. B. CO2 evasion along streams driven by groundwater inputs and geomorphic controls. Nat. Geosci. 11, 813–818 (2018). DOI: 10.1038/s41561-018-0245-y
Ulseth, A. J. et al. Distinct air-water gas exchange regimes in low- and high-energy streams. Nat. Geosci. 12, 259–263 (2019). DOI: 10.1038/s41561-019-0324-8
Crawford, J. T., Dornblaser, M. M., Stanley, E. H., Clow, D. W. & Striegl, R. G. Source limitation of carbon gas emissions in high-elevation mountain streams and lakes. J. Geophys. Res. Biogeosci. 120, 952–964 (2015). DOI: 10.1002/2014JG002861
Abril, G. et al. Amazon River carbon dioxide outgassing fuelled by wetlands. Nature 505, 395–398 (2014). DOI: 10.1038/nature12797
Abril, G. & Borges, A. V. Carbon leaks from flooded land: do we need to re-plumb the inland water active pipe? Biogeosciences 16, 769–784 (2019). DOI: 10.5194/bg-16-769-2019
Melack, J.M. Aquatic ecosystems. In: Nagy, L., Forsberg, B.R., Artaxo, P. (Eds.), Interactions between Biosphere, Atmosphere and Human Land Use in the Amazon Basin. Springer Berlin Heidelberg, Berlin, Heidelberg, pp. 119–148 (2016).
Johnson, M. S. et al. CO2 efflux from Amazonian headwater streams represents a significant fate for deep soil respiration. Geophys. Res. Lett. 35, L17401 (2008). DOI: 10.1029/2008GL034619
Richey, J. E., Melack, J. M., Aufdenkampe, A. K., Ballester, V. M. & Hess, L. Outgassing from Amazonian rivers and wetlands as a large tropical source of atmospheric CO2. Nature 416, 617–620 (2002). DOI: 10.1038/416617a
Melack, J. M. et al. Regionalization of methane emissions in the Amazon Basin with microwave remote sensing. Glob. Change Biol. 10, 530–544 (2004). DOI: 10.1111/j.1365-2486.2004.00763.x
Barbosa, P. M. et al. Diffusive methane fluxes from Negro, Solimões and Madeira rivers and fringing lakes in the Amazon basin. Limnol. Oceanogr. 61, S221–S237 (2016). DOI: 10.1002/lno.10358
Basso, L. S. et al. Amazon methane budget derived from multi-year airborne observations highlights regional variations in emissions. Commun. Earth Environ. 2, 246 (2021). DOI: 10.1038/s43247-021-00314-4
Pangala, S. R. et al. Large emissions from floodplain trees close the Amazon methane budget. Nature 552, 230–234 (2017). DOI: 10.1038/nature24639
Richey, J. E., Devol, A. H., Wofy, S. C., Victoria, R. & Riberio, M. N. G. Biogenic gases and the oxidation and reduction of carbon in Amazon River and floodplain waters. Limnol. Oceanogr. 33, 551–561 (1988). DOI: 10.4319/lo.1988.33.4.0551
Rasera, M. F. F. L. et al. Estimating the surface area of small rivers in the southwestern Amazon and their role in CO2 outgassing. Earth Interact. 12, 1–15 (2008). DOI: 10.1175/2008EI257.1
Alin, S. R. et al. Physical controls on carbon dioxide transfer velocity and flux in low‐gradient river systems and implications for regional carbon budgets. J. Geophys. Res. 116, G01009 (2011). DOI: 10.1029/2010JG001398
Rasera, M. F. F. L., Krusch, A. V., Richey, J. E., Ballester, M. V. R. & Victória, R. L. Spatial and temporal variability of pCO2 and CO2 efflux in seven Amazonian Rivers. Biogeochemistry 116, 241–259 (2013). DOI: 10.1007/s10533-013-9854-0
Scofield, V. et al. Carbon dioxide outgassing from Amazonian aquatic ecosystems in the Negro River basin. Biogeochemistry 129, 77–91 (2016). DOI: 10.1007/s10533-016-0220-x
Mitchell, C. et al. Radon-traced pore-water as a potential source of CO2 and CH4 to receding black and clear water environments in the Amazon Basin. Limnol. Oceanogr. Lett. 3, 375–383 (2018). DOI: 10.1002/lol2.10089
