[en] Carbon dioxide (CO2) uptake by plant photosynthesis, referred to as gross primary production (GPP) at the ecosystem level, is sensitive to environmental factors, including pollutant exposure, pollutant uptake, and changes in the scattering of solar shortwave irradiance (SWin) - the energy source for photosynthesis. The 2020 spring lockdown due to COVID-19 resulted in improved air quality and atmospheric transparency, providing a unique opportunity to assess the impact of air pollutants on terrestrial ecosystem functioning. However, detecting these effects can be challenging as GPP is influenced by other meteorological drivers and management practices. Based on data collected from 44 European ecosystem-scale CO2 flux monitoring stations, we observed significant changes in spring GPP at 34 sites during 2020 compared to 2015-2019. Among these, 14 sites showed an increase in GPP associated with higher SWin, 10 sites had lower GPP linked to atmospheric and soil dryness, and seven sites were subjected to management practices. The remaining three sites exhibited varying dynamics, with one experiencing colder and rainier weather resulting in lower GPP, and two showing higher GPP associated with earlier spring melts. Analysis using the regional atmospheric chemical transport model (LOTOS-EUROS) indicated that the ozone (O3) concentration remained relatively unchanged at the research sites, making it unlikely that O3 exposure was the dominant factor driving the primary production anomaly. In contrast, SWin increased by 9.4 % at 36 sites, suggesting enhanced GPP possibly due to reduced aerosol optical depth and cloudiness. Our findings indicate that air pollution and cloudiness may weaken the terrestrial carbon sink by up to 16 %. Accurate and continuous ground-based observations are crucial for detecting and attributing subtle changes in terrestrial ecosystem functioning in response to environmental and anthropogenic drivers.
Disciplines :
Environmental sciences & ecology
Author, co-author :
Tang, Angela Che Ing; ISPA, Bordeaux Sciences Agro, INRAE, Villenave d'Ornon, France, Department of Environmental Sciences, University of Toledo, Toledo, OH, USA. Electronic address: tang.angelaci@gmail.com
Flechard, Christophe R; UMR SAS, INRAE, Institut Agro, Rennes, France
Arriga, Nicola; Joint Research Centre, European Commission, Ispra, Italy
Papale, Dario; University of Tuscia DIBAF, Viterbo, Italy, EuroMediterranean Center on Climate Change, CMCC IAFES, Viterbo, Italy
Stoy, Paul C; Department of Biological Systems Engineering, University of Wisconsin-Madison, Madison, WI, USA
Buchmann, Nina; Department of Environmental Systems Science, ETH Zurich, Zurich, Switzerland
Cuntz, Matthias; Université de Lorraine, AgroParisTech, INRAE, UMR Silva, Nancy, France
Douros, John; Royal Netherlands Meteorological Institute (KNMI), De Bilt, The Netherlands
Fares, Silvano; National Research Council of Italy, Institute for Agriculture and Forestry Systems in the Mediterranean, Naples, Italy
Knohl, Alexander; Bioclimatology, University of Göttingen, Göttingen, Germany
Šigut, Ladislav; Department of Matter and Energy Fluxes, Global Change Research Institute of the Czech Academy of Sciences, Brno, Czech Republic
Simioni, Guillaume; URFM, INRAE, Avignon, France
Timmermans, Renske; Climate Air and Sustainability Unit, Netherlands Organisation for Applied Scientific Research (TNO), Utrecht, The Netherlands
Grünwald, Thomas; Faculty of Environmental Sciences, Institute of Hydrology and Meteorology, Technische Universität Dresden, Tharandt, Germany
Ibrom, Andreas; Technical University of Denmark (DTU), DTU-Sustain, Kgs. Lyngby, Denmark
Loubet, Benjamin; UMR ECOSYS, AgroParisTech, INRAE, Université Paris-Saclay, Thiverval-Grignon, France
Mammarella, Ivan; Institute for Atmospheric and Earth System Research/Physics, University of Helsinki, Helsinki, Finland
Belelli Marchesini, Luca; Research and Innovation Centre, Fondazione Edmund Mach, San Michele all'Adige, Italy
Nilsson, Mats; Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå, Sweden
Peichl, Matthias; Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå, Sweden
Rebmann, Corinna; Department of Computational Hydrosystems, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany
Schmidt, Marius; Institute of Bio- and Geosciences: Agrosphere (IBG-3), Jülich Research Centre, Jülich, Germany
Bernhofer, Christian; Faculty of Environmental Sciences, Institute of Hydrology and Meteorology, Technische Universität Dresden, Tharandt, Germany
Berveiller, Daniel; Université Paris-Saclay, CNRS, AgroParisTech, Ecologie Systématique et Evolution, Orsay, France
Cremonese, Edoardo; Environmental Protection Agency of Aosta Valley - Climate Change Unit, Saint-Christophe, Italy
El-Madany, Tarek S; Max Planck Institute for Biogeochemistry, Department of Biogeochemical Integration, Jena, Germany
Gharun, Mana; Department of Environmental Systems Science, ETH Zurich, Zurich, Switzerland, Faculty of Geosciences, University of Münster, Münster, Germany
Gianelle, Damiano; Research and Innovation Centre, Fondazione Edmund Mach, San Michele all'Adige, Italy
