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1. Monitoring of carbon-water fluxes at Eurasian meteorological stations using random forest and remote sensing

Author

Mingjuan Xie, Xiaofei Ma, Yuangang Wang, Chaofan Li, Haiyang Shi, Xiuliang Yuan, Olaf Hellwich, Chunbo Chen, Wenqiang Zhang, Chen Zhang, Qing Ling, Ruixiang Gao, Yu Zhang, Friday Uchenna Ochege, Amaury Frankl, Philippe De Maeyer, Nina Buchmann, Iris Feigenwinter, Jørgen E. Olesen, Radoslaw Juszczak, Adrien Jacotot, Aino Korrensalo, Andrea Pitacco, Andrej Varlagin, Ankit Shekhar, Annalea Lohila, Arnaud Carrara, Aurore Brut, Bart Kruijt, Benjamin Loubet, Bernard Heinesch, Bogdan Chojnicki, Carole Helfter, Caroline Vincke, Changliang Shao, Christian Bernhofer, Christian Brümmer, Christian Wille, Eeva-Stiina Tuittila, Eiko Nemitz, Franco Meggio, Gang Dong, Gary Lanigan, Georg Niedrist, Georg Wohlfahrt, Guoyi Zhou, Ignacio Goded, Thomas Gruenwald, Janusz Olejnik, Joachim Jansen, Johan Neirynck, Juha-Pekka Tuovinen, Junhui Zhang, Katja Klumpp, Kim Pilegaard, Ladislav Šigut, Leif Klemedtsson, Luca Tezza, Lukas Hörtnagl, Marek Urbaniak, Marilyn Roland, Marius Schmidt, Mark A. Sutton, Markus Hehn, Matthew Saunders, Matthias Mauder, Mika Aurela, Mika Korkiakoski, Mingyuan Du, Nadia Vendrame, Natalia Kowalska, Paul G. Leahy, Pavel Alekseychik, Peili Shi, Per Weslien, Shiping Chen, Silvano Fares, Thomas Friborg, Tiphaine Tallec, Tomomichi Kato, Torsten Sachs, Trofim Maximov, Umberto Morra di Cella, Uta Moderow, Yingnian Li, Yongtao He, Yoshiko Kosugi, and Geping Luo

Subjects
Science
Abstract

Abstract Simulating the carbon-water fluxes at more widely distributed meteorological stations based on the sparsely and unevenly distributed eddy covariance flux stations is needed to accurately understand the carbon-water cycle of terrestrial ecosystems. We established a new framework consisting of machine learning, determination coefficient (R2), Euclidean distance, and remote sensing (RS), to simulate the daily net ecosystem carbon dioxide exchange (NEE) and water flux (WF) of the Eurasian meteorological stations using a random forest model or/and RS. The daily NEE and WF datasets with RS-based information (NEE-RS and WF-RS) for 3774 and 4427 meteorological stations during 2002–2020 were produced, respectively. And the daily NEE and WF datasets without RS-based information (NEE-WRS and WF-WRS) for 4667 and 6763 meteorological stations during 1983–2018 were generated, respectively. For each meteorological station, the carbon-water fluxes meet accuracy requirements and have quasi-observational properties. These four carbon-water flux datasets have great potential to improve the assessments of the ecosystem carbon-water dynamics.

Published
2023
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2. A Functional Trait-Based Approach to Evaluate the Resilience of Key Ecosystem Functions of Tropical Savannas

Author

Morgane Dendoncker, Simon Taugourdeau, Christian Messier, and Caroline Vincke

Subjects
tropical savanna, woody vegetation, trait-based approach, response diversity, functional redundancy, drought, Plant ecology, QK900-989
Abstract

The persistence of the woody vegetation of the Sahelian savannas, and their supported ecosystem functions, have been questioned since the great drought of 1970s–1980s. To assess the resilience of this vegetation to drought and grazing, we undertook a trait-based approach using field inventory, historical survey databases, and traits data literature. Using a hierarchical clustering approach, we gathered the species present from 1970 to 2015 into functional groups according to their effect traits related to primary productivity and biogeochemical cycles. First, we studied the evolution of functional redundancy (FRe) and response diversity (RDiv) of the functional effect groups to drought and grazing, two indicators of resilience, since the 1970s. Second, we looked at the spatial variation of these two indices in 2015, according to local topography. FRe and RDiv of 80% of the functional groups examined declined since 1970, endangering the persistence of the studied functions. Local topography strongly influenced current FRe and RDiv, with depressions presenting higher values. Finally, by examining species’ abundances, their regeneration, and the functional group to which they belong, we determined some key species that could benefit from protection to ensure the persistence of the ecosystem functions supported by the woody vegetation. This study has expanded knowledge about the savanna’s response to pressures and has shown how a functional traits-based approach could be an effective tool to guide the management of tropical savannas.

Published
2023
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3. Method comparison of indirect assessments of understory leaf area index (LAIu): A case study across the extended network of ICOS forest ecosystem sites in Europe

Author

Jan-Peter George, Wei Yang, Hideki Kobayashi, Tobias Biermann, Arnaud Carrara, Edoardo Cremonese, Matthias Cuntz, Silvano Fares, Giacomo Gerosa, Thomas Grünwald, Niklas Hase, Michael Heliasz, Andreas Ibrom, Alexander Knohl, Bart Kruijt, Holger Lange, Jean-Marc Limousin, Denis Loustau, Petr Lukeš, Riccardo Marzuoli, Meelis Mölder, Leonardo Montagnani, Johan Neirynck, Matthias Peichl, Corinna Rebmann, Marius Schmidt, Francisco Ramon Lopez Serrano, Kamel Soudani, Caroline Vincke, and Jan Pisek

Subjects
Forest background reflectivity, Fractional vegetation cover, Leaf area index, NDVI, Simple ratio, Diversity, Ecology, QH540-549.5
Abstract

Leaf area index (LAI) is a key ecological indicator for describing the structure of canopies and for modelling energy exchange between atmosphere and biosphere. While LAI of the forest overstory can be accurately assessed over large spatial scales via remote sensing, LAI of the forest understory (LAIu) is still largely ignored in ecological studies and ecosystem modelling due to the fact that it is often too complex to be destructively sampled or approximated by other site parameters. Additionally, so far only few attempts have been made to retrieve understory LAI via remote sensing, because dense canopies with high LAI are often hindering retrieval algorithms to produce meaningful estimates for understory LAI. Consequently, the forest understory still constitutes a poorly investigated research realm impeding ecological studies to properly account for its contribution to the energy absorption capacity of forest stands. This study aims to compare three conceptually different indirect retrieval methodologies for LAIu over a diverse panel of forest understory types distributed across Europe. For this we carried out near-to-surface measurements of understory reflectance spectra as well as digital surface photography over the extended network of Integrated Carbon Observation System (ICOS) forest ecosystem sites. LAIu was assessed by exploiting the empirical relationship between vegetation cover and light absorption (Beer-Lambert- Bouguer law) as well as by utilizing proposed relationships with two prominent vegetation indices: normalized difference vegetation index (NDVI) and simple ratio (SR). Retrievals from the three methods were significantly correlated with each other (r = 0.63–0.99, RMSE = 0.53–0.72), but exhibited also significant bias depending on the LAI scale. The NDVI based retrieval approach most likely overestimates LAI at productive sites when LAIu > 2, while the simple ratio algorithm overestimates LAIu at sites with sparse understory vegetation and presence of litter or bare soil. The purely empirical method based on the Beer-Lambert law of light absorption seems to offer a good compromise, since it provides reasonable LAIu values at both low and higher LAI ranges. Surprisingly, LAIu variation among sites seems to be largely decoupled from differences in climate and light permeability of the overstory, but significantly increased with vegetation diversity (expressed as species richness) and hence proposes new applications of LAIu in ecological modelling.

Published
2021
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4. Author Correction: The FLUXNET2015 dataset and the ONEFlux processing pipeline for eddy covariance data

Author

Gilberto Pastorello, Carlo Trotta, Eleonora Canfora, Housen Chu, Danielle Christianson, You-Wei Cheah, Cristina Poindexter, Jiquan Chen, Abdelrahman Elbashandy, Marty Humphrey, Peter Isaac, Diego Polidori, Markus Reichstein, Alessio Ribeca, Catharine van Ingen, Nicolas Vuichard, Leiming Zhang, Brian Amiro, Christof Ammann, M. Altaf Arain, Jonas Ardö, Timothy Arkebauer, Stefan K. Arndt, Nicola Arriga, Marc Aubinet, Mika Aurela, Dennis Baldocchi, Alan Barr, Eric Beamesderfer, Luca Belelli Marchesini, Onil Bergeron, Jason Beringer, Christian Bernhofer, Daniel Berveiller, Dave Billesbach, Thomas Andrew Black, Peter D. Blanken, Gil Bohrer, Julia Boike, Paul V. Bolstad, Damien Bonal, Jean-Marc Bonnefond, David R. Bowling, Rosvel Bracho, Jason Brodeur, Christian Brümmer, Nina Buchmann, Benoit Burban, Sean P. Burns, Pauline Buysse, Peter Cale, Mauro Cavagna, Pierre Cellier, Shiping Chen, Isaac Chini, Torben R. Christensen, James Cleverly, Alessio Collalti, Claudia Consalvo, Bruce D. Cook, David Cook, Carole Coursolle, Edoardo Cremonese, Peter S. Curtis, Ettore D’Andrea, Humberto da Rocha, Xiaoqin Dai, Kenneth J. Davis, Bruno De Cinti, Agnes de Grandcourt, Anne De Ligne, Raimundo C. De Oliveira, Nicolas Delpierre, Ankur R. Desai, Carlos Marcelo Di Bella, Paul di Tommasi, Han Dolman, Francisco Domingo, Gang Dong, Sabina Dore, Pierpaolo Duce, Eric Dufrêne, Allison Dunn, Jiří Dušek, Derek Eamus, Uwe Eichelmann, Hatim Abdalla M. ElKhidir, Werner Eugster, Cacilia M. Ewenz, Brent Ewers, Daniela Famulari, Silvano Fares, Iris Feigenwinter, Andrew Feitz, Rasmus Fensholt, Gianluca Filippa, Marc Fischer, John Frank, Marta Galvagno, Mana Gharun, Damiano Gianelle, Bert Gielen, Beniamino Gioli, Anatoly Gitelson, Ignacio Goded, Mathias Goeckede, Allen H. Goldstein, Christopher M. Gough, Michael L. Goulden, Alexander Graf, Anne Griebel, Carsten Gruening, Thomas Grünwald, Albin Hammerle, Shijie Han, Xingguo Han, Birger Ulf Hansen, Chad Hanson, Juha Hatakka, Yongtao He, Markus Hehn, Bernard Heinesch, Nina Hinko-Najera, Lukas Hörtnagl, Lindsay Hutley, Andreas Ibrom, Hiroki Ikawa, Marcin Jackowicz-Korczynski, Dalibor Janouš, Wilma Jans, Rachhpal Jassal, Shicheng Jiang, Tomomichi Kato, Myroslava Khomik, Janina Klatt, Alexander Knohl, Sara Knox, Hideki Kobayashi, Georgia Koerber, Olaf Kolle, Yoshiko Kosugi, Ayumi Kotani, Andrew Kowalski, Bart Kruijt, Julia Kurbatova, Werner L. Kutsch, Hyojung Kwon, Samuli Launiainen, Tuomas Laurila, Bev Law, Ray Leuning, Yingnian Li, Michael Liddell, Jean-Marc Limousin, Marryanna Lion, Adam J. Liska, Annalea Lohila, Ana López-Ballesteros, Efrén López-Blanco, Benjamin Loubet, Denis Loustau, Antje Lucas-Moffat, Johannes Lüers, Siyan Ma, Craig Macfarlane, Vincenzo Magliulo, Regine Maier, Ivan Mammarella, Giovanni Manca, Barbara Marcolla, Hank A. Margolis, Serena Marras, William Massman, Mikhail Mastepanov, Roser Matamala, Jaclyn Hatala Matthes, Francesco Mazzenga, Harry McCaughey, Ian McHugh, Andrew M. S. McMillan, Lutz Merbold, Wayne Meyer, Tilden Meyers, Scott D. Miller, Stefano Minerbi, Uta Moderow, Russell K. Monson, Leonardo Montagnani, Caitlin E. Moore, Eddy Moors, Virginie Moreaux, Christine Moureaux, J. William Munger, Taro Nakai, Johan Neirynck, Zoran Nesic, Giacomo Nicolini, Asko Noormets, Matthew Northwood, Marcelo Nosetto, Yann Nouvellon, Kimberly Novick, Walter Oechel, Jørgen Eivind Olesen, Jean-Marc Ourcival, Shirley A. Papuga, Frans-Jan Parmentier, Eugenie Paul-Limoges, Marian Pavelka, Matthias Peichl, Elise Pendall, Richard P. Phillips, Kim Pilegaard, Norbert Pirk, Gabriela Posse, Thomas Powell, Heiko Prasse, Suzanne M. Prober, Serge Rambal, Üllar Rannik, Naama Raz-Yaseef, Corinna Rebmann, David Reed, Victor Resco de Dios, Natalia Restrepo-Coupe, Borja R. Reverter, Marilyn Roland, Simone Sabbatini, Torsten Sachs, Scott R. Saleska, Enrique P. Sánchez-Cañete, Zulia M. Sanchez-Mejia, Hans Peter Schmid, Marius Schmidt, Karl Schneider, Frederik Schrader, Ivan Schroder, Russell L. Scott, Pavel Sedlák, Penélope Serrano-Ortíz, Changliang Shao, Peili Shi, Ivan Shironya, Lukas Siebicke, Ladislav Šigut, Richard Silberstein, Costantino Sirca, Donatella Spano, Rainer Steinbrecher, Robert M. Stevens, Cove Sturtevant, Andy Suyker, Torbern Tagesson, Satoru Takanashi, Yanhong Tang, Nigel Tapper, Jonathan Thom, Michele Tomassucci, Juha-Pekka Tuovinen, Shawn Urbanski, Riccardo Valentini, Michiel van der Molen, Eva van Gorsel, Ko van Huissteden, Andrej Varlagin, Joseph Verfaillie, Timo Vesala, Caroline Vincke, Domenico Vitale, Natalia Vygodskaya, Jeffrey P. Walker, Elizabeth Walter-Shea, Huimin Wang, Robin Weber, Sebastian Westermann, Christian Wille, Steven Wofsy, Georg Wohlfahrt, Sebastian Wolf, William Woodgate, Yuelin Li, Roberto Zampedri, Junhui Zhang, Guoyi Zhou, Donatella Zona, Deb Agarwal, Sebastien Biraud, Margaret Torn, and Dario Papale

Subjects
Science
Abstract

A Correction to this paper has been published: https://doi.org/10.1038/s41597-021-00851-9.

Published
2021
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5. Quantifying the effect of forest age in annual net forest carbon balance

Author

Simon Besnard, Nuno Carvalhais, M Altaf Arain, Andrew Black, Sytze de Bruin, Nina Buchmann, Alessandro Cescatti, Jiquan Chen, Jan G P W Clevers, Ankur R Desai, Christopher M Gough, Katerina Havrankova, Martin Herold, Lukas Hörtnagl, Martin Jung, Alexander Knohl, Bart Kruijt, Lenka Krupkova, Beverly E Law, Anders Lindroth, Asko Noormets, Olivier Roupsard, Rainer Steinbrecher, Andrej Varlagin, Caroline Vincke, and Markus Reichstein

Subjects
carbon cycle, eddy covariance, net ecosystem production, empirical modelling, forest age, climate, Environmental technology. Sanitary engineering, TD1-1066, Environmental sciences, GE1-350, Science, Physics, QC1-999
Abstract

Forests dominate carbon (C) exchanges between the terrestrial biosphere and the atmosphere on land. In the long term, the net carbon flux between forests and the atmosphere has been significantly impacted by changes in forest cover area and structure due to ecological disturbances and management activities. Current empirical approaches for estimating net ecosystem productivity (NEP) rarely consider forest age as a predictor, which represents variation in physiological processes that can respond differently to environmental drivers, and regrowth following disturbance. Here, we conduct an observational synthesis to empirically determine to what extent climate, soil properties, nitrogen deposition, forest age and management influence the spatial and interannual variability of forest NEP across 126 forest eddy-covariance flux sites worldwide. The empirical models explained up to 62% and 71% of spatio-temporal and across-site variability of annual NEP, respectively. An investigation of model structures revealed that forest age was a dominant factor of NEP spatio-temporal variability in both space and time at the global scale as compared to abiotic factors, such as nutrient availability, soil characteristics and climate. These findings emphasize the importance of forest age in quantifying spatio-temporal variation in NEP using empirical approaches.

