T. A., Blanken, P. D., Bohrer, G., Bracho, R., Brown, S., Brunsell, N. A., Chen, J., Chen, X., Clark, K., Desai, A.R.,DMan, T., Durden, D., Fares, S., Forbrich, I., Gammon, J. A., Gough, C. M., Griffis, T., Helbig, M., Hollinger, D., Humphreys, E., Ikawa, H., Iwata, H., Ju, Y., Knowles, J. F., Knox, S. H., Kobayashi, H., Kolb, T., Law, B., Lee, X., Litvak, M., Liu, H., Munger, J. W., Noormets, A., Novick, K., Oberbauer, S. F., Oechel, W., Oikawa, P., Papuga, S. A., Pendall, E., Prajapati, P., Prueger, J., Quinton, W. L., Richardson, A. D., Russel, E. S., Scott, R. L., Starr, G., Staebler, R., Stoy, P., Stuart-Haentjens, E., Sonnentag, O., Sullivan, R. C., Suyker, A., Ueyama, M., Vargas, R., Wood, J. D., and Zona, D.: Representativeness of Eddy-Covariance flux footprints for areas surrounding AmeriFlux sites, Agr. Forest Meteorol., 301-302, 108350, https://doi.org/10.1016/j.agrformet.2021.108350, 2021.

Dalcin Martins, P., Hoyt, D. W., Bansal, S., Mills, C. T., Tfaily, M., Tangen, B. A., Finocchiaro, R. G., Johnston, M. D., McAdams, B. C., Solensky, M. J., Smith, G. J., Chin, Y.-P., and Wilkins, M. J.: Abundant carbon substrates drive extremely high sulfate reduction rates and methane fluxes in Prairie Pothole Wetlands, Glob. Change Biol., 23, 3107–3120, https://doi.org/10.1111/gcb.13633, 2017.

Dean, J. F., Middelburg, J. J., Röckmann, T., Aerts, R., Blauw, L. G., Egger, M., Jetten, M. S. M., de Jong, A. E. E., Meisel, O. H., Rasigraf, O., Slomp, C. P., in't Zandt, M. H., and Dolman, A. J.: Methane Feedbacks to the Global Climate System in a Warmer World, Rev. Geophys., 56, 207–250, https://doi.org/10.1002/2017rg000559, 2018.

Deemer, B. R., Harrison, J. A., Li, S., Beaulieu, J. J., DelSontro, T., Barros, N., Bezerra-Neto, J. F., Powers, S. M., Dos Santos, M. A., and Vonk, J. A.: Greenhouse Gas Emissions from Reservoir Water Surfaces: A New Global Synthesis, Bioscience, 66, 949–964, https://doi.org/10.1093/biosci/biw117, 2016.

Dengel, S., Zona, D., Sachs, T., Aurela, M., Jammet, M., Parmentier, F. J. W., Oechel, W., and Vesala, T.: Testing the applicability of neural networks as a gap-filling method using CH₄ flux data from high latitude wetlands, Biogeosciences, 10, 8185–8200, https://doi.org/10.5194/bg-10-8185-2013, 2013.

Delwiche, K. B., Knox, S. H., Malhotra, A., Fluet-Chouinard, E., McNicol, G., Feron, S., Ouyang, Z., Papale, D., Trotta, C., Canfora, E., Cheah, Y.-W., Christianson, D., Alberto, M. C. R., Alekseychik, P., Aurela, M., Baldocchi, D., Bansal, S., Billesbach, D. P., Bohrer, G., Bracho, R., Buchmann, N., Campbell, D. I., Celis, G., Chen, J., Chen, W., Chu, H., Dalmagro, H.J., Dengel, S., Desai, A. R., Detto, M., Dolman, H., Eichelmann, E., Euskirchen, E., Famulari, D., Friborg, T., Fuchs, K., Goeckede, M., Gogo, S., Gondwe, M. J., Goodrich, J. P., Gottschalk, P., Graham, S. L., Heimann, M., Helbig, M., Helfter, C., Hemes, K. S., Hirano, T., Hollinger, D., Hörtnagl, L., Iwata, H., Jacobot, A., Jansen, J., Jurasinski, G., Kang, M., Kasak, K., King, J., Klatt, J., Koebsch, F., Krauss, K. W., Lai, D. Y. F., Mammarella, I., Manca, G., Marchesini, L. B., Matthes, J. H., Maximon, T., Merbold, L., Mitra, B., Morin, T. H., Nemitz, E., Nilsson, M. B., Niu, S., Oechel, W.C., Oikawa, P. Y., Ono, K., Peichl, M., Peltola, O., Reba, M. L., Richardson, A. D., Riley, W., Runkle, B. R. K., Ryu, Y., Sachs, T., Sakabe, A., Sanchez, C. R., Schuur, E. A., Schäfer, K. V. R., Sonnentag, O., Sparks, J. P., Stuart-Haëntjens, E., Sturtevant, C., Sullivan, R. C., Szutu, D. J., Thom, J. E., Torn, M. S., Tuittila, E.-S., Turner, J., Ueyama,

M., Valach, A. C., Vargas, R., Varlagin, A., Vazquez-Lule, A., Verfaillie, J. G., Vesala, T., Vourlitis, G. L., Ward, E. J., Wille, C., Wohlfahrt, G., Wong, G. X., Zhang, Z., Zona, D., Windham-Myers, L., Poulter, B., and Jackson, R. B.: FLUXNET-CH₄: A global, multi-ecosystem dataset and analysis of methane seasonality from freshwater wetlands (Appendix B and Figure 3), Zenodo [data set], https://doi.org/10.5281/zenodo.4672601, 2021.

Deshmukh, C. S., Julius, D., Evans, C. D., Nardi, Susanto, A. P., Page, S. E., Gauci, V., Laurén, A., Sabiham, S., Agus, F., Asyhari, A., Kurnianto, S., Suardiwerianto, Y., and Desai, A. R.: Impact of forest plantation on methane emissions from tropical peatland, Glob. Change Biol., 26, 2477–2495, https://doi.org/10.1111/gcb.15019, 2020.

Desai, A. R.: FLUXNET-CH₄ US-Los Lost Creek, United States, FLUXNET-CH4 Community Product [data set], https://doi.org/10.18140/FLX/1669682, 2020a.

Desai, A. R.: FLUXNET-CH₄ US-PFa Park Falls/WLEF, United States, FLUXNET-CH4 Community Product [data set], https://doi.org/10.18140/FLX/1669691, 2020b.

Desjardins, R. L.: A technique to measure CO₂ exchange under field conditions, Int. J. Biometeorol., 18, 76–83, https://doi.org/10.1007/bf01450667, 1974.

Detto, M., Sturtevant, C., Oikawa, P., Verfaillie, J., and Baldocchi, D.: FLUXNET-CH₄ US-Snd Sherman Island, United States, FLUXNET-CH4 Community Product [data set], https://doi.org/10.18140/FLX/1669692, 2020.

Didan, K.: MOD13A3 MODIS/Terra vegetation Indices Monthly L3 Global 1km SIN Grid V006, NASA EOSDIS Land Processes DAAC [data set], https://doi.org/10.5067/MODIS/MOD13A3.006, 2015.

Dise, N.: Winter fluxes of methane from Minnesota peatlands, Biogeochemistry, 17, 17–83, https://doi.org/10.1007/bf00002641, 1992.

Dolman, H., Hendriks, D., van Huissteden, K., and Belelli, L.: FLUXNET-CH₄ NL-Hor Horstermeer, Netherlands, FLUXNET-CH4 Community Product [data set], https://doi.org/10.18140/FLX/1669651, 2020a.

Dolman, H., Maximov, T., Parmentier, F., Budishev, A., and Marchesini, L. B.: FLUXNET-CH₄ RU-Cok Chokurdakh, Russian Federation, FLUXNET-CH4 Community Product [data set], https://doi.org/10.18140/FLX/1669656, 2020b.

