Articles | Volume 23, issue 14
https://doi.org/10.5194/bg-23-5035-2026
© Author(s) 2026. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/bg-23-5035-2026
© Author(s) 2026. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Net ecosystem exchange of extensive green roofs: the role of coupled energy, carbon, and water fluxes quantified by long-term micrometeorological observations
Niklas Markolf
CORRESPONDING AUTHOR
Climatology and Environmental Meteorology, Institute of Geoecology, Technische Universität Braunschweig, 38106 Braunschweig, Germany
Stephan Weber
Climatology and Environmental Meteorology, Institute of Geoecology, Technische Universität Braunschweig, 38106 Braunschweig, Germany
Related authors
No articles found.
Aurélien Mirebeau, Cécile de Munck, Bertrand Bonan, Christine Delire, Aude Lemonsu, Valéry Masson, and Stephan Weber
Geosci. Model Dev., 18, 5329–5349, https://doi.org/10.5194/gmd-18-5329-2025, https://doi.org/10.5194/gmd-18-5329-2025, 2025
Short summary
Short summary
The greening of cities is recommended to limit the effects of climate change. In particular, green roofs can provide numerous environmental benefits, such as urban cooling, water retention, and carbon sequestration. The aim of this research is to develop a new module for calculating green roof CO2 fluxes within a model that can already simulate hydrological and thermal processes of such roofs. The calibration and evaluation of this module take advantage of long-term experimental data.
Ajit Ahlawat, Kay Weinhold, Jesus Marval, Paolo Tronville, Ari Leskinen, Mika Komppula, Holger Gerwig, Lars Gerling, Stephan Weber, Rikke Bramming Jørgensen, Thomas Nørregaard Jensen, Marouane Merizak, Ulrich Vogt, Carla Ribalta, Mar Viana, Andre Schmitz, Maria Chiesa, Giacomo Gerosa, Lothar Keck, Markus Pesch, Gerhard Steiner, Thomas Krinke, Torsten Tritscher, Wolfram Birmili, and Alfred Wiedensohler
Atmos. Meas. Tech. Discuss., https://doi.org/10.5194/amt-2022-155, https://doi.org/10.5194/amt-2022-155, 2022
Revised manuscript not accepted
Short summary
Short summary
Measurements of ultrafine particles must be done with quality-assured instruments. The performance of portable instruments such as NanoScan SMPS, and GRIMM Mini WRAS spectrometer measuring the particle number size distribution in the range from 10 to 200 nm were investigated. The influence of different aerosol types and maintenance activities on these instruments were explored. The results show that these portable instruments are suitable for mobile UFP measurements for source identification.
Agnes Straaten and Stephan Weber
Atmos. Chem. Phys., 21, 18707–18726, https://doi.org/10.5194/acp-21-18707-2021, https://doi.org/10.5194/acp-21-18707-2021, 2021
Short summary
Short summary
Cities show high concentrations of ultrafine particles due to multiple emission sources such as traffic and industry. To analyse turbulent urban surface–atmosphere exchange of particles, we quantified multi-annual size-resolved particle number fluxes in Berlin, Germany. The site was a net source of particles with a dominant contribution of traffic-related emission, especially very small particles < 30 nm. Particle fluxes clearly varied as a function of anthropogenic activity and urban land use.
Cited articles
Akbari, H. and Rose, L. S.: Urban Surfaces and Heat Island Mitigation Potentials, JHES, 11, 85–101, https://doi.org/10.1618/jhes.11.85, 2008.
Aubinet, M., Vesala, T., and Papale, D. (Eds.): Eddy Covariance: A Practical Guide to Measurement and Data Analysis, Springer Netherlands, Dordrecht, https://doi.org/10.1007/978-94-007-2351-1, 2012.
Birch, H. F.: The effect of soil drying on humus decomposition and nitrogen availability, Plant Soil, 10, 9–31, https://doi.org/10.1007/BF01343734, 1958.