Published
2018
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6. Linking Forest Cover to Water Quality: A Multivariate Analysis of Large Monitoring Datasets

Author

Delphine Brogna, Adrien Michez, Sander Jacobs, Marc Dufrêne, Caroline Vincke, and Nicolas Dendoncker

Subjects
physico-chemical water quality, land cover, land use, forests, agriculture, Wallonia, Belgium, monitoring network, water framework directive, redundancy analysis, Hydraulic engineering, TC1-978, Water supply for domestic and industrial purposes, TD201-500
Abstract

Forested catchments are generally assumed to provide higher quality water. However, this hypothesis must be validated in various contexts as interactions between multiple land use and land cover (LULC) types, ecological variables and water quality variables render this relationship highly complex. This paper applies a straightforward multivariate approach on a typical large monitoring dataset of a highly managed and densely populated area (Wallonia, Belgium; 10-year dataset), quantifying forest cover effects on nine physico-chemical water quality variables. Results show that forest cover explains about one third of the variability of water quality and is positively correlated with higher quality water. When controlling for spatial autocorrelation, forest cover still explains 9% of water quality. Unlike needle-leaved forest cover, broad-leaved forest cover presents an independent effect from ecological variables and explains independently 4.8% of water quality variability while it shares 5.8% with cropland cover. This study demonstrates clear independent effects of forest cover on water quality, and presents a method to tease out independent LULC effects from typical large multivariate monitoring datasets. Further research on explanatory variables, spatial distribution effects and water quality datasets could lead to effective strategies to mitigate pollution and reach legal targets.

Published
2017
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7. Pedunculate oak decline in southern Belgium: a long-term process highlighting the complex interplay among drought, winter frost, biotic attacks, and masting

Author

Julie Losseau, Mathieu Jonard, and Caroline Vincke

Subjects
Mortality -- Belgium -- France -- Eastern Europe, Droughts -- Belgium -- Eastern Europe -- France, Climatic changes -- Health aspects, Water balance (Hydrology) -- Health aspects, Earth sciences
Abstract

Since 2013, pedunculate oak (Quercus robur L.) mortality has been observed in the Ardennes region of Belgium. We aimed to understand the current decline by retrospectively (1945-2015) studying radial growth patterns of trees classified by three health statuses (reference, declining, and dying) and by linking them to abiotic and biotic hazard history, which we recorded and quantified. Our results show that oak mortality in the Ardennes is a long-term process, with 1987 as a tipping point for growth trajectories of declining and dying trees. That year was preceded by two growth crises (1976-1981 and 1984-1987), and it falls within the last major episode of oak decline in Belgium. Among hazards, very cold winters and caterpillar outbreaks have significant impacts on growth-pattern differentiation. Apart from 1976, extreme drought is still rare; however, mild spring droughts, especially in the years n - 1 and n - 2, explain some of the growth loss relative to the reference trees. Finally, masting appears to be an important contributing factor for the death of weakened trees. Given the direct and delayed impacts of the extreme drought of 1976 and subsequent water balance impairment due to winter frosts and mild spring droughts, the health of pedunculate oak is giving cause for concern in the context of climate change. Key words: dendrochronology, forest decline, Quercus robur L., biotic and climatic hazards, mortality process. Resume : La mortalite du chene pedoncule (Quercus robur L.) est observee depuis 2013 dans la region des Ardennes en Belgique. Nous avons cherche a comprendre la cause du deperissement actuel en etudiant retrospectivement (1945-2015) les courbes de croissance radiale des arbres classes selon leur etat de sante (temoin, deperissant et mourant) et en les reliant aux aleas biotiques et abiotiques passes que nous avons notes et quantifies. Nos resultats montrent que la mortalite du chene dans les Ardennes est un processus a long terme et que 1987 est un point tournant dans les trajectoires de croissance des arbres deperissants et mourants. Cette annee a ete precedee par deux crises de croissance (1976-1981 et 1984-1987) et cela correspond au dernier episode majeur de deperissement du chene en Belgique. Parmi les aleas, des hivers tres froids et des epidemies de chenilles ont des impacts significatifs sur la differentiation des courbes de croissance. A l'exception de 1976, la secheresse extreme est encore rare; cependant, de legeres secheresses printanieres, particulierement lors des annees n - 1 et n - 2 expliquent une partie de la perte de croissance relativement aux arbres temoins. Finalement, la production massive de semences semble etre un facteur qui contribue de facon importante a la mort des arbres affaiblis. Etant donne les impacts directs et a retardement de la secheresse extreme de 1976 et la perturbation subsequente de l'equilibre hydrique a cause des gels hivernaux et des legeres secheresses printanieres, l'etat de sante du chene pedoncule est une source de preoccupation dans le contexte du changement climatique. [Traduit par la Redaction] Mots-cles : dendrochronologie, deperissement des forets, Quercus robur L., aleas biotiques et climatiques, processus de mortalite., 1. Introduction Several pedunculate oak (Quercus robur L.) decline crises were recorded and studied in Europe over the course of the 20th century (Delatour 1983; Haavik et al. 2015). The [...]

Published
2020
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8. Increasing soil water deficit negatively impacts European beech radial growth: a case study combining long-term monitoring (1996-2020) and modeling approaches

Author

Wafa Chebbi, Mathieu Jonard, and Caroline Vincke

Abstract

Beech (Fagus sylvatica L.), is one of the most socio-economically valuable and widely distributed broadleaved trees in Europe. European beech favorable edaphic and climatic conditions are sufficient moisture in summer and mild temperatures in winter. This highly competitive species is also known to be drought-sensitive and thus may become more vulnerable to expected increasing number of heat waves and drought spells. A better understanding of beech response to soil drought is therefore crucial for forestry planning and forest management in a future warmer world. In this study, we investigate the water balance and radial growth dynamics of a beech stand in an ICOS site in Belgium (BE-Vielsalm), with a special focus on soil drought impacts, based on about three decades of observations (1996-2020). The continuous decreasing trend of beech radial growth (dendrochronological time series) coupled with recent crown defoliation raised concern about the vitality of this stand. On the basis of this site-specific data set, the calibration and the validation of the model HETEROFOR were performed in order to i) simulate the water balance and fluxes at the stand level; ii) track the occurrence and intensity of soil-induced transpiration deficit during the whole study period; iii) characterize the tree water uptake patterns according to soil depth for contrasted years (dry, intermediate and wet) and iv) evaluate the current and lag effects of spring and summer transpiration deficit on the observed annual radial growth of beech trees obtained from dendrochronological analysis. A good agreement between predicted and observed evapotranspiration and extractable water was obtained and showed the robustness of the model. The predicted transpiration deficit revealed an increasing trend, especially after 2010. We observed a negative effect of the spring transpiration deficit on tree radial growth during the current year as well as a carryover effect (i.e., a negative effect of the summer transpiration deficit of the previous year). This study will enrich the state of knowledge about the ongoing debate on the vulnerability of beech trees to drought in Europe.Keywords: Fagus sylvatica, radial growth, soil water balance, forest evapotranspiration, drought, process-based modeling, eddy covariance.

Published
2023

9. Variations des caractéristiques physiques et mécaniques du bois de Balanites aegyptiaca en fonction de trois provenances

Author

Jean Gérard, Dao Dougabka, Rémy Marchal, Alban Guyot, Daniel Guibal, Tikri Bianzeube, Caroline Vincke, Morgane Dendoncker, and UCL - SST/ELI/ELIE - Environmental Sciences

Subjects
K50 - Technologie des produits forestiers, Matériaux [Sciences de l'ingénieur], Ecology, Evolution, Forestry, Behavior and Systematics, Propriété mécanique, Provenance, Propriété technologique, Balanites aegyptiaca, Ecology, Evolution, Behavior and Systematics, Propriété du bois, Propriété physicochimique
Abstract

Balanites aegyptiaca est une espèce caractéristique et emblématique des zones sèches d’Afrique et d’Asie. Elle revêt une grande importance socio-économique dans toute sa zone naturelle de répartition du fait de ses multiples usages. Toutefois, les propriétés technologiques de son bois sont mal connues, d’où des utilisations parfois inappropriées mais qui pourraient être élargies. Afin de mieux adapter ses applications à ses caractéristiques, nous avons déterminé les indicateurs de stabilité physique (masse volumique, infradensité, retrait radial total, retrait tangentiel total, retrait volumique total et point de saturation des fibres) et les indicateurs de comportement mécanique (module d’élasticité longitudinal, contrainte de rupture en flexion et compression) de ce bois. Quatre-vingt-treize éprouvettes prélevées dans 13 arbres provenant des zones sahélienne et soudanienne tchadiennes, et de la zone sahélienne sénégalaise ont été testées. Les résultats obtenus montrent que, pour les trois provenances, le bois de B. aegyptiaca est mi-lourd (797 kg/m3) avec une stabilité dimensionnelle moyenne : l’anisotropie de retrait est supérieure à 2 (2,2), le retrait radial total et le retrait tangentiel total sont moyens, respectivement égaux à 4 % et 8,5 %. Ses caractéristiques mécaniques sont moyennes (contraintes de rupture en compression et flexion statique respectivement égales à 49,4 MPa et 104,5 MPa) à faible (module d’élasticité longitudinal de 10 473 MPa). Une comparaison des résultats obtenus en fonction des zones de prélèvement a mis en évidence des tendances variables selon les caractéristiques étudiées. Ces variations entre les trois provenances restent cependant limitées. Les résultats de l’étude montrent que le bois de B. aegyptiaca pourrait être utilisé de façon appropriée sous forme de matériau pour une plus large gamme d’emplois, sous réserve de la mise en place d’une gestion adaptée permettant sa restauration par plantation.

Published
2021

10. Forest and woodland replacement patterns following drought-related mortality

Author

Juan Carlos Linares, Yamila Sasal, Abdallah Bentouati, Miranda D. Redmond, C. John Burk, Joseph L. Ganey, Thomas T. Veblen, Francesco Ripullone, Christof Bigler, Lucía Galiano, Suzanne B. Marchetti, William R. L. Anderegg, Caroline Vincke, Ermias Aynekulu, J. Julio Camarero, Jeffrey M. Kane, Maria Laura Suarez, Andreas Rigling, Anna L. Jacobsen, Tuomas Aakala, Michael Michaelian, Enric Batllori, Francisco Lloret, R. B. Pratt, Roderick Fensham, Gabriel Sangüesa-Barreda, M. Lisa Floyd, Thomas Kitzberger, Albert Vilà-Cabrera, Rafael M. Navarro-Cerrillo, Sandra Saura-Mas, Devin P. Bendixsen, Ben J. Zeeman, George Matusick, Michele Colangelo, Patrick Gonzalez, Jonathan D. Coop, UCL - SST/ELI/ELIE - Environmental Sciences, Department of Forest Sciences, Boreal forest dynamics and biodiversity research group, and Forest Ecology and Management

Subjects
DYNAMICS, 0106 biological sciences, 010504 meteorology & atmospheric sciences, Biome, ved/biology.organism_classification_rank.species, Ecological succession, Woodland, Forests, FIRE, 01 natural sciences, Shrub, Forest dynamics, Trees, Ecosystem services, Drought-induced mortality, global tree mortality, Global tree mortality, RESEARCH FRONTIERS, Climate change, MAXIMUM-LIKELIHOOD, 4112 Forestry, Multidisciplinary, Ecology, food and beverages, Biodiversity, Biological Sciences, Droughts, Geography, Forest resilience, forest dynamics, Climate Change, drought-unduced motality, 010603 evolutionary biology, INDUCED TREE, Species Specificity, REGRESSION, MANAGEMENT, Dominance (ecology), VEGETATION SHIFTS, Ecosystem, forest resilience, 0105 earth and related environmental sciences, ved/biology, RESILIENCE, 15. Life on land, 13. Climate action, drought-induced mortality
Abstract

Significance Forests are experiencing growing risks of drought-induced mortality in a warming world. Yet, ecosystem dynamics following drought mortality remain unknown, representing a major limitation to our understanding of the ecological consequences of climate change. We provide an emerging picture of postdrought ecological trajectories based on field indicators of forest dynamics. Replacement patterns following mortality indicate limited short-term persistence of predrought dominant tree species, highlighting the potential for major ecosystem reorganization in the coming decades. The great variability of the observed dynamics within and among species reinforces the primary influence of drought characteristics and ecosystem legacies, modulated by land use, management, and past disturbances, on ongoing drought-related species turnover and their potential implications for future forest biodiversity and ecosystem services., Forest vulnerability to drought is expected to increase under anthropogenic climate change, and drought-induced mortality and community dynamics following drought have major ecological and societal impacts. Here, we show that tree mortality concomitant with drought has led to short-term (mean 5 y, range 1 to 23 y after mortality) vegetation-type conversion in multiple biomes across the world (131 sites). Self-replacement of the dominant tree species was only prevalent in 21% of the examined cases and forests and woodlands shifted to nonwoody vegetation in 10% of them. The ultimate temporal persistence of such changes remains unknown but, given the key role of biological legacies in long-term ecological succession, this emerging picture of postdrought ecological trajectories highlights the potential for major ecosystem reorganization in the coming decades. Community changes were less pronounced under wetter postmortality conditions. Replacement was also influenced by management intensity, and postdrought shrub dominance was higher when pathogens acted as codrivers of tree mortality. Early change in community composition indicates that forests dominated by mesic species generally shifted toward more xeric communities, with replacing tree and shrub species exhibiting drier bioclimatic optima and distribution ranges. However, shifts toward more mesic communities also occurred and multiple pathways of forest replacement were observed for some species. Drought characteristics, species-specific environmental preferences, plant traits, and ecosystem legacies govern postdrought species turnover and subsequent ecological trajectories, with potential far-reaching implications for forest biodiversity and ecosystem services.

Published
2020

11. Pedunculate oak decline in southern Belgium: a long-term process highlighting the complex interplay among drought, winter frost, biotic attacks, and masting

Author

Caroline Vincke, Mathieu Jonard, Julie Losseau, and UCL - SST/ELI/ELIE - Environmental Sciences

Subjects
0106 biological sciences, Global and Planetary Change, biotic attacks, 010504 meteorology & atmospheric sciences, Ecology, Oak decline, Forestry, 01 natural sciences, masting, Quercus robur L, oak, Frost, Environmental science, Pedunculate, winter frost, 010606 plant biology & botany, 0105 earth and related environmental sciences
Abstract

Since 2013, pedunculate oak (Quercus robur L.) mortality has been observed in the Ardennes region of Belgium. We aimed to understand the current decline by retrospectively (1945–2015) studying radial growth patterns of trees classified by three health statuses (reference, declining, and dying) and by linking them to abiotic and biotic hazard history, which we recorded and quantified. Our results show that oak mortality in the Ardennes is a long-term process, with 1987 as a tipping point for growth trajectories of declining and dying trees. That year was preceded by two growth crises (1976–1981 and 1984–1987), and it falls within the last major episode of oak decline in Belgium. Among hazards, very cold winters and caterpillar outbreaks have significant impacts on growth-pattern differentiation. Apart from 1976, extreme drought is still rare; however, mild spring droughts, especially in the years n − 1 and n − 2, explain some of the growth loss relative to the reference trees. Finally, masting appears to be an important contributing factor for the death of weakened trees. Given the direct and delayed impacts of the extreme drought of 1976 and subsequent water balance impairment due to winter frosts and mild spring droughts, the health of pedunculate oak is giving cause for concern in the context of climate change.