Eichelmann, E., Knox, S., Rey Sanchez, C., Valach, A., Sturtevant, C., Szutu, D., Verfaillie, J., and Baldocchi, D.: FLUXNET-CH₄ US-Tw4 Twitchell East End Wetland, United States, FLUXNET-CH4 Community Product [data set], https://doi.org/10.18140/FLX/1669698, 2020.

Eklundh, L. and Jönsson, P.: TIMESAT: A Software Package for Time-Series Processing and Assessment of Vegetation Dynamics, Remote Sensing Time Series, Springer International Publishing, 141–158, https://doi.org/10.1007/978-3-319-15967-6_7. 2015.

Etheridge, D. M., Steele, L. P., Francey, R. J., and Langenfelds, R. L.: Atmospheric methane between 1000 A.D. and present: Evidence of anthropogenic emissions and climatic variability, J. Geophys. Res.-Atmos., 103, 15979–15993, https://doi.org/10.1029/98jd00923, 1998.

Etminan, M., Myhre, G., Highwood, E. J., and Shine, K. P.: Radiative forcing of carbon dioxide, methane, and nitrous oxide: A significant revision of the methane radiative forcing, Geophys. Res.
Lett., 43, 12614–12623, https://doi.org/10.1002/2016gl071930, 2016.

Euskirchen, E. and Edgar, C.: FLUXNET-CH₄ US-BZB Bonanza Creek Thermokarst Bog, United States, FLUXNET-CH4 Community Product [data set], https://doi.org/10.18140/FLX/1669668, 2020a.

Euskirchen, E. and Edgar, C.: FLUXNET-CH₄ US-BZF Bonanza Creek Rich Fen, United States, FLUXNET-CH4 Community Product [data set], https://doi.org/10.18140/FLX/1669669, 2020b.

Euskirchen, E. and Edgar, C.: FLUXNET-CH₄ US-BZS Bonanza Creek Black Spruce, United States, FLUXNET-CH4 Community Product [data set], https://doi.org/10.18140/FLX/1669670, 2020c.

Euskirchen, E., Bret-Harte, M., and Edgar, C.: FLUXNET-CH₄ US-ICs Imnavait Creek Watershed Wet Sedge Tundra, United States, FLUXNET-CH4 Community Product [data set], https://doi.org/10.18140/FLX/1669678, 2020.

Famulari, D.: FLUXNET-CH₄ IT-BCi Borgo Cioffi, Italy, FLUXNET-CH4 Community Product [data set], https://doi.org/10.18140/FLX/1669644, 2020.

Fick, S. E. and Hijmans, R. J.: WorldClim: 2: new 1km spatial resolution climate surfaces for global land areas, Int. J. Climatol., 37, 4302–4315, 2017.

Friborg, T., Christensen, T. R., and Søgaard, H.: Rapid response of greenhouse gas emission to early spring thaw in a subarctic mire as shown by micrometeorological techniques, Geophys. Res. Lett., 24, 3061–3064, https://doi.org/10.1029/97gl03024, 1997.

Gallant, A.: The Challenges of Remote Monitoring of Wetlands, Remote Sensing, 7, 10938–10950, https://doi.org/10.3390/rs70810938, 2015.

Göckede, M., Kittler, F., and Schaller, C.: Quantifying the impact of emission outbursts and non-stationary flow on eddy-covariance CH₄ flux measurements using wavelet techniques, Biogeosciences, 16, 3113–3131, https://doi.org/10.5194/bg-16-3113-2019, 2019.

Goeckede, M.: FLUXNET-CH₄ RU-Ch2 Chersky reference, Russian Federation, FLUXNET-CH4 Community Product [data set], https://doi.org/10.18140/FLX/1669654, 2020.

Gu, L., Post, W. M., Baldocchi, D. D., Andrew Black, T., Suyker, A. E., Verma, S. B., Vesala, T., and Wofsy, S. C.: Characterizing the Seasonal Dynamics of Plant Community Photosynthesis Across a Range of Vegetation Types, in: Phenology of Ecosystem Processes, edited by: Noormets, A., Springer, New York, NY, 35–58, https://doi.org/10.1007/978-1-4419-0026-5_2, 2009.

Hargreaves, K. J., Fowler, D., Pitcairn, C. E. R., and Aurela, M.: Annual methane emission from Finnish mires estimated from eddy covariance campaign measurements, Theor. Appl. Climatol., 70, 203–213, https://doi.org/10.1007/s007040170015, 2001.

Hargrove, W. W., Hoffman, F. M., and Law, B. E.: New analysis reveals representativeness of the AmeriFlux network, Eos T. Am. Geophys., 84, 529, https://doi.org/10.1029/2003EO480001, 2003.

Hatala, J. A., Detto, M., and Baldocchi, D. D.: Gross ecosystem photosynthesis causes a diurnal pattern in methane emission from rice, Geophys. Res. Lett., 39, L06409m https://doi.org/10.1029/2012gl051303, 2012.

Helbig, M., Quinton, W. L., and Sonnentag, O.: Warmer spring conditions increase annual methane emissions from a boreal

peat landscape with sporadic permafrost, Environ. Res. Lett., 12, 115009, https://doi.org/10.1088/1748-9326/aa8c85, 2017.

Helfter, C.: FLUXNET-CH₄ BW-Gum Guma, Botswana, FLUXNET-CH4 Community Product [data set], https://doi.org/10.18140/FLX/1669370, 2020a.

Helfter, C.: FLUXNET-CH₄ BW-Nxr Nxaraga, Botswana, FLUXNET-CH4 Community Product [data set], https://doi.org/10.18140/FLX/1669518, 2020b.

Helfter, C.: FLUXNET-CH₄ UK-LBT London_BT, United Kingdom, FLUXNET-CH4 Community Product [data set], https://doi.org/10.18140/FLX/1670207, 2020c.

Helfter, C., Tremper, A. H., Halios, C. H., Kotthaus, S., Bjorkegren, A., Grimmond, C. S. B., Barlow, J. F., and Nemitz, E.: Spatial and temporal variability of urban fluxes of methane, carbon monoxide and carbon dioxide above London, UK, Atmos. Chem. Phys., 16, 10543–10557, https://doi.org/10.5194/acp-16-10543-2016, 2016.

Hinkle, C. R. and Bracho, R.: FLUXNET-CH₄ US-DPW Disney Wilderness Preserve Wetland, United States, FLUXNET-CH4 Community Product [data set], https://doi.org/10.18140/FLX/1669672, 2020.

Hoffman, F. M., Kumar, J., Mills, R. T., and Hargrove, W. W.: Representativeness-based sampling network design for the State of Alaska, Landscape Ecol., 28, 1567–1586, https://doi.org/10.1007/s10980-013-9902-0, 2013.

Hollinger, D. Y. and Richardson, A. D.: Uncertainty in Eddy Covariance Measurements and Its Application to Physiological Models, Tree Physiol., 25, 873–885, https://doi.org/10.1093/treephys/25.7.873, 2005.

Holm, G. O., Perez, B. C., McWhorter, D. E., Krauss, K. W., Raynie, R. C., and Killebrew, C. J.: FLUXNET-CH₄ US-LA1 Pointe-aux-Chenes Brackish Marsh, United States, FLUXNET-CH4 Community Product [data set], https://doi.org/10.18140/FLX/1669680, 2020a.

Holm, G. O., Perez, B. C., McWhorter, D. E., Krauss, K. W., Raynie, R. C., and Killebrew, C. J.: FLUXNET-CH₄ US-LA2 Salvador WMA Freshwater Marsh, United States, FLUXNET-CH4 Community Product [data set], https://doi.org/10.18140/FLX/1669681, 2020b.

Hwang, Y., Ryu, Y., Huang, Y., Kim, J., Iwata, H., and Kang, M.: Comprehensive assessments of carbon dynamics in an intermittently-irrigated rice paddy, Agr. Forest Meteorol., 285–286, 107933, https://doi.org/10.1016/j.agrformet.2020.107933, 2020.