Schneider, C. L. et al. Carbon dioxide (CO2) fluxes from terrestrial and aquatic environments in a high‐altitude tropical catchment. J. Geophys. Res. Biogeosci. 125, e2020JG005844 (2020). DOI: 10.1029/2020JG005844
Whitmore, K. M., Stewart, N., Encalada, A. C., Suárez, E. & Riveros-Iregui, D. A. Spatiotemporal variability of gas transfer velocity in a tropical high-elevation stream using two independent methods. Ecosphere 12, e03647 (2021). DOI: 10.1002/ecs2.3647
Kirschbaum, M. The temperature dependence of soil organic matter decomposition, and the effect of global warming on soil organic C storage. Soil Biol. Biochem. 27, 753–760 (1995). DOI: 10.1016/0038-0717(94)00242-S
Cardoso, S. J., Enrich-Prast, A., Pace, M. L. & Roland, F. Do models of organic carbon mineralization extrapolate to warmer tropical sediments? Limnol. Oceanogr. 59, 48–54 (2014). DOI: 10.4319/lo.2014.59.1.0048
Yvon-Durocher, G. et al. Methane fluxes show consistent temperature dependence across microbial to ecosystem scales. Nature 507, 488–491 (2014). DOI: 10.1038/nature13164
McClain, M. E. & Naiman, R. J. Andean Influences on the Biogeochemistry and ecology of the Amazon River. BioScience 58, 325–338 (2008). DOI: 10.1641/B580408
McClain, M. E., Richey, J. E., Brandes, J. A. & Pimentel, T. P. Dissolved organic matter and terrestrial-lotic linkages in the central Amazon basin of Brazil. Glob. Biogeochem. Cycles 11, 295–311 (1997). DOI: 10.1029/97GB01056
Raymond, P. A. et al. Scaling the gas transfer velocity and hydraulic geometry in streams and small rivers. Limnol. Oceanogr.: Fluids Environm. 2, 41–53 (2012). DOI: 10.1215/21573689-1597669
Pineda, P. A. L. et al. Ideas and perspectives: patterns of soil CO2, CH4, and N2O fluxes along an altitudinal gradient–a pilot study from an Ecuadorian neotropical montane forest. Biogeosciences 18, 413–421 (2021). DOI: 10.5194/bg-18-413-2021
Allan, J. D. et al. Limnology of Andean piedmont rivers of Venezuela. J. N. Am. Benthol. Soc. 25, 66–81 (2006). DOI: 10.1899/0887-3593(2006)25[66:LOAPRO]2.0.CO;2
Brookshire, E. N. J., Hedin, L. O., Newbold, J. D., Sigman, D. M. & Jackson, J. K. Sustained losses of bioavailable nitrogen from montane tropical forests. Nat. Geosci. 5, 123–126 (2012). DOI: 10.1038/ngeo1372
Brookshire, E. N. J., Gerber, S., Menge, D. N. L. & Hedin, L. O. Large losses of inorganic nitrogen from tropical rainforests suggest a lack of nitrogen limitation. Ecol. Lett. 15, 9–16 (2012). DOI: 10.1111/j.1461-0248.2011.01701.x
Templer, P. H. et al. Sinks for nitrogen inputs in terrestrial ecosystems: a meta-analysis of 15N tracer field studies. Ecology 93, 1816–1829 (2012). DOI: 10.1890/11-1146.1
Fu, B.-J., Liu, S.-L., Chen, L.-D., Lü, Y.-H. & Qiu, J. Soil quality regime in relation to land cover and slope position across a highly modified slope landscape. Ecol. Res. 19, 111–118 (2004). DOI: 10.1111/j.1440-1703.2003.00614.x
Becker, J. C. et al. Physiographic gradients determine nutrient concentrations more than land use in a Gulf Slope (USA) river system. Freshw. Sci. 33, 731–744 (2014). DOI: 10.1086/676635
Reynolds, C. S. The long, the short and the stalled: on the attributes of phytoplankton selected by physical mixing in lakes and rivers. Hydrobiologia 289, 9–21 (1994). DOI: 10.1007/BF00007405
Rosamond, M. S., Thuss, S. J. & Schiff, S. L. Dependence of riverine nitrous oxide emissions on dissolved oxygen levels. Nat. Geosci. 5, 715–718 (2012). DOI: 10.1038/ngeo1556
Herreid, A. M., Wymore, A. S., Varner, R. K., Potter, J. D. & McDowell, W. H. Divergent controls on stream greenhouse gas concentrations across a land-use gradient. Ecosystems 24, 1299–1316 (2021). DOI: 10.1007/s10021-020-00584-7