Hörtnagl, Lukas; Department of Environmental Systems Science, ETH Zurich, Zurich, Switzerland
Roland, Marilyn; Department of Biology, University of Antwerp, Wilrijk, Belgium
Varlagin, Andrej; A.N. Severtsov Institute of Ecology and Evolution, Russian Academy of Sciences, Moscow, Russia
Fu, Zheng; Laboratoire des Sciences du Climat et de l'Environnement, LSCE/IPSL, CEA-CNRS-UVSQ, Université Paris-Saclay, Gif-sur-Yvette, France
Heinesch, Bernard ; Université de Liège - ULiège > Département GxABT > Biosystems Dynamics and Exchanges (BIODYNE)
Janssens, Ivan; Department of Biology, University of Antwerp, Wilrijk, Belgium
Kowalska, Natalia; Department of Matter and Energy Fluxes, Global Change Research Institute of the Czech Academy of Sciences, Brno, Czech Republic
Dušek, Jiří; Department of Matter and Energy Fluxes, Global Change Research Institute of the Czech Academy of Sciences, Brno, Czech Republic
Gerosa, Giacomo; Università Cattolica del Sacro Cuore, Brescia, Italy
Mölder, Meelis; Department of Physical Geography and Ecosystem Science, Lund University, Lund, Sweden
Tuittila, Eeva-Stiina; School of Forest Sciences, University of Eastern Finland, Joensuu, Finland
Loustau, Denis; ISPA, Bordeaux Sciences Agro, INRAE, Villenave d'Ornon, France
INRAE - Institut National de Recherche pour l'Agriculture, l'Alimentation et l'Environnement
Funding text :
We acknowledge the utilization of eddy covariance data obtained and shared by the ICOS research infrastructure and site investigators. The processing and harmonization of the eddy covariance data were conducted by the ICOS Ecosystem Thematic Centre. ACI Tang was funded by the Department of Ecology and Biodiversity ( ECODIV ) of INRAE. We also acknowledge the support provided by INRAE for the execution of this study. We thank Tom Taborski for his assistance in downloading and processing the CAMS radiation data. DP thanks the support of the PRIN 2020 MULTIFOR project (prot. 2020E52THS). Lastly, we would like to pay tribute to the late Werner Eugster for his invaluable contributions.We acknowledge the utilization of eddy covariance data obtained and shared by the ICOS research infrastructure and site investigators. The processing and harmonization of the eddy covariance data were conducted by the ICOS Ecosystem Thematic Centre. ACI Tang was funded by the Department of Ecology and Biodiversity (ECODIV) of INRAE. We also acknowledge the support provided by INRAE for the execution of this study. We thank Tom Taborski for his assistance in downloading and processing the CAMS radiation data. DP thanks the support of the PRIN 2020 MULTIFOR project (prot. 2020E52THS). Lastly, we would like to pay tribute to the late Werner Eugster for his invaluable contributions.
Akaike, H., A new look at the statistical model identification. IEEE Trans. Automat. Contr. 19 (1976), 716–723.
Aslan, T., Kolari, P., Launiainen, S., Peltola, O., Back, J., Vesala, T., Aalto, J., Mammarella, I., Short-term effect of thinning of carbon dioxide and water vapour fluxes in a boreal pine forest. Manuscr. Prep., 2023.
Barnett, T.P., Adam, J.C., Lettenmaier, D.P., Potential impacts of a warming climate on water availability in snow-dominated regions. Nature 438 (2005), 303–309, 10.1038/nature04141.
Barré, J., Petetin, H., Colette, A., Guevara, M., Peuch, V.H., Rouil, L., Engelen, R., Inness, A., Flemming, J., Pérez García-Pando, C., Bowdalo, D., Meleux, F., Geels, C., Christensen, J.H., Gauss, M., Benedictow, A., Tsyro, S., Friese, E., Struzewska, J., Kaminski, J.W., Douros, J., Timmermans, R., Robertson, L., Adani, M., Jorba, O., Joly, M., Kouznetsov, R., Estimating lockdown-induced European NO2 changes using satellite and surface observations and air quality models. Atmos. Chem. Phys. 21 (2021), 7373–7394, 10.5194/acp-21-7373-2021.
Bartoń, K., MuMIn: Multi-Model Inference. R package version, 1(43), 2020, 17.
Bastos, A., Ciais, P., Friedlingstein, P., Sitch, S., Pongratz, J., Fan, L., Wigneron, J.P., Weber, U., Reichstein, M., Fu, Z., Anthoni, P., Arneth, A., Haverd, V., Jain, A.K., Joetzjer, E., Knauer, J., Lienert, S., Loughran, T., McGuire, P.C., Tian, H., Viovy, N., Zaehle, S., Direct and seasonal legacy effects of the 2018 heat wave and drought on European ecosystem productivity. Sci. Adv. 6 (2020), 1–14, 10.1126/sciadv.aba2724.
Bauwens, M., Compernolle, S., Stavrakou, T., Müller, J.F., van Gent, J., Eskes, H., Levelt, P.F., van Der A, R., Veefkind, J.P., Vlietinck, J., Yu, H., Zehner, C., Impact of coronavirus outbreak on NO2 pollution assessed using TROPOMI and OMI observations. Geophys. Res. Lett. 47 (2020), 1–9, 10.1029/2020GL087978.
Bressi, M., Sciare, J., Ghersi, V., Mihalopoulos, N., Petit, J.E., Nicolas, J.B., Moukhtar, S., Rosso, A., Féron, A., Bonnaire, N., Poulakis, E., Theodosi, C., Sources and geographical origins of fine aerosols in Paris (France). Atmos. Chem. Phys. 14 (2014), 8813–8839, 10.5194/acp-14-8813-2014.
Buras, A., Rammig, A.S., Zang, C., Quantifying impacts of the 2018 drought on European ecosystems in comparison to 2003. Biogeosciences 17 (2020), 1655–1672, 10.5194/bg-17-1655-2020.