Iwata, H.: FLUXNET-CH₄ JP-Mse Mase rice paddy field, Japan, FLUXNET-CH4 Community Product [data set], https://doi.org/10.18140/FLX/1669647, 2020a.

Iwata, H.: FLUXNET-CH₄ JP-SwL Suwa Lake, Japan, FLUXNET-CH4 Community Product [data set], https://doi.org/10.18140/FLX/1669648, 2020b.

Iwata, H., Mano, M., Ono, K., Tokida, T., Kawazoe, T., Kosugi, Y., Sakabe, A., Takahashi, K., and Miyata, A.: Exploring sub-daily to seasonal variations in methane exchange in a single-crop rice paddy in central Japan, Atmos. Environ., 179, 156–165, https://doi.org/10.1016/j.atmosenv.2018.02.015, 2018.

Iwata, H., Ueyama, M., and Harazono, Y.: FLUXNET-CH₄ US-Uaf University of Alaska, Fairbanks, United States, FLUXNET-CH4 Community Product [data set], https://doi.org/10.18140/FLX/1669701, 2020.
Jacotot, A., Gogo, S., and Laggoun-Défarge, F.: FLUXNET-CH₄ FR-LGt La Guette, France, FLUXNET-CH4 Community Product [data set], https://doi.org/10.18140/FLX/1669641, 2020.

Jönsson, P. and Eklundh, L.: Seasonality extraction by function fitting to time-series of satellite sensor data, IEEE T. Geosci. Remote, 40, 1824–1832, https://doi.org/10.1109/tgrs.2002.802519, 2002.

Jönsson, P. and Eklundh, L.: TIMESAT – a program for analyzing time-series of satellite sensor data. Comput. Geosci., 30, 833–845, https://doi.org/10.1016/j.cageo.2004.05.006, 2004.

Jung, M., Reichstein, M., and Bondeau, A.: Towards global empirical upscaling of FLUXNET eddy covariance observations: validation of a model tree ensemble approach using a biosphere model, Biogeosciences, 6, 2001–2013, https://doi.org/10.5194/bg-6-2001-2009, 2009.

Jung, M., Schwalm, C., Migliavacca, M., Walther, S., Camps-Valls, G., Koirala, S., Anthoni, P., Besnard, S., Bodesheim, P., Carvalhais, N., Chevallier, F., Gans, F., Goll, D. S., Haverd, V., Köhler, P., Ichii, K., Jain, A. K., Liu, J., Lombardozzi, D., Nabel, J. E. M. S., Nelson, J. A., O’Sullivan, M., Pallandt, M., Papale, D., Peters, W., Pongratz, J., Rödenbeck, C., Sitch, S., Tramontana, G., Walker, A., Weber, U., and Reichstein, M.: Scaling carbon fluxes from eddy covariance sites to globe: synthesis and evaluation of the FLUXCOM approach, Biogeosciences, 17, 1343–1365, https://doi.org/10.5194/bg-17-1343-2020, 2020.

Kim, Y., Johnson, M. S., Knox, S. H., Andrew Black, T., Dalmagro, H. J., Kang, M., Kim, J., and Baldocchi, D.: Gap-filling approaches for eddy covariance methane fluxes: A comparison of three machine learning algorithms and a traditional method with principal component analysis, Glob. Change Biol., 26, 1499–1518, https://doi.org/10.1111/gcb.14845, 2020.

Kittler, F., Heimann, M., Kolle, O., Zimov, N., Zimov, S., and Göckede, M.: Long-Term Drainage Reduces CO₂ Uptake and CH₄ Emissions in a Siberian Permafrost Ecosystem: Drainage impact on Arctic carbon cycle, Global Biogeochem. Cy., 31, 1704–1717, https://doi.org/10.1002/2017GB005774, 2017.

Knox, S., Matthes, J. H., Verfaillie, J., and Baldocchi, D.: FLUXNET-CH₄ US-Twt Twitchell Island, United States, FLUXNET-CH4 Community Product [data set], https://doi.org/10.18140/FLX/1669700, 2020.

Knox, S. H., Sturtevant, C., Matthes, J. H., Koteen, L., Verfaillie, J., and Baldocchi, D.: Agricultural peatland restoration: effects of land-use change on greenhouse gas (CO₂ and CH₄) fluxes in the Sacramento-San Joaquin Delta, Glob. Change Biol., 21, 750–765, https://doi.org/10.1111/gcb.12745, 2015.

Knox, S. H., Matthes, J. H., Sturtevant, C., Oikawa, P. Y., Verfaillie, J., and Baldocchi, D.: Biophysical controls on interannual variability in ecosystem-scale CO₂ and CH₄ exchange in a California rice paddy, J. Geophys. Res.-Biogeo., 121, 978–1001, https://doi.org/10.1002/2015jg003247, 2016.

Knox, S. H., Jackson, R. B., Poulter, B., McNicol, G., Fluet-Chouinard, E., Zhang, Z., Hugelius, G., Bousquet, P., Canadell, J. G., Saunois, M., Papale, D., Chu, H., Keenan, T. F., Baldocchi, D., Torn, M. S., Mammarella, I., Trotta, C., Aurela, M., Bohrer, G., Campbell, D.I., Cescatti, A., Chamberlain, S., Chen, J., Chen, W., Dengel, S., Desai, A. R., Euskirchen, E., Friborg, T., Gasbarra, D., Goded, I., Goeckede, M., Heimann, M., Helbig, M., Hirano, T., Hollinger, D. Y., Iwata, H., Jurasinski, G., Kang, M., Koebsch, F., Mammarella, I., Nilsson, M. B., Ono, K., Peichl,

M., Peltola, O., Ryu, Y., Sachs, T., Sakabe, A., Sparks, J., Tuittila, E.-S., Vourlitis, G. L., Wong, G. X., Windham-Myers, L., Poulter, B., and Jackson, R. B.: FLUXNET-CH₄ Synthesis Activity: Objectives, Observations, and Future Directions, B. Am. Meterol. Soc., 100, 2607–2632, https://doi.org/10.1175/bams-d18-0268.1, 2019.

Koebsch, F. and Jurasinski, G.: FLUXNET-CH₄ DE-Hte Huetelmoor, Germany, FLUXNET-CH4 Community Product [data set], https://doi.org/10.18140/FLX/1669634, 2020.

Koebsch, F., Jurasinski, G., Koch, M., Hofmann, J., and Glatzel, S.: Controls for multi-scale temporal variation in ecosystem methane exchange during the growing season of a permanently inundated fen, Agr. Forest Meteorol., 204, 94–105, https://doi.org/10.1016/j.agrformet.2015.02.002, 2015.

Koebsch, F., Winkel, M., Liebner, S., Liu, B., Westphal, J., Schmiedinger, I., Spitzy, A., Gehre, M., Jurasinski, G., Köhler, S., Unger, V., Koch, M., Sachs, T., and Böttcher, M. E.: Sulfate deprivation triggers high methane production in a disturbed and rewetted coastal peatland, Biogeosciences, 16, 1937–1953, https://doi.org/10.5194 bg-16-1937-2019, 2019.

Kuznetsova, A., Brockhoff, P. B., and Christensen, R. H. B.: lmerTest Package: Tests in Linear Mixed Effects Models, J. Stat. Softw., 82, 1–26, https://doi.org/10.18637/jss.v082.i13, 2017.

Kwon, M. J., Beulig, F., Ilie, I., Wildner, M., Küsel, K., Merbold, L., Mahecha, M. D., Zimov, N., Zimov, S. A., Heimann, M., Schuur, E. A. G., Kostka, J. E., Kolle, O., Hilke, I., and Göckede, M.: Plants, microorganisms, and soil temperatures contribute to a decrease in methane fluxes on a drained Arctic floodplain, Glob. Change Biol., 23, 2396–2412, https://doi.org/10.1111/gcb.13558, 2017.

