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Gourlez de la Motte L, Beauclaire Q, Heinesch B, Cuntz M, Foltýnová L, Šigut L, Kowalska N, Manca G, Ballarin IG, 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. Philos Trans R Soc Lond B Biol Sci 2020; 375:20190527. [PMID: 32892725 DOI: 10.1098/rstb.2019.0527] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Severe drought events are known to cause important reductions of gross primary productivity (GPP) in forest ecosystems. However, it is still unclear whether this reduction originates from stomatal closure (Stomatal Origin Limitation) and/or non-stomatal limitations (Non-SOL). In this study, we investigated the impact of edaphic drought in 2018 on GPP and its origin (SOL, NSOL) using a dataset of 10 European forest ecosystem flux towers. In all stations where GPP reductions were observed during the drought, these were largely explained by declines in the maximum apparent canopy scale carboxylation rate VCMAX,APP (NSOL) when the soil relative extractable water content dropped below around 0.4. Concurrently, we found that the stomatal slope parameter (G1, related to SOL) of the Medlyn et al. unified optimization model linking vegetation conductance and GPP remained relatively constant. These results strengthen the increasing evidence that NSOL should be included in stomatal conductance/photosynthesis models to faithfully simulate both GPP and water fluxes in forest ecosystems during severe drought. This article is part of the theme issue 'Impacts of the 2018 severe drought and heatwave in Europe: from site to continental scale'.
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Affiliation(s)
- Louis Gourlez de la Motte
- Terra Teaching and Research Center, University of Liège - Gembloux Agro-Bio Tech, 5030 Gembloux, Belgium
| | - Quentin Beauclaire
- Terra Teaching and Research Center, University of Liège - Gembloux Agro-Bio Tech, 5030 Gembloux, Belgium
| | - Bernard Heinesch
- Terra Teaching and Research Center, University of Liège - Gembloux Agro-Bio Tech, 5030 Gembloux, Belgium
| | - Mathias Cuntz
- Université de Lorraine, AgroParisTech, INRA, UMR Silva, 54000 Nancy, France
| | | | - Ladislav Šigut
- Global Change Research Institute CAS, Brno, Czech Republic
| | | | - Giovanni Manca
- European Commission, Joint Research Centre (JRC), Ispra, Italy
| | | | - Caroline Vincke
- Earth and Life Institute, UCLouvain, Louvain-la-Neuve, Belgium
| | - Marilyn Roland
- Plants and Ecosystems, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium
| | - Andreas Ibrom
- Department of Environmental Engineering, Technical University of Denmark (DTU), Bygningstorvet 115, 2800 Lyngby, Denmark
| | | | - Lukas Siebicke
- Bioclimatology, University of Goettingen, Büsgenweg 2, 37077 Goettingen, Germany
| | - Johan Neiryink
- Institute for Nature and Forest Research, INBO, Havenlaan 88 Box 73, 1000 Brussels, Belgium
| | - Bernard Longdoz
- Terra Teaching and Research Center, University of Liège - Gembloux Agro-Bio Tech, 5030 Gembloux, Belgium
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