CO2 flux; UAV remote sensing; Peatland; Soil respiration
Abstract :
[en] CO2 emissions from peatlands exhibit substantial spatiotemporal variability, presenting challenges for identifying the underlying drivers and for accurately quantifying and modeling CO2 fluxes. Here, we integrated field measurements with Unmanned Aerial Vehicle (UAV)-based multi-sensor remote sensing to investigate soil respiration across a temperate peatland landscape. Our research addressed two key questions: (1) How do environmental factors control the spatiotemporal distribution of soil respiration across complex landscapes? (2) How do spatial and temporal peaks (i.e., hot spots and hot moments) of biogeochemical processes influence landscape-level CO2 fluxes? We find that dynamic variables (i.e., soil temperature and moisture) play significant roles in shaping CO2 flux variations, contributing 43 % to seasonal variability and 29 % to spatial variance, followed by semi-dynamic variables (i.e., Normalized Difference Vegetation Index (NDVI) and root biomass) (19 % and 24 %). Relatively static variables (i.e., soil organic carbon stock and carbon to nitrogen ratio) have a minimal influence on seasonal variation (2 %) but contribute more to spatial variance (10 %). Additionally, predicting time series of CO2 fluxes is feasible by using key environmental variables (test set: coefficient of determination (R2) = 0.74, Root Mean Square Error (RMSE) = 0.57 µmolm-2s-1, Kling-Gupta Efficiency (KGE) = 0.77), while UAV remote sensing is an effective tool for mapping daily daytime soil respiration (test set: R2=0.75, RMSE = 0.56 µmolm-2s-1, KGE = 0.83). By the integration of in-situ high-resolution time-lapse monitoring and spatial mapping, we find that despite occurring in 10 % of the year, hot moments (i.e., periods of time which have a disproportional high (>90th percentile) CO2 fluxes compared to the surrounding) contribute 28 %–31 % of the annual CO2 fluxes. Meanwhile, hot spots (i.e., locations which CO2 fluxes higher than 90th percentile) – representing 10 % of the area – account for about 20 % of CO2 fluxes across the landscape. Our study demonstrates that integrating UAV-based remote sensing with field surveys improves the understanding of soil respiration mechanisms across timescales in complex landscapes. This will provide insights into carbon dynamics and supporting peatland conservation and climate change mitigation efforts.
Jonard, François ✱; Université de Liège - ULiège > Département de géographie ; Université de Liège - ULiège > Sphères ; Université de Liège - ULiège > Département de géographie > Earth Observation and Ecosystem Modelling (EOSystM Lab)
Van Oost, Kristof ✱
✱ These authors have contributed equally to this work.
Language :
English
Title :
Hot spots, hot moments, and spatiotemporal drivers of soil CO2 flux in temperate peatlands using UAV remote sensing
Abdalla, M., Hastings, A., Bell, M. J., Smith, J. U., Richards, M., Nilsson, M. B., Peichl, M., Löfvenius, M. O., Lund, M., Helfter, C., Nemitz, E., Sutton, M. A., Aurela, M., Lohila, A., Laurila, T., Dolman, A. J., Belelli-Marchesini, L., Pogson, M., Jones, E., Drewer, J., Drosler, M., and Smith, P.: Simulation of CO2 and Attribution Analysis at Six European Peatland Sites Using the ECOSSE Model, Water, Air, & Soil Pollution, 225, 2182, https://doi.org/10.1007/s11270-014-2182-8, 2014.
Acosta, M., Juszczak, R., Chojnicki, B., Pavelka, M., Havránková, K., Lesny, J., Krupková, L., Urbaniak, M., Machaĉová, K., and Olejnik, J.: CO2 Fluxes from Different Vegetation Communities on a Peatland Ecosystem, Wetlands, 37, 423-435, https://doi.org/10.1007/s13157-017-0878-4, 2017.
Anthony, T. L. and Silver, W. L.: Hot moments drive extreme nitrous oxide and methane emissions from agricultural peatlands, Global Change Biology, 27, 5141-5153, https://doi.org/10.1111/gcb.15802, 2021.
Anthony, T. L. and Silver, W. L.: Hot spots and hot moments of greenhouse gas emissions in agricultural peatlands, Biogeochemistry, 167, 461-477, https://doi.org/10.1007/s10533-023-01095-y, 2023.
Arias-Navarro, C., Díaz-Pinés, E., Klatt, S., Brandt, P., Rufino, M. C., Butterbach-Bahl, K., and Verchot, L. V.: Spatial variability of soil N2O and CO2 fluxes in different topographic positions in a tropical montane forest in Kenya, Journal of Geophysical Research: Biogeosciences, 122, 514-527, https://doi.org/10.1002/2016JG003667, 2017.