Lai, D. Y. F.: Methane Dynamics in Northern Peatlands: A Review, Pedosphere, 19, 409–421, https://doi.org/10.1016/s1002-0160(09)00003-4, 2009.

Lai, D. Y. F., Roulet, N. T., and Moore, T. R.: The spatial and temporal relationships between CO₂ and CH₄ exchange in a temperate ombrotrophic bog, Atmos. Environ, 89, 249–259, https://doi.org/10.1016/j.atmosenv.2014.02.034, 2014.

Lai, D. Y. F.: FLUXNET-CH₄ HK-MPM Mai Po Mangrove, Hong Kong, FLUXNET-CH4 Community Product [data set], https://doi.org/10.18140/FLX/1669642, 2020.

Lasslop, G., Reichstein, M., Papale, D., Richardson, A. D., Arneth, A., Barr, A., Stoy, P., and Wohlfahrt, G.: Separation of net ecosystem exchange into assimilation and respiration using a light response curve approach: critical issues and global evaluation, Glob. Change Biol., 16, 187–208, https://doi.org/10.1111/j.1365-2486.2009.02041.x, 2010.

Liu, J., Zhou, Y., Valach, A., Shortt, R., Kasak, K., Rey-Sanchez, C., Hemes, K. S., Baldocchi, D., and Lai, D. Y. F.: Methane emissions reduce the radiative cooling effect of a subtropical estuarine mangrove wetland by half, Glob. Change Biol., 26, 4998–5016, https://doi.org/10.1111/gcb.15247, 2020.

Lohila, A., Aurela, M., Tuovinen, J.-P., Laurila, T., Hatakka, J., Rainne, J., and Mäkelä, T.: FLUXNET-CH₄ FI-Lom Lompolojankka, Finland, FLUXNET-CH4 Community Product [data set], https://doi.org/10.18140/FLX/1669638, 2020.

Madsen, K., Nielsen, H. B., and Tingleff, O.: Methods for nonlinear least squares problems, Informatics and Mathematical Modelling, Technical Univeristy of Denmark, 2nd Edn., 2004.
Maier, R., Hörtnagl, L., and Buchmann, N.: FLUXNET-CH₄ CH-Oe2 Oensingen crop, FLUXNET-CH4 Community Product [data set], Switzerland, https://doi.org/10.18140/FLX/1669631, 2020.

Mahecha, M. D., Gans, F., Sippel, S., Donges, J. F., Kaminski, T., Metzger, S., Migliavacca, M., Papale, D., Rammig, A., and Zscheischler, J.: Detecting impacts of extreme events with ecological in situ monitoring networks, Biogeosciences, 14, 4255–4277, https://doi.org/10.5194/bg-14-4255-2017, 2017.

Malhotra, A. and Roulet, N. T.: Environmental correlates of peatland carbon fluxes in a thawing landscape: do transitional thaw stages matter?, Biogeosciences, 12, 3119–3130, https://doi.org/10.5194/bg-12-3119-2015, 2015.

Mammarella, I., Rannik, Ü., Kolari, P., Levula, J., and Vesala, T.: FLUXNET-CH₄ FI-Hyy Hyytiala, Finland, FLUXNET-CH4 Community Product [data set], https://doi.org/10.18140/FLX/1669637, 2020.

Manca, G. and Goded, I. FLUXNET-CH₄ IT-Cas Castellaro, Italy, FLUXNET-CH4 Community Product [data set], https://doi.org/10.18140/FLX/1669645, 2020.

Mastepanov, M., Sigsgaard, C., Tagesson, T., Ström, L., Tamstorf, M. P., Lund, M., and Christensen, T. R.: Revisiting factors controlling methane emissions from high-Arctic tundra, Biogeosciences, 10, 5139–5158, https://doi.org/10.5194/bg-10-5139-2013, 2013.

Matthes, J. H., Sturtevant, C., Oikawa, P., Chamberlain, S. D., Szutu, D., Ortiz, A. A., Verfaillie, J., and Baldocchi, D.: FLUXNET-CH₄ US-Myb Mayberry Wetland, United States, FLUXNET-CH4 Community Product [data set], https://doi.org/10.18140/FLX/1669685, 2020.

Matthews, E., Johnson, M. S., Genovese, V., Du, J., and Bastviken, D.: Methane emission from high latitude lakes: methane-centric lake classification and satellite-driven annual cycle of emissions. Sci. Rep.-UK, 10, 12465, https://doi.org/10.1038/s41598-020-68246-1, 2020.

Megonigal, J. P., Whalen, S. C., Tissue, D. T., Bovard, B. D., Allen, A. S., and Albert, D. B.: A Plant-Soil-Atmosphere Microcosm for Tracing Radiocarbon from Photosynthesis through Methanogenesis, Soil Sci. Soc. Am. J., 63, 665–671, https://doi.org/10.2136/sssaj1999.03615995006300030033x, 1999.

Meijide, A., Manca, G., Goded, I., Magliulo, V., di Tommasi, P., Seufert, G., and Cescatti, A.: Seasonal trends and environmental controls of methane emissions in a rice paddy field in Northern Italy, Biogeosciences, 8, 3809–3821, https://doi.org/10.5194/bg-8-3809-2011, 2011.

Melloh, R. A. and Crill, P. M.: Winter methane dynamics in a temperate peatland, Global Biogeochem. Cy., 10, 247–254, https://doi.org/10.1029/96gb00365, 1996.

Melton, J. R., Wania, R., Hodson, E. L., Poulter, B., Ringeval, B., Spahni, R., Bohn, T., Avis, C. A., Beerling, D. J., Chen, G., Eliseev, A. V., Denisov, S. N., Hopcroft, P. O., Lettenmaier, D. P., Riley, W. J., Singarayer, J. S., Subin, Z. M., Tian, H., Zürcher, S., Brovkin, V., van Bodegom, P. M., Kleinen, T., Yu, Z. C., and Kaplan, J. O.: Present state of global wetland extent and wetland methane modelling: conclusions from a model intercomparison project (WETCHIMP), Biogeosciences, 10, 753–788, https://doi.org/10.5194/bg-10-753-2013, 2013.

Merbold, L.: FLUXNET-CH₄ RU-Che Cherski, Russian Federation, FLUXNET-CH4 Community Product [data set], https://doi.org/10.18140/FLX/1669655, 2020.

Merbold, L., Fuchs, K., Buchmann, N., and Hörtnagl, L.: FLUXNET-CH₄ CH-Cha Chamau, Switzerland, FLUXNET-CH4 Community Product [data set], https://doi.org/10.18140/FLX/1669629, 2020a.

Merbold, L., Hörtnagl, L., and Buchmann, N.: FLUXNET-CH₄ CH-Dav Davos, Switzerland, FLUXNET-CH4 Community Product [data set], https://doi.org/10.18140/FLX/1669630, 2020b.

Meyer, H. and Pebesma, E.: Predicting into unknown space? Estimating the area of applicability of spatial prediction models, arXiv [preprint], arXiv:2005.07939, 2020.

Mishra, S. R., Pattnaik, P., Sethunathan, N., and Adhya, T. K.: Anion-Mediated Salinity Affecting Methane Production in a Flooded Alluvial Soil. Geomicrobiol. J., 20, 579–586, https://doi.org/10.1080/713851167, 2003.

Moffat, A. M., Papale, D., Reichstein, M., Hollinger, D. Y., Richardson, A. D., Barr, A. G., Beckstein, C., Braswell, B. H., Churkina, G., Desai, A. R., Falge, E., Gove, J. H., Heimann, M., Hui, D., Jarvis, A. J., Kattge, J., Noormets, A., and Stauch, V. J.: Comprehensive comparison of gap-filling techniques for eddy covariance net carbon fluxes, Agr. Forest Meteorol., 147, 209–232, https://doi.org/10.1016/j.agrformet.2007.08.011, 2007.