Burkhardt, J., Hygroscopic particles on leaves: nutrients or desiccants?. Ecol. Monogr. 80 (2010), 369–399, 10.1890/09-1988.1.
Burkhardt, J., Basi, S., Pariyar, S., Hunsche, M., Stomatal penetration by aqueous solutions – an update involving leaf surface particles. New Phytol. 196 (2012), 774–787, 10.1111/j.1469-8137.2012.04307.x.
Carbone, C., Decesari, S., Paglione, M., Giulianelli, L., Rinaldi, M., Marinoni, A., Cristofanelli, P., Didiodato, A., Bonasoni, P., Fuzzi, S., Facchini, M.C., 3-year chemical composition of free tropospheric PM1 at the Mt. Cimone GAW global station - South Europe - 2165m a.s.l. Atmos. Environ. 87 (2014), 218–227, 10.1016/j.atmosenv.2014.01.048.
Choler, P., Growth response of temperate mountain grasslands to inter-annual variations in snow cover duration. Biogeosciences 12 (2015), 3885–3897, 10.5194/bg-12-3885-2015.
Ciais, P., Reichstein, M., Viovy, N., Granier, A., Ogée, J., Allard, V., Aubinet, M., Buchmann, N., Bernhofer, C., Carrara, A., Chevallier, F., De Noblet, N., Friend, A.D., Friedlingstein, P., Grünwald, T., Heinesch, B., Keronen, P., Knohl, A., Krinner, G., Loustau, D., Manca, G., Matteucci, G., Miglietta, F., Ourcival, J.M., Papale, D., Pilegaard, K., Rambal, S., Seufert, G., Soussana, J.F., Sanz, M.J., Schulze, E.D., Vesala, T., Valentini, R., Europe-wide reduction in primary productivity caused by the heat and drought in 2003. Nature 437 (2005), 529–533, 10.1038/nature03972.
Copernicus, 2020 Warmest Year on Record for Europe; Globally, 2020 Ties with 2016 for Warmest Year Recorded. Copernicus Clim. Chang. Serv. URL https://climate.copernicus.eu/copernicus-2020-warmest-year-record-europe-globally-2020-ties-2016-warmest-year-recorded, 2021.
Coyne, P.I., Bingham, G.E., Photosynthesis and stomatal light responses in snap beans exposed to hydrogen sulfide and ozone. J. Air Pollut. Control Assoc. 28 (1978), 1119–1123, 10.1080/00022470.1978.10470715.
Desai, A.R., Wohlfahrt, G., Zeeman, M.J., Katata, G., Eugster, W., Montagnani, L., Gianelle, D., Mauder, M., Schmid, H.P., Montane ecosystem productivity responds more to global circulation patterns than climatic trends. Environ. Res. Lett., 11, 2016, 10.1088/1748-9326/11/2/024013.
Diémoz, H., Barnaba, F., Magri, T., Pession, G., Dionisi, D., Pittavino, S., Tombolato, I.K.F., Campanelli, M., Ceca, L.S. Della, Hervo, M., Di Liberto, L., Ferrero, L., Gobbi, G.P., Transport of Po Valley aerosol pollution to the northwestern Alps – Part 1: Phenomenology. Atmos. Chem. Phys. 19 (2019), 3065–3095, 10.5194/acp-19-3065-2019.
Diémoz, H., Gobbi, G.P., Magri, T., Pession, G., Pittavino, S., Tombolato, I.K.F., Campanelli, M., Barnaba, F., Transport of Po Valley aerosol pollution to the northwestern Alps – Part 2: Long-term impact on air quality. Atmos. Chem. Phys. 19 (2019), 10129–10160, 10.5194/acp-19-3065-2019.
El-Madany, T.S., Reichstein, M., Carrara, A., Martín, M.P., Moreno, G., Gonzalez-Cascon, R., Peñuelas, J., Ellsworth, D.S., Burchard-Levine, V., Hammer, T.W., Knauer, J., Kolle, O., Luo, Y., Pacheco-Labrador, J., Nelson, J.A., Perez-Priego, O., Rolo, V., Wutzler, T., Migliavacca, M., How nitrogen and phosphorus availability change water use efficiency in a Mediterranean savanna ecosystem. J. Geophys. Res. Biogeosci., 126, 2021, 10.1029/2020JG006005.
Escalona, J.M., Flexas, J., Medrano, H., Stomatal and non-stomatal limitations of photosynthesis under water stress in field-grown grapevines. Aust. J. Plant Physiol. 26 (1999), 421–433.
Ezhova, E., Ylivinkka, I., Kuusk, J., Komsaare, K., Vana, M., Krasnova, A., Noe, S., Arshinov, M., Belan, B., Park, S.Bin, Lavric, J.V., Heimann, M., Petäjä, T., Vesala, T., Mammarella, I., Kolari, P., Bäck, J., Rannik, U., Kerminen, V.M., Kulmala, M., Direct effect of aerosols on solar radiation and gross primary production in boreal and hemiboreal forests. Atmos. Chem. Phys. 18 (2018), 17863–17881, 10.5194/acp-18-17863-2018.