Published
2020

12. HETEROFOR 1.0: a spatially explicit model for exploring the response of structurally complex forests to uncertain future conditions – Part 1: Carbon fluxes and tree dimensional growth

Author

Frédéric André, Caroline Vincke, Louis de Wergifosse, Quentin Ponette, François de Coligny, Nicolas Beudez, Hendrik Davi, Gauthier Ligot, and Mathieu Jonard

Subjects
Maintenance respiration, business.industry, media_common.quotation_subject, Environmental resource management, lcsh:QE1-996.5, Primary production, Climate change, Vegetation, lcsh:Geology, Tree (data structure), Forest ecology, Environmental science, Psychological resilience, business, Silviculture, media_common
Abstract

Given the multiple abiotic and biotic stressors resulting from global changes, management systems and practices must be adapted in order to maintain and reinforce the resilience of forests. Among others, the transformation of monocultures into uneven-aged and mixed stands is an avenue to improve forest resilience. To explore the forest response to these new silvicultural practices under a changing environment, one needs models combining a process-based approach with a detailed spatial representation, which is quite rare. We therefore decided to develop our own model (HETEROFOR for HETEROgeneous FORest) according to a spatially explicit approach, describing individual tree growth based on resource sharing (light, water and nutrients). HETEROFOR was progressively elaborated within Capsis (Computer-Aided Projection for Strategies in Silviculture), a collaborative modelling platform devoted to tree growth and stand dynamics. This paper describes the carbon-related processes of HETEROFOR (photosynthesis, respiration, carbon allocation and tree dimensional growth) and evaluates the model performances for three broadleaved stands with different species compositions (Wallonia, Belgium). This first evaluation showed that HETEROFOR predicts well individual radial growth (Pearson's correlation of 0.83 and 0.63 for the European beech and sessile oak, respectively) and is able to reproduce size–growth relationships. We also noticed that the net to gross primary production (npp to gpp) ratio option for describing maintenance respiration provides better results than the temperature-dependent routine, while the process-based (Farquhar model) and empirical (radiation use efficiency) approaches perform similarly for photosynthesis. To illustrate how the model can be used to predict climate change impacts on forest ecosystems, we simulated the growth dynamics of the mixed stand driven by three IPCC climate scenarios. According to these simulations, the tree growth trends will be governed by the CO2 fertilization effect, with the increase in vegetation period length and the increase in water stress also playing a role but offsetting each other.

Published
2020

13. HETEROFOR 1.0: a spatially explicit model for exploring the response of structurally complex forests to uncertain future conditions – Part 2: Phenology and water cycle

Author

Mathieu Jonard, François Jonard, Hugues Goosse, Caroline Vincke, Louis de Wergifosse, Quentin Ponette, François de Coligny, Hugues Titeux, Frédéric André, Nicolas Beudez, UCL - SST/ELI/ELIE - Environmental Sciences, and UCL - SST/ELI/ELIC - Earth & Climate

Subjects
Sylviculture, forests, HETEROFOR, biology, Phenology, lcsh:QE1-996.5, Climate change, General Medicine, water cycle, biology.organism_classification, Atmospheric sciences, phenology, lcsh:Geology, Water balance, Fagus sylvatica, Forest ecology, Environmental science, Quercus petraea, Water cycle, Beech
Abstract

Climate change affects forest growth in numerous and sometimes opposite ways, and the resulting trend is often difficult to predict for a given site. Integrating and structuring the knowledge gained from the monitoring and experimental studies into process-based models is an interesting approach to predict the response of forest ecosystems to climate change. While the first generation of models operates at stand level, one now needs spatially explicit individual-based approaches in order to account for individual variability, local environment modification and tree adaptive behaviour in mixed and uneven-aged forests that are supposed to be more resilient under stressful conditions. The local environment of a tree is strongly influenced by the neighbouring trees, which modify the resource level through positive and negative interactions with the target tree. Among other things, drought stress and vegetation period length vary with tree size and crown position within the canopy. In this paper, we describe the phenology and water balance modules integrated in the tree growth model HETEROFOR (HETEROgenous FORest) and evaluate them on six heterogeneous sessile oak and European beech stands with different levels of mixing and development stages and installed on various soil types. More precisely, we assess the ability of the model to reproduce key phenological processes (budburst, leaf development, yellowing and fall) as well as water fluxes. Two two-phase models differing regarding their response function to temperature during the chilling period (optimum and sigmoid functions) and a simplified one-phase model are used to predict budburst date. The two-phase model with the optimum function is the least biased (overestimation of 2.46 d), while the one-phase model best accounts for the interannual variability (Pearson's r=0.68). For the leaf development, yellowing and fall, predictions and observations are in accordance. Regarding the water balance module, the predicted throughfall is also in close agreement with the measurements (Pearson's r=0.856; bias =-1.3 %), and the soil water dynamics across the year are well reproduced for all the study sites (Pearson's r was between 0.893 and 0.950, and bias was between −1.81 and −9.33 %). The model also reproduced well the individual transpiration for sessile oak and European beech, with similar performances at the tree and stand scale (Pearson's r of 0.84–0.85 for sessile oak and 0.88–0.89 for European beech). The good results of the model assessment will allow us to use it reliably in projection studies to evaluate the impact of climate change on tree growth in structurally complex stands and test various management strategies to improve forest resilience.

Published
2020

14. Two types of installation of 3D-printed zero tension lysimeter for soil leaching and water bucket model validation

Author

Ariza‐Carricondo Cristina, Eric Struyf, Marilyn Roland, Bert Gielen, Caroline Vincke, Ivan A. Janssens, and UCL - SST/ELI/ELIE - Environmental Sciences

Subjects
sampler design, water balance, flux validation, dissolved compounds tracing, Soil Science, Soil drainage, Biology
Abstract

Quantifying and analysing leaching water is essential to understand water and nutrient cycles and the vertical transport of elements through soils. Zero tension lysimeters (ZTLs) have been widely used to capture the soil solution leaching by gravity. This study designed and evaluated a 3D-printed ZTL (ZTL(3D)) with specific characteristics and materials to quantitatively capture dissolved element fluxes. By 3D-printing the ZTLs, we were able to include specific 3D structures and precise details in the design allowing installation of samplers from the surface rather than trenches, and thus avoiding the need for installation trenches to remain open. The ZTLs(3D) connect directly with the surface, do not depend on secondary collectors, can be installed at any depth, and samplers are easily retractable when dismantling the field set up. The material used, Nylon 12, was tested for dissolved organic carbon (DOC) release. The ZTL(3D) design was printed in two different external shapes while characteristics and internal design were identical. The difference in external shape was to study the effects of two contrasting types of installation: a cylindrical sampler for vertical installation (by soil coring from the surface) and a rectangular samplers for horizontal installation (from a pit or a trench wall). We installed them at different depths (2, 30 and 75 cm) in a forest soil and conducted rainfall simulation experiments. A water bucket model (WBM), created to calculate the water drainage fluxes that the ZTLs(3D) should collect, reproduced very well the variation in soil water content measured by soil moisture sensors installed adjacent to the ZTLs(3D) at 16, 30, 50 and 75 cm depth. Drainage fluxes simulated by the WBM showed that the vertical installation performed better at collecting water at all depths than the horizontal installation, but overall the ZTLs(3D) failed to collect the simulated amounts of drainage water. Nonetheless, the ZTLs(3D) did collect leachate water, enabling their chemical analysis. Combining the concentrations in the water collected by the ZTLs(3D) with the modelled drainage fluxes does allow estimation of DOC- and elemental leaching rates. This article presents the novel design of these two types of ZTLs(3D) because future improvements may result in better performance, and discusses their (dis)agreement with the modelled WBM fluxes. Highlights New 3D-printed zero tension lysimeters (ZTLs) to capture element fluxes when installed vertically (cylindrical design) or horizontally (cubic design) were tested. Two external sampler shapes were created to optimise the installation process and both collected drainage water successfully. Vertical installation ZTLs worked better than horizontal types, but neither well-reflected drainage fluxes simulated by water bucket model (WBM). Combined with WBM, both ZTL types provided a reliable method for quantifying nutrient and organic carbon leaching at different soil depths.

Published
2022

15. Uncovering the critical soil moisture thresholds of plant water stress for European ecosystems

Author

Zheng Fu, Philippe Ciais, David Makowski, Ana Bastos, Paul C. Stoy, Andreas Ibrom, Alexander Knohl, Mirco Migliavacca, Matthias Cuntz, Ladislav Šigut, Matthias Peichl, Denis Loustau, Tarek S. El‐Madany, Nina Buchmann, Mana Gharun, Ivan Janssens, Christian Markwitz, Thomas Grünwald, Corinna Rebmann, Meelis Mölder, Andrej Varlagin, Ivan Mammarella, Pasi Kolari, Christian Bernhofer, Michal Heliasz, Caroline Vincke, Andrea Pitacco, Edoardo Cremonese, Lenka Foltýnová, Jean‐Pierre Wigneron, Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), ICOS-ATC (ICOS-ATC), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Mathématiques et Informatique Appliquées (MIA Paris-Saclay), AgroParisTech-Université Paris-Saclay-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Max Planck Institute for Biogeochemistry (MPI-BGC), Max-Planck-Gesellschaft, University of Wisconsin-Madison, Danmarks Tekniske Universitet = Technical University of Denmark (DTU), Georg-August-University = Georg-August-Universität Göttingen, SILVA (SILVA), AgroParisTech-Université de Lorraine (UL)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Global Change Research Centre (CzechGlobe), Swedish University of Agricultural Sciences (SLU), Interactions Sol Plante Atmosphère (UMR ISPA), Ecole Nationale Supérieure des Sciences Agronomiques de Bordeaux-Aquitaine (Bordeaux Sciences Agro)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Department of Environmental Systems Science [ETH Zürich] (D-USYS), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), University of Antwerp (UA), Institute of Hydrology and Meteorology [Dresden], Technische Universität Dresden = Dresden University of Technology (TU Dresden), Helmholtz Zentrum für Umweltforschung = Helmholtz Centre for Environmental Research (UFZ), Department of Physical Geography and Ecosystem Science [Lund], Lund University [Lund], A.N. Severtsov Institute of Ecology and Evolution, Russian Academy of Sciences [Moscow] (RAS), Helsingin yliopisto = Helsingfors universitet = University of Helsinki, Centre for Environmental and Climate Research [Lund] (CEC), Earth and Life Institute [Louvain-La-Neuve] (ELI), Université Catholique de Louvain = Catholic University of Louvain (UCL), Università degli Studi di Padova = University of Padua (Unipd), Funding information European Research Council Synergy project, Grant/Award Number: SyG2013-610028, European Project: 610028,EC:FP7:ERC,ERC-2013-SyG,IMBALANCE-P(2014), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), and Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)

Subjects
surface energy partitioning, critical soil moisture threshold, 010504 meteorology & atmospheric sciences, Gross primary production, Surface energy partitioning, 0207 environmental engineering, drought, 02 engineering and technology, Forests, 01 natural sciences, Vapor pressure deficit, Soil, Europe, evaporative fraction, gross primary production, vapor pressure deficit, SDG 13 - Climate Action, Humans, Environmental Chemistry, [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment, 020701 environmental engineering, Evaporative fraction, Biology, Ecosystem, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, General Environmental Science, SDG 15 - Life on Land, [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, Global and Planetary Change, Dehydration, Ecology, Drought, 15. Life on land, Droughts, Chemistry, 13. Climate action, Critical soil moisture threshold
Abstract

Understanding the critical soil moisture (SM) threshold (θcrit) of plant water stress and land surface energy partitioning is a basis to evaluate drought impacts and improve models for predicting future ecosystem condition and climate. Quantifying the θcrit across biomes and climates is challenging because observations of surface energy fluxes and SM remain sparse. Here, we used the latest database of eddy covariance measurements to estimate θcrit across Europe by evaluating evaporative fraction (EF)-SM relationships and investigating the covariance between vapor pressure deficit (VPD) and gross primary production (GPP) during SM dry-down periods. We found that the θcrit and soil matric potential threshold in Europe are 16.5% and −0.7 MPa, respectively. Surface energy partitioning characteristics varied among different vegetation types; EF in savannas had the highest sensitivities to SM in water-limited stage, and the lowest in forests. The sign of the covariance between daily VPD and GPP consistently changed from positive to negative during dry-down across all sites when EF shifted from relatively high to low values. This sign of the covariance changed after longer period of SM decline in forests than in grasslands and savannas. Estimated θcrit from the VPD–GPP covariance method match well with the EF–SM method, showing this covariance method can be used to detect the θcrit. We further found that soil texture dominates the spatial variability of θcrit while shortwave radiation and VPD are the major drivers in determining the spatial pattern of EF sensitivities. Our results highlight for the first time that the sign change of the covariance between daily VPD and GPP can be used as an indicator of how ecosystems transition from energy to SM limitation. We also characterized the corresponding θcrit and its drivers across diverse ecosystems in Europe, an essential variable to improve the representation of water stress in land surface models., Global Change Biology, 28 (6), ISSN:1354-1013, ISSN:1365-2486

Published
2022

16. The Size of Topographic Depressions in a Sahelian Savanna is a Driver of Woody Vegetation Diversity

Author

Morgane Dendoncker, Caroline Vincke, Samantha Bazan, Mady Parfait Noé Madingou, and Simon Taugourdeau

Subjects
Ecology, F40 - Écologie végétale, Cartographie, Composition botanique, Topographie, biodiversité forestière, Écosystème forestier, Écosystèmes arides, Ecology, Evolution, Behavior and Systematics, Savane, Earth-Surface Processes, Population végétale
Abstract

In drylands, water availability is the main limiting factor for plant growth. Topographic depressions in the Sahel that reveal a more favorable water balance display greater tree diversity compared to their surroundings. However, the environmental factors that drive differences in botanical composition between depressions remain unknown. Here, we investigated the depression features, and the landscape and connectivity metrics responsible for woody vegetation composition in a savanna of Senegal. We mapped depressions in a 700 km2 area and inventoried woody vegetation in 61 depressions varying in area. Simple linear models were applied between (i) indicators of richness and botanical composition and (ii) depression attributes, landscape and connectivity metrics. We found that the area of a depression increased species richness. The number of vegetation strata and the presence of a temporary pond also positively influenced species richness. Yet, while large depressions always had high richness, some small depressions did too. We were not able to identify additional factors to explain this diversity between small depressions. In the context of decreasing richness and composition shift observed in the Sahel over recent decades, depressions, as biodiversity hotspots, are key elements in ecosystem functioning. Further studies are needed to understand other potential drivers of species diversity, such as soil water availability.