Bruno, G., Avanzi, F., Gabellani, S., Ferraris, L., Cremonese, E., Galvagno, M., and Massari, C.: Disentangling the role of subsurface storage in the propagation of drought through the hydrological cycle, Adv. Water Resour., 169, 104305, https://doi.org/10.1016/j.advwatres.2022.104305, 2022.
Croux, C. and Dehon, C.: Influence functions of the Spearman and Kendall correlation measures, Stat. Method Appl., 19, 497–515, https://doi.org/10.1007/s10260-010-0142-z, 2010.
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., Pilegaard, K., Rannik, Ü., Rebmann, C., Suyker, A., Tenhunen, J., Tu, K., Verma, S., Vesala, T., Wilson, K., and Wofsy, S.: Gap filling strategies for defensible annual sums of net ecosystem exchange, Agr. Forest Meteorol., 107, 43–69, https://doi.org/10.1016/S0168-1923(00)00225-2, 2001a.
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., Ta Lai, C., Law, B. E., Meyers, T., Moncrieff, J., Moors, E., William Munger, J., Pilegaard, K., Rannik, Ü., Rebmann, C., Suyker, A., Tenhunen, J., Tu, K., Verma, S., Vesala, T., Wilson, K., and Wofsy, S.: Gap filling strategies for long term energy flux data sets, Agr. Forest Meteorol., 107, 71–77, https://doi.org/10.1016/S0168-1923(00)00235-5, 2001b.
Ferreira, C. S. S., Potočki, K., Kapović-Solomun, M., and Kalantari, Z.: Nature-Based Solutions for Flood Mitigation and Resilience in Urban Areas, in: Nature-Based Solutions for Flood Mitigation, edited by: Ferreira, C. S. S., Kalantari, Z., Hartmann, T., and Pereira, P., Springer International Publishing, Cham, 59–78, https://doi.org/10.1007/698_2021_758, 2022.
Foken, T. and Mauder, M.: Grundgleichungen der atmosphärischen Turbulenz, in: Angewandte Meteorologie: Mikrometeorologische Methoden, Springer Berlin Heidelberg, Berlin, Heidelberg, 75, https://doi.org/10.1007/978-3-662-68333-0_2, 2024.
Foken, T., Göockede, M., Mauder, M., Mahrt, L., Amiro, B., and Munger, W.: Post-Field Data Quality Control, in: Handbook of Micrometeorology: A Guide for Surface Flux Measurement and Analysis, edited by: Lee, X., Massman, W., and Law, B., Springer Netherlands, Dordrecht, 181–208, https://doi.org/10.1007/1-4020-2265-4_9, 2005.
Formanek, S., Mauss, K., Peritsch, M., and Schultes, C.: Green Market Report: Bauwerksbegrünung in Österreich 2019–2022, Vienna GRÜNSTATTGRAU Forschungs- und Innovations GmbH, 2024.
Francis, L. F. M. and Jensen, M. B.: Benefits of green roofs: A systematic review of the evidence for three ecosystem services, Urban For. Urban Gree., 28, 167–176, https://doi.org/10.1016/j.ufug.2017.10.015, 2017.
Fratini, G. and Mauder, M.: Towards a consistent eddy-covariance processing: an intercomparison of EddyPro and TK3, Atmos. Meas. Tech., 7, 2273–2281, https://doi.org/10.5194/amt-7-2273-2014, 2014.
Getter, K. L., Rowe, D. B., Robertson, G. P., Cregg, B. M., and Andresen, J. A.: Carbon sequestration potential of extensive green roofs, Environmental Science & Technology, 43, 7564–7570, https://doi.org/10.1021/es901539x, 2009.