Falge, E., Baldocchi, D., Olson, R., Anthoni, P., Aubinet, M., Bernhofer, C., Burba, G., Ceulemans, R., Clement, R., Dolman, H., Granier, A., Gross, P., Grünwald, T., Hollinger, D., Jensen, N.O., Katul, G., Keronen, P., Kowalski, A., Lai, C.T., Law, B.E., Meyers, T., Moncrieff, J., Moors, E., Munger, J.W., Pilegaard, K., Rannik, Ü., Rebmann, C., Suyker, A., Tenhunen, J., Tu, K., Verma, S., Vesala, T., Wilson, K., Wofsy, S., Gap filling strategies for defensible annual sums of net ecosystem exchange. Agric. For. Meteorol. 107 (2001), 43–69, 10.1016/S0168-1923(00)00225-2.
Fares, S., Vargas, R., Detto, M., Goldstein, A.H., Karlik, J., Paoletti, E., Vitale, M., Tropospheric ozone reduces carbon assimilation in trees: estimates from analysis of continuous flux measurements. Glob. Chang. Biol. 19 (2013), 2427–2443, 10.1111/gcb.12222.
Finardi, S., Silibello, C., D'Allura, A., Radice, P., Analysis of pollutants exchange between the Po Valley and the surrounding European region. Urban Clim. 10 (2014), 682–702, 10.1016/j.uclim.2014.02.002.
Flechard, C.R., Ibrom, A., Skiba, U.M., De Vries, W., Van Oijen, M., Cameron, D.R., Dise, N.B., Korhonen, J.F.J., Buchmann, N., Legout, A., Simpson, D., Sanz, M.J., Aubinet, M., Loustau, D., Montagnani, L., Neirynck, J., Janssens, I.A., Pihlatie, M., Kiese, R., Siemens, J., Francez, A.J., Augustin, J., Varlagin, A., Olejnik, J., Juszczak, R., Aurela, M., Berveiller, D., Chojnicki, B.H., Dämmgen, U., Delpierre, N., Djuricic, V., Drewer, J., Dufrêne, E., Eugster, W., Fauvel, Y., Fowler, D., Frumau, A., Granier, A., Gross, P., Hamon, Y., Helfter, C., Hensen, A., Horvath, L., Kitzler, B., Kruijt, B., Kutsch, W.L., Lobo-Do-Vale, R., Lohila, A., Longdoz, B., Marek, M.V., Matteucci, G., Mitosinkova, M., Moreaux, V., Neftel, A., Ourcival, J.M., Pilegaard, K., Pita, G., Sanz, F., Schjoerring, J.K., Sebastià, M.T., Sim Tang, Y., Uggerud, H., Urbaniak, M., Van DIjk, N., Vesala, T., Vidic, S., Vincke, C., Weidinger, T., Zechmeister-Boltenstern, S., Butterbach-Bahl, K., Nemitz, E., Sutton, M.A., Carbon–nitrogen interactions in European forests and semi-natural vegetation – Part 1: Fluxes and budgets of carbon, nitrogen and greenhouse gases from ecosystem monitoring and modelling. Biogeosciences 17 (2020), 1583–1620, 10.5194/bg-17-1583-2020.
Flechard, C.R., Van Oijen, M., Cameron, D.R., De Vries, W., Ibrom, A., Buchmann, N., Dise, N.B., Janssens, I.A., Neirynck, J., Montagnani, L., Varlagin, A., Loustau, D., Legout, A., Ziemblińska, K., Aubinet, M., Aurela, M., Chojnicki, B.H., Drewer, J., Eugster, W., Francez, A.J., Juszczak, R., Kitzler, B., Kutsch, W.L., Lohila, A., Longdoz, B., Matteucci, G., Moreaux, V., Neftel, A., Olejnik, J., Sanz, M.J., Siemens, J., Vesala, T., Vincke, C., Nemitz, E., Zechmeister-Boltenstern, S., Butterbach-Bahl, K., Skiba, U.M., Sutton, M.A., Carbon–nitrogen interactions in European forests and semi-natural vegetation – Part 2: Untangling climatic, edaphic, management and nitrogen deposition effects on carbon sequestration potentials. Biogeosciences 17 (2020), 1621–1654, 10.5194/bg-17-1621-2020.
Flexas, J., Medrano, H., Drought‐inhibition of photosynthesis in C3 plants: Stomatal and non‐stomatal limitations revisited. Ann. Bot. 89 (2002), 183–189, 10.1093/aob/mcf027.
Fu, Z., Ciais, P., Prentice, I.C., Gentine, P., Makowski, D., Bastos, A., Luo, X., Green, J.K., Stoy, P.C., Yang, H., Hajima, T., Atmospheric dryness reduces photosynthesis along a large range of soil water deficits. Nat. Commun. 13 (2022), 1–10, 10.1038/s41467-022-28652-7.
Gharun, M., Hörtnagl, L., Paul-Limoges, E., Ghiasi, S., Feigenwinter, I., Burri, S., Marquardt, K., Etzold, S., Zweifel, R., Eugster, W., Buchmann, N., Physiological response of Swiss ecosystems to 2018 drought across plant types and elevation. Philos. Trans. R. Soc. B Biol. Sci., 375, 2020, 10.1098/rstb.2019.0521.
Gourlez de la Motte, L., Beauclaire, Q., Heinesch, B., Cuntz, M., Foltýnová, L., Šigut, L., Kowalska, N., Manca, G., Ballarin, I.G., Vincke, C., Roland, M., Ibrom, A., Lousteau, D., Siebicke, L., Neiryink, J., Longdoz, B., Non-stomatal processes reduce gross primary productivity in temperate forest ecosystems during severe edaphic drought: edaphic drought in forest ecosystems. Philos. Trans. R. Soc. B Biol. Sci., 375, 2020, 10.1098/rstb.2019.0527.