Published
2022

17. Method comparison of indirect assessments of understory leaf area index (LAIu): A case study across the extended network of ICOS forest ecosystem sites in Europe

Author

Wei Yang, Jan Pisek, Corinna Rebmann, Jan-Peter George, Andreas Ibrom, Silvano Fares, Francisco Ramón López Serrano, Caroline Vincke, Giacomo Gerosa, Michael Heliasz, Thomas Grünwald, Holger Lange, Jean-Marc Limousin, Meelis Mölder, Bart Kruijt, Johannes Neirynck, A. Carrara, Hideki Kobayashi, Matthias Cuntz, Matthias Peichl, Kamel Soudani, Denis Loustau, Leonardo Montagnani, Marius Schmidt, Niklas Hase, Petr Lukes, Edoardo Cremonese, Riccardo Marzuoli, Tobias Biermann, Alexander Knohl, Tartu Observatory, Chiba University, Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Lund University [Lund], Fundacion CEAM, Universidad de Alicante, Aosta Valley Regional Environmental Protection Agency (ARPA), SILVA (SILVA), AgroParisTech-Université de Lorraine (UL)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Consiglio Nazionale delle Ricerche [Roma] (CNR), Università cattolica del Sacro Cuore [Brescia] (Unicatt), Technische Universität Dresden = Dresden University of Technology (TU Dresden), Helmholtz Zentrum für Umweltforschung = Helmholtz Centre for Environmental Research (UFZ), Technical University of Denmark [Lyngby] (DTU), University of Göttingen - Georg-August-Universität Göttingen, Wageningen University and Research [Wageningen] (WUR), Norwegian Institute of Bioeconomy Research (NIBIO), Centre d’Ecologie Fonctionnelle et Evolutive (CEFE), Université Paul-Valéry - Montpellier 3 (UPVM)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud])-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Interactions Sol Plante Atmosphère (UMR ISPA), Ecole Nationale Supérieure des Sciences Agronomiques de Bordeaux-Aquitaine (Bordeaux Sciences Agro)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Global Change Research Institute, Czech Academy of Sciences [Prague] (CAS), Free University of Bozen-Bolzano, Research Institute for Nature and Forest (INBO), Swedish University of Agricultural Sciences (SLU), Forschungszentrum Jülich GmbH | Centre de recherche de Juliers, Helmholtz-Gemeinschaft = Helmholtz Association, ETSIAM Campus Rabanales, Universidad de Cordoba, Ecologie Systématique et Evolution (ESE), AgroParisTech-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Université Catholique de Louvain = Catholic University of Louvain (UCL), This study was supported from Estonian Research Council Grant PUT1355 and Mobilitas Pluss MOBERC11. Field campaign at Brasschaat site was funded by the Transnational Access scheme of eLTER (Horizon 2020 project grant agreement no. 654359)., UCL - SST/ELI/ELIE - Environmental Sciences, National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Danmarks Tekniske Universitet = Technical University of Denmark (DTU), Georg-August-University = Georg-August-Universität Göttingen, Norsk institutt for bioøkonomi=Norwegian Institute of Bioeconomy Research (NIBIO), Université Paul-Valéry - Montpellier 3 (UPVM)-École Pratique des Hautes Études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud])-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut Agro - Montpellier SupAgro, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), Global Change Research Centre (CzechGlobe), Universidad de Córdoba = University of Córdoba [Córdoba], University of Tartu, ARPA VALLE D'AOSTA SAINT CHRISTOPHE ITA, Partenaires IRSTEA, Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), CNR – National Research Council, Rome, Università cattolica del Sacro Cuore [Milano] (Unicatt), Université de Goettingen, Université Paul-Valéry - Montpellier 3 (UPVM)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud])-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut Agro Montpellier, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Université de Montpellier (UM), Institute of Microbiology of the Czech Academy of Sciences [Prague, Czech Republic] (MBU / CAS), and Universidad de Castilla-La Mancha (UCLM)

Subjects
0106 biological sciences, Evolution, NDVI, General Decision Sciences, Understory layer, 010501 environmental sciences, Fjernmåling, Atmospheric sciences, 010603 evolutionary biology, 01 natural sciences, Normalized Difference Vegetation Index, Behavior and Systematics, Settore BIO/07 - ECOLOGIA, Forest ecology, SDG 13 - Climate Action, Simple ratio, ddc:630, Ecosystem, Leaf area index, Settore FIS/06 - FISICA PER IL SISTEMA TERRA E IL MEZZO CIRCUMTERRESTRE, Ecology, Evolution, Behavior and Systematics, QH540-549.5, 0105 earth and related environmental sciences, Diversity, WIMEK, Ecology, Fractional vegetation cover, Earth-monitoring satellites, Biosphere, Understory, Vegetation, 15. Life on land, Remote sensing, Ecological indicator, [SDE]Environmental Sciences, Environmental science, Water Systems and Global Change, Jordobservasjon fra satellitter, Forest background reflectivity
Abstract

Leaf area index (LAI) is a key ecological indicator for describing the structure of canopies and for modelling energy exchange between atmosphere and biosphere. While LAI of the forest overstory can be accurately assessed over large spatial scales via remote sensing, LAI of the forest understory (LAIu) is still largely ignored in ecological studies and ecosystem modelling due to the fact that it is often too complex to be destructively sampled or approximated by other site parameters. Additionally, so far only few attempts have been made to retrieve understory LAI via remote sensing, because dense canopies with high LAI are often hindering retrieval algorithms to produce meaningful estimates for understory LAI. Consequently, the forest understory still constitutes a poorly investigated research realm impeding ecological studies to properly account for its contribution to the energy absorption capacity of forest stands. This study aims to compare three conceptually different indirect retrieval methodologies for LAIu over a diverse panel of forest understory types distributed across Europe. For this we carried out near-to-surface measurements of understory reflectance spectra as well as digital surface photography over the extended network of Integrated Carbon Observation System (ICOS) forest ecosystem sites. LAIu was assessed by exploiting the empirical relationship between vegetation cover and light absorption (Beer-Lambert- Bouguer law) as well as by utilizing proposed relationships with two prominent vegetation indices: normalized difference vegetation index (NDVI) and simple ratio (SR). Retrievals from the three methods were significantly correlated with each other (r = 0.63–0.99, RMSE = 0.53–0.72), but exhibited also significant bias depending on the LAI scale. The NDVI based retrieval approach most likely overestimates LAI at productive sites when LAIu > 2, while the simple ratio algorithm overestimates LAIu at sites with sparse understory vegetation and presence of litter or bare soil. The purely empirical method based on the Beer-Lambert law of light absorption seems to offer a good compromise, since it provides reasonable LAIu values at both low and higher LAI ranges. Surprisingly, LAIu variation among sites seems to be largely decoupled from differences in climate and light permeability of the overstory, but significantly increased with vegetation diversity (expressed as species richness) and hence proposes new applications of LAIu in ecological modelling.