Gilmanov, T. G., Soussana, J. F., Aires, L., Allard, V., Ammann, C., Balzarolo, M., Barcza, Z., Bernhofer, C., Campbell, C. L., Cernusca, A., Cescatti, A., Clifton-Brown, J., Dirks, B., Dore, S., Eugster, W., Fuhrer, J., Gimeno, C., Gruenwald, T., Haszpra, L., Hensen, A., Ibrom, A., Jacobs, A., Jones, M. B., Lanigan, G., Laurila, T., Lohila, A., Manca, G., Marcolla, B., Nagy, Z., Pilegaard, K., Pinter, K., Pio, C., Raschi, A., Rogiers, N., Sanz, M. J., Stefani, P., Sutton, M., Tuba, Z., Valentini, R., Williams, M. L., and Wohlfahrt, G.: Partitioning European grassland net ecosystem CO2 exchange into gross primary productivity and ecosystem respiration using light response function analysis, Agriculture, Ecosystems & Environment, 121, 93–120, https://doi.org/10.1016/j.agee.2006.12.008, 2007.
Greve, P., Gudmundsson, L., Orlowsky, B., and Seneviratne, S. I.: A two-parameter Budyko function to represent conditions under which evapotranspiration exceeds precipitation, Hydrol. Earth Syst. Sci., 20, 2195–2205, https://doi.org/10.5194/hess-20-2195-2016, 2016.
Grossiord, C., Buckley, T. N., Cernusak, L. A., Novick, K. A., Poulter, B., Siegwolf, R. T. W., Sperry, J. S., and McDowell, N. G.: Plant responses to rising vapor pressure deficit, New Phytol., 226, 1550–1566, https://doi.org/10.1111/nph.16485, 2020.
Halim, M. A., Vantellingen, J., Gorgolewski, A. S., Rose, W. K., Drake, J. A. P., Margolis, L., and Thomas, S. C.: Greenhouse gases and green roofs: carbon dioxide and methane fluxes in relation to substrate characteristics, Urban Ecosyst., 25, 487–498, https://doi.org/10.1007/s11252-021-01166-8, 2022.
Han, J., Yang, Y., Roderick, M. L., McVicar, T. R., Yang, D., Zhang, S., and Beck, H. E.: Assessing the Steady-State Assumption in Water Balance Calculation Across Global Catchments, Water Resour. Res., 56, https://doi.org/10.1029/2020WR027392, 2020.
Hansen, P., Heusinger, J., and Weber, S.: Carbon and water exchange in extensive green roofs: A comparison between eddy covariance and soil flux chamber observations, Urban For. Urban Gree., 113, 129099, https://doi.org/10.1016/j.ufug.2025.129099, 2025.
Heusinger, J. and Weber, S.: Surface energy balance of an extensive green roof as quantified by full year eddy-covariance measurements, Sci. Total Environ., 577, 220–230, https://doi.org/10.1016/j.scitotenv.2016.10.168, 2017a.
Heusinger, J. and Weber, S.: Extensive green roof CO2 exchange and its seasonal variation quantified by eddy covariance measurements, Sci. Total Environ., 607–608, 623–632, https://doi.org/10.1016/j.scitotenv.2017.07.052, 2017b.
Heusinger, J., Sailor, D. J., and Weber, S.: Modeling the reduction of urban excess heat by green roofs with respect to different irrigation scenarios, Build. Environ., 131, 174–183, https://doi.org/10.1016/j.buildenv.2018.01.003, 2018.
Kljun, N., Calanca, P., Rotach, M. W., and Schmid, H. P.: A simple two-dimensional parameterisation for Flux Footprint Prediction (FFP), Geosci. Model Dev., 8, 3695–3713, https://doi.org/10.5194/gmd-8-3695-2015, 2015.
Klosterhalfen, A., Fellert, D., Koebsch, F., Kreilein, H., Markwitz, C., Mund, M., Peksa, M., Tiedemann, F., Tunsch, E., and Knohl, A.: Analysis of a 23-years Long Eddy-covariance Fluxes Dataset from a Mixed Deciduous Forest in Germany, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23–13689, https://doi.org/10.5194/egusphere-egu23-13689, 2023.
Konopka, J., Heusinger, J., and Weber, S.: Extensive Urban Green Roof Shows Consistent Annual Net Uptake of Carbon as Documented by 5 Years of Eddy-Covariance Flux Measurements, J. Geophys. Res.-Biogeo., 126, https://doi.org/10.1029/2020JG005879, 2021.