Myhre, G., Shindell, D., Bréon, F.-M., Collins, W., Fuglestvedt, J., Huang, J., Koch, D., Lamarque, J.-F., Lee, D., Mendoza, B., Nakajima, T., Robock, A., Stephens, G., Takemura, T., and Zhang, H.: Anthropogenic and Natural Radiative Forcing Supplementary Material, in: Climate Change 2013: The Physical Science Basis, Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change, edited by: Stocker, T. F., Qin, D., Plattner, G.-K., Tignor, M., Allen, S. K., Boschung, J., Nauels, A., Xia, Y., Bex, V., and Midgley, P. M., 2013.

Nemitz, E., Mammarella, I., Ibrom, A., Aurela, M., Burba, G. G., Dengel, S., Gielen, B., Grelle, A., Heinesch, B., Herbst, M., Hörtnagl, L., Klemedtsson, L., Lindroth, A., Lohila, A., McDermitt, D. K., Meier, P., Merbold, L., Nelson, D., Nicolini, G., Nilsson, M. B., Peltola, O., Rinne, J., and Zahniser, M.: Standardisation of eddy-covariance flux measurements of methane and nitrous oxide, Int. Agrophy., 32, 517–549, https://doi.org/10.1515/intag-2017-0042, 2018.

Nielsen, H. B.: Damping parameter in Marquardt's method, Department of Mathematical Modeling, IMM, Technical University of Denmark, Technical Report, IMM-REP-1999-05, 1999.

Nilsson, M. B. and Peichl, M.: FLUXNET-CH₄ SE-Deg Degero, Sweden, FLUXNET-CH4 Community Product [data set], https://doi.org/10.18140/FLX/1669659, 2020.

Niu, S. and Chen, W.: FLUXNET-CH₄ CN-Hgu Hongyuan, China, FLUXNET-CH4 Community Product [data set], https://doi.org/10.18140/FLX/1669632, 2020.

Noormets, A., King, J., Mitra, B., Miao, G., Aguilos, W., Minick, W., Prajapati, P., and Domec, J.-C.: FLUXNET-CH₄ US-NC4 NC_AlligatorRiver, United States, FLUXNET-CH4 Community Product [data set], https://doi.org/10.18140/FLX/1669686, 2020.

Oikawa, P. Y., Jenerette, G. D., Knox, S. H., Sturtevant, C., Verfaillie, J., Dronova, I., Poindexter, C. M., Eichelmann, E., and Baldocchi, D. D.: Evaluation of a hierarchy of models reveals
importance of substrate limitation for predicting carbon dioxide and methane exchange in restored wetlands, J. Geophys. Res.-Biogeo., 122, 145-167, https://doi.org/10.1002/2016JG003438, 2017.

Oikawa, P.: FLUXNET-CH₄ US-EDN Eden Landing Ecological Reserve, United States, FLUXNET-CH4 Community Product [data set], https://doi.org/10.18140/FLX/1669673, 2020.

Olefeldt, D., Turetsky, M. R., Crill, P. M., and McGuire, A. D.: Environmental and physical controls on northern terrestrial methane emissions across permafrost zones, Glob. Change Biol., 19, 589-603, https://doi.org/10.1111/gcb.12071, 2013.

Papale, D., Andrew Black, T., Carvalhais, N., Cescatti, A., Chen, J., Jung, M., Kiely, G., Lasslop, G., Mahecha, M. D., Mar-golis, H., Merbold, L., Montagnani, L., Moors, E., Olesen, J. E., Reichstein, M., Tramontana, G., van Gorsel, E., Wohlfahrt, G., and Ráduly, B.: Effect of spatial sampling from European flux towers for estimating carbon and water fluxes with artifi-cial neural networks, J. Geophys. Res.-Biogeo., 120, 1941-1957, https://doi.org/10.1002/2015jg002997, 2015.

Parmentier, F. J. W., van Huissteden, J., van der Molen, M. K., Schaepman-Strub, G., Karsanaev, S. A., Maximov, T. C., and Dolman, A. J.: Spatial and temporal dynamics in eddy covariance observations of methane fluxes at a tun-dra site in northeastern Siberia, J. Geophys. Res., 116, 1368, https://doi.org/10.1029/2010JG001637, 2011.

Pastorello, G., Trotta, C., Canfora, E., Chu, H., Christianson, D., Cheah, Y.-W., Poindexter, C., Chen, J., Elbashandy, A., Humphrey, M., Isaac, P., Polidori, D., Ribeca, A., van Ingen, C., Zhang, L., Amiro, B., Ammann, C., Arain, M. A., Ardö, J., et al.: The FLUXNET2015 dataset and the ONEFlux pro-cessing pipeline for eddy covariance data, Sci. Data, 7, 225, https://doi.org/10.1038/s41597-020-0534-3, 2020.

Pattnaik, P., Mishra, S. R., Bharati, K., Mohanty, S. R., Sethunathan, N., and Adhya, T. K.: Influence of salinity on methanogenesis and associated microflora in tropical rice soils, Microbiol. Res., 155, 215-220, https://doi.org/10.1016/S0944-5013(00)80035-X, 2000.

Poffenbarger, H. J., Needelman, B. A., and Patrick Megonigal, J.: Salinity Influence on Methane Emissions from Tidal Marshes, Wetlands, 31, 831-842, https://doi.org/10.1007/s13157-011-0197-0, 2011.

Poulter, B., Bousquet, P., Canadell, J. G., Ciais, P., Peregon, A., Saunois, M., Arora, V. K., Beerling, D. J., Brovkin, V., Jones, C. D., Joos, F., Gedney, N., Ito, A., Kleinen, T., Koven, C. D., McDonald, K., Melton, J. R., Peng, C., Peng, S., Prigent, C., Schroeder, R., Riley, W. J., Saito, M., Spahni, R., Tian, H., Taylor, L., Viovy, N., Wilton, D., Wiltshire, A., Xu, X., Zhang, B., Zhang, Z., and Zhu, Q.: Global wetland contribu-tion to 2000-2012 atmospheric methane growth rate dynamics, Environ. Res. Lett., 12, 094013, https://doi.org/10.1088/1748-9326/aa8391, 2017.

R Core Team: R: A Language and Environment for Statistical Com-puting. R Foundation for Statistical Computing, Vienna, 2018.

Reba, M., Runkle, B., and Suvocarev, K.: FLUXNET-CH₄ US-HRC Humnoke Farm Rice Field - Field C, United States, FLUXNET-CH4 Community Product [data set], https://doi.org/10.18140/FLX/1669677, 2020.

Reichstein, M., Falge, E., Baldocchi, D., Papale, D., Aubinet, M., Berbigier, P., Bernhofer, C., Buchmann, N., Gilmanov,

T., Granier, A., Grunwald, T., Havrankova, K., Ilvesniemi, H., Janous, D., Knohl, A., Laurila, T., Lohila, A., Loustau, D., Mat-teucci, G., Meyers, T., Miglietta, F., Ourcival, J.-M., Pumpanen, J., Rambal, S., Rotenberg, E., Sanz, M., Tenhunen, J., Seufert, G., Vaccari, F., Vesala, T., Yakir, D., and Valentini, R.: On the separation of net ecosystem exchange into assimilation and ecosystem respiration: review and improved algorithm, Glob. Change Biol., 11, 1424-1439, https://doi.org/10.1111/j.1365-2486.2005.001002.x, 2005.

Rey-Sanchez, C., Szutu, D., Shortt, R., Chamberlain, S. D., Ver-faillie, J., and Baldocchi, D.: FLUXNET-CH₄ US-Bi1 Bouldin Island Alfalfa, United States, FLUXNET-CH4 Community Prod-uct [data set], https://doi.org/10.18140/FLX/1669666, 2020a.