Published
2021

18. The FLUXNET2015 dataset and the ONEFlux processing pipeline for eddy covariance data

Author

Eddy Moors, Uwe Eichelmann, Christian Brümmer, Stefano Minerbi, Barbara Marcolla, Gil Bohrer, Leonardo Montagnani, Üllar Rannik, Han Dolman, Janina Klatt, Samuli Launiainen, Elizabeth A. Walter-Shea, Nina Buchmann, Hank A. Margolis, Beniamino Gioli, Peter S. Curtis, Margaret S. Torn, Gabriela Posse, Luca Belelli Marchesini, Gianluca Filippa, Kenneth J. Davis, Leiming Zhang, Alexander Graf, Ray Leuning, Andrew Feitz, Simone Sabbatini, Harry McCaughey, Werner Eugster, Juha Pekka Tuovinen, Timothy J. Arkebauer, N. N. Vygodskaya, Adam J. Liska, Rosvel Bracho, Sebastian Wolf, Marc Aubinet, Jiří Dušek, Eugénie Paul-Limoges, Christof Ammann, Daniel Berveiller, Zoran Nesic, Giacomo Nicolini, Jaclyn Hatala Matthes, Russell L. Scott, David E. Reed, Frans-Jan W. Parmentier, Changliang Shao, Penélope Serrano-Ortiz, Yingnian Li, Jason Beringer, Marc Fischer, Deb Agarwal, Rasmus Fensholt, Russell K. Monson, Agnès de Grandcourt, Stefan K. Arndt, Timo Vesala, Uta Moderow, Joseph Verfaillie, Mika Aurela, Bev Law, Nina Hinko-Najera, Taro Nakai, Richard P. Phillips, Lindsay B. Hutley, Benjamin Loubet, Michele Tomassucci, Ayumi Kotani, Hans Peter Schmid, Raimundo Cosme de Oliveira, Anatoly A. Gitelson, Domenico Vitale, Regine Maier, Caitlin E. Moore, Xiaoqin Dai, Damien Bonal, John M. Frank, Yuelin Li, Christopher M. Gough, Shijie Han, Shirley A. Papuga, Edoardo Cremonese, Shawn Urbanski, Sébastien C. Biraud, Scott D. Miller, Mana Gharun, Annalea Lohila, Ian McHugh, Giovanni Manca, Bert Gielen, Wayne S. Meyer, Pierpaolo Duce, Bruce D. Cook, Carsten Gruening, Hiroki Ikawa, B.R. Reverter, Marian Pavelka, Andrew M. S. McMillan, Gang Dong, Isaac Chini, Kimberly A. Novick, Dalibor Janouš, Anne De Ligne, E. Beamesderfer, Marty Humphrey, Virginie Moreaux, Christian Wille, Markus Hehn, Hideki Kobayashi, Allen H. Goldstein, Walter C. Oechel, Richard Silberstein, Francisco Domingo, Francesco Mazzenga, Elise Pendall, Juha Hatakka, Lutz Merbold, Xingguo Han, Daniela Famulari, Carlo Trotta, Naama Raz-Yaseef, Dario Papale, Jean Marc Ourcival, Benoit Burban, Pavel Sedlák, Diego Polidori, Asko Noormets, Huimin Wang, Birger Ulf Hansen, Thomas Grünwald, Caroline Vincke, Robert M. Stevens, Carole Coursolle, D. P. Billesbach, Karl Schneider, Guoyi Zhou, Marcin Jackowicz-Korczynski, Paul V. Bolstad, Iris Feigenwinter, Shiping Chen, Julia Boike, Ivan Schroder, D. S. Christianson, Junhui Zhang, Pierre Cellier, Catharine van Ingen, Andrej Varlagin, A. Ribeca, Claudia Consalvo, Derek Eamus, Jason Brodeur, Alan G. Barr, Denis Loustau, Andreas Ibrom, Ankur R. Desai, Andrew E. Suyker, Efrén López-Blanco, Peter Cale, Nicola Arriga, William J. Massman, Abdelrahman Elbashandy, Yoshiko Kosugi, Pauline Buysse, Cove Sturtevant, T. A. Black, Housen Chu, David R. Bowling, Sabina Dore, Albin Hammerle, Tilden P. Meyers, M. Altaf Arain, Hatim Abdalla M. ElKhidir, Ignacio Goded, Roberto Zampedri, Alessio Collalti, Torsten Sachs, Tuomas Laurila, Cristina Poindexter, E. Canfora, Alexander Knohl, Donatella Spano, Silvano Fares, Scott R. Saleska, Michiel K. van der Molen, Suzanne M. Prober, Marryanna Lion, Steven C. Wofsy, Michael L. Goulden, Matthew Northwood, Antje Lucas-Moffat, Christine Moureaux, Jean-Marc Limousin, Sara H. Knox, Damiano Gianelle, Olaf Kolle, Jørgen E. Olesen, Mikhail Mastepanov, Bernard Heinesch, Christian Bernhofer, Peter D. Blanken, Hyojung Kwon, Georg Wohlfahrt, Peili Shi, Yann Nouvellon, Allison L. Dunn, Onil Bergeron, Mauro Cavagna, Heiko Prasse, Natalia Restrepo-Coupe, Yanhong Tang, Donatella Zona, Andrew S. Kowalski, Eric Dufrêne, Kim Pilegaard, Serena Marras, Yongtao He, Brent E. Ewers, Siyan Ma, Jean Marc Bonnefond, Jonas Ardö, Ko van Huissteden, Roser Matamala, Robin Weber, Nigel J. Tapper, Humberto Ribeiro da Rocha, Eva van Gorsel, Torbern Tagesson, Frederik Schrader, Frank Tiedemann, Myroslava Khomik, Torben R. Christensen, Jonathan E. Thom, James Cleverly, Víctor Resco de Dios, Ivan Shironya, Jeffrey P. Walker, You Wei Cheah, Ana López-Ballesteros, Georgia R. Koerber, J. William Munger, Shicheng Jiang, Johannes Lüers, Bruno De Cinti, Gilberto Pastorello, David R. Cook, Werner L. Kutsch, Paul Di Tommasi, Nicolas Delpierre, Peter Isaac, Carlos Marcelo Di Bella, Jiquan Chen, Craig Macfarlane, Dennis D. Baldocchi, William Woodgate, Riccardo Valentini, Marilyn Roland, Ladislav Šigut, Tomomichi Kato, Sebastian Westermann, Ivan Mammarella, Bart Kruijt, Marta Galvagno, Marius Schmidt, Serge Rambal, J. Kurbatova, Sean P. Burns, Ettore D'Andrea, Chad Hanson, Vincenzo Magliulo, Anne Griebel, Brian D. Amiro, M. Goeckede, Enrique P. Sánchez-Cañete, Thomas L. Powell, Marcelo D. Nosetto, Cacilia Ewenz, Michael J. Liddell, Satoru Takanashi, Lukas Hörtnagl, Zulia Mayari Sanchez-Mejia, W.W.P. Jans, N. Pirk, Johan Neirynck, Rainer Steinbrecher, Lukas Siebicke, Matthias Peichl, Rachhpal S. Jassal, Costantino Sirca, Earth and Climate, Earth Sciences, Institute for Atmospheric and Earth System Research (INAR), INAR Physics, Micrometeorology and biogeochemical cycles, Viikki Plant Science Centre (ViPS), Ecosystem processes (INAR Forest Sciences), Lawrence Berkeley National Laboratory [Berkeley] (LBNL), Università degli studi della Tuscia [Viterbo], California State University [Sacramento], Michigan State University System, University of Virginia, Max Planck Institute for Biogeochemistry (MPI-BGC), Max-Planck-Gesellschaft, Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Chinese Academy of Sciences [Beijing] (CAS), University of Manitoba [Winnipeg], Agroscope, McMaster University [Hamilton, Ontario], Lund University [Lund], University of Nebraska–Lincoln, University of Nebraska System, University of Melbourne, University of Antwerp (UA), Université de Liège, Finnish Meteorological Institute (FMI), University of California [Berkeley] (UC Berkeley), University of California (UC), University of Saskatchewan [Saskatoon] (U of S), Peoples Friendship University of Russia [RUDN University] (RUDN), The University of Western Australia (UWA), Technische Universität Dresden = Dresden University of Technology (TU Dresden), Ecologie Systématique et Evolution (ESE), AgroParisTech-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), University of British Columbia (UBC), University of Colorado [Colorado Springs] (UCCS), Ohio State University [Columbus] (OSU), Humboldt University Of Berlin, University of Minnesota System, SILVA (SILVA), AgroParisTech-Université de Lorraine (UL)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Interactions Sol Plante Atmosphère (UMR ISPA), Ecole Nationale Supérieure des Sciences Agronomiques de Bordeaux-Aquitaine (Bordeaux Sciences Agro)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), University of Utah, University of Central Florida [Orlando] (UCF), Thunen Institute of Climate-Smart Agriculture, Department of Environmental Systems Science [ETH Zürich] (D-USYS), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), Ecologie des forêts de Guyane (UMR ECOFOG), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-AgroParisTech-Université de Guyane (UG)-Centre National de la Recherche Scientifique (CNRS)-Université des Antilles (UA)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Ecologie fonctionnelle et écotoxicologie des agroécosystèmes (ECOSYS), AgroParisTech-Université Paris-Saclay-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Fondazione Edmund Mach - Edmund Mach Foundation [Italie] (FEM), Aarhus University [Aarhus], University of Technology Sydney (UTS), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), NASA Goddard Space Flight Center (GSFC), Argonne National Laboratory [Lemont] (ANL), Université Laval [Québec] (ULaval), Universidade de São Paulo = University of São Paulo (USP), Pennsylvania State University (Penn State), Penn State System, Ecologie fonctionnelle et biogéochimie des sols et des agro-écosystèmes (UMR Eco&Sols), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut de Recherche pour le Développement (IRD)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut Agro Montpellier, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), University of Wisconsin-Madison, Vrije Universiteit Amsterdam [Amsterdam] (VU), Centro de Investigaciones Biológicas (CSIC), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Shanxi University (SXU), Worcester State University [Worcester], Czech Academy of Sciences [Prague] (CAS), Centre d’Ecologie Fonctionnelle et Evolutive (CEFE), Université Paul-Valéry - Montpellier 3 (UPVM)-École Pratique des Hautes Études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud])-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut Agro - Montpellier SupAgro, Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut de Recherche pour le Développement (IRD)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), UCL - SST/ELI/ELIE - Environmental Sciences, GILBERTO PASTORELLO, Lawrence Berkeley National Laboratory, THOMAS ANDREW BLACK, University of British Columbia, PETER D. BLANKEN, University of Colorado, GIL BOHRER, Ohio State University, JULIA BOIKE, Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research / Humboldt-Universität zu Berlin, PAUL V. BOLSTAD, University of Minnesota, JEAN-MARC BONNEFOND, ISPA Bordeaux Sciences Agro, DAVID R. BOWLING, University of Utah, ROSVEL BRACHO, University of Florida, JASON BRODEUR, McMaster University, CHRISTIAN BRÜMMER, Thünen Institute of Climate-Smart Agriculture, NINA BUCHMANN, ETH Zurich, BENOIT BURBAN, INRAE UMR ECOFOG, AGNES DE GRANDCOURT, UMR Eco&Sols, CIRAD, ANNE DE LIGNE, University of Liege, RAIMUNDO COSME DE OLIVEIRA JUNIOR, CPATU, HAN DOLMAN, Universiteit Amsterdam, FRANCISCO DOMINGO, CSIC, GANG DONG, Shanxi University, SABINA DORE, HydroFocus, PIERPAOLO DUCE, National Research Council of Italy, MARTA GALVAGNO, Environmental Protection Agency of Aosta Valley, MANA GHARUN, ETH Zurich, DAMIANO GIANELLE, Fondazione Edmund Mach, MARCIN JACKOWICZ-KORCZYNSKI, Lund University / Aarhus University, DALIBOR JANOUS, Global Change Research Institute of the Czech Academy of Sciences, WILMA JANS, Wageningen University and Research, RACHHPAL JASSAL, University of British Columbia, SHICHENG JIANG, Northeast Normal University, ANA LÓPEZ-BALLESTEROS, Trinity College Dublin, EFRÉN LÓPEZ-BLANCO, Aarhus University, BENJAMIN LOUBET, Université Paris-Saclay, DENIS LOUSTAU, ISPA - INRA, JOHANNES LÜERS, University of Bayreuth, JOHAN NEIRYNCK, Research Institute for Nature and Forest, ZORAN NESIC, University of British Columbia, GIACOMO NICOLINI, University of Tuscia / CMCC, ASKO NOORMETS, Texas A&M University, MATTHEW NORTHWOOD, Charles Darwin University, KIMBERLY NOVICK, Indiana University Bloomington, MARILYN ROLAND, University of Antwerp, SIMONE SABBATINI, University of Tuscia, TORSTEN SACHS, GFZ German Research Centre for Geosciences, SCOTT R. SALESKA, University of Arizona, ENRIQUE P. SÁNCHEZ-CAÑETE, University of Granada / CEAMA-IISTA, ZULIA M. SANCHEZ-MEJIA, Instituto Tecnológico de Sonora, RAINER STEINBRECHER, Karlsruhe Institute of Technology, ROBERT M. STEVENS, Sentek Pty Ltd, COVE STURTEVANT, National Ecological Observatory Network Program, ANDY SUYKER, University of Nebraska-Lincoln, TORBERN TAGESSON, Lund University / University of Copenhagen, SATORU TAKANASHI, Forestry and Forest Products Research Institute, DOMENICO VITALE, University of Tuscia / CMCC, NATALIA VYGODSKAYA, Russian Academy of Sciences, JEFFREY P. WALKER, Monash University, ELIZABETH WALTER-SHEA, University of Nebraska-Lincoln, HUIMIN WANG, Chinese Academy of Sciences, ROBIN WEBER, University of California Berkeley, SEBASTIAN WESTERMANN, Instituto Nacional de Tecnologia Agropecuaria (INTA), CHRISTIAN WILLE, GFZ German Research Centre for Geosciences, STEVEN WOFSY, Harvard University, GEORG WOHLFAHRT, University of Innsbruck, SEBASTIAN WOLF, ETH Zurich, WILLIAM WOODGATE, CSIRO Land and Water, YUELIN LI, Chinese Academy of Sciences, DONATELLA ZONA, San Diego State University / University of Sheffield, DEB AGARWAL, Lawrence Berkeley National Laboratory, SEBASTIEN BIRAUD, Lawrence Berkeley National Laboratory, MARGARET TORN, Lawrence Berkeley National Laboratory, DARIO PAPALE, University of Tuscia / CMCC., ALLISON DUNN, Worcester State University, JIRÍ DUSEK, Global Change Research Institute of the Czech Academy of Sciences, DEREK EAMUS, University of Technology Sydney, UWE EICHELMANN, Technische Universität Dresden, HOUSEN CHU, Lawrence Berkeley National Laboratory, DANIELLE CHRISTIANSON, Lawrence Berkeley National Laboratory, YOU-WEI CHEAH, Lawrence Berkeley National Laboratory, CRISTINA POINDEXTER, California State University, JIQUAN CHEN, Michigan State University, ABDELRAHMAN ELBASHANDY, Lawrence Berkeley National Laboratory, MARTY HUMPHREY, University of Virginia, PETER ISAAC, TERN Ecosystrem Processes, DIEGO POLIDORI, University of Tuscia / CMCC, ALESSIO RIBECA, University of Tuscia / CMCC, CATHARINE VAN INGEN, Lawrence Berkeley National Laboratory, LEIMINGZ HANG, Chinese Academy of Sciences, BRIAN AMIRO, University of Manitoba, CHRISTOF AMMANN, Agroscope Research Institute, M. ALTAF ARAIN, McMaster University, JONAS ARDÖ, Lund University, TIMOTHY ARKEBAUER, University of Nebraska-Lincoln, STEFAN K. ARNDT, The University of Melbourne, NICOLA ARRIGA, University of Antwerp / Joint Research Centre, MARC AUBINET, University of Liege, MIKA AURELA, Finnish Meteorological Institute, DENNIS BALDOCCHI, University of California Berkeley, ALAN BARR, University of Saskatchewan / Environment and Climate Change Canada, DAMIEN BONAL, Université de Lorraine, SEAN P. BURNS, University of Colorado / National Center for Atmospheric Research, PAULINE BUYSSE, Université Paris-Saclay, PETER CALE, Australian Landscape Trust, MAURO CAVAGNA, Fondazione Edmund Mach, PIERRE CELLIER, Université Paris-Saclay, SHIPING CHEN, Chinese Academy of Sciences, ISAAC CHINI, Fondazione Edmund Mach, TORBEN R . CHRISTENSEN, Aarhus University, JAMES CLEVERLY, University of Technology Sydney, ALESSIO COLLALTI, University of Tuscia / National Research Council of Italy, CLAUDIA CONSALVO, University of Tuscia / National Research Council of Italy, BRUCE D. COOK, NASA Goddard Space Flight Center, DAVID COOK, Argonne National Laboratory, CAROLE COURSOLLE, Natural Resources Canada / Université Laval, EDOARDO CREMONESE, Climate Change Unit, PETER S. CURTIS, Ohio State University, ETTORE DANDREA, National Research Council of Italy, HUMBERTO DA ROCHA, USP, XIAOQIN DAI, Chinese Academy of Sciences, KENNETH J. DAVIS, The Pennsylvania State University, BRUNO DE CINTI, National Research Council of Italy, NICOLAS DELPIERRE, Université Paris-Saclay, ANKUR R . DESAI, University of Wisconsin-Madison, CARLOS MARCELO DI BELLA, Facultad de Agronomía, UBA, Buenos Aires., PAUL DI TOMMASI, National Research Council of Italy, ERIC DUFRÊNE, Université Paris-Saclay, MARIUS SCHMIDT, Agrosphere (IBG3), HATIM ABDALLA M. ELKHIDIR, ElObeid Research Station, WERNER EUGSTER, ETH Zurich, CACILIA M. EWENZ, TERN Ecosystem Processes Central Node, BRENT EWERS, University of Wyoming, DANIELA FAMULARI, National Research Council of Italy, SILVANO FARES, National Research Council of Italy / Research Centre for Forestry and Wood, IRIS FEIGENWINTER, ETH Zurich, ANDREW FEITZ, Geoscience Australia, RASMUS FENSHOLT, University of Copenhagen, GIANLUCA FILIPPA, Environmental Protection Agency of Aosta Valley, MARC FISCHER, Lawrence Berkeley National Laboratory, JOHN FRANK, USDA Forest Service, BERT GIELEN, University of Antwerp, BENIAMINO GIOLI, National Research Council of Italy, ANATOLY GITELSON, University of Nebraska-Lincoln, IGNACIO BALLARIN GODED, Joint Research Centre, MATHIAS GOECKEDE, University of Nebraska-Lincoln, ALLEN H. GOLDSTEIN, University of California Berkeley, CHRISTOPHER M. GOUGH, Virginia Commonwealth University, MICHAEL L. GOULDEN, University of California, ALEXANDER GRAF, Forschungszentrum Jülich, ANNE GRIEBEL, The University of Melbourne, CARSTEN GRUENING, Joint Research Centre, THOMAS GRÜNWALD, Technische Universität Dresden, ALBIN HAMMERLE, University of Innsbruck, SHIJIE HAN, Henan University / Chinese Academy of Sciences, XINGGUO HAN, Chinese Academy of Sciences, BIRGER ULF HANSEN, University of Copenhagen, CHAD HANSON, Oregon State University, JUHA HATAKKA, Finnish Meteorological Institute, YONGTAO HE, Chinese Academy of Sciences / University of Chinese Academy of Sciences, MARKUS HEHN, Technische Universität Dresden, BERNARD HEINESCH, University of Liege, NINA HINKO-NAJERA, The University of Melbourne, LUKAS HÖRTNAGL, ETH Zurich, LINDSAY HUTLEY, Charles Darwin University, ANDREAS IBROM, Technical University of Denmark, HIROKI IKAWA, National Agriculture and Food Research Organization, TOMOMICHI KATO, Hokkaido University, MYROSLAVA KHOMIK, McMaster University / Geography and Environmental Management, JANINA KLATT, Karlsruhe Institute of Technology, ALEXANDER KNOHL, University of Goettingen, SARA KNOX, The University of British Columbia, HIDEKI KOBAYASHI, Institute of Arctic Climate and Environment Research, GEORGIA KOERBER, University of Adelaide, OLAF KOLLE, Max Planck Institute for Biogeochemistry, YOSHIKO KOSUGI, Kyoto University, AYUMI KOTANI, Nagoya University, ANDREW KOWALSKI, University of Granada, BART KRUIJT, Wageningen University, JULIA KURBATOVA, Russian Academy of Sciences, WERNER L. KUTSCH, ICOS ERIC, HYOJUNG KWON, Oregon State University, SAMULI LAUNIAINEN, Natural Resources Institute Finland, TUOMAS LAURILA, Finnish Meteorological Institute, BEV LAW, Oregon State University, RAY LEUNING, In memoriam, YINGNIAN LI, Chinese Academy of Sciences, MICHAEL LIDDELL, James Cook University, JEAN-MARC LIMOUSIN, Univ Montpellier, KARL SCHNEIDER, University of Cologne, MARRYANNA LION, Forest Research Institute Malaysia, ADAM J. LISKA, University of Nebraska-Lincoln, ANNALEA LOHILA, Finnish Meteorological Institute / University of Helsinki, ANTJE LUCAS-MOFFAT, Thünen Institute of Climate-Smart Agriculture / Centre for Agrometeorological Research, SIYAN MA, University of California Berkeley, CRAIG MACFARLANE, CSIRO Land and Water, VINCENZO MAGLIULO, National Research Council of Italy, REGINE MAIER, ETH Zurich, IVAN MAMMARELLA, University of Helsinki, GIOVANNI MANCA, Joint Research Centre, BARBARA MARCOLLA, Fondazione Edmund Mach, HANK A . MARGOLIS, Université Laval, SERENA MARRAS, CMCC / University of Sassari, WILLIAM MASSMAN, USDA Forest Service, MIKHAIL MASTEPANOV, Aarhus University / University of Oulu, ROSER MATAMALA, Argonne National Laboratory, JACLYN HATALA MATTHES, Wellesley College, FRANCESCO MAZZENGA, National Research Council of Italy, HARRY MCCAUGHEY, Queen’s University, IAN MCHUGH, The University of Melbourne, ANDREW M. S. MCMILLAN, Environmental Analytics NZ, LUTZ MERBOLD, International Livestock Research Institute, WAYNE MEYER, University of Adelaide, TILDEN MEYERS, NOAA/OAR/Air Resources Laboratory, SCOTT D. MILLER, State University of New York at Albany, STEFANO MINERBI, Forest Department of South Tyrol, UTA MODEROW, Technische Universität Dresden, RUSSELL K. MONSON, University of Arizona, LEONARDO MONTAGNANI, Forest Department of South Tyrol / Free University of Bolzano, CAITLIN E. MOORE, University of Illinois at Urbana-Champaign, EDDY MOORS, IHE Delft / VU Amsterdam, VIRGINIE MOREAUX, ISPA / University Grenoble Alpes, CHRISTINE MOUREAUX, University of Liege, J. WILLIAM MUNGER, Harvard University, TARO NAKAI, National Taiwan University / University of Alaska Fairbanks, MARCELO NOSETTO, Instituto de Matemática Aplicada San Luis / UNER, YANN NOUVELLON, Univ Montpellier-CIRAD-INRA-IRD-Montpellier SupAgro, WALTER OECHEL, San Diego State University / University of Exeter, JORGEN EIVIND OLESEN, Aarhus University, JEAN-MARC OURCIVAL, Univ Montpellier, SHIRLEY A. PAPUGA, Wayne State University, FRANS-JAN PARMENTIER, Lund University / University of Oslo, EUGENIE PAUL-LIMOGES, University of Zurich, MARIAN PAVELKA, Global Change Research Institute of the Czech Academy of Sciences, MATTHIAS PEICHL, Swedish University of Agricultural Sciences, ELISE PENDALL, Western Sydney University, RICHARD P. PHILLIPS, Indiana University Bloomington, KIM PILEGAARD, Technical University of Denmark, NORBERT PIRK, Lund University / CSIRO Land and Water, GABRIELA POSSE, Instituto Nacional de Tecnologia Agropecuaria (INTA), THOMAS POWELL, Lawrence Berkeley National Laboratory, HEIKO PRASSE, Technische Universität Dresden, SUZANNE M. PROBER, CSIRO Land and Water, SERGE RAMBAL, Univ Montpellier, ÜLLAR RANNIK, University of Helsinki, DAVID REED, Michigan State University, VICTOR RESCO DE DIOS, Western Sydney University / Southwest University of Science and Technology, NATALIA RESTREPO-COUPE, University of Arizona, BORJA R. REVERTER, Universidade Federal da Paraiba, HANS PETER SCHMID, Karlsruhe Institute of Technology, FREDERIK SCHRADER, Federal Research Institute of Rural Areas, IVAN SCHRODER, Geoscience Australia, RUSSELL L. SCOTT, Southwest Watershed Research Center, PAVEL SEDLÁK, Global Change Research Institute of the Czech Academy of Sciences / Institute of Atmospheric Physics of the Czech Academy of Sciences, PENÉLOPE SERRANO-ORTÍZ, CEAMA-IISTA / University of Granada, CHANGLIANG SHAO, Chinese Academy of Agricultural Sciences, PEILI SHI, Chinese Academy of Sciences, IVAN SHIRONYA, Russian Academy of Sciences, LUKAS SIEBICKE, Bioclimatology, University of Goettingen, LADISLAV SIGUT, Global Change Research Institute of the Czech Academy of Sciences, RICHARD SILBERSTEIN, University of Western Australia / Edith Cowan University, COSTANTINO SIRCA, CMCC / University of Sassari, DONATELLA SPANO, CMCC / University of Sassari, YANHONG TANG, Peking University, NIGEL TAPPER, Monash University, JONATHAN THOM, University of Wisconsin-Madison, FRANK TIEDEMANN, University of Goettingen, MICHELE TOMASSUCCI, University of Tuscia / Terrasystem srl, JUHA-PEKKA TUOVINEN, Finnish Meteorological Institute, SHAWN URBANSKI, Rocky Mountain Research Station, RICCARDO VALENTINI, University of Tuscia / CMCC, MICHIEL VAN DER MOLEN, Wageningen University, EVA VAN GORSEL, Australian National University Canberra, KO VAN HUISSTEDEN, Vrije Universiteit Amsterdam, ANDREJ VARLAGIN, Russian Academy of Sciences, JOSEPH VERFAILLIE, University of California Berkeley, TIMO VESALA, University of Helsinki, CAROLINE VINCKE, Chinese Academy of Sciences, ROBERTO ZAMPEDRI, Fondazione Edmund Mach, JUNHUI ZHANG, Chinese Academy of Sciences, GUOYI ZHOU, Nanjing University of Information Science & Technology, NAAMA RAZ-YASEEF, Lawrence Berkeley National Laboratory, ERIC BEAMESDERFER, McMaster University, CARLO TROTTA, University of Tuscia, ELEONORA CANFORA, University of Tuscia / CMCC, LUCA BELELLI MARCHESINI, Fondazione Edmund Mach / RUDN University, ONIL BERGERON, Ministère du Développement durable de l’Environnement et de la Lutte contre les changements climatiques, JASON BERINGER, University of Western Australia, CHRISTIAN BERNHOFER, Technische Universität Dresden, DANIEL BERVEILLER, Université Paris-Saclay, and DAVE BILLESBACH, University of Nebraska-Lincoln