Kuronuma, T. and Watanabe, H.: Relevance of Carbon Sequestration to the Physiological and Morphological Traits of Several Green Roof Plants during the First Year after Construction, AJPS, 8, 14–27, https://doi.org/10.4236/ajps.2017.81002, 2017.
LI-COR Biosciences: Eddy Covariance Processing Software (EddyPro, Version 7.0.9) [Software], https://www.licor.com/products/eddy-covariance/eddypro (last access: 20 July 2026), 2022.
Liebethal, C., Huwe, B., and Foken, T.: Sensitivity analysis for two ground heat flux calculation approaches, Agr. Forest Meteorol., 132, 253–262, https://doi.org/10.1016/j.agrformet.2005.08.001, 2005.
Liu, W., Feng, Q., Chen, W., Wei, W., and Deo, R. C.: The influence of structural factors on stormwater runoff retention of extensive green roofs: new evidence from scale-based models and real experiments, J. Hydrol., 569, 230–238, https://doi.org/10.1016/j.jhydrol.2018.11.066, 2019.
Lloyd, J. and Taylor, J. A.: On the Temperature Dependence of Soil Respiration, Functional Ecology, 8, 315, https://doi.org/10.2307/2389824, 1994.
Mann, G. and Landwehr, R.: BuGG-Marktreport Gebäudegrün 2024: Dach-, Fassaden- und Innenraumbegrünung Deutschland, Bundesverband GebäudeGrün e.V. (BuGG), ISSN 2750-3763, 2024.
Markolf, N., Heusinger, J., and Weber, S.: Water storage levels and water storage capacity of an extensive green roof quantified from multi-year eddy covariance measurements, Ecol. Eng., 206, 107333, https://doi.org/10.1016/j.ecoleng.2024.107333, 2024.
McAdam, S. A. M. and Brodribb, T. J.: The evolution of mechanisms driving the stomatal response to vapor pressure deficit, Plant Physiol., 167, 833–843, https://doi.org/10.1104/pp.114.252940, 2015.
Moncrieff, J. B., Massheder, J. M., Bruin, H. de, Elbers, J., Friborg, T., Heusinkveld, B., Kabat, P., Scott, S., Soegaard, H., and Verhoef, A.: A system to measure surface fluxes of momentum, sensible heat, water vapour and carbon dioxide, J. Hydrol., 188–189, 589–611, https://doi.org/10.1016/S0022-1694(96)03194-0, 1997.
Nowak, D. J., Greenfield, E. J., Hoehn, R. E., and Lapoint, E.: Carbon storage and sequestration by trees in urban and community areas of the United States, Environ. Pollut., 178, 229–236, https://doi.org/10.1016/j.envpol.2013.03.019, 2013.
Oke, T. R.: The energetic basis of the urban heat island, Q. J. Ro. Meteor. Soc., 108, 1–24, https://doi.org/10.1002/qj.49710845502, 1982.
Pereira, P., Yin, C., and Hua, T.: Nature-based solutions, ecosystem services, disservices, and impacts on well-being in urban environments, Current Opinion in Environmental Science & Health, 33, 100465, https://doi.org/10.1016/j.coesh.2023.100465, 2023.
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., 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.
Schultz, I., Sailor, D. J., and Starry, O.: Effects of substrate depth and precipitation characteristics on stormwater retention by two green roofs in Portland OR, J. Hydrol., 18, 110–118, https://doi.org/10.1016/j.ejrh.2018.06.008, 2018.
Shafique, M., Xue, X., and Luo, X.: An overview of carbon sequestration of green roofs in urban areas, Urban For. Urban Gree., 47, 126515, https://doi.org/10.1016/j.ufug.2019.126515, 2020.
Soltanifard, H. and Amani-Beni, M.: The cooling effect of urban green spaces as nature-based solutions for mitigating urban heat: insights from a decade-long systematic review, Climate Risk Management, 49, 100731, https://doi.org/10.1016/j.crm.2025.100731, 2025.
