Altered energy partitioning across terrestrial ecosystems in the European drought year 2018

Alexander Graf*, Anne Klosterhalfen, Nicola Arriga, Christian Bernhofer, Heye Bogena, Frédéric Bornet, Nicolas Brüggemann, Christian Brümmer, Nina Buchmann, Jinshu Chi, Christophe Chipeaux, Edoardo Cremonese, Matthias Cuntz, Jiří Dušek, Tarek S El-Madany, Silvano Fares, Milan Fischer, Lenka Foltýnová, Mana Gharun, Shiva GhiasiBert Gielen, Pia Gottschalk, Thomas Grünwald, Günther Heinemann, Bernard Heinesch, Michal Heliasz, Jutta Holst, Lukas Hörtnagl, Andreas Ibrom, Joachim Ingwersen, Gerald Jurasinski, Janina Klatt, Alexander Knohl, Franziska Koebsch, Jan Konopka, Mika Korkiakoski, Natalia Kowalska, Pascal Kremer, Bart Kruijt, Sebastien Lafont, Joël Léonard, Anne De Ligne, Bernard Longdoz, Denis Loustau, Vincenzo Magliulo, Ivan Mammarella, Giovanni Manca, Matthias Mauder, Mirco Migliavacca, Meelis Mölder, Johan Neirynck, Patrizia Ney, Mats Nilsson, Eugénie Paul-Limoges, Matthias Peichl, Andrea Pitacco, Arne Poyda, Corinna Rebmann, Marilyn Roland, Torsten Sachs, Marius Schmidt, Frederik Schrader, Lukas Siebicke, Ladislav Šigut, Eeva-Stiina Tuittila, Andrej Varlagin, Nadia Vendrame, Caroline Vincke, Ingo Völksch, Stephan Weber, Christian Wille, Hans-Dieter Wizemann, Matthias Zeeman, Harry Vereecken

*Corresponding author for this work

Research output: Contribution to journalJournal articleResearchpeer-review

Abstract

Drought and heat events, such as the 2018 European drought, interact with the exchange of energy between the land surface and the atmosphere, potentially affecting albedo, sensible and latent heat fluxes, as well as CO2 exchange. Each of these quantities may aggravate or mitigate the drought, heat, their side effects on productivity, water scarcity and global warming. We used measurements of 56 eddy covariance sites across Europe to examine the response of fluxes to extreme drought prevailing most of the year 2018 and how the response differed across various ecosystem types (forests, grasslands, croplands and peatlands). Each component of the surface radiation and energy balance observed in 2018 was compared to available data per site during a reference period 2004-2017. Based on anomalies in precipitation and reference evapotranspiration, we classified 46 sites as drought affected. These received on average 9% more solar radiation and released 32% more sensible heat to the atmosphere compared to the mean of the reference period. In general, drought decreased net CO2 uptake by 17.8%, but did not significantly change net evapotranspiration. The response of these fluxes differed characteristically between ecosystems; in particular, the general increase in the evaporative index was strongest in peatlands and weakest in croplands. This article is part of the theme issue 'Impacts of the 2018 severe drought and heatwave in Europe: from site to continental scale'.

Original languageEnglish
Article number20190524
JournalPhilosophical Transactions of the Royal Society B: Biological Sciences
Volume375
Issue number1810
Number of pages8
ISSN0962-8436
DOIs
Publication statusPublished - 2020

Cite this

Graf, A., Klosterhalfen, A., Arriga, N., Bernhofer, C., Bogena, H., Bornet, F., Brüggemann, N., Brümmer, C., Buchmann, N., Chi, J., Chipeaux, C., Cremonese, E., Cuntz, M., Dušek, J., El-Madany, T. S., Fares, S., Fischer, M., Foltýnová, L., Gharun, M., ... Vereecken, H. (2020). Altered energy partitioning across terrestrial ecosystems in the European drought year 2018. Philosophical Transactions of the Royal Society B: Biological Sciences, 375(1810), [20190524]. https://doi.org/10.1098/rstb.2019.0524