Grene, R., Oxidative stress and acclimation mechanisms in plants. Arab. B., 1, 2002, e0036, 10.1199/tab. 0036.1.
Gschwind, B., Wald, L., Blanc, P., Lefèvre, M., Schroedter-Homscheidt, M., Arola, A., Improving the McClear model estimating the downwelling solar radiation at ground level in cloud-free conditions - McClear-v3. Meteorol. Zeitschrift 28 (2019), 147–163, 10.1127/metz/2019/0946.
Guevara, M., Jorba, O., Soret, A., Petetin, H., Bowdalo, D., Serradell, K., Tena, C., Van Der Gon, H.D., Kuenen, J., Peuch, V.H., Pérez Garciá-Pando, C., Time-resolved emission reductions for atmospheric chemistry modelling in Europe during the COVID-19 lockdowns. Atmos. Chem. Phys. 21 (2021), 773–797, 10.5194/acp-21-773-2021.
van Heerwaarden, C.C., Mol, W.B., Veerman, M.A., Benedict, I., Heusinkveld, B.G., Knap, W.H., Kazadzis, S., Kouremeti, N., Fiedler, S., Record high solar irradiance in Western Europe during first COVID-19 lockdown largely due to unusual weather. Commun. Earth Environ. 2 (2021), 1–7, 10.1038/s43247-021-00110-0.
Hollinger, D.Y., Richardson, A.D., Uncertainty in eddy covariance measurements and its application to physiological models. Tree Physiol. 25 (2005), 873–885, 10.1093/treephys/25.7.873.
Jactel, H., Petit, J., Desprez-Loustau, M.L., Delzon, S., Piou, D., Battisti, A., Koricheva, J., Drought effects on damage by forest insects and pathogens: a meta-analysis. Glob. Chang. Biol. 18 (2012), 267–276, 10.1111/j.1365-2486.2011.02512.x.
Knohl, A., Baldocchi, D.D., Effects of diffuse radiation on canopy gas exchange processes in a forest ecosystem. J. Geophys. Res. Biogeosciences 113 (2008), 1–17, 10.1029/2007JG000663.
Lasslop, G., Reichstein, M., Papale, D., Richardson, A., Arneth, A., Barr, A., Stoy, P., Wohlfahrt, G., Separation of net ecosystem exchange into assimilation and respiration using a light response curve approach: critical issues and global evaluation. Glob. Chang. Biol. 16 (2010), 187–208, 10.1111/j.1365-2486.2009.02041.x.
Lefèvre, M., Oumbe, A., Blanc, P., Espinar, B., Gschwind, B., Qu, Z., Wald, L., Schroedter-Homscheidt, M., Hoyer-Klick, C., Arola, A., Benedetti, A., Kaiser, J.W., Morcrette, J.J., McClear: a new model estimating downwelling solar radiation at ground level in clear-sky conditions. Atmos. Meas. Tech. 6 (2013), 2403–2418, 10.5194/amt-6-2403-2013.
Li, X., Wang, Y.P., Lu, X., Yan, J., Diagnosing the impacts of climate extremes on the interannual variations of carbon fluxes of a subtropical evergreen mixed forest. Agric. For. Meteorol., 307, 2021, 108507, 10.1016/j.agrformet.2021.108507.
Liu, P., Zha, T., Jia, X., Black, T.A., Jassal, R.S., Ma, J., Bai, Y., Wu, Y., Different effects of spring and summer droughts on ecosystem carbon and water exchanges in a semiarid Shrubland ecosystem in Northwest China. Ecosystems 22 (2019), 1869–1885, 10.1007/s10021-019-00379-5.
Mammarella, I., Thomas, A., Aslan, T., Aalto, J., Back, J., Kolari, P., Launiainen, S., Peltola, O., Vesala, T., Effect of thinning on turbulence structure, energy and gas exchange in a boreal forest. EGU general assembly 2023, 2023, 10.5194/egusphere-egu23-12230 Vienna.
Manders, A.M.M., Builtjes, P.J.H., Curier, L., Gon, H.A.C.D. Vander, Hendriks, C., Jonkers, S., Kranenburg, R., Kuenen, J.J.P., Segers, A.J., Timmermans, R.M.A., Visschedijk, A.J.H., Kruit, R.J.W., Pul, W.A.J.V., Sauter, F.J., Van Der Swaluw, E., Swart, D.P.J., Douros, J., Eskes, H., Van Meijgaard, E., Van Ulft, B., Van Velthoven, P., Banzhaf, S., Mues, A.C., Stern, R., Fu, G., Lu, S., Heemink, A., Van Velzen, N., Schaap, M., Curriculum vitae of the LOTOS-EUROS (v2.0) chemistry transport model. Geosci. Model Dev. 10 (2017), 4145–4173, 10.5194/gmd-10-4145-2017.
Manders-Groot, A.M.M., Segers, A.J., Jonkers, S., Schaap, M., Timmermans, R., Hendriks, C., Sauter, F., Kruit, R.W., Swaluw, E. Van Der, Eskes, H., Banzhaf, S., 2016. LOTOS-EUROS v2.0 Reference Guide. TNO Rep. 2016 R10898 77.
Menut, L., Bessagnet, B., Siour, G., Mailler, S., Pennel, R., Cholakian, A., Impact of lockdown measures to combat Covid-19 on air quality over western Europe. Sci. Total Environ., 741, 2020, 140426, 10.1016/j.scitotenv.2020.140426.
Mercado, L.M., Bellouin, N., Sitch, S., Boucher, O., Huntingford, C., Wild, M., Cox, P.M., Impact of changes in diffuse radiation on the global land carbon sink. Nature 458 (2009), 1014–1017, 10.1038/nature07949.