Subjects
Meteorologie en Luchtkwaliteit, Data Descriptor, 010504 meteorology & atmospheric sciences, Settore AGR/05 - ASSESTAMENTO FORESTALE E SELVICOLTURA, dataset provides ecosystem, UNCERTAINTY, Eddy covariance, Observation météorologique, 01 natural sciences, ecosystem-scale data, lcsh:Science, SITES, Energy, Respiration, Statistics, Uncertainty, Carbon cycle, Biological measurements, Terrestrial biome, RESPIRATION, gapfilling, [SDE]Environmental Sciences, Assimilation, Anhídrid carbònic, ddc:500, Net ecosystem exchange, Écosystème, STORAGE, Information Systems, Statistics and Probability, ecosystem approaches [EN], Meteorology and Air Quality, ASSIMILATION, Library and Information Sciences, Education, collection [EN], Donnée climatique, Data collection, Water, 15. Life on land, Earth system science, Climate Resilience, Klimaatbestendigheid, lcsh:Q, processing, Climate sciences, Ecophysiology, Storage, Oceanography, Hydrology, Water Resources, 010501 environmental sciences, CARBON-DIOXIDE, ENERGY-BALANCE CLOSURE, ddc:550, Échange d'énergie, FLUXNET2015, Biosphere, Energy balance closure, fluxnet, Computer Science Applications, Collecte de données, Energia, P01 - Conservation de la nature et ressources foncières, Statistics, Probability and Uncertainty, INTERANNUAL VARIABILITY, Eddy Covariance, SDG 6 - Clean Water and Sanitation, Engineering sciences. Technology, Sensoriamento Remoto, FLUX, 1171 Geosciences, Consistency (database systems), eau, Life Science, Time series, Remote sensing studies, Measurement device, 0105 earth and related environmental sciences, Remote sensing, Ecosystem respiration and photosynthetic, WIMEK, NET ECOSYSTEM EXCHANGE, Pipeline (software), Environmental sciences, Metadata, Earth sciences, Carbon dioxide, 13. Climate action, Environmental science, Probability and Uncertainty, Water Systems and Global Change, Dioxyde de carbone
Abstract

The FLUXNET2015 dataset provides ecosystem-scale data on CO2, water, and energy exchange between the biosphere and the atmosphere, and other meteorological and biological measurements, from 212 sites around the globe (over 1500 site-years, up to and including year 2014). These sites, independently managed and operated, voluntarily contributed their data to create global datasets. Data were quality controlled and processed using uniform methods, to improve consistency and intercomparability across sites. The dataset is already being used in a number of applications, including ecophysiology studies, remote sensing studies, and development of ecosystem and Earth system models. FLUXNET2015 includes derived-data products, such as gap-flled time series, ecosystem respiration and photosynthetic uptake estimates, estimation of uncertainties, and metadata about the measurements, presented for the frst time in this paper. In addition, 206 of these sites are for the frst time distributed under a Creative Commons (CC-BY 4.0) license. This paper details this enhanced dataset and the processing methods, now made available as open-source codes, making the dataset more accessible, transparent, and reproducible., European Union (EU), United States Department of Energy (DOE)

Published
2020

19. 50 years of woody vegetation changes in the Ferlo (Senegal) assessed by high-resolution imagery and field surveys

Author

Kjeld Rasmussen, Morgane Dendoncker, Compton J. Tucker, Martin Brandt, Simon Taugourdeau, Rasmus Fensholt, Caroline Vincke, Université Catholique de Louvain = Catholic University of Louvain (UCL), Department of Geosciences and Natural Resource Management [Copenhagen] (IGN), Faculty of Science [Copenhagen], University of Copenhagen = Københavns Universitet (KU)-University of Copenhagen = Københavns Universitet (KU), Systèmes d'élevage méditerranéens et tropicaux (UMR SELMET), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Département Environnements et Sociétés (Cirad-ES), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad), NASA Goddard Space Flight Center (GSFC), INRS, AXA Research Fund, Fonds pour la Formation à la Recherche dans l’Industrie et dans l’Agriculture, Dorrance Family Foundation 9064-00049B DFF, and UCL - SST/ELI/ELIE - Environmental Sciences

Subjects
Plante ligneuse, 010504 meteorology & atmospheric sciences, F40 - Écologie végétale, media_common.quotation_subject, [SDV]Life Sciences [q-bio], Temporal trends, Acacia, Context (language use), Imagerie par satellite, 010501 environmental sciences, 01 natural sciences, Woody vegetation, Abundance (ecology), Sahel, Balanites aegyptiaca, High-resolution imagery, 0105 earth and related environmental sciences, media_common, 2. Zero hunger, Global and Planetary Change, Combretum glutinosum, biology, Inventaire forestier, Species diversity, Forestry, Vegetation, Changement de couvert végétal, 15. Life on land, biology.organism_classification, Acacia tortilis, Senegal, Geography, Desertification, Field inventory, Combretum, P01 - Conservation de la nature et ressources foncières, U30 - Méthodes de recherche, woody vegetation
Abstract

International audience; Woody vegetation dynamics in the Sahel have been debated since the great droughts of the 1970s–1980s. Here, we combined high-resolution satellite and aerial imagery, field inventory, and historical botanical records to study woody vegetation trends over the years 1965, 1980, 2008, and 2018 in the Ferlo, the Sahelian sylvo-pastoral zone of Senegal. While tree density has decreased from 1965 (14.8 trees ha−1) to 1980 (13.4 trees ha−1) and 2008 (11.9 trees ha−1), tree density has stabilized in 2018 (12.2 trees ha−1). The relatively moderate decrease in tree density over 50 years characterized by extensive human pressure and droughts, as well as the rather stable woody cover following the drought years after the 1980s, do not support narratives of widespread desertification in this region. However, we observed a shift in the composition of species. While the drought-resistant tree Balanites aegyptiaca showed a stable abundance, Acacia tortilis showed strong increases and other species like Sclerocarya birrea and Combretum glutinosum decreased. In addition, recent field surveys show that the ratio between shrubs and trees has increased towards more shrubs. The observed loss of species diversity combined with the increase of drought-resistant species is in line with current observations for savanna ecosystems in the context of an increased aridity.

Published
2020

20. Retrieval and validation of forest background reflectivity from daily MODIS bidirectional reflectance distribution function (BRDF) data across European forests

Author

Jan Pisek, Angela Erb, Lauri Korhonen, Tobias Biermann, Arnaud Carrara, Edoardo Cremonese, Matthias Cuntz, Silvano Fares, Giacomo Gerosa, Thomas Grünwald, Niklas Hase, Michal Heliasz, Andreas Ibrom, Alexander Knohl, Johannes Kobler, Bart Kruijt, Holger Lange, Leena Leppänen, Jean-Marc Limousin, Francisco Ramon Lopez Serrano, Denis Loustau, Petr Lukeš, Lars Lundin, Riccardo Marzuoli, Meelis Mölder, Leonardo Montagnani, Johan Neirynck, Matthias Peichl, Corinna Rebmann, Eva Rubio, Margarida Santos-Reis, Crystal Schaaf, Marius Schmidt, Guillaume Simioni, Kamel Soudani, and Caroline Vincke

Subjects
Geosciences, Multidisciplinary
Abstract

Information about forest background reflectance is needed for accurate biophysical parameter retrieval from forest canopies (overstory) with remote sensing. Separating under and overstory signals would enable more accurate modeling of forest carbon and energy fluxes. We retrieved values of normalized difference vegetation index (NDVI) of forest understory with multi-angular Moderate Resolution Imaging Spectroradiometer (MODIS) bidirectional reflectance distribution function (BRDF)/albedo data (gridded 500 meter daily Collection 6 product), using a method originally developed for boreal forests. The forest floor background reflectance estimates from MODIS data were compared with in situ understory reflectance measurements carried out at an extensive set of forest ecosystem experimental sites across Europe. The reflectance estimates from MODIS data were hence tested across diverse forest conditions and phenological phases during the growing season, to examine its applicability on ecosystems other than boreal forests. Here we report the method can deliver good retrievals especially over different forest types with open canopies (low foliage cover). The performance of the method was found limited over forests with closed canopies (high foliage cover), where the signal from understory gets much attenuated. The spatial heterogeneity of individual field sites as well as the limitations and documented quality of the MODIS BRDF product are shown to be important for correct assessment and validation of the retrievals obtained with remote sensing.

Published
2020

21. Sensitivity of gross primary productivity to climatic drivers during the summer drought of 2018 in Europe

Author

Philippe Ciais, Bingxue Wang, Zhaolei Li, Zheng Fu, Julia K. Green, Nadia Vendrame, Andrej Varlagin, Christian Brümmer, Louis Gourlez de la Motte, Ladislav Šigut, Caroline Vincke, Mana Gharun, Edoardo Cremonese, Matthias Cuntz, Nina Buchmann, Ana Bastos, Hui Yang, Alexander Knohl, Kailiang Yu, Paul C. Stoy, Yuanyuan Huang, Tarek S. El-Madany, Franziska Koebsch, Marilyn Roland, Nicola Arriga, Matthias Peichl, Silvano Fares, Mirco Migliavacca, E. Magliulo, Andrea Pitacco, Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), ICOS-ATC (ICOS-ATC), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Ludwig-Maximilians-Universität München (LMU), SILVA (SILVA), AgroParisTech-Université de Lorraine (UL)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), European Research Council Synergy project SyG-2013-610028 IMBALANCE-PFrench National Research Agency (ANR) National Science Foundation (NSF)1552976Alexander von Humboldt Foundation Swiss National Science Foundation project ICOS-CH Phase 2 20FI20_173691Russian Foundation for Basic Research (RFBR)19-04-01234-asuccessive European projects European regional development programmes Region Grand-Est French National Research Agency (ANR) SOERE F-ORE-T ADEME INRA Department of Forest, Grassland and Freshwater Ecology University of Padova CDPA148553project VitiSOM LIFE15 ENV/IT/000392FWO Ministry of Education, Youth and Sports of the Czech Republic within the CzeCOS program LM2015061SustES-Adaptation strategies for sustainable ecosystem services and food security under adverse environmental conditions CZ.02.1.01/0.0/0.0/16_019/0000797European regional development programs French National Research Agency (ANR)ANR-11-LABX-0002-01, Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), European Research Council Synergy project SyG-2013-610028 IMBALANCE-PNational Science Foundation (NSF)1552976Alexander von Humboldt Foundation Swiss National Science Foundation project ICOS-CH Phase 2 20FI20_173691Russian Foundation for Basic Research (RFBR)19-04-01234-asuccessive European projects European regional development programmes Region Grand-Est SOERE F-ORE-T ADEME INRA Department of Forest, Grassland and Freshwater Ecology University of Padova CDPA148553project VitiSOM LIFE15 ENV/IT/000392FWO Ministry of Education, Youth and Sports of the Czech Republic within the CzeCOS program LM2015061SustES-Adaptation strategies for sustainable ecosystem services and food security under adverse environmental conditions CZ.02.1.01/0.0/0.0/16_019/0000797European regional development programs, ANR-11-LABX-0002,ARBRE,Recherches Avancées sur l'Arbre et les Ecosytèmes Forestiers(2011), and UCL - SST/ELI/ELIE - Environmental Sciences

Subjects
0106 biological sciences, 010504 meteorology & atmospheric sciences, Climate Change, Biome, evapotranspiration, Eddy covariance, Genetics and Molecular Biology, drought, Forests, Atmospheric sciences, 010603 evolutionary biology, 01 natural sciences, General Biochemistry, Genetics and Molecular Biology, Gross primary productivity, primary productivity, [SDV.EE.ECO]Life Sciences [q-bio]/Ecology, environment/Ecosystems, Ecosystem carbon, eddy covariance, climate change, Sensitivity (control systems), [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment, Water content, Biology, Plant Physiological Phenomena, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, Atmosphere, gross primary productivity, sensitivity, Europe, soil moisture, Articles, 15. Life on land, Grassland, Droughts, 13. Climate action, General Biochemistry, [SDE]Environmental Sciences, Environmental science, climatic drivers, Seasons, Human medicine, General Agricultural and Biological Sciences
Abstract

In summer 2018, Europe experienced a record drought, but it remains unknown how the drought affected ecosystem carbon dynamics. Using observations from 34 eddy covariance sites in different biomes across Europe, we studied the sensitivity of gross primary productivity (GPP) to environmental drivers during the summer drought of 2018 versus the reference summer of 2016. We found a greater drought-induced decline of summer GPP in grasslands (−38%) than in forests (−10%), which coincided with reduced evapotranspiration and soil water content (SWC). As compared to the ‘normal year’ of 2016, GPP in different ecosystems exhibited more negative sensitivity to summer air temperature (Ta) but stronger positive sensitivity to SWC during summer drought in 2018, that is, a stronger reduction of GPP with soil moisture deficit. We found larger negative effects of Ta and vapour pressure deficit (VPD) but a lower positive effect of photosynthetic photon flux density on GPP in 2018 compared to 2016, which contributed to reduced summer GPP in 2018. Our results demonstrate that high temperature-induced increases in VPD and decreases in SWC aggravated drought impacts on GPP. This article is part of the theme issue ‘Impacts of the 2018 severe drought and heatwave in Europe: from site to continental scale’., Philosophical Transactions of the Royal Society B: Biological Sciences, 375 (1810), ISSN:0962-8436, ISSN:1471-2970, ISSN:0080-4622