Zhang, L. et al. Unexpectedly minor nitrous oxide emissions from fluvial networks draining permafrost catchments of the East Qinghai-Tibet Plateau. Nat. Commun. 13, 950 (2022). DOI: 10.1038/s41467-022-28651-8
Skiba, U., Hergoualc’h, K., Drewer, J., Meijide, A. & Knohl, A. Oil palm plantations are large sources of nitrous oxide, but where are the data to quantify the impact on global warming? Curr. Opin. Environ. Sustain. 47, 81–88 (2020). DOI: 10.1016/j.cosust.2020.08.019
Wallin, M. B. et al. Carbon dioxide and methane emissions of Swedish low-order streams - a national estimate and lessons learnt from more than a decade of observations. Limnol. Oceanogr. Lett. 3, 156–167 (2018). DOI: 10.1002/lol2.10061
Butman, D. & Raymond, P. A. Significant efflux of carbon dioxide from streams and rivers in the United States. Nat. Geosci. 4, 839–842 (2011). DOI: 10.1038/ngeo1294
Borges, A. V. et al. Effects of agricultural land use on fluvial carbon dioxide, methane and nitrous oxide concentrations in a large European river, the Meuse (Belgium). Sci. Total Environ. 610-611, 342–355 (2018). DOI: 10.1016/j.scitotenv.2017.08.047
Wainwright, J. et al. The concept of transport capacity in geomorphology. Rev. Geophys. 53, 1155–1202 (2015). DOI: 10.1002/2014RG000474
Rocher-Ros, G., Sponseller, R. A., Lidberg, W., Mörth, C.-M. & Giesler, R. Landscape process domains drive patterns of CO2 evasion from river networks. Limnol. Oceanogr. Lett. 4, 87–95 (2019). DOI: 10.1002/lol2.10108
Vauchel, P. et al. (2017) A reassessment of the suspended sediment load in the Madeira River basin from the Andes of Peru and Bolivia to the Amazon River in Brazil, based on 10 years of data from the HYBAM monitoring programme. J. Hydrol. 553, 35–48 (2017). DOI: 10.1016/j.jhydrol.2017.07.018
Keller, M. et al. Soil-atmosphere exchange of nitrous oxide, nitric oxide, methane and carbon dioxide in logged and undisturbed forest in Tapajos National Forest, Brazil. Earth Interact 9, 1–28 (2005). DOI: 10.1175/EI125.1
Bernoux, M., Arrouays, D., Cerri, C. C. & Bourennane, H. Modeling vertical distribution of carbon in oxisols of the western Brazilian Amazon (Rondonia). Soil Sci. 163, 941–951 (1998). DOI: 10.1097/00010694-199812000-00004
Linke, S. et al. Global hydro-environmental sub-basin and river reach characteristics at high spatial resolution. Sci. Data 6, 283 (2019). DOI: 10.1038/s41597-019-0300-6
Teodoru, C. et al. Spatial variability and temporal dynamics of greenhouse gas (CO2, CH4, N2O) concentrations and fluxes along the Zambezi River mainstem and major tributaries. Biogeosciences 12, 2431–2453 (2015). DOI: 10.5194/bg-12-2431-2015
Oliveira, C.B. et al. Preliminary measurements of N2O partial pressures in rivers of Amazon Basin, Brazil, American Geophysical Union, Fall Meeting 2006, abstract id. B31C-B31126 (2006).
Lauerwald, R., Hartmann, J., Moosdorf, N., Kempe, S. & Raymond, P. A. What controls the spatial patterns of the riverine carbonate system? - A case study for North America. Chem. Geol. 337-338, 114–127 (2013). DOI: 10.1016/j.chemgeo.2012.11.011
Chen, S., Zou, J., Hu, Z., Chen, H. & Lu, Y. Global annual soil respiration in relation to climate, soil properties and vegetation characteristics: Summary of available data. Agric. For. Meteorol. 198-199, 335–346 (2014). DOI: 10.1016/j.agrformet.2014.08.020
Flint, J. J. Stream gradient as a function of order, magnitude, and discharge. Water Resour. Res. 10, 969–973 (1974). DOI: 10.1029/WR010i005p00969
Puy, A. et al. Models with higher effective dimensions tend to produce more uncertain estimates. Sci. Adv. 8, 10.1126/sciadv.abn9450 (2022).