Nicolini, G., Antoniella, G., Carotenuto, F., Christen, A., Ciais, P., Feigenwinter, C., Gioli, B., Stagakis, S., Velasco, E., Vogt, R., Ward, H.C., Barlow, J., Chrysoulakis, N., Duce, P., Graus, M., Helfter, C., Heusinkveld, B., Järvi, L., Karl, T., Marras, S., Masson, V., Matthews, B., Meier, F., Nemitz, E., Sabbatini, S., Scherer, D., Schume, H., Sirca, C., Steeneveld, G.J., Vagnoli, C., Wang, Y., Zaldei, A., Zheng, B., Papale, D., Direct observations of CO2 emission reductions due to COVID-19 lockdown across European urban districts. Sci. Total Environ., 830, 2022, 10.1016/j.scitotenv.2022.154662.
Nyeki, S., Eleftheriadis, K., Baltensperger, U., Colbeck, I., Fiebig, M., Fix, A., Kiemle, C., Lazaridis, M., Petzold, A., Airborne lidar and in-situ aerosol observations of an elevated layer, leeward of the european alps and apennines. Geophys. Res. Lett. 29 (2002), 3–6, 10.1029/2002GL014897.
Oldani, K.M., Mladenov, N., Williams, M.W., Campbell, C.M., Lipson, D.A., Seasonal patterns of dry deposition at a high-elevation site in the Colorado Rocky Mountains. J. Geophys. Res. Atmos. 122 (2017), 11183–11200.
Ordóñez, C., Garrido-Perez, J.M., García-Herrera, R., Early spring near-surface ozone in Europe during the COVID-19 shutdown: Meteorological effects outweigh emission changes. Sci. Total Environ., 747, 2020, 141322, 10.1016/j.scitotenv.2020.141322.
Park, S.Bin, Knohl, A., Lucas-Moffat, A.M., Migliavacca, M., Gerbig, C., Vesala, T., Peltola, O., Mammarella, I., Kolle, O., Lavric, J.V., Prokushkin, A., Heimann, M., Strong radiative effect induced by clouds and smoke on forest net ecosystem productivity in central Siberia. Agric. For. Meteorol. 250–251 (2018), 376–387, 10.1016/j.agrformet.2017.09.009.
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., Arkebauer, T., Arndt, S.K., Arriga, N., Aubinet, M., Aurela, M., Baldocchi, D., Barr, A., Beamesderfer, E., Marchesini, L.B., Bergeron, O., Beringer, J., Bernhofer, C., Berveiller, D., Billesbach, D., Black, T.A., Blanken, P.D., Bohrer, G., Boike, J., Bolstad, P.V., Bonal, D., Bonnefond, J.M., Bowling, D.R., Bracho, R., Brodeur, J., Brümmer, C., Buchmann, N., Burban, B., Burns, S.P., Buysse, P., Cale, P., Cavagna, M., Cellier, P., Chen, S., Chini, I., Christensen, T.R., Cleverly, J., Collalti, A., Consalvo, C., Cook, B.D., Cook, D., Coursolle, C., Cremonese, E., Curtis, P.S., D'Andrea, E., da Rocha, H., Dai, X., Davis, K.J., De Cinti, B., de Grandcourt, A., De Ligne, A., De Oliveira, R.C., Delpierre, N., Desai, A.R., Di Bella, C.M., di Tommasi, P., Dolman, H., Domingo, F., Dong, G., Dore, S., Duce, P., Dufrêne, E., Dunn, A., Dušek, J., Eamus, D., Eichelmann, U., ElKhidir, H.A.M., Eugster, W., Ewenz, C.M., Ewers, B., Famulari, D., Fares, S., Feigenwinter, I., Feitz, A., Fensholt, R., Filippa, G., Fischer, M., Frank, J., Galvagno, M., Gharun, M., Gianelle, D., Gielen, B., Gioli, B., Gitelson, A., Goded, I., Goeckede, M., Goldstein, A.H., Gough, C.M., Goulden, M.L., Graf, A., Griebel, A., Gruening, C., Grünwald, T., Hammerle, A., Han, S., Han, X., Hansen, B.U., Hanson, C., Hatakka, J., He, Y., Hehn, M., Heinesch, B., Hinko-Najera, N., Hörtnagl, L., Hutley, L., Ibrom, A., Ikawa, H., Jackowicz-Korczynski, M., Janouš, D., Jans, W., Jassal, R., Jiang, S., Kato, T., Khomik, M., Klatt, J., Knohl, A., Knox, S., Kobayashi, H., Koerber, G., Kolle, O., Kosugi, Y., Kotani, A., Kowalski, A., Kruijt, B., Kurbatova, J., Kutsch, W.L., Kwon, H., Launiainen, S., Laurila, T., Law, B., Leuning, R., Li, Yingnian, Liddell, M., Limousin, J.M., Lion, M., Liska, A.J., Lohila, A., López-Ballesteros, A., López-Blanco, E., Loubet, B., Loustau, D., Lucas-Moffat, A., Lüers, J., Ma, S., Macfarlane, C., Magliulo, V., Maier, R., Mammarella, I., Manca, G., Marcolla, B., Margolis, H.A., Marras, S., Massman, W., Mastepanov, M., Matamala, R., Matthes, J.H., Mazzenga, F., McCaughey, H., McHugh, I., McMillan, A.M.S., Merbold, L., Meyer, W., Meyers, T., Miller, S.D., Minerbi, S., Moderow, U., Monson, R.K., Montagnani, L., Moore, C.E., Moors, E., Moreaux, V., Moureaux, C., Munger, J.W., Nakai, T., Neirynck, J., Nesic, Z., Nicolini, G., Noormets, A., Northwood, M., Nosetto, M., Nouvellon, Y., Novick, K., Oechel, W., Olesen, J.E., Ourcival, J.M., Papuga, S.A., Parmentier, F.J., Paul-Limoges, E., Pavelka, M., Peichl, M., Pendall, E., Phillips, R.P., Pilegaard, K., Pirk, N., Posse, G., Powell, T., Prasse, H., Prober, S.M., Rambal, S., Rannik, Ü., Raz-Yaseef, N., Reed, D., de