Rey-Sanchez, C., Szutu, D., Hemes, K., Verfaillie, J., and Bal-docchi, D.: FLUXNET-CH₄ US-Bi2 Bouldin Island corn, United States, FLUXNET-CH4 Community Product [data set], https://doi.org/10.18140/FLX/1669667, 2020b.

Richardson, A. D. and Hollinger, D. Y.: A method to estimate the additional uncertainty in gap-filled NEE resulting from long gaps in the CO₂ flux record, Agr. Forest Meteorol., 147, 199-208, https://doi.org/10.1016/j.agrformet.2007.06.004, 2007.

Richardson, A. D. and Hollinger, D. Y.: FLUXNET-CH₄ US-Ho1 Howland Forest (main tower), United States, FLUXNET-CH4 Community Product [data set], https://doi.org/10.18140/FLX/1669675, 2020.

Richardson, A. D., Hollinger, D. Y., Burba, G. G., Davis, K. J., Flanagan, L. B., Katul, G. G., William Munger, J., Ricciuto, D. M., Stoy, P. C., Suyker, A. E., Verma, S. B., and Wofsy, S. C.: A multi-site analysis of random error in tower-based measure-ments of carbon and energy fluxes, Agr. Forest Meteorol., 136, 1-18, https://doi.org/10.1016/j.agrformet.2006.01.007, 2006.

Richardson, A. D., Mahecha, M. D., Falge, E., Kattge, J., Mof-fat, A. M., Papale, D., Reichstein, M., Stauch, V. J., Braswell, B. H., Churkina, G., Kruijt, B., and Hollinger, D. Y.: Statisti-cal properties of random CO₂ flux measurement uncertainty in-ferred from model residuals, Agr. Forest Meteorol., 148, 38-50, https://doi.org/10.1016/j.agrformet.2007.09.001, 2008.

Richardson, A. D., Aubinet, M., Barr, A. G., Hollinger, D. Y., Ibrom, A., Lasslop, G., and Reichstein, M.: Uncertainty quan-tification, Eddy Covariance: A Practical Guide to Measurement and Data Analysis, edited by: Aubinet, M., Vesala, T., and Pa-pale, D.: Springer Atmospheric Sciences, 2012.

Rinne, J., Riutta, T., Pihlatie, M., Aurela, M., Haapanala, S., Tuovi-nen, J.-P., Tuiltila, E.-S., and Vesala, T.: Annual cycle of methane emission from a boreal fen measured by the eddy covariance technique, Tellus B, 59, 449-457, https://doi.org/10.1111/j.1600-0889.2007.00261.x, 2007.

Runkle, B., Reba, M., and Suvocarev, K.: FLUXNET-CH₄ US-HRA Humnoke Farm Rice Field - Field A, United States, FLUXNET-CH4 Community Product [data set], https://doi.org/10.18140/FLX/1669676, 2020.

Runkle, B. R. K., Suvočarev, K., Reba, M. L., Reavis, C. W., Smith, S. F., Chiu, Y.-L., and Fong, B.: Methane Emission Reductions from the Alternate Wetting and Drying of Rice Fields Detected Using the Eddy Covariance Method, Environ. Sci. Technol., 53, 671-681, https://doi.org/10.1021/acs.est.8b05535, 2019.

Ryu, Y., Kang, M., and Kim, J.: FLUXNET-CH₄ KR-CRK Cheor-won Rice paddy, Korea, Republic of, FLUXNET-CH4 Commu-
nity Product [data set], https://doi.org/10.18140/FLX/1669649, 2020.

Sachs, T. and Wille, C.: FLUXNET-CH₄ DE-Dgw Dagowsee, Germany, FLUXNET-CH4 Community Product [data set], https://doi.org/10.18140/FLX/1669633, 2020a.

Sachs, T. and Wille, C.: FLUXNET-CH₄ DE-Zrk Zarnekow, Germany, FLUXNET-CH4 Community Product [data set], https://doi.org/10.18140/FLX/1669636, 2020b.

Sachs, T., Giebels, M., Boike, J., and Kutzbach, L.: Environmental controls on CH₄ emission from polygonal tundra on the microsite scale in the Lena river delta, Siberia: controls on tundra CH₄ flux and scaling, Glob. Change Biol., 16, 3096–3110, https://doi.org/10.1111/j.1365-2486.2010.02232.x, 2010.

Sakabe, A., Itoh, M., Hirano, T., and Kusin, K.: FLUXNET-CH₄ ID-Pag Palangkaraya undrained forest, Indonesia, FLUXNET-CH4 Community Product [data set], https://doi.org/10.18140/FLX/1669643, 2020.

Saunois, M., Bousquet, P., Poulter, B., Peregon, A., Ciais, P., Canadell, J. G., Dlugokencky, E. J., Etiope, G., Bastviken, D., Houweling, S., Janssens-Maenhout, G., Tubiello, F. N., Castaldi, S., Jackson, R. B., Alexe, M., Arora, V. K., Beerling, D. J., Bergamaschi, P., Blake, D. R., Brailsford, G., Brovkin, V., Bruhwiler, L., Crevoisier, C., Crill, P., Covey, K., Curry, C., Frankenberg, C., Gedney, N., Höglund-Isaksson, L., Ishizawa, M., Ito, A., Joos, F., Kim, H.-S., Kleinen, T., Krummel, P., Lamarque, J.-F., Langenfelds, R., Locatelli, R., Machida, T., Maksyutov, S., McDonald, K. C., Marshall, J., Melton, J. R., Morino, I., Naik, V., O'Doherty, S., Parmentier, F.-J. W., Patra, P. K., Peng, C., Peng, S., Peters, G. P., Pison, I., Prigent, C., Prinn, R., Ramonet, M., Riley, W. J., Saito, M., Santini, M., Schroeder, R., Simpson, I. J., Spahni, R., Steele, P., Takizawa, A., Thornton, B. F., Tian, H., Tohjima, Y., Viovy, N., Voulgarakis, A., van Weele, M., van der Werf, G. R., Weiss, R., Wiedinmyer, C., Wilton, D. J., Wiltshire, A., Worthy, D., Wunch, D., Xu, X., Yoshida, Y., Zhang, B., Zhang, Z., and Zhu, Q.: The global methane budget 2000–2012, Earth Syst. Sci. Data, 8, 697–751, https://doi.org/10.5194/essd-8-697-2016, 2016.

Saunois, M., Stavert, A. R., Poulter, B., Bousquet, P., Canadell, J. G., Jackson, R. B., Raymond, P. A., Dlugokencky, E. J., Houweling, S., Patra, P. K., Ciais, P., Arora, V. K., Bastviken, D., Bergamaschi, P., Blake, D. R., Brailsford, G., Bruhwiler, L., Carlson, K. M., Carrol, M., Castaldi, S., Chandra, N., Crevoisier, C., Crill, P. M., Covey, K., Curry, C. L., Etiope, G., Frankenberg, C., Gedney, N., Hegglin, M. I., Höglund-Isaksson, L., Hugelius, G., Ishizawa, M., Ito, A., Janssens-Maenhout, G., Jensen, K. M., Joos, F., Kleinen, T., Krummel, P. B., Langenfelds, R. L., Laruelle, G. G., Liu, L., Machida, T., Maksyutov, S., McDonald, K. C., McNorton, J., Miller, P. A., Melton, J. R., Morino, I., Müller, J., Murguia-Flores, F., Naik, V., Niwa, Y., Noce, S., O'Doherty, S., Parker, R. J., Peng, C., Peng, S., Peters, G. P., Prigent, C., Prinn, R., Ramonet, M., Regnier, P., Riley, W. J., Rosentreter, J. A., Segers, A., Simpson, I. J., Shi, H., Smith, S. J., Steele, L. P., Thornton, B. F., Tian, H., Tohjima, Y., Tubiello, F. N., Tsuruta, A., Viovy, N., Voulgarakis, A., Weber, T. S., van Weele, M., van der Werf, G. R., Weiss, R. F., Worthy, D., Wunch, D., Yin, Y., Yoshida, Y., Zhang, W., Zhang, Z., Zhao, Y., Zheng, B., Zhu, Q., Zhu, Q., and Zhuang, Q.: The Global Methane Budget 2000–2017, Earth Syst. Sci. Data, 12, 1561–1623, https://doi.org/10.5194/essd-12-1561-2020, 2020.

