6533b7cefe1ef96bd1257c2d

RESEARCH PRODUCT

Statistical upscaling of ecosystem CO2 fluxes across the terrestrial tundra and boreal domain: Regional patterns and uncertainties

Torsten SachsS. PotterMatthias PeichlAnna-maria VirkkalaAleksi LehtonenHiroki IwataSteven F. OberbauerClaire C. TreatTorben R. ChristensenMin Jung KwonHideki KobayashiCarolina VoigtCarolina VoigtWalter C. OechelWalter C. OechelMiska LuotoM. GoeckedeOliver SonnentagGerardo CelisEdward A. G. SchuurBrendan M. RogersPeter M. LafleurDavid HollMaija E. MarushchakMaija E. MarushchakMasahito UeyamaElyn HumphreysHan DolmanTorbern TagessonTorbern TagessonJärvi JärveojaBo ElberlingMats NilssonSusan M. NataliJinshu ChiFrans-jan W. ParmentierFrans-jan W. ParmentierMargaret S. TornEugénie S. EuskirchenStef BokhorstMarguerite MauritzJuha AaltoJuha AaltoRafael PoyatosPertti J. MartikainenSang Jong ParkEfrén López-blancoNamyi ChaeChristina BiasiDonatella ZonaDonatella ZonaJohn KochendorferIvan MammarellaCraig A. EmmertonVincent L. St. LouisJennifer D. Watts

subject

hiilidioksidi0106 biological sciences010504 meteorology & atmospheric sciencesBiomeikiroutaNORTHERN PEATLANDAtmospheric sciences01 natural sciencesCarbon Dioxide/analysisSoilremote sensingArctic/dk/atira/pure/sustainabledevelopmentgoals/climate_actionSDG 13 - Climate ActionEXCHANGEComputingMilieux_MISCELLANEOUSGeneral Environmental ScienceARCTIC TUNDRA[SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmospherearktinen alueGlobal and Planetary ChangeCLIMATE-CHANGEEcologyCARBON-DIOXIDE BALANCEUncertaintyCO balancekasvihuonekaasutBLACK SPRUCE FORESTgreenhouse gasTerrestrial ecosystemSeasonsEcosystem respiration1171 GeosciencesEddy covariancepaikkatietoanalyysiSOIL-MOISTURE010603 evolutionary biology114 Physical sciencesEnvironmental Chemistry[SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces environmentTundraEcosystem0105 earth and related environmental sciencesCO2 balanceReproducibility of ResultsENERGY FLUXES15. Life on landTundraPERMAFROST CARBONCarbonlandBorealhiilinielut13. Climate actionGROWING-SEASONSpatial ecologyEnvironmental scienceSpatial variabilitykaukokartoitusempiricalpermafrost

description

The regional variability in tundra and boreal carbon dioxide (CO2) fluxes can be high, complicating efforts to quantify sink-source patterns across the entire region. Statistical models are increasingly used to predict (i.e., upscale) CO2 fluxes across large spatial domains, but the reliability of different modeling techniques, each with different specifications and assumptions, has not been assessed in detail. Here, we compile eddy covariance and chamber measurements of annual and growing season CO2 fluxes of gross primary productivity (GPP), ecosystem respiration (ER), and net ecosystem exchange (NEE) during 1990–2015 from 148 terrestrial high-latitude (i.e., tundra and boreal) sites to analyze the spatial patterns and drivers of CO2 fluxes and test the accuracy and uncertainty of different statistical models. CO2 fluxes were upscaled at relatively high spatial resolution (1 km2) across the high-latitude region using five commonly used statistical models and their ensemble, that is, the median of all five models, using climatic, vegetation, and soil predictors. We found the performance of machine learning and ensemble predictions to outperform traditional regression methods. We also found the predictive performance of NEE-focused models to be low, relative to models predicting GPP and ER. Our data compilation and ensemble predictions showed that CO2 sink strength was larger in the boreal biome (observed and predicted average annual NEE −46 and −29 g C m−2 yr−1, respectively) compared to tundra (average annual NEE +10 and −2 g C m−2 yr−1). This pattern was associated with large spatial variability, reflecting local heterogeneity in soil organic carbon stocks, climate, and vegetation productivity. The terrestrial ecosystem CO2 budget, estimated using the annual NEE ensemble prediction, suggests the high-latitude region was on average an annual CO2 sink during 1990–2015, although uncertainty remains high.

https://pub.epsilon.slu.se/25505/