Dios, V.R., Restrepo-Coupe, N., Reverter, B.R., Roland, M., Sabbatini, S., Sachs, T., Saleska, S.R., Sánchez-Cañete, E.P., Sanchez-Mejia, Z.M., Schmid, H.P., Schmidt, M., Schneider, K., Schrader, F., Schroder, I., Scott, R.L., Sedlák, P., Serrano-Ortíz, P., Shao, C., Shi, P., Shironya, I., Siebicke, L., Šigut, L., Silberstein, R., Sirca, C., Spano, D., Steinbrecher, R., Stevens, R.M., Sturtevant, C., Suyker, A., Tagesson, T., Takanashi, S., Tang, Y., Tapper, N., Thom, J., Tiedemann, F., Tomassucci, M., Tuovinen, J.P., Urbanski, S., Valentini, R., van der Molen, M., van Gorsel, E., van Huissteden, K., Varlagin, A., Verfaillie, J., Vesala, T., Vincke, C., Vitale, D., Vygodskaya, N., Walker, J.P., Walter-Shea, E., Wang, H., Weber, R., Westermann, S., Wille, C., Wofsy, S., Wohlfahrt, G., Wolf, S., Woodgate, W., Li, Yuelin, Zampedri, R., Zhang, J., Zhou, G., Zona, D., Agarwal, D., Biraud, S., Torn, M., Papale, D., The FLUXNET2015 dataset and the ONEFlux processing pipeline for eddy covariance data. Sci. data, 7, 2020, 225, 10.1038/s41597-020-0534-3.
Pell, E.J., Schlagnhaufer, C.D., Arteca, R.N., Ozone-induced oxidative stress: mechanisms of action and reaction. Physiol. Plant. 100 (1997), 264–273, 10.1034/j.1399-3054.1997.1000207.x.
Pereira, J.S., Mateus, J.A., Aires, L.M., Pita, G., Pio, C., David, J.S., Andrade, V., Banza, J., David, T.S., Paço, T.A., Rodrigues, A., Net ecosystem carbon exchange in three contrasting Mediterranean ecosystems - the effect of drought. Biogeosciences 4 (2007), 791–802, 10.5194/bg-4-791-2007.
Philip, E., Effects of low concentrations of SO2 and NOX on the photosynthetic characteristics of Pongamia pinnata. J. Trop. For. Sci. 14 (2002), 474–484.
Putaud, J.P., Pozzoli, L., Pisoni, E., Martins Dos Santos, S., Lagler, F., Lanzani, G., Dal Santo, U., Colette, A., Impacts of the COVID-19 lockdown on air pollution at regional and urban background sites in northern Italy. Atmos. Chem. Phys. 21 (2021), 7597–7609, 10.5194/acp-21-7597-2021.
Qu, Z., Oumbe, A., Blanc, P., Espinar, B., Gesell, G., Gschwind, B., Klüser, L., Lefèvre, M., Saboret, L., Schroedter-Homscheidt, M., Wald, L., Fast radiative transfer parameterisation for assessing the surface solar irradiance: The Heliosat-4 method. Meteorol. Zeitschrift 26 (2017), 33–57, 10.1127/metz/2016/0781.
Reichstein, M., Falge, E., Baldocchi, D., Papale, D., Aubinet, M., Berbigier, P., Bernhofer, C., Buchmann, N., Gilmanov, T., Granier, A., Grünwald, T., Havránková, K., Ilvesniemi, H., Janous, D., Knohl, A., Laurila, T., Lohila, A., Loustau, D., Matteucci, 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., Valentini, R., On the separation of net ecosystem exchange into assimilation and ecosystem respiration: review and improved algorithm. Glob. Chang. Biol. 11 (2005), 1424–1439, 10.1111/j.1365-2486.2005.001002.x.
Reichstein, M., Stoy, P.C., Desai, A.R., Lasslop, G., Richardson, A.D., Partitioning of net fluxes. Aubinet, M., Vesala, T., Papale, D., (eds.) Eddy Covariance, 2012, Springer, Dordrecht, 10.1007/978-94-007-2351-1_9.
Roderick, M.L., Farquhar, G.D., Berry, S.L., Noble, I.R., On the direct effect of clouds and atmospheric particles on the productivity and structure of vegetation. Oecologia 129 (2001), 21–30, 10.1007/s004420100760.
Schroedter-Homscheidt, M., Azam, F., Betcke, J., Hoyer-Klick, C., Lefèvre, M., Saint-Drenan, Y.-M., Wey, E., Saboret, L., User's Guide to the CAMS Radiation Service (CRS): Status December 2021. 2021 (Copernicus Atmosphere Monitoring Service).