Starry, O., Lea-Cox, J. D., Kim, J., and van Iersel, M. W.: Photosynthesis and water use by two Sedum species in green roof substrate, Environ. Exp. Bot., 107, 105–112, https://doi.org/10.1016/j.envexpbot.2014.05.014, 2014.
Stovin, V.: The potential of green roofs to manage Urban Stormwater, Water Environ. J., 24, 192–199, https://doi.org/10.1111/j.1747-6593.2009.00174.x, 2010.
Stovin, V., Vesuviano, G., and Kasmin, H.: The hydrological performance of a green roof test bed under UK climatic conditions, J. Hydrol., 414–415, 148–161, https://doi.org/10.1016/j.jhydrol.2011.10.022, 2012.
Teemusk, A., Kull, A., Kanal, A., and Mander, Ü.: Environmental factors affecting greenhouse gas fluxes of green roofs in temperate zone, Sci. the Total Environ., 694, 133699, https://doi.org/10.1016/j.scitotenv.2019.133699, 2019.
Thölix, L., Backman, L., Havu, M., Karvinen, E., Soininen, J., Trémeau, J., Nevalainen, O., Ahongshangbam, J., Järvi, L., and Kulmala, L.: Carbon sequestration in different urban vegetation types in Southern Finland, Biogeosciences, 22, 725–749, https://doi.org/10.5194/bg-22-725-2025, 2025.
United Nations, Department of Economic and Social Affairs, Population Division: World Urbanization Prospects: The 2018 Revision (ST/ESA/SER.A/420), New York, ISBN: 978-92-1-148319-2, 2019.
Ürge-Vorsatz, D., Chatterjee, S., Cabeza, L. F., and Molnár, G.: Global and regional estimation and evaluation of suitable roof area for solar and green roof applications, Developments in the Built Environment, 21, 100607, https://doi.org/10.1016/j.dibe.2025.100607, 2025.
VanWoert, N. D., Rowe, D. B., Andresen, J. A., Rugh, C. L., Fernandez, R. T., and Xiao, L.: Green Roof Stormwater Retention, Journal of Environment Quality, 34, 1036–1044, https://doi.org/10.2134/jeq2004.0364, 2005.
Weber, S.: Comparison of in-situ measured ground heat fluxes within a heteorogeneous urban ballast layer, Theor. Appl. Climatol., 83, 169–179, https://doi.org/10.1007/s00704-005-0137-0, 2006.
Xue, B.-L., Wang, L., Li, X., Yang, K., Chen, D., and Sun, L.: Evaluation of evapotranspiration estimates for two river basins on the Tibetan Plateau by a water balance method, J. Hydrol., 492, 290–297, https://doi.org/10.1016/j.jhydrol.2013.04.005, 2013.
Yan, Z., Liu, C., Todd-Brown, K. E., Liu, Y., Bond-Lamberty, B., and Bailey, V. L.: Pore-scale investigation on the response of heterotrophic respiration to moisture conditions in heterogeneous soils, Biogeochemistry, 131, 121–134, https://doi.org/10.1007/s10533-016-0270-0, 2016.
Yang, S., Kong, F., Yin, H., Zhang, N., Tan, T., Middel, A., and Liu, H.: Carbon dioxide reduction from an intensive green roof through carbon flux observations and energy consumption simulations, Sustain. Cities Soc., 99, 104913, https://doi.org/10.1016/j.scs.2023.104913, 2023.
Short summary
Urban green roofs (GRs) were shown to provide various ecosystem services, such as carbon sequestration. We investigate the coupling between carbon, water, and energy exchange of a large, extensive GR using nine years of eddy-covariance data to determine their role in shaping the net ecosystem exchange. The GR acted as a moderate carbon sink with distinct annual and seasonal variation influenced by the coupled exchange processes. This highlights the importance of long-term flux monitoring.
Urban green roofs (GRs) were shown to provide various ecosystem services, such as carbon...
Altmetrics
Final-revised paper
Preprint