Langeveld, J. et al. Estimating dissolved carbon concentrations in global soils: a global database and model. SN Appl. Sci. 2, 1–21 (2020). 1626. DOI: 10.1007/s42452-020-03290-0
Moore, I. D., Grayson, R. B. & Ladson, A. R. Digital terrain modelling: A review of hydrological, geomorphological, and biological applications. Hydrol. Process. 5, 3–30 (1991). DOI: 10.1002/hyp.3360050103
Thompson, J. A. & Kolka, R. K. Soil carbon storage estimation in a forested watershed using quantitative soil-landscape modeling. Soil Sci. Soc. Am. J. 69, 1086–1093 (2005). DOI: 10.2136/sssaj2004.0322
de Brogniez, D. et al. A map of the topsoil organic carbon content of Europe generated by a generalized additive model. Eur. J. Soil Sci. 66, 121–134 (2015). DOI: 10.1111/ejss.12193
Connolly, C. T. et al. Watershed slope as a predictor of fluvial dissolved organic matter and nitrate concentrations across geographical space and catchment size in the Arctic. Environ. Res. Lett. 13, 1–9 (2018). 104015. DOI: 10.1088/1748-9326/aae35d
Leach, J. A. et al. Evaluating topography-based predictions of shallow lateral groundwater discharge zones for a boreal lake-stream system. Water Resour. Res. 53, 5420–5543 (2017). DOI: 10.1002/2016WR019804
McGuire, K. J. et al. The role of topography on catchment-scale water residence time. Water Resour. Res. 41, W05002 (2005). DOI: 10.1029/2004WR003657
Merot, P. et al. Testing a climato-topographic index for predicting wetlands distribution along an European climate gradient. Ecol. Modell. 163, 51–71 (2003). DOI: 10.1016/S0304-3800(02)00387-3
Rodhe, A. & Seibert, J. Wetland occurrence in relation to topography: a test of topographic indices as moisture indicators. Agric. For. Meteorol. 98-99, 325–340 (1999). DOI: 10.1016/S0168-1923(99)00104-5
Mulholland, P. J. Dissolved organic matter concentration and flux in streams. J. North Am. Benthol. Soc. 16, 131–141 (1997). DOI: 10.2307/1468246
Parry, L. E. et al. The influence of slope and peatland vegetation type on riverine dissolved organic carbon and water colour at different scales. Sci. Total Environ. 527-528, 530–539 (2015). DOI: 10.1016/j.scitotenv.2015.03.036
Harms, T. K. et al. Catchment influence on nitrate and dissolved organic matter in Alaskan streams across a latitudinal gradient. J. Geophys. Res. Biogeosci. 121, 350–369 (2016). DOI: 10.1002/2015JG003201
Ran, L. et al. Riverine CO2 emissions in the Wuding River catchment on the Loess Plateau: Environmental controls and dam impoundment impact. J. Geophys. Res. Biogeosci. 122, 1439–1455 (2017). DOI: 10.1002/2016JG003713
Rasilo, T., Hutchins, R. H. S., Ruiz-González, C. & del Giorgio, P. A. Transport and transformation of soil-derived CO2, CH4 and DOC sustain CO2 supersaturation in small boreal streams. Sci. Total Environ. 579, 902–912 (2017). DOI: 10.1016/j.scitotenv.2016.10.187
Willgoose, G. A physical explanation for an observed area-slope-elevation relationship for catchments with declining relief. Water Resour. Res. 30, 151–159 (1994). DOI: 10.1029/93WR01810
Hua, T. et al. Spatial consistency assessments for global land-cover datasets: A comparison among GLC2000, CCI LC, MCD12, GLOBCOVER and GLCNMO. Remote Sens. 10, 1846 (2018). DOI: 10.3390/rs10111846
Gao, H., Jia, G. S. & Fu, Y. Identifying and quantifying pixel-level uncertainty among major satellite derived global land cover products. J. Meteor. Res. 34, 806–821 (2020). DOI: 10.1007/s13351-020-9183-x
Liu, Y. et al. Satellite-derived LAI products exhibit large discrepancies and can lead to substantial uncertainty in simulated carbon and water fluxes. Remote Sens. Environ. 206, 174–188 (2018). DOI: 10.1016/j.rse.2017.12.024
Zhang, Y. & Ye, A. Uncertainty analysis of multiple terrestrial gross primary productivity products. Glob. Ecol. Biogeogr. 31, 2204–2218 (2022). DOI: 10.1111/geb.13578
Huotari, J., Haapanala, S., Pumpanen, J., Vesala, T. & Ojala, A. Efficient gas exchange between a boreal river and the atmosphere. Geophys. Res. Lett. 40, 5683–5686 (2013). DOI: 10.1002/2013GL057705
Van Dam, B. R., Edson, J. B. & Tobias, C. Parameterizing air-water gas exchange in the shallow, microtidal New River estuary. J. Geophys. Res. Biogeosci. 124, 2351–2363 (2019). DOI: 10.1029/2018JG004908
Lorke, A. et al. Technical note: drifting versus anchored flux chambers for measuring greenhouse gas emissions from running waters. Biogeosciences 12, 7013–7024 (2015). DOI: 10.5194/bg-12-7013-2015
Vingiani, F. et al. Evaluating stream CO2 outgassing via drifting and anchored flux chambers in a controlled flume experiment. Biogeosciences 18, 1223–1240 (2021). DOI: 10.5194/bg-18-1223-2021
Belanger, T. V. & Korzum, E. A. Critique of floating dome technique for estimating reaeration rates. J. Environ. Eng. 117, 144–150 (1991). DOI: 10.1061/(ASCE)0733-9372(1991)117:1(144)
Campeau, A., Lapierre, J.-F., Vachon, D. del Giorgio, P.A. Regional contribution of CO2 and CH4 fluxes from the fluvial network in a lowland boreal landscape of Québec. Glob. Biogeochem. Cycles 28, https://doi.org/10.1002/2013GB004685 (2014).
Lim, A. G. et al. Carbon emission and export from the Ket River, western Siberia. Biogeosciences 19, 5859–5877 (2022). DOI: 10.5194/bg-19-5859-2022
Allen, G. H. & Pavelsky, T. M. Global extent of rivers and streams. Science 361, 585–588 (2018). DOI: 10.1126/science.aat0636
Anderson, E. P. et al. Fragmentation of Andes-to-Amazon connectivity by hydropower dams. Sci. Adv. 4, aao1642 (2018). DOI: 10.1126/sciadv.aao1642
Laraque, A. et al. Sediment budget of the Napo River, Amazon basin, Ecuador and Peru. Hydrol. Process. 23, 3509–3524 (2009). DOI: 10.1002/hyp.7463
Hall, R. O., Tank, J. L., Baker, M. A., Rosi-Marshall, E. J. & Hotchkiss, E. R. Metabolism, gas exchange, and carbon spiraling in rivers. Ecosystems 19, 73–86 (2016). DOI: 10.1007/s10021-015-9918-1
Gómez-Gener, L. et al. Global carbon dioxide efflux from rivers enhanced by high nocturnal emissions. Nat. Geosci. 14, 289–294 (2021). DOI: 10.1038/s41561-021-00722-3
Descy, J.-P. et al. Phytoplankton dynamics in the Congo River. Freshw. Biol. 62, 87–101 (2017). DOI: 10.1111/fwb.12851
Abril, G., Commarieu, M.-V. & Guérin, F. Enhanced methane oxidation in an estuarine turbidity maximum. Limnol. Oceanogr. 52, 470–475 (2007). DOI: 10.4319/lo.2007.52.1.0470
Weiss, R. F. Determinations of carbon dioxide and methane by dual catalyst flame ionization chromatography and nitrous oxide by electron capture chromatography. J. Chromatogr. Sci. 19, 611–616 (1981). DOI: 10.1093/chromsci/19.12.611
Dickson, A.G., Sabine, C.L. & Christian, J.R. (Eds.) Guide to best practices for ocean CO2 measurements. PICES Special Publication 3, 191 pp. (2007).
Weiss, R. F. & Price, B. A. Nitrous oxide solubility in water and seawater. Mar. Chem. 8, 347–359 (1980). DOI: 10.1016/0304-4203(80)90024-9
American Public Health Association. Standard methods for the examination of water and wastewater, (APHA, 1998).
Standing committee of Analysts (1981). Ammonia in waters. Methods for the examination of waters and associated materials. 16 pp (HMSO, 1981).
Abril, G. et al. Technical Note: Large overestimation of calculated pCO2 in acidic, organic-rich freshwaters. Biogeosciences 12, 67–78 (2015). DOI: 10.5194/bg-12-67-2015