Schuldt, B., Buras, A., Arend, M., Vitasse, Y., Beierkuhnlein, C., Damm, A., Gharun, M., Grams, T.E.E., Hauck, M., Hajek, P., Hartmann, H., Hiltbrunner, E., Hoch, G., Holloway-Phillips, M., Körner, C., Larysch, E., Lübbe, T., Nelson, D.B., Rammig, A., Rigling, A., Rose, L., Ruehr, N.K., Schumann, K., Weiser, F., Werner, C., Wohlgemuth, T., Zang, C.S., Kahmen, A., A first assessment of the impact of the extreme 2018 summer drought on central European forests. Basic Appl. Ecol. 45 (2020), 86–103, 10.1016/j.baae.2020.04.003.
Sciare, J., D'Argouges, O., Zhang, Q.J., Sarda-Estève, R., Gaimoz, C., Gros, V., Beekmann, M., Sanchez, O., Comparison between simulated and observed chemical composition of fine aerosols in Paris (France) during springtime: contribution of regional versus continental emissions. Atmos. Chem. Phys. 10 (2010), 11987–12004, 10.5194/acp-10-11987-2010.
Tang, A.C.I., Stoy, P.C., Hirata, R., Musin, K.K., Aeries, E.B., Wenceslaus, J., Melling, L., Eddy covariance measurements of methane flux at a tropical peat forest in Sarawak, Malaysian Borneo. Geophys. Res. Lett. 45 (2018), 4390–4399, 10.1029/2017GL076457.
Venter, Z.S., Aunan, K., Chowdhury, S., Lelieveld, J., COVID-19 lockdowns cause global air pollution declines. Proc. Natl. Acad. Sci. 117 (2020), 18984–18990, 10.1073/pnas.2006853117.
Viatte, C., Petit, J.E., Yamanouchi, S., Van Damme, M., Doucerain, C., Germain-Piaulenne, E., Gros, V., Favez, O., Clarisse, L., Coheur, P.F., Strong, K., Clerbaux, C., Ammonia and PM2.5 air pollution in Paris during the 2020 COVID lockdown. Atmosphere, 12, 2021, 160, 10.3390/atmos12020160.
Voigt, C., Lelieveld, J., Schlager, H., Schneider, J., Curtius, J., Meerkötter, R., Sauer, D., Bugliaro, L., Bohn, B., Crowley, J.N., Erbertseder, T., Groß, S., Hahn, V., Li, Q., Mertens, M., Pöhlker, M.L., Pozzer, A., Schumann, U., Tomsche, L., Williams, J., Zahn, A., Andreae, M., Borrmann, S., Bräuer, T., Dörich, R., Dörnbrack, A., Edtbauer, A., Ernle, L., Fischer, H., Giez, A., Granzin, M., Grewe, V., Harder, H., Heinritzi, M., Holanda, B.A., Jöckel, P., Kaiser, K., Krüger, O.O., Lucke, J., Marsing, A., Martin, A., Matthes, S., Pöhlker, C., Pöschl, U., Reifenberg, S., Ringsdorf, A., Scheibe, M., Tadic, I., Zauner-Wieczorek, M., Henke, R., Rapp, M., Cleaner skies during the COVID-19 lockdown. Bull. Am. Meteorol. Soc. 103 (2022), E1796–E1827, 10.1175/BAMS-D-21-0012.1.
Wang, X., Wu, J., Chen, M., Xu, X., Wang, Z., Wang, B., Wang, C., Piao, S., Lin, W., Miao, G., Deng, M., Qiao, C., Wang, J., Xu, S., Liu, L., Field evidences for the positive effects of aerosols on tree growth. Glob. Chang. Biol. 24 (2018), 4983–4992, 10.1111/gcb.14339.
Wang, Y., Okochi, H., Igawa, M., Long term trends of dry and wet deposition of air pollutants at declining forest site of Mt. Oyama in Japan during 1994–2019. Water Air Soil Pollut., 234, 2023, 10.1007/s11270-023-06270-3.
Warm Winter 2020 Team & ICOS Ecosystem Thematic Centre, 2022. Warm Winter 2020 ecosystem eddy covariance flux product for 73 stations in FLUXNET-Archive format—release 2022–1 (Version 1.0). ICOS Carbon Portal. URL doi: 10.18160/2G60-ZHAK.
Wittig, V.E., Ainsworth, E.A., Naidu, S.L., Karnosky, D.F., Long, S.P., Quantifying the impact of current and future tropospheric ozone on tree biomass, growth, physiology and biochemistry: a quantitative meta-analysis. Glob. Chang. Biol. 15 (2009), 396–424, 10.1111/j.1365-2486.2008.01774.x.
World Health Organisation, WHO Director-General's opening remarks at the media briefing on COVID-19 - 13 march 2020. https://www.who.int/director-general/speeches/detail/who-director-general-s-opening-remarks-at-the-mission-briefing-on-covid-19—13-march-2020, 2020.
Xie, J., Kneubühler, M., Garonna, I., Notarnicola, C., De Gregorio, L., De Jong, R., Chimani, B., Schaepman, M.E., Altitude-dependent influence of snow cover on alpine land surface phenology. J. Geophys. Res. Biogeosci. 122 (2017), 1107–1122, 10.1002/2016JG003728.
Yu, X., Orth, R., Reichstein, M., Bahn, M., Klosterhalfen, A., Knohl, A., Koebsch, F., Contrasting drought legacy effects on gross primary productivity in a mixed versus pure beech forest. Biogeosciences 19 (2022), 4315–4329.
Zhao, M., Running, S.W., Drought-induced reduction in global terrestrial net primary production from 2000 through 2009. Science 329 (2010), 940–943, 10.1126/science.334.6062.1496.