Schäfer, K.: FLUXNET-CH₄ US-MRM Marsh Resource Meadows Mitigation Bank, United States, FLUXNET-CH4 Community Product [data set], https://doi.org/10.18140/FLX/1669684, 2020.

Schmid, H. P. and Klatt, J.: FLUXNET-CH₄ DE-SfN Schechenfilz Nord, Germany, FLUXNET-CH4 Community Product [data set], https://doi.org/10.18140/FLX/1669635, 2020.

Schuur, E. A.: FLUXNET-CH₄ US-EML Eight Mile Lake Permafrost thaw gradient, Healy Alaska, United States, FLUXNET-CH4 Community Product [data set], https://doi.org/10.18140/FLX/1669674, 2020.

Seyfferth, A. L., Bothfeld, F., Vargas, R., Stuckey, J. W., Wang, J., Kearns, K., Michael, H. A., Guimond, J., Yu, X., and Sparks, D. L.: Spatial and temporal heterogeneity of geochemical controls on carbon cycling in a tidal salt marsh, Geochim. Cosmochim. Ac., 282, 1–18, https://doi.org/10.1016/j.gca.2020.05.013, 2020.

Shortt, R., Hemes, K., Szutu, D., Verfaillie, J., and Baldocchi, D.: FLUXNET-CH₄ US-Sne Sherman Island Restored Wetland, United States, FLUXNET-CH4 Community Product [data set], https://doi.org/10.18140/FLX/1669693, 2020.

Sims, D. A., Rahman, A. F., Cordova, V. D., El-Masri, B. Z., Baldocchi, D. D., Flanagan, L. B., Goldstein, A. H., Hollinger, D. Y., Misson, L., Monson, R. K., Oechel, W. C., Schmid, H. P., Wofsy, S. C., and Xu, L.: On the use of MODIS EVI to assess gross primary productivity of North American ecosystems, J. Geophys. Res.-Biogeo., 111, G04015, https://doi.org/10.1029/2006jg000162, 2006.

Sonnentag, O. and Helbig, M.: FLUXNET-CH₄ CA-SCB Scotty Creek Bog, Canada, FLUXNET-CH4 Community Product [data set], https://doi.org/10.18140/FLX/1669613, 2020a.

Sonnentag, O. and Helbig, M.: FLUXNET-CH₄ CA-SCC Scotty Creek Landscape, Canada, FLUXNET-CH4 Community Product [data set], https://doi.org/10.18140/FLX/1669628, 2020b.

Spahni, R., Wania, R., Neef, L., van Weele, M., Pison, I., Bousquet, P., Frankenberg, C., Foster, P. N., Joos, F., Prentice, I. C., and van Velthoven, P.: Constraining global methane emissions and uptake by ecosystems, Biogeosciences, 8, 1643–1665, https://doi.org/10.5194/bg-8-1643-2011, 2011.

Sparks, J. P.: FLUXNET-CH₄ US-MAC MacArthur Agro-Ecology, United States, FLUXNET-CH4 Community Product [data set], https://doi.org/10.18140/FLX/1669683, 2020.

Sturtevant, C. S., Ruddell, B. L., Knox, S. H., Verfaillie, J. G., Matthes, J. H., Oikawa, P. Y., and Baldocchi, D. D.: Identifying scale-emergent, nonlinear, asynchronous processes of wetland methane exchange, J. Geophys. Res.-Biogeo., 121, 188–204, https://doi.org/10.1002/2015JG003054, 2016.

Tagesson, T., Mölder, M., Mastepanov, M., Sigsgaard, C., Tampstorf, M. P., Lund, M., Falk, J. M., Lindroth, A., Christensen, T. R., and Ström, L.: Land-atmosphere exchange of methane from soil thawing to soil freezing in a high-Arctic wet tundra ecosystem, Glob. Change Biol., 18, 1928–1940, https://doi.org/10.1111/j.1365-2486.2012.02647.x, 2012.

Taoka, T., Iwata, H., Hirata, R., Takahashi, Y., Miyabara, Y., and Itoh, M.: Environmental Controls on Diffusive and Ebullitive Methane Emission at a Sub-Daily Time Scale in the Littoral Zone of a Mid-Latitude Shallow Lake, J. Geophys. Res.-Biogeo., 125, e2020JG005753, https://doi.org/10.1029/2020JG005753, 2020.

Torn, M. and Dengel, S.: FLUXNET-CH₄ US-NGB NGEE Arctic Barrow, United States, FLUXNET-CH4 Community Product [data set], https://doi.org/10.18140/FLX/1669684, 2020.
uct [data set], https://doi.org/10.18140/FLX/1669687,
2020a.

Torn, M. and Dengel, S.: FLUXNET-CH₄ US-NGC NGEE Arc-
tic Council, United States, FLUXNET-CH4 Community Product
(data set), https://doi.org/10.18140/FLX/1669688, 2020b.

Treat, C. C., Anthony Bloom, A., and Marushchak, M. E.: Non-
growing season methane emissions-a significant component of
annual emissions across northern ecosystems, Glob. Change
Biol., 24, 3331–3343, https://doi.org/10.1111/gcb.14137, 2018.

Turetsky, M. R., Kotowska, A., Bubier, J., Dise, N. B., Crill, P., Hornibrook, E. R. C., Minkkinen, K., Moore, T. R., Myers-Smith, I. H., Nykänen, H., Olefeldt, D., Rinne, J., Saarnio, S., Shurpali, N., Tuittila, E.-S., Waddington, J. M., White, J. R., Wickland, K. P., and Wilmking, M.: A synthesis of methane emissions from 71 northern, temperate, and subtropical wetlands, Glob. Change Biol., 20, 2183–2197, https://doi.org/10.1111/gcb.12580, 2014.

Ueyama, M., Hirano, T., and Kominami, Y.: FLUXNET-CH₄ JP-
BBY Bibai bog, Japan, FLUXNET-CH4 Community Product
(data set), https://doi.org/10.18140/FLX/1669646, 2020.

Valach, A., Szutu, D., Eichelmann, E., Knox, S., Verfaillie, J., and
Baldocchi, D.: FLUXNET-CH₄ US-Tw1 Twitchell Wetland West
Pond, United States, FLUXNET-CH4 Community Product [data
set], https://doi.org/10.18140/FLX/1669696, 2020a.

Valach, A., Kasak, K., Szutu, D., Verfaillie, J., and Bal-
docchi, D.: FLUXNET-CH₄ US-Tw5 East Pond Wetland,
United States, FLUXNET-CH4 Community Product [data set],
https://doi.org/10.18140/FLX/1669699, 2020b.

Varlagin, A.: FLUXNET-CH₄ RU-Fy2 Fyodorovskoye dry spruce, Russian Federation, FLUXNET-CH4 Community Product [data set], https://doi.org/10.18140/FLX/1669657, 2020.

Vazquez-Lule, A. and Vargas, R.: FLUXNET-CH₄ US-StJ St Jones
Reserve, United States, FLUXNET-CH4 Community Product
(data set), https://doi.org/10.18140/FLX/1669695, 2020.

Vázquez-Lule, A. and Vargas, R.: Biophysical drivers of net ecosystem and methane exchange across phenological phases in a tidal salt marsh, Agr. Forest Meteorol., 300, 108309, https://doi.org/10.1016/j.agrformet.2020.108309, 2021.

Verma, S. B., Ullman, F. G., Billesbach, D., Clement, R. J., Kim, J., and Verry, E. S.: Eddy correlation measurements of methane flux in a northern peatland ecosystem, Bound.-Lay. Meteorol., 58, 289–304, https://doi.org/10.1007/BF02033829, 1992.