Azevedo, O., Parker, T. C., Siewert, M. B., and Subke, J.-A.: Predicting Soil Respiration from Plant Productivity (NDVI) in a Sub-Arctic Tundra Ecosystem, Remote Sensing, 13, 2571, https://doi.org/10.3390/rs13132571, 2021.
Baird, A. J., Beckwith, C. W., Waldron, S., and Waddington, J. M.: Ebullition of methane-containing gas bubbles from near-surface Sphagnum peat, Geophysical Research Letters, 31, L21505, https://doi.org/10.1029/2004GL021157, 2004.
Becker, T., Kutzbach, L., Forbrich, I., Schneider, J., Jager, D., Thees, B., and Wilmking, M.: Do we miss the hot spots?-The use of very high resolution aerial photographs to quantify carbon fluxes in peatlands, Biogeosciences, 5, 1387-1393, https://doi.org/10.5194/bg-5-1387-2008, 2008.
Berglund, Ö. and Berglund, K.: Influence of water table level and soil properties on emissions of greenhouse gases from cultivated peat soil, Soil Biology and Biochemistry, 43, 923-931, https://doi.org/10.1016/j.soilbio.2011.01.002, 2011.
Bragazza, L., Parisod, J., Buttler, A., and Bardgett, R. D.: Biogeochemical plant-soil microbe feedback in response to climate warming in peatlands, Nature Climate Change, 3, 273-277, https://doi.org/10.1038/nclimate1781, 2013.
Briones, M. J. I., McNamara, N. P., Poskitt, J., Crow, S. E., and Ostle, N. J.: Interactive biotic and abiotic regulators of soil carbon cycling: evidence from controlled climate experiments on peatland and boreal soils, Global Change Biology, 20, 2971-2982, https://doi.org/10.1111/gcb.12585, 2014.
Bubier, J. L., Bhatia, G., Moore, T. R., Roulet, N. T., and Lafleur, P. M.: Spatial and Temporal Variability in Growing-Season Net Ecosystem Carbon Dioxide Exchange at a Large Peatland in Ontario, Canada, Ecosystems, 6, 353-367, https://doi.org/10.1007/s10021-003-0125-0, 2003.
Crow, S. E. and Wieder, R. K.: SOURCES OF CO2 EMISSION FROM A NORTHERN PEATLAND: ROOT RESPIRATION, EXUDATION, AND DECOMPOSITION, Ecology, 86, 1825-1834, https://doi.org/10.1890/04-1575, 2005.
Danevĉiĉ, T., Mandic-Mulec, I., Stres, B., Stopar, D., and Hacin, J.: Emissions of CO2, CH4 and N2O from Southern European peatlands, Soil Biology and Biochemistry, 42, 1437-1446, https://doi.org/10.1016/j.soilbio.2010.05.004, 2010.
Deshmukh, C. S., Julius, D., Desai, A. R., Asyhari, A., Page, S. E., Nardi, N., Susanto, A. P., Nurholis, N., Hendrizal, M., Kurnianto, S., Suardiwerianto, Y., Salam, Y. W., Agus, F., Astiani, D., Sabiham, S., Gauci, V., and Evans, C. D.: Conservation slows down emission increase from a tropical peatland in Indonesia, Nature Geoscience, 14, 484-490, https://doi.org/10.1038/s41561-021-00785-2, 2021.
Dettmann, U., Kraft, N. N., Rech, R., Heidkamp, A., and Tiemeyer, B.: Analysis of peat soil organic carbon, total nitrogen, soil water content and basal respiration: Is there a "best" drying temperature?, Geoderma, 403, 115231, https://doi.org/10.1016/j.geoderma.2021.115231, 2021.
Dorrepaal, E., Toet, S., van Logtestijn, R. S. P., Swart, E., van de Weg, M. J., Callaghan, T. V., and Aerts, R.: Carbon respiration from subsurface peat accelerated by climate warming in the subarctic, Nature, 460, 616-619, https://doi.org/10.1038/nature08216, 2009.
Dunn, O. J.: Multiple Comparisons Using Rank Sums, Technometrics, 6, 241-252, https://doi.org/10.2307/1266041, 1964.
Evans, C. D., Peacock, M., Baird, A. J., Artz, R. R. E., Burden, A., Callaghan, N., Chapman, P. J., Cooper, H. M., Coyle, M., Craig, E., Cumming, A., Dixon, S., Gauci, V., Grayson, R. P., Helfter, C., Heppell, C. M., Holden, J., Jones, D. L., Kaduk, J., Levy, P., Matthews, R., McNamara, N. P., Misselbrook, T., Oakley, S., Page, S. E., Rayment, M., Ridley, L. M., Stanley, K. M., Williamson, J. L., Worrall, F., and Morrison, R.: Overriding water table control on managed peatland greenhouse gas emissions, Nature, 593, 548-552, https://doi.org/10.1038/s41586-021-03523-1, 2021.