Published
2020

22. Non-stomatal processes reduce gross primary productivity in temperate forest ecosystems during severe edaphic drought

Author

Natalia Kowalska, Lukas Siebicke, Andreas Ibrom, Lenka Foltýnová, Johan Neiryink, Ladislav Šigut, Ignacio Goded Ballarin, Louis Gourlez de la Motte, Giovanni Manca, Marilyn Roland, Mathias Cuntz, Denis Lousteau, Bernard Longdoz, Caroline Vincke, Bernard Heinesch, Quentin Beauclaire, Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), SILVA (SILVA), Institut National de la Recherche Agronomique (INRA)-Université de Lorraine (UL)-AgroParisTech, FWO Service Public de Wallonie 1217769project 'SustES -Adaptation strategies for sustainable ecosystem services and food security under adverse environmental conditions' CZ.02.1.01/0.0/0.0/16_019/0000797University of Goettingen German Research Foundation (DFG) Federal Ministry of Education & Research (BMBF) Technical University of Denmark (DTU) Det Frie Forskningsrad (DFF)DFF -1323-00182Danish Ministry of Higher Education and Science 5072-00008BEU research infrastructure project RINGO EU research infrastructure project ICOS INRA, UCL - SST/ELI/ELIE - Environmental Sciences, Université de Liège - Gembloux, Institut National de la Recherche Agronomique (INRA)-AgroParisTech-Université de Lorraine (UL), Global Change Research Institute CAS, European Commission - Joint Research Centre [Ispra] (JRC), Université Catholique de Louvain = Catholic University of Louvain (UCL), University of Antwerp (UA), Technical University of Denmark [Lyngby] (DTU), Interactions Sol Plante Atmosphère (UMR ISPA), Ecole Nationale Supérieure des Sciences Agronomiques de Bordeaux-Aquitaine (Bordeaux Sciences Agro)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), University of Göttingen - Georg-August-Universität Göttingen, and Research Institute for Nature and Forest (INBO)

Subjects
0106 biological sciences, Stomatal conductance, 010504 meteorology & atmospheric sciences, Climate Change, Eddy covariance, Genetics and Molecular Biology, Forests, Photosynthesis, 01 natural sciences, General Biochemistry, Genetics and Molecular Biology, Gross primary productivity, Trees, Forest ecology, Ecosystem, Forest, edaphic drought, Biology, 0105 earth and related environmental sciences, model, Drought, Atmosphere, Ecology, Temperate forest, Edaphic, Articles, 15. Life on land, temperate forest ecosystems, Droughts, Europe, climate change, 13. Climate action, Plant Stomata, General Biochemistry, [SDE]Environmental Sciences, Environmental science, Human medicine, General Agricultural and Biological Sciences, 010606 plant biology & botany
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 V CMAX,APP (NSOL) when the soil relative extractable water content dropped below around 0.4. Concurrently, we found that the stomatal slope parameter ( G 1 , 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’.

Published
2020

23. HETEROFOR 1.0: a spatially explicit model for exploring the response of structurally complex forests to uncertain future conditions. I. Carbon fluxes and tree dimensional growth

Author

Mathieu Jonard, Frédéric André, François de Coligny, Louis de Wergifosse, Nicolas Beudez, Hendrik Davi, Gauthier Ligot, Quentin Ponette, Caroline Vincke, Earth and Life Institute, Environmental Sciences, Université Catholique de Louvain = Catholic University of Louvain (UCL), Botanique et Modélisation de l'Architecture des Plantes et des Végétations (UMR AMAP), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud])-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Unité de Recherches Forestières Méditerranéennes (URFM), Institut National de la Recherche Agronomique (INRA), Université de Liège - Gembloux, Catholic University of Leuven - Katholieke Universiteit Leuven (KU Leuven), Université Catholique de Louvain (UCL), and Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut de Recherche pour le Développement (IRD [France-Sud])-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)

Subjects
CAPSIS, Tree growth, [SDV.EE.ECO]Life Sciences [q-bio]/Ecology, environment/Ecosystems, HETEROFOR, 13. Climate action, 15. Life on land, [SDV.BV.BOT]Life Sciences [q-bio]/Vegetal Biology/Botanics, [SDE.BE]Environmental Sciences/Biodiversity and Ecology, [SDV.BID.SPT]Life Sciences [q-bio]/Biodiversity/Systematics, Phylogenetics and taxonomy, Carbon-related process
Abstract

Given the multiple abiotic and biotic stressors resulting from global changes, management systems and practices must be adapted in order to maintain and reinforce the resilience of forests. Among others, the transformation of monocultures into uneven-aged and mixed stands is an avenue to improve forest resilience. To explore the forest response to these new silvicultural practices under a changing environment, one need models combining a process-based approach with a detailed spatial representation, which is very rare. We therefore decided to develop our own model (HETEROFOR) according to a spatially explicit approach describing individual tree growth based on resource sharing (light, water and nutrients). HETEROFOR was progressively elaborated through the integration of various modules (light interception, phenology, water cycling, photosynthesis and respiration, carbon allocation, mineral nutrition and nutrient cycling) within CAPSIS, a collaborative modelling platform devoted to tree growth and stand dynamics. The advantage of using such a platform is to use common development environment, model execution system, user- interface and visualization tools and to share data structures, objects, methods and libraries. This paper describes the carbon-related processes of HETEROFOR (photosynthesis, respiration, carbon allocation and tree dimensional growth) and evaluates the model performances for a mixed oak and beech stand in Wallonia (Belgium). This first evaluation showed that HETEROFOR predicts well individual radial growth and is able to reproduce size-growth relationships. We also noticed that the more empirical options for describing maintenance respiration and crown extension provide the best results while the process-based approach best performs for photosynthesis. To illustrate how the model can be used to predict climate change impacts on forest ecosystems, the growth dynamics in this stand was simulated according to four IPCC climate scenarios. According to these simulations, the tree growth trends will be governed by the CO2 fertilization effect with the increase in vegetation period length and in water stress also playing a role but offsetting each other.

Published
2020

24. HETEROFOR 1.0: a spatially explicit model for exploring the response of structurally complex forests to uncertain future conditions. II. Phenology and water cycle

Author

Louis de Wergifosse, Frédéric André, Nicolas Beudez, François de Coligny, Hugues Goosse, François Jonard, Quentin Ponette, Hugues Titeux, Caroline Vincke, Mathieu Jonard, Université Catholique de Louvain = Catholic University of Louvain (UCL), Botanique et Modélisation de l'Architecture des Plantes et des Végétations (UMR AMAP), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud])-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Institut d'Astronomie et de Géophysique Georges Lemaître (UCL-ASTR), Earth and Life Institute, Environmental Sciences, Catholic University of Leuven - Katholieke Universiteit Leuven (KU Leuven), Université Catholique de Louvain (UCL), and Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut de Recherche pour le Développement (IRD [France-Sud])-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)

Subjects
Tree growth model, 010504 meteorology & atmospheric sciences, HETEROFOR, Belgian, 0207 environmental engineering, 02 engineering and technology, 15. Life on land, [SDV.BV.BOT]Life Sciences [q-bio]/Vegetal Biology/Botanics, [SDV.BID.SPT]Life Sciences [q-bio]/Biodiversity/Systematics, Phylogenetics and taxonomy, 01 natural sciences, [SDV.EE.ECO]Life Sciences [q-bio]/Ecology, environment/Ecosystems, Phenology, 13. Climate action, Forest growth, Climate change, [SDE.BE]Environmental Sciences/Biodiversity and Ecology, 020701 environmental engineering, 0105 earth and related environmental sciences
Abstract

Climate change affects forest growth in numerous and sometimes opposite ways and the resulting trend is often difficult to predict for a given site. Integrating and structuring the knowledge gained from the monitoring and experimental studies into process-based models is an interesting approach to predict the response of forest ecosystems to climate change. While the first generation of such models operates at stand level, we need now individual-based and spatially-explicit approaches in order to account for structurally complex stands whose importance is increasingly recognized in the changing environment context. Among the climate-sensitive drivers of forest growth, phenology and water availability are often cited as crucial elements. They influence, for example, the length of the vegetation period during which photosynthesis takes place and the stomata opening, which determines the photosynthesis rate. In this paper, we describe the phenology and water balance modules integrated in the tree growth model HETEROFOR and evaluate them on six Belgian sites. More precisely, we assess the ability of the model to reproduce key phenological processes (budburst, leaf development, yellowing and fall) as well as water fluxes. Three variants are used to predict budburst (Uniforc, Unichill and Sequential), which differ regarding the inclusion of chilling and/or forcing periods and the calculation of the coldness or heat accumulation. Among the three, the Sequential approach is the least biased (overestimation of 2.46 days) while Uniforc (chilling not considered) best accounts for the interannual variability (Pearson’s R = 0.68). For the leaf development, yellowing and fall, predictions and observation are in accordance. Regarding the water balance module, the predicted throughfall is also in close agreement with the measurements (Pearson’s R = 0.856, bias = −1.3 %) and the soil water dynamics across the year is well-reproduced for all the study sites (Pearson’s R comprised between 0.893 and 0.950, and bias between −1.81 and −9.33 %). The positive results from the model assessment will allow us to use it reliably in projection studies to evaluate the impact of climate change on tree growth and test how diverse forestry practices can adapt forests to these changes.

Published
2020

25. Inter-annual variability of Net Ecosystem Productivity for a temperate mixed forest: A predominance of carry-over effects?

Author

Marc Aubinet, Anne De Ligne, Tanguy Manise, Henri Chopin, Alain Debacq, Caroline Vincke, Quentin Hurdebise, and Bernard Heinesch

Subjects
0106 biological sciences, Canopy, Atmospheric Science, Global and Planetary Change, Biomass (ecology), 010504 meteorology & atmospheric sciences, biology, Vapour Pressure Deficit, Eddy covariance, Forestry, Vegetation, Atmospheric sciences, biology.organism_classification, 01 natural sciences, Photosynthetic capacity, Forest ecology, Environmental science, Agronomy and Crop Science, Beech, 010606 plant biology & botany, 0105 earth and related environmental sciences
Abstract

This study presents twenty years of Net Ecosystem Productivity estimations obtained using eddy covariance in a mixed forest, dominated by beech with sparse conifers, at the Vielsalm station, in the Belgian Ardennes. First the quality and reliability of the data set is discussed. An uncertainty analysis showed that if, on one hand, the site heterogeneity and set-up changes may strongly affect yearly NEP estimates, questioning thus the total carbon budget relevance, on the other hand, robust inter-annual anomalies may be obtained as long as a site dedicated data treatment is carefully applied. A validation of the anomalies by comparison with a growth index derived from tree ring measurements is given. The resulting anomalies (range: [−206; + 123] g C m−2 yr−1, standard deviation: 93 g C m−2 yr−1) being larger than their own uncertainty (∼30 g C m−2 yr−1), an inter-annual variability analysis is possible. This analysis shows that the sources of NEP inter-annual variability at the Vielsalm station are multiple but the most prominent causes are biotic processes driven by carry-over effects of preceding meteorological events. The lowest observed NEP, in 2000, resulted from a bark beetle attack probably prompted by an early frost event in 1998. Besides, the robust lagged correlation between NEP anomalies and mean vapor pressure deficit during the preceding vegetation season also suggests a carry-over effect of water limitation during the previous year on the beech NEP. Mechanisms driving this carry-over effect are supposedly linked to tree physiology, which is confirmed by a dependency of canopy photosynthetic capacity to previous year water limitation. Some hypotheses, involving biomass allocation and bud formation, are proposed to explain its lagged impact on canopy photosynthetic capacity. Other causes of NEP inter-annual variability are the radiation during the current vegetation season and the temperature at the end of the winter but the latter variable rather indicates an effect on the conifers interspersed in the plot. Overall, the photosynthetic capacity combined with these two factors explained about 75% of NEP inter-annual variability.

Published
2018

26. Reduction of tree cover in West African woodlands and promotion in semi-arid farmlands

Author

Cheikh Mbow, Xiaoye Tong, Caroline Vincke, Rasmus Fensholt, Morgane Dendoncker, Compton J. Tucker, Ole Mertz, Feng Tian, Kjeld Rasmussen, Stefanie M. Herrmann, K. A. Melocik, Martin Brandt, John L. David, Pierre Hiernaux, Laurent Kergoat, NASA Goddard Space Flight Center (GSFC), Géosciences Environnement Toulouse (GET), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD), and START International Inc

Subjects
2. Zero hunger, Biomass (ecology), 010504 meteorology & atmospheric sciences, Agroforestry, business.industry, Carbon sink, Woodland, Vegetation, 010501 environmental sciences, 15. Life on land, 01 natural sciences, Arid, Article, Ecosystem services, Basal area, Geography, Agriculture, General Earth and Planetary Sciences, [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment, business, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences
Abstract

Woody vegetation in farmland acts as a carbon sink and provides ecosystem services for local people, but no macroscale assessments of the impact of management and climate on woody cover exist for drylands. Here we make use of very high spatial resolution satellite imagery to derive wall-to-wall woody cover patterns in tropical West African drylands. Our study reveals that mean woody cover in farmlands along all semi-arid and sub-humid rainfall zones is 16%, on average only 6% lower than in savannahs. In semi-arid Sahel, farmland management promotes woody cover around villages (11%), while neighbouring savannahs had on average less woody cover. However, farmlands in sub-humid zones have a greatly reduced woody cover (21%) as compared with savannahs (33%). In the region as a whole, rainfall, terrain and soil are the most important (80%) determinants of woody cover, while management factors play a smaller (20%) role. We conclude that agricultural expansion causes a considerable reduction of trees in woodlands, but observations in Sahel indicate that villagers safeguard trees on nearby farmlands which contradicts simplistic ideas of a high negative correlation between population density and woody cover.

Published
2018

27. Forest cover correlates with good biological water quality. Insights from a regional study (Wallonia, Belgium)

Author

Delphine Brogna, Marc Dufrêne, Sander Jacobs, Nicolas Dendoncker, Adrien Latli, Adrien Michez, Caroline Vincke, and UCL - SST/ELI/ELIE - Environmental Sciences

Subjects
Environmental Engineering, 010504 meteorology & atmospheric sciences, macroinvertebrates, Land cover, Forests, 010501 environmental sciences, Management, Monitoring, Policy and Law, 01 natural sciences, Ecoregion, Belgium, Rivers, Water Quality, water framework directive, Environmental monitoring, Humans, Riparian forest, Waste Management and Disposal, Ecosystem, 0105 earth and related environmental sciences, Riparian zone, Diatoms, geography, geography.geographical_feature_category, Macroinvertebrates, Land use, Agriculture, General Medicine, Water Framework Directive, Water framework directive, Environmental science, Monitoring network, Physical geography, Water quality, Environmental Monitoring
Abstract

Forested catchments are generally assumed to provide higher quality water in opposition to agricultural and urban catchments. However, this should be tested in various ecological contexts and through the study of multiple variables describing water quality. Indeed, interactions between ecological variables, multiple land use and land cover (LULC) types, and water quality variables render the relationship between forest cover and water quality highly complex. Furthermore, the question of the scale at which land use within stream catchments most influences stream water quality and ecosystem health remains only partially answered. This paper quantifies, at the regional scale and across five natural ecoregions of Wallonia (Belgium), the forest cover effect on biological water quality indices (based on diatoms and macroinvertebrates) at the riparian and catchment scales. Main results show that forest cover – considered alone – explains around one third of the biological water quality at the regional scale and from 15 to 70% depending on the ecoregion studied. Forest cover is systematically positively correlated with higher biological water quality. When removing spatial, local morphological variations, or population density effect, forest cover still accounts for over 10% of the total biological water quality variation. Partitioning variance shows that physico-chemical water quality is one of the main drivers of biological water quality and that anthropogenic pressures often explain an important part of it (shared or not with forest cover). The proportion of forest cover in each catchment at the regional scale and across all ecoregions but the Loam region is more positively correlated with high water quality than when considering the proportion of forest cover in the riparian zones only. This suggests that catchment-wide impacts and a fortiori catchment-wide protection measures are the main drivers of river ecological water quality. However, distinctive results from the agricultural and highly human impacted Loam region show that riparian forests are positively linked to water quality and should therefore be preserved.