Vermote, E.: MOD09A1 MODIS Surface Reflectance 8-Day L3 Global 500m SIN Grid V006, NASA EOSDIS Land Processes DAAC [data set], https://doi.org/10.5067/MODIS/MOD09A1.006 (Terra), 2015.

Vesala, T., Tuittila, E.-S., Mammarella, I., and Aleksey-
chik, P.: FLUXNET-CH₄ FI-Si2 Siikaneva-2 Bog, Fin-
land, FLUXNET-CH4 Community Product [data set],
https://doi.org/10.18140/FLX/1669639, 2020a.

Vesala, T., Tuittila, E.-S., Mammarella, I., and Rinne,
J.: FLUXNET-CH₄ FI-Sii Siikaneva, Finland,
FLUXNET-CH4 Community Product [data set],
https://doi.org/10.18140/FLX/1669640, 2020b.

Villarreal, S., Guevara, M., Alcaraz-Segura, D., Brunsell,
N. A., Hayes, D., Loescher, H. W., and Vargas, R.: Ecosystem functional diversity and the representative-
ness of environmental networks across the contermini-

nous United States, Agr. Forest Meteorol., 262, 423–433,
https://doi.org/10.1016/j.agrformet.2018.07.016, 2018.

Villarreal, S., Guevara, M., Alcaraz-Segura, D., and Vargas, R.: Optimizing an Environmental Observatory Network Design Using Publicly Available Data, J. Geophys. Res.-Biogeo., 124, 1812–1826, https://doi.org/10.1029/2018JG004714, 2019.

Vourlitis, G., Dalmagro, H., de Nogueira, J. S., Johnson, M., and
Arruda, P. FLUXNET-CH₄ BR-Npw Northern Pantanal Wet-
land, Brazil, FLUXNET-CH4 Community Product [data set],
https://doi.org/10.18140/FLX/1669368, 2020.

Vuichard, N. and Papale, D.: Filling the gaps in meteorological continuous data measured at FLUXNET sites with ERA-Interim reanalysis, Earth Syst. Sci. Data, 7, 157–171, https://doi.org/10.5194/essd-7-157-2015, 2015.

Weston, N. B., Dixon, R. E., and Joye, S. B.: Ramifications of increased salinity in tidal freshwater sediments: Geochemistry and microbial pathways of organic matter mineralization, J. Geophys. Res., 111, G01009, https://doi.org/10.1029/2005jg000071, 2006.

Weston, N. B., Vile, M. A., Neubauer, S. C., and Velinsky, D. J.: Ac-
celerated microbial organic matter mineralization following salt-
water intrusion into tidal freshwater marsh soils, Biogeochem-
istry, 102, 135–151, https://doi.org/10.1007/s10533-010-9427-4,
2011.

Wik, M., Crill, P. M., Varner, R. K., and Bastviken, D.: Multiyear measurements of ebullitive methane flux from three subarctic lakes, J. Geophys. Res.-Biogeo., 118, 1307–1321, https://doi.org/10.1002/jgrg.20103, 2013.

Windham-Myers, L., Stuart-Haëntjens, E., Bergamaschi, B., and
Knox, S.: FLUXNET-CH₄ US-Srr Suisun marsh – Rush Ranch,
United States, FLUXNET-CH4 Community Product [data set],
https://doi.org/10.18140/FLX/1669694, 2020.

Windsor, J., Moore, T. R., and Roulet, N. T.: Episodic fluxes of methane from subarctic fens, Can. J. Soil Sci., 72, 441–452, https://doi.org/10.4141/cjss92-037, 1992.

Wohlfahrt, G.: FLUXNET-CH₄ AT-Neu Neustift, Austria, FLUXNET-CH4 Community Product [data set], https://doi.org/10.18140/FLX/1669365, 2020.

Wong, G. X., Melling, L., Tang, A. C. I. Aeries, E. B., Waili, J. W., Musin, K. K., Lo, K. S., and Kiew, F.: FLUXNET-CH₄ MY-MLM Maludam National Park, Malaysia, FLUXNET-CH4 Community Product [data set], https://doi.org/10.18140/FLX/1669650, 2020.

Wutzler, T., Lucas-Moffat, A., Migliavacca, M., Knauer, J., Sickel, K., Šigut, L., Menzer, O., and Reichstein, M.: Basic and extensible post-processing of eddy covariance flux data with REddyProc, Biogeosciences, 15, 5015–5030, https://doi.org/10.5194/bg-15-5015-2018, 2018.

Xu, X., Riley, W. J., Koven, C. D., Billesbach, D. P., Chang, R. Y.-W., Commane, R., Euskirchen, E. S., Hartery, S., Harazono, Y., Iwata, H., McDonald, K. C., Miller, C. E., Oechel, W. C., Poulter, B., Raz-Yaseef, N., Sweeney, C., Torn, M., Wofsy, S. C., Zhang, Z., and Zona, D.: A multi-scale comparison of modeled and observed seasonal methane emissions in northern wetlands, Biogeosciences, 13, 5043–5056, https://doi.org/10.5194/bg-13-5043-2016, 2016.

Yvon-Durocher, G., Allen, A. P., Bastviken, D., Conrad, R., Gu-
dasz, C., St-Pierre, A., Thanh-Duc, N., and del Giorgio, P.
A.: Methane fluxes show consistent temperature dependence
across microbial to ecosystem scales, Nature, 507, 488–491,
https://doi.org/10.1038/nature13164, 2014.

Zhang, Z., Fluet-Choinard, E., Jensen, K., McDonald, K., Hugelius,
G., Gumbricht, T., Carrol, M., Prigent, C., Bartsch, A., and Poul-
ter, B.: Development of a global dataset of Wetland Area and
Dynamics for Methane Modeling (WAD2M), Zenodo [data set],
https://doi.org/10.5281/zenodo.3998454, 2020.

Zhang, Z., Fluet-Chouinard, E., Jensen, K., McDonald, K., Hugelius, G., Gumbricht, T., Carroll, M., Prigent, C., Bartsch, A., and Poulter, B.: Development of the global dataset of Wetland Area and Dynamics for Methane Modeling (WAD2M), Earth Syst. Sci. Data, 13, 2001–2023, https://doi.org/10.5194/essd-13-2001-2021, 2021.

Zona, D. and Oechel, W. C.: FLUXNET-CH₄ US-Atq Atqasuk, United States, FLUXNET-CH4 Community Product [data set], https://doi.org/10.18140/FLX/1669663, 2020a.

Zona, D. and Oechel, W. C.: FLUXNET-CH₄ US-Beo Bar-
row Environmental Observatory (BEO) tower, United
States, FLUXNET-CH4 Community Product [data set],
https://doi.org/10.18140/FLX/1669664, 2020b.

Zona, D. and Oechel, W. C.: FLUXNET-CH₄ US-Bes Barrow-Bes (Biocomplexity Experiment South tower), United States, FLUXNET-CH4 Community Product [data set], https://doi.org/10.18140/FLX/1669665, 2020c.

Zona, D. and Oechel, W. C.: FLUXNET-CH₄ US-Ivo Ivotuk, United States, FLUXNET-CH4 Community Product [data set], https://doi.org/10.18140/FLX/1669679, 2020d.

Zona, D., Gioli, B., Commane, R., Lindaas, J., Wofsy, S. C., Miller, C. E., Dinardo, S. J., Dengel, S., Sweeney, C., Karion, A., Chang, R. Y.-W., Henderson, J. M., Murphy, P. C., Goodrich, J. P., Moreaux, V., Liljedahl, A., Watts, J. D., Kimball, J. S., Lipson, D. A., and Oechel, W. C.: Cold season emissions dominate the Arctic tundra methane budget, P. Natl. Acad. Sci. USA, 113, 40–45, https://doi.org/10.1073/pnas.1516017113, 2016.