Fang, C. and Moncrieff, J. B.: The dependence of soil CO2 efflux on temperature, Soil Biology and Biochemistry, 33, 155-165, https://doi.org/10.1016/S0038-0717(00)00125-5, 2001.
Farmer, J., Matthews, R., Smith, J. U., Smith, P., and Singh, B. K.: Assessing existing peatland models for their applicability for modelling greenhouse gas emissions from tropical peat soils, Current Opinion in Environmental Sustainability, 3, 339-349, https://doi.org/10.1016/j.cosust.2011.08.010, 2011.
Fernandez-Bou, A. S., Dierick, D., Allen, M. F., and Harmon, T. C.: Precipitation-drainage cycles lead to hot moments in soil carbon dioxide dynamics in a Neotropical wet forest, Global Change Biology, 26, 5303-5319, https://doi.org/10.1111/gcb.15194, 2020.
Fox, J. and Monette, G.: Generalized Collinearity Diagnostics, Journal of the American Statistical Association, 87, 178-183, https://doi.org/10.2307/2290467, 1992.
Frankard, P., Ghiette, P., Hindryckx, M.-N., Schumacker, R., and Wastiaux, C.: Peatlands ofWallony (S-Belgium), SUO, Helsinki, Finland, 01/01, 33-37, 1998.
Frei, S., Knorr, K. H., Peiffer, S., and Fleckenstein, J. H.: Surface micro-topography causes hot spots of biogeochemical activity in wetland systems: A virtual modeling experiment, Journal of Geophysical Research: Biogeosciences, 117, https://doi.org/10.1029/2012JG002012, 2012.
Gachibu Wangari, E., Mwangada Mwanake, R., Houska, T., Kraus, D., Gettel, G. M., Kiese, R., Breuer, L., and Butterbach-Bahl, K.: Identifying landscape hot and cold spots of soil greenhouse gas fluxes by combining field measurements and remote sensing data, Biogeosciences, 20, 5029-5067, https://doi.org/10.5194/bg-20-5029-2023, 2023.
García-García, A., Cuesta-Valero, F. J., Miralles, D. G., Mahecha, M. D., Quaas, J., Reichstein, M., Zscheischler, J., and Peng, J.: Soil heat extremes can outpace air temperature extremes, Nature Climate Change, 13, 1237-1241, https://doi.org/10.1038/s41558-023-01812-3, 2023.
Goemaere, E., Demarque, S., Dreesen, R., and Declercq, P.-Y. J. G.: The geological and cultural heritage of the Caledonian Stavelot-Venn Massif, Belgium, Geoheritage, 8, 211-233, https://doi.org/10.1007/s12371-015-0155-y, 2016.
Gupta, H. V., Kling, H., Yilmaz, K. K., and Martinez, G. F.: Decomposition of the mean squared error and NSE performance criteria: Implications for improving hydrological modelling, Journal of Hydrology, 377, 80-91, https://doi.org/10.1016/j.jhydrol.2009.08.003, 2009.
Hair, J., Black, W., Babin, B., and Anderson, R.: Multivariate Data Analysis: A Global Perspective, 7, Pearson Education, ISBN: 9780135153093, ISBN: 0135153093, 2010.
Harris, A. and Baird, A. J.: Microtopographic Drivers of Vegetation Patterning in Blanket Peatlands Recovering from Erosion, Ecosystems, 22, 1035-1054, https://doi.org/10.1007/s10021-018-0321-6, 2019.
Hatala, J. A., Detto, M., Sonnentag, O., Deverel, S. J., Verfaillie, J., and Baldocchi, D. D.: Greenhouse gas (CO2, CH4, H2O) fluxes from drained and flooded agricultural peatlands in the Sacramento-San Joaquin Delta, Agriculture, Ecosystems & Environment, 150, 1-18, https://doi.org/10.1016/j.agee.2012.01.009, 2012.
Henrion, M., Li, Y., Koganti, T., Bechtold, M., Jonard, F., Opfergelt, S., Vanacker, V., Van Oost, K., and Lambot, S.: Mapping and monitoring peatlands in the Belgian Hautes Fagnes: Insights from Ground-penetrating radar and Electromagnetic induction characterization, Geoderma Regional, 37, e00795, https://doi.org/10.1016/j.geodrs.2024.e00795, 2024.
Henrion, M., Li, Y., Wu, K., Jonard, F., Opfergelt, S., Vanacker, V., Van Oost, K., and Lambot, S.: Drone-borne groundpenetrating radar reveals spatiotemporal moisture dynamics in peatland root zones, Science of Remote Sensing, 12, 100311, https://doi.org/10.1016/j.srs.2025.100311, 2025.
Hopple, A. M., Wilson, R. M., Kolton, M., Zalman, C. A., Chanton, J. P., Kostka, J., Hanson, P. J., Keller, J. K., and Bridgham, S. D.: Massive peatland carbon banks vulnerable to rising temperatures, Nature Communications, 11, 2373, https://doi.org/10.1038/s41467-020-16311-8, 2020.
Hoyos-Santillan, J., Lomax, B. H., Large, D., Turner, B. L., Boom, A., Lopez, O. R., and Sjögersten, S.: Quality not quantity: Organic matter composition controls of CO2 and CH4 fluxes in neotropical peat profiles, Soil Biology and Biochemistry, 103, 86-96, https://doi.org/10.1016/j.soilbio.2016.08.017, 2016.
Hoyt, A. M., Gandois, L., Eri, J., Kai, F. M., Harvey, C. F., and Cobb, A. R.: CO2 emissions from an undrained tropical peatland: Interacting influences of temperature, shading and water table depth, Global Change Biology, 25, 2885-2899, https://doi.org/10.1111/gcb.14702, 2019.
Huang, N., Gu, L., Black, T. A., Wang, L., and Niu, Z.: Remote sensing-based estimation of annual soil respiration at two contrasting forest sites, Journal of Geophysical Research: Biogeosciences, 120, 2306-2325, https://doi.org/10.1002/2015JG003060, 2015.
Huang, Y., Ciais, P., Luo, Y., Zhu, D., Wang, Y., Qiu, C., Goll, D. S., Guenet, B., Makowski, D., De Graaf, I., Leifeld, J., Kwon, M. J., Hu, J., and Qu, L.: Tradeoff of CO2 and CH4 emissions from global peatlands under water-table drawdown, Nature Climate Change, 11, 618-622, https://doi.org/10.1038/s41558-021-01059-w, 2021.
Ishikura, K., Darung, U., Inoue, T., and Hatano, R.: Variation in Soil Properties Regulate Greenhouse Gas Fluxes and Global Warm-ing Potential in Three Land Use Types on Tropical Peat, Atmosphere, 9, 465, https://doi.org/10.3390/atmos9120465, 2018.
Jovani-Sancho, A. J., Cummins, T., and Byrne, K. A.: Soil carbon balance of afforested peatlands in the maritime temperate climatic zone, Global Change Biology, 27, 3681-3698, https://doi.org/10.1111/gcb.15654, 2021.
Junttila, S., Kelly, J., Kljun, N., Aurela, M., Klemedtsson, L., Lohila, A., Nilsson, M. B., Rinne, J., Tuittila, E.-S., Vestin, P., Weslien, P., and Eklundh, L.: Upscaling Northern Peatland CO2 Fluxes Using Satellite Remote Sensing Data, Remote Sensing, 13, 818, https://doi.org/10.3390/rs13040818, 2021.
Juszczak, R., Humphreys, E., Acosta, M., Michalak-Galczewska, M., Kayzer, D., and Olejnik, J.: Ecosystem respiration in a heterogeneous temperate peatland and its sensitivity to peat temperature and water table depth, Plant and Soil, 366, 505-520, https://doi.org/10.1007/s11104-012-1441-y, 2013.
Kannenberg, S. A., Bowling, D. R., and Anderegg, W. R. L.: Hot moments in ecosystem fluxes: High GPP anomalies exert outsized influence on the carbon cycle and are differentially driven by moisture availability across biomes, Environmental Research Letters, 15, 054004, https://doi.org/10.1088/1748-9326/ab7b97, 2020.
Kechavarzi, C., Dawson, Q., Bartlett, M., and Leeds-Harrison, P. B.: The role of soil moisture, temperature and nutrient amendment on CO2 efflux from agricultural peat soil microcosms, Geoderma, 154, 203-210, https://doi.org/10.1016/j.geoderma.2009.02.018, 2010.
Kelly, J., Kljun, N., Eklundh, L., Klemedtsson, L., Liljebladh, B., Olsson, P.-O., Weslien, P., and Xie, X.: Modelling and upscaling ecosystem respiration using thermal cameras and UAVs: Application to a peatland during and after a hot drought, Agricultural and Forest Meteorology, 300, 108330, https://doi.org/10.1016/j.agrformet.2021.108330, 2021.
Kim, J. and Verma, S. B.: Soil surface CO2 flux in a Minnesota peatland, Biogeochemistry, 18, 37-51, https://doi.org/10.1007/BF00000425, 1992.
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, Global Change Biology, 21, 750-765, https://doi.org/10.1111/gcb.12745, 2015.
Krichels, A. H. and Yang, W. H.: Dynamic Controls on Field-Scale Soil Nitrous Oxide Hot Spots and Hot Moments Across a Microtopographic Gradient, Journal of Geophysical Research: Biogeosciences, 124, 3618-3634, https://doi.org/10.1029/2019JG005224, 2019.
Kuzyakov, Y. and Blagodatskaya, E.: Microbial hotspots and hot moments in soil: Concept & review, Soil Biology and Biochemistry, 83, 184-199, https://doi.org/10.1016/j.soilbio.2015.01.025, 2015.
Lai, D. Y. F., Roulet, N. T., Humphreys, E. R., Moore, T. R., and Dalva, M.: The effect of atmospheric turbulence and chamber deployment period on autochamber CO2 and CH4 flux measurements in an ombrotrophic peatland, Biogeosciences, 9, 3305-3322, https://doi.org/10.5194/bg-9-3305-2012, 2012.
Lai, J., Zou, Y., Zhang, S., Zhang, X., and Mao, L.: glmm.hp: an R package for computing individual effect of predictors in generalized linear mixed models, Journal of Plant Ecology, 15, 1302-1307, https://doi.org/10.1093/jpe/rtac096, 2022.
Lai, J., Zhu, W., Cui, D., and Mao, L.: Extension of the glmm.hp package to zero-inflated generalized linear mixed models and multiple regression, Journal of Plant Ecology, 16, rtad038, https://doi.org/10.1093/jpe/rtad038, 2023.
Lees, K. J., Quaife, T., Artz, R. R. E., Khomik, M., and Clark, J. M.: Potential for using remote sensing to estimate carbon fluxes across northern peatlands-A review, Science of The Total Environment, 615, 857-874, https://doi.org/10.1016/j.scitotenv.2017.09.103, 2018.
Leifeld, J. and Menichetti, L.: The underappreciated potential of peatlands in global climate change mitigation strategies, Nature Communications, 9, 1071, https://doi.org/10.1038/s41467-018-03406-6, 2018.
Leifeld, J., Steffens, M., and Galego-Sala, A.: Sensitivity of peatland carbon loss to organic matter quality, Geophysical Research Letters, 39, L14704, https://doi.org/10.1029/2012GL051856, 2012.
Leifeld, J., Wüst-Galley, C., and Page, S.: Intact and managed peatland soils as a source and sink of GHGs from 1850 to 2100, Nature Climate Change, 9, 945-947, https://doi.org/10.1038/s41558-019-0615-5, 2019.
Leifeld, J., Klein, K., and Wüst-Galley, C.: Soil organic matter stoichiometry as indicator for peatland degradation, Scientific Reports, 10, 7634, https://doi.org/10.1038/s41598-020-64275-y, 2020.
Leon, E., Vargas, R., Bullock, S., Lopez, E., Panosso, A. R., and La Scala, N.: Hot spots, hot moments, and spatio-temporal controls on soil CO2 efflux in a waterlimited ecosystem, Soil Biology and Biochemistry, 77, 12-21, https://doi.org/10.1016/j.soilbio.2014.05.029, 2014.
Li, Y., Henrion, M., Moore, A., Lambot, S., Opfergelt, S., Vanacker, V., Jonard, F., and Van Oost, K.: Factors controlling peat soil thickness and carbon storage in temperate peatlands based on UAV high-resolution remote sensing, Geoderma, 449, 117009, https://doi.org/10.1016/j.geoderma.2024.117009, 2024.
Li, Y., Henrion, M., Moore, A., Lambot, S., Opfergelt, S., Vanacker, V., Jonard, F., and Oost, K. V.: Research data-Hot spots, hot moments, and spatiotemporal drivers of soil CO2 flux in temperate peatlands using UAV remote sensing, HydroShare [code and data set], 95, https://doi.org/10.4211/hs.a4efce8d4d114b939f0d92a18b3168c6, 2025.
Li, Z.-L., Wu, H., Wang, N., Qiu, S., Sobrino, J. A., Wan, Z., Tang, B.-H., and Yan, G.: Land surface emissivity retrieval from satellite data, International Journal of Remote Sensing, 34, 3084-3127, https://doi.org/10.1080/01431161.2012.716540, 2013.
Marwanto, S. and Agus, F.: Is CO2 flux from oil palm plantations on peatland controlled by soil moisture and/or soil and air temperatures?, Mitigation and Adaptation Strategies for Global Change, 19, 809-819, https://doi.org/10.1007/s11027-013-9518-3, 2014.
Mason, C. W., Stoof, C. R., Richards, B. K., Das, S., Goodale, C. L., and Steenhuis, T. S.: Hotspots of Nitrous Oxide Emission in Fertilized and Unfertilized Perennial Grasses, Soil Science Society of America Journal, 81, 450-458, https://doi.org/10.2136/sssaj2016.08.0249, 2017.
McClain, M. E., Boyer, E. W., Dent, C. L., Gergel, S. E., Grimm, N. B., Groffman, P. M., Hart, S. C., Harvey, J. W., Johnston, C. A., Mayorga, E., McDowell, W. H., and Pinay, G.: Biogeochemical Hot Spots and Hot Moments at the Interface of Terrestrial and Aquatic Ecosystems, Ecosystems, 6, 301-312, https://doi.org/10.1007/s10021-003-0161-9, 2003.
McNamara, N. P., Plant, T., Oakley, S., Ward, S., Wood, C., and Ostle, N.: Gully hotspot contribution to landscape methane (CH4) and carbon dioxide (CO2) fluxes in a northern peatland, Science of The Total Environment, 404, 354-360, https://doi.org/10.1016/j.scitotenv.2008.03.015, 2008.
Meehl, G. A. and Tebaldi, C.: More Intense, More Frequent, and Longer Lasting Heat Waves in the 21st Century, Science, 305, 994-997, https://doi.org/10.1126/science.1098704, 2004.
Minasny, B., Berglund, Ö., Connolly, J., Hedley, C., de Vries, F., Gimona, A., Kempen, B., Kidd, D., Lilja, H., Malone, B., McBratney, A., Roudier, P., O'Rourke, S., Rudiyanto, Padarian, J., Poggio, L., ten Caten, A., Thompson, D., Tuve, C., and Widyatmanti, W.: Digital mapping of peatlands-A critical review, Earth-Science Reviews, 196, 102870, https://doi.org/10.1016/j.earscirev.2019.05.014, 2019.
Moore, H. E., Comas, X., Briggs, M. A., Reeve, A. S., and Slater, L. D.: Indications of preferential groundwater seepage feeding northern peatland pools, Journal of Hydrology, 638, 131479, https://doi.org/10.1016/j.jhydrol.2024.131479, 2024.
Moore, P. A., Lukenbach, M. C., Thompson, D. K., Kettridge, N., Granath, G., and Waddington, J. M.: Assessing the peatland hummock-hollow classification framework using highresolution elevation models: implications for appropriate complexity ecosystem modeling, Biogeosciences, 16, 3491-3506, https://doi.org/10.5194/bg-16-3491-2019, 2019.
Mormal, P. and Tricot, C.: Aperçu climatique des Hautes-Fagnes, Institut Royal météorologique de Belgique, Brussel, 20-25, 2004.
Murdoch, D. J. and Chow, E. D.: A Graphical Display of Large Correlation Matrices, The American Statistician, 50, 178-180, https://doi.org/10.2307/2684435, 1996.
Nakagawa, S., Johnson, P. C. D., and Schielzeth, H.: The coefficient of determination R2 and intra-class correlation coefficient from generalized linear mixed-effects models revisited and expanded, Journal of The Royal Society Interface, 14, 20170213, https://doi.org/10.1098/rsif.2017.0213, 2017.
Nichols, D. S.: Temperature of upland and peatland soils in a north central Minnesota forest, Canadian Journal of Soil Science, 78, 493-509, https://doi.org/10.4141/S96-030, 1998.
Pajula, R. and Purre, A.-H.: NDVI as a proxy to estimate the CO2 fluxes in peatlands: example of alkaline fen, The 16th International Peatland Congress: Peatland and Peat-Source of Ecosystem Services, Tallinn, Estonia, 3-6 May 2021, ID 62654, 2021.
Pinheiro, J. C. and Bates, D. M.: Fitting Linear Mixed-Effects Models, in: Mixed-Effects Models in S and S-PLUS, reprint ed., edited by: Pinheiro, J. C. and Bates, D. M., Springer New York, New York, NY, 133-199, https://doi.org/10.1007/0-387-22747-4_4, 2000.
Prananto, J. A., Minasny, B., Comeau, L.-P., Rudiyanto, R., and Grace, P.: Drainage increases CO2 and N2O emissions from tropical peat soils, Global Change Biology, 26, 4583-4600, https://doi.org/10.1111/gcb.15147, 2020.
Rey-Sanchez, C., Arias-Ortiz, A., Kasak, K., Chu, H., Szutu, D., Verfaillie, J., and Baldocchi, D.: Detecting Hot Spots of Methane Flux Using Footprint-Weighted Flux Maps, Journal of geophysical research: Biogeosciences, 127, e2022JG006977, https://doi.org/10.1029/2022jg006977, 2022.
Risk, D., Nickerson, N., Creelman, C., McArthur, G., and Owens, J.: Forced Diffusion soil flux: A new technique for continuous monitoring of soil gas efflux, Agricultural and Forest Meteorology, 151, 1622-1631, https://doi.org/10.1016/j.agrformet.2011.06.020, 2011.
Rowson, J., Worrall, F., Evans, M., and Dixon, S.: Predicting soil respiration from peatlands, Science of The Total Environment, 442C, 397-404, https://doi.org/10.1016/j.scitotenv.2012.10.021, 2012.
Ryan, M. G. and Law, B. E.: Interpreting, measuring, and modeling soil respiration, Biogeochemistry, 73, 3-27, https://doi.org/10.1007/s10533-004-5167-7, 2005.
Schubert, P., Eklundh, L., Lund, M., and Nilsson, M.: Estimating northern peatland CO2 exchange from MODIS time series data, Remote Sensing of Environment, 114, 1178-1189, https://doi.org/10.1016/j.rse.2010.01.005, 2010.
Shrout, P. E. and Fleiss, J. L.: Intraclass correlations: Uses in assessing rater reliability, Psychological Bulletin, 86, 420-428, https://doi.org/10.1037/0033-2909.86.2.420, 1979.
Simpson, G.: Drivers of peatland CO2 balance: a fusion of UAV remote sensing and micrometeorology, Doctoral dissertation, School of GeoSciences, The University of Edinburgh, U.K., 57-157 pp., https://doi.org/10.7488/era/3228, 2023.
Snyder, W. C., Wan, Z., Zhang, Y., and Feng, Y. Z.: Classificationbased emissivity for land surface temperature measurement from space, International Journal of Remote Sensing, 19, 2753-2774, https://doi.org/10.1080/014311698214497, 1998.
Sougnez, N. and Vanacker, V.: The topographic signature of Quaternary tectonic uplift in the Ardennes massif (Western Europe), Hydrol. Earth Syst. Sci., 15, 1095-1107, https://doi.org/10.5194/hess-15-1095-2011, 2011.
Steenvoorden, J., Bartholomeus, H., and Limpens, J.: Less is more: Optimizing vegetation mapping in peatlands using unmanned aerial vehicles (UAVs), International Journal of Applied Earth Observation and Geoinformation, 117, 103220, https://doi.org/10.1016/j.jag.2023.103220, 2023.
Stoy, P. C., Street, L. E., Johnson, A. V., Prieto-Blanco, A., and Ewing, S. A.: Temperature, Heat Flux, and Reflectance of Common Subarctic Mosses and Lichens under Field Conditions: Might Changes to Community Composition Impact Climate-Relevant Surface Fluxes?, Arctic, Antarctic, and Alpine Research, 44, 500-508, https://doi.org/10.1657/1938-4246-44.4.500, 2012.
Swails, E. E., Ardón, M., Krauss, K. W., Peralta, A. L., Emanuel, R. E., Helton, A. M., Morse, J. L., Gutenberg, L., Cormier, N., Shoch, D., Settlemyer, S., Soderholm, E., Boutin, B. P., Peoples, C., and Ward, S.: Response of soil respiration to changes in soil temperature and water table level in drained and restored peatlands of the southeastern United States, Carbon Balance and Management, 17, 18, https://doi.org/10.1186/s13021-022-00219-5, 2022.
Tokida, T., Miyazaki, T., Mizoguchi, M., Nagata, O., Takakai, F., Kagemoto, A., and Hatano, R.: Falling atmospheric pressure as a trigger for methane ebullition from peatland, Global Biogeochemical Cycles, 21, GB2003, https://doi.org/10.1029/2006GB002790, 2007.
Tokida, T., Miyazaki, T., and Mizoguchi, M.: Ebullition of methane from peat with falling atmospheric pressure, Geophysical Research Letters, 32, https://doi.org/10.1029/2005GL022949, 2005.
Turetsky, M. R., Benscoter, B., Page, S., Rein, G., van der Werf, G. R., and Watts, A.: Global vulnerability of peatlands to fire and carbon loss, Nature Geoscience, 8, 11-14, https://doi.org/10.1038/ngeo2325, 2015.
UNEP: Global Peatlands Assessment-The State of the World's Peatlands: Evidence for action toward the conservation, restoration, and sustainable management of peatlands, Global Peatlands Initiative, United Nations Environment Programme9789280739916, 125-154, https://doi.org/10.59117/20.500.11822/41222, 2022.
van Giersbergen, Q., Barthelmes, A., Couwenberg, j., Fritz, C., Lång, K., Martin, N., and Tanneberger, F.: Identifying hotspots of greenhouse gas emissions from drained peatlands in the European Union, Research Square [preprint], https://doi.org/10.21203/rs.3.rs-4629642/v1, 2024.
Walcker, R., Le Lay, C., Gandois, L., Elger, A., and Jassey, V. E. J.: High-resolution mapping of peatland CO2 fluxes using drone multispectral images, Ecological Informatics, 86, 103060, https://doi.org/10.1016/j.ecoinf.2025.103060, 2025.
Walker, T. N., Garnett, M. H., Ward, S. E., Oakley, S., Bardgett, R. D., and Ostle, N. J.: Vascular plants promote ancient peatland carbon loss with climate warming, Global Change Biology, 22, 1880-1889, https://doi.org/10.1111/gcb.13213, 2016.
Wang, H., Richardson, C. J., and Ho, M.: Dual controls on carbon loss during drought in peatlands, Nature Climate Change, 5, 584-587, https://doi.org/10.1038/NCLIMATE2643, 2015a.
Wang, H., Tian, J., Chen, H., Ho, M., Vilgalys, R., Bu, Z.-J., Liu, X., and Richardson, C. J.: Vegetation and microbes interact to preserve carbon in many wooded peatlands, Communications Earth & Environment, 2, 67, https://doi.org/10.1038/s43247-021-00136-4, 2021.
Wang, M., Moore, T. R., Talbot, J., and Riley, J. L.: The stoichiometry of carbon and nutrients in peat formation, Global Biogeochemical Cycles, 29, 113-121, https://doi.org/10.1002/2014GB005000, 2015b.
Wangari, E. G., Mwanake, R. M., Kraus, D., Werner, C., Gettel, G. M., Kiese, R., Breuer, L., Butterbach-Bahl, K., and Houska, T.: Number of Chamber Measurement Locations for Accurate Quantification of Landscape-Scale Greenhouse Gas Fluxes: Importance of Land Use, Seasonality, and Greenhouse Gas Type, Journal of Geophysical Research: Biogeosciences, 127, e2022JG006901, https://doi.org/10.1029/2022JG006901, 2022.
Webster, K. L., Creed, I. F., Beall, F. D., and Bourbonnière, R. A.: Sensitivity of catchment-aggregated estimates of soil carbon dioxide efflux to topography under different climatic conditions, Journal of Geophysical Research: Biogeosciences, 113, G03040, https://doi.org/10.1029/2008JG000707, 2008.
Widyastuti, M. T., Minasny, B., Padarian, J., Maggi, F., Aitkenhead, M., Beucher, A., Connolly, J., Fiantis, D., Kidd, D., Ma, Y., Macfarlane, F., Robb, C., Rudiyanto, Setiawan, B. I., and Taufik, M.: Digital mapping of peat thickness and carbon stock of global peatlands, CATENA, 258, 109243, https://doi.org/10.1016/j.catena.2025.109243, 2025.
Wilkinson, S. L., Andersen, R., Moore, P. A., Davidson, S. J., Granath, G., and Waddington, J. M.: Wildfire and degradation accelerate northern peatland carbon release, Nature Climate Change, 13, 456-461, https://doi.org/10.1038/s41558-023-01657-w, 2023.
Wilson, D., Dixon, S. D., Artz, R. R. E., Smith, T. E. L., Evans, C. D., Owen, H. J. F., Archer, E., and Renou-Wilson, F.: Derivation of greenhouse gas emission factors for peatlands managed for extraction in the Republic of Ireland and the United Kingdom, Biogeosciences, 12, 5291-5308, https://doi.org/10.5194/bg-12-5291-2015, 2015.
Wood, T. E., Detto, M., and Silver, W. L.: Sensitivity of Soil Respiration to Variability in Soil Moisture and Temperature in a Humid Tropical Forest, PLOS ONE, 8, e80965, https://doi.org/10.1371/journal.pone.0080965, 2013.
Wright, E. L., Black, C. R., Turner, B. L., and Sjögersten, S.: Environmental controls of temporal and spatial variability in and fluxes in a neotropical peatland, Global Change Biology, 19, 3775-3789, https://doi.org/10.1111/gcb.12330, 2013.
Wutzler, T., Perez-Priego, O., Morris, K., El-Madany, T. S., and Migliavacca, M.: Soil CO2 efflux errors are lognormally distributed-implications and guidance, Geosci. Instrum. Method. Data Syst., 9, 239-254, https://doi.org/10.5194/gi-9-239-2020, 2020.
Zhang, C., Comas, X., and Brodylo, D.: A Remote Sensing Technique to Upscale Methane Emission Flux in a Subtropical Peatland, Journal of Geophysical Research: Biogeosciences, 125, e2020JG006002, https://doi.org/10.1029/2020JG006002, 2020.
Zou, J., Ziegler, A. D., Chen, D., McNicol, G., Ciais, P., Jiang, X., Zheng, C., Wu, J., Wu, J., Lin, Z., He, X., Brown, L. E., Holden, J., Zhang, Z., Ramchunder, S. J., Chen, A., and Zeng, Z.: Rewetting global wetlands effectively reduces major greenhouse gas emissions, Nature Geoscience, 15, 627-632, https://doi.org/10.1038/s41561-022-00989-0, 2022.