Published
2018

28. Author Correction

Author

Pierpaolo Duce, B.R. Reverter, Bruce D. Cook, Marian Pavelka, Lindsay B. Hutley, Francesco Mazzenga, Caroline Vincke, Benoit Burban, Damiano Gianelle, Üllar Rannik, William J. Massman, Claudia Consalvo, Scott R. Saleska, D. P. Billesbach, Guoyi Zhou, Julia Boike, Michiel K. van der Molen, Werner Eugster, Hyojung Kwon, Thomas Grünwald, Thomas L. Powell, T. A. Black, Caitlin E. Moore, Albin Hammerle, Yingnian Li, Cristina Poindexter, Uwe Eichelmann, Marcelo D. Nosetto, Xiaoqin Dai, Cacilia Ewenz, Gilberto Pastorello, Carlos Marcelo Di Bella, Damien Bonal, Stefano Minerbi, Rosvel Bracho, Kim Pilegaard, Serena Marras, Michael J. Liddell, Mika Aurela, N. Pirk, Shawn Urbanski, Scott D. Miller, Janina Klatt, Eugénie Paul-Limoges, Jean-Marc Limousin, Hideki Kobayashi, Juha Hatakka, Georg Wohlfahrt, Diego Polidori, Mana Gharun, Olaf Kolle, Jørgen E. Olesen, Peili Shi, Yann Nouvellon, Johan Neirynck, Rainer Steinbrecher, Lukas Siebicke, Satoru Takanashi, Eva van Gorsel, Domenico Vitale, Regine Maier, Hans Peter Schmid, Raimundo Cosme de Oliveira, Torben R. Christensen, Giovanni Manca, Elizabeth A. Walter-Shea, Leonardo Montagnani, Jonathan E. Thom, James Cleverly, Andrew Feitz, Nina Buchmann, Andrew M. S. McMillan, N. N. Vygodskaya, E. Canfora, Richard Silberstein, David E. Reed, Marc Fischer, Ankur R. Desai, Leiming Zhang, Alexander Graf, Sébastien C. Biraud, Samuli Launiainen, Siyan Ma, Bart Kruijt, Carlo Trotta, Nicola Arriga, Christopher M. Gough, Elise Pendall, Peter S. Curtis, Margaret S. Torn, Gabriela Posse, Ivan Shironya, Silvano Fares, You Wei Cheah, Karl Schneider, Robin Weber, D. S. Christianson, Carsten Gruening, Hiroki Ikawa, Christine Moureaux, Paul V. Bolstad, Lukas Hörtnagl, Zulia Mayari Sanchez-Mejia, W.W.P. Jans, Alan G. Barr, Sebastian Wolf, Marc Aubinet, Christof Ammann, Penélope Serrano-Ortiz, Timothy J. Arkebauer, Shicheng Jiang, Han Dolman, Iris Feigenwinter, Junhui Zhang, A. Ribeca, Ana López-Ballesteros, Johannes Lüers, Chad Hanson, Hank A. Margolis, Nicolas Delpierre, Onil Bergeron, Mauro Cavagna, Jiří Dušek, Benjamin Loubet, Jason Brodeur, M. Altaf Arain, Kimberly A. Novick, Dalibor Janouš, Anne De Ligne, Marty Humphrey, Christian Wille, Daniel Berveiller, Changliang Shao, Pauline Buysse, Kenneth J. Davis, Annalea Lohila, Deb Agarwal, Ian McHugh, Ray Leuning, Anne Griebel, Natalia Restrepo-Coupe, Russell L. Scott, Russell K. Monson, Christian Brümmer, Dennis D. Baldocchi, Brian D. Amiro, Andrew E. Suyker, Naama Raz-Yaseef, Timo Vesala, David R. Cook, William Woodgate, Rasmus Fensholt, Uta Moderow, Richard P. Phillips, Stefan K. Arndt, Xingguo Han, Jason Beringer, Riccardo Valentini, Robert M. Stevens, Luca Belelli Marchesini, Shirley A. Papuga, Gianluca Filippa, Roser Matamala, John M. Frank, Peter Isaac, Werner L. Kutsch, Paul Di Tommasi, Yuelin Li, Andrej Varlagin, Ladislav Šigut, Francisco Domingo, E. Beamesderfer, Edoardo Cremonese, Eddy Moors, Joseph Verfaillie, Huimin Wang, Jiquan Chen, M. Goeckede, Craig Macfarlane, Enrique P. Sánchez-Cañete, Harry McCaughey, Tomomichi Kato, Dario Papale, Jean Marc Ourcival, Birger Ulf Hansen, Pierre Cellier, Bev Law, Derek Eamus, Carole Coursolle, Myroslava Khomik, Wayne S. Meyer, Taro Nakai, Mikhail Mastepanov, Nina Hinko-Najera, Peter Cale, Donatella Spano, Beniamino Gioli, Gang Dong, David R. Bowling, Sabina Dore, Shiping Chen, Isaac Chini, Jeffrey P. Walker, Eric Dufrêne, Sebastian Westermann, Marcin Jackowicz-Korczynski, Marryanna Lion, Barbara Marcolla, Marius Schmidt, Serge Rambal, Víctor Resco de Dios, Jean Marc Bonnefond, Ivan Mammarella, Hatim Abdalla M. ElKhidir, Ko van Huissteden, Suzanne M. Prober, Gil Bohrer, Markus Reichstein, Heiko Prasse, Nigel J. Tapper, Corinna Rebmann, J. Kurbatova, Abdelrahman Elbashandy, J. William Munger, Catharine van Ingen, Humberto Ribeiro da Rocha, Andreas Ibrom, Sean P. Burns, Simone Sabbatini, Marilyn Roland, Zoran Nesic, Tuomas Laurila, Giacomo Nicolini, Bruno De Cinti, Jaclyn Hatala Matthes, Georgia R. Koerber, Yoshiko Kosugi, Efrén López-Blanco, Cove Sturtevant, Matthew Northwood, Ettore D'Andrea, Torsten Sachs, Housen Chu, Matthias Peichl, Nicolas Vuichard, Alexander Knohl, Steven C. Wofsy, Michael L. Goulden, Vincenzo Magliulo, Antje Lucas-Moffat, Peter D. Blanken, Donatella Zona, Allison L. Dunn, Yanhong Tang, Marta Galvagno, Rachhpal S. Jassal, Jonas Ardö, Torbern Tagesson, Frederik Schrader, Ignacio Goded, Costantino Sirca, Shijie Han, Markus Hehn, Allen H. Goldstein, Bernard Heinesch, Christian Bernhofer, Yongtao He, Brent E. Ewers, Adam J. Liska, Michele Tomassucci, Virginie Moreaux, Denis Loustau, Agnès de Grandcourt, Tilden P. Meyers, Roberto Zampedri, Alessio Collalti, Sara H. Knox, Ayumi Kotani, Anatoly A. Gitelson, Andrew S. Kowalski, Walter C. Oechel, Lutz Merbold, Daniela Famulari, Pavel Sedlák, Asko Noormets, Juha Pekka Tuovinen, Frans-Jan W. Parmentier, Bert Gielen, Ivan Schroder, Earth Sciences, Earth and Climate, and UCL - SST/ELI/ELIE - Environmental Sciences

Subjects
Data descriptor, Statistics and Probability, Code development, 010504 meteorology & atmospheric sciences, Pipeline (computing), Science, 0207 environmental engineering, Eddy covariance, ComputingMilieux_LEGALASPECTSOFCOMPUTING, 02 engineering and technology, Library and Information Sciences, 01 natural sciences, Education, ddc:550, 020701 environmental engineering, Author Correction, 0105 earth and related environmental sciences, Information retrieval, Published Erratum, Substitution (logic), Statistics, Carbon cycle, Computer Science Applications, Environmental sciences, Earth sciences, Probability and Uncertainty, ddc:500, Statistics, Probability and Uncertainty, Climate sciences, Downscaling, Information Systems
Abstract

The following authors were omitted from the original version of this Data Descriptor: Markus Reichstein and Nicolas Vuichard. Both contributed to the code development and N. Vuichard contributed to the processing of the ERA-Interim data downscaling. Furthermore, the contribution of the co-author Frank Tiedemann was re-evaluated relative to the colleague Corinna Rebmann, both working at the same sites, and based on this re-evaluation a substitution in the co-author list is implemented (with Rebmann replacing Tiedemann). Finally, two affiliations were listed incorrectly and are corrected here (entries 190 and 193). The author list and affiliations have been amended to address these omissions in both the HTML and PDF versions. © 2021, This is a U.S. government work and not under copyright protection in the U.S.; foreign copyright protection may apply.

Published
2021

29. How does forest cover impact water flows and ecosystem services? Insights from 'real-life' catchments in Wallonia (Belgium)

Author

Yves Brostaux, Caroline Vincke, Delphine Brogna, Marc Dufrêne, Nicolas Dendoncker, and Hélène Soyeurt

Subjects
Land cover, 010504 meteorology & atmospheric sciences, 0208 environmental biotechnology, General Decision Sciences, Water supply, 02 engineering and technology, Forests, 01 natural sciences, Ecosystem services, Belgium, Indicators, Ecosystem, Natural resource management, Ecology, Evolution, Behavior and Systematics, 0105 earth and related environmental sciences, Baseflow, Ecology, Flood myth, business.industry, Water, Hydrological services, Vegetation, 020801 environmental engineering, Environmental science, business, Water resource management
Abstract

While planet boundaries are being crossed and ecosystems degraded, the Ecosystem Service (ES) concept represents a potential decision-making tool for improved natural resources management. The main aim of this paper is to assess the impact of forest cover on water related ES in Wallonia (Belgium) in terms of quantity and timing. We developed an approach based on easily accessible data, monitored in several countries and using straightforward statistical methods. This led us to study ES at “real-life” catchments scale: 22 catchments – from 30 to 250 km2– with mixed land covers were studied. We approached the water supply and flood protection services through 5 indicators extracted from 10 hydrological years (2005–2014) discharge data series. These were computed annually and seasonally (vegetation period from March to September and “non-vegetation” period the rest of the year). The water supply was assessed through the specific volume Vs, the baseflow index BFI and the specific discharge exceeded 95% of the time Q95s whereas the flood protection service was approached through the specific discharge exceeded 5% of the time Q05s and the flashiness index FI. Our study gives two main insights. First, statistical analyses show that forest cover negatively impact water supply when studying annual and “non-vegetation” period flows in general (Vs) but positively when studying low flows (Q95s). Regarding flood protection a slightly negative impact of forest cover on high flows (Q05s) was highlighted in the “non-vegetation” period. Results also show a negative impact of forests annually and in the vegetation period on the flashy behaviour of the catchment thus a positive impact on the flood protection ES. The “year” effect is overall highly significant testifying the importance of climatic factors. Rainfall is often significant and can be considered as a main driver of these ES. Secondly, analyzing the quality of the models produced and the results overall we assume that other variables characterizing the catchments such as topography or soil types do play a significant role in the delivery of these ES. This questions the use of land cover proxies in assessing and mapping of hydrological ES at a complex landscape scale. We thus recommend further research to keep improving land cover proxies if they are used.

Published
2017

30. Supplementary material to 'Carbon / nitrogen interactions in European forests and semi-natural vegetation. Part I: Fluxes and budgets of carbon, nitrogen and greenhouse gases from ecosystem monitoring and modelling'

Author

Chris R. Flechard, Andreas Ibrom, Ute M. Skiba, Wim de Vries, Marcel van Oijen, David R. Cameron, Nancy B. Dise, Janne F. J. Korhonen, Nina Buchmann, Arnaud Legout, David Simpson, Maria J. Sanz, Marc Aubinet, Denis Loustau, Leonardo Montagnani, Johan Neirynck, Ivan A. Janssens, Mari Pihlatie, Ralf Kiese, Jan Siemens, André-Jean Francez, Jürgen Augustin, Andrej Varlagin, Janusz Olejnik, Radosław Juszczak, Mika Aurela, Bogdan H. Chojnicki, Ulrich Dämmgen, Vesna Djuricic, Julia Drewer, Werner Eugster, Yannick Fauvel, David Fowler, Arnoud Frumau, André Granier, Patrick Gross, Yannick Hamon, Carole Helfter, Arjan Hensen, László Horváth, Barbara Kitzler, Bart Kruijt, Werner L. Kutsch, Raquel Lobo-do-Vale, Annalea Lohila, Bernard Longdoz, Michal V. Marek, Giorgio Matteucci, Marta Mitosinkova, Virginie Moreaux, Albrecht Neftel, Jean-Marc Ourcival, Kim Pilegaard, Gabriel Pita, Francisco Sanz, Jan K. Schjoerring, Maria-Teresa Sebastià, Y. Sim Tang, Hilde Uggerud, Marek Urbaniak, Netty van Dijk, Timo Vesala, Sonja Vidic, Caroline Vincke, Tamás Weidinger, Sophie Zechmeister-Boltenstern, Klaus Butterbach-Bahl, Eiko Nemitz, and Mark A. Sutton

Published
2019

31. Carbon / nitrogen interactions in European forests and semi-natural vegetation. Part II: Untangling climatic, edaphic, management and nitrogen deposition effects on carbon sequestration potentials

Author

Chris R. Flechard, Marcel van Oijen, David R. Cameron, Wim de Vries, Andreas Ibrom, Nina Buchmann, Nancy B. Dise, Ivan A. Janssens, Johan Neirynck, Leonardo Montagnani, Andrej Varlagin, Denis Loustau, Arnaud Legout, Klaudia Ziemblińska, Marc Aubinet, Mika Aurela, Bogdan H. Chojnicki, Julia Drewer, Werner Eugster, André-Jean Francez, Radosław Juszczak, Barbara Kitzler, Werner L. Kutsch, Annalea Lohila, Bernard Longdoz, Giorgio Matteucci, Virginie Moreaux, Albrecht Neftel, Janusz Olejnik, Maria J. Sanz, Jan Siemens, Timo Vesala, Caroline Vincke, Eiko Nemitz, Sophie Zechmeister-Boltenstern, Klaus Butterbach-Bahl, Ute M. Skiba, and Mark A. Sutton

Subjects
0106 biological sciences, 010504 meteorology & atmospheric sciences, 13. Climate action, 010604 marine biology & hydrobiology, 15. Life on land, 01 natural sciences, 0105 earth and related environmental sciences
Abstract

The effects of atmospheric nitrogen deposition (Ndep) on carbon (C) sequestration in forests have often been assessed by relating differences in productivity to spatial variations of Ndep across a large geographic domain. These correlations generally suffer from covariation of other confounding variables related to climate and other growth-limiting factors, as well as large uncertainties in total (dry + wet) reactive nitrogen (Nr) deposition. We propose a methodology for untangling the effects of Ndep from those of meteorological variables, soil water retention capacity and stand age, using a mechanistic forest growth model in combination with eddy covariance CO2 exchange fluxes from a Europe-wide network of forest flux towers. Total Nr deposition rates were estimated from local measurements as far as possible. The forest data were compared with data from natural or semi-natural, non-woody vegetation sites. The carbon sequestration response of forests to nitrogen deposition (dC / dN) was estimated after accounting for the effects of the co-correlates by means of a meta-modelling standardization procedure, which resulted in a reduction by a factor of about 2 of the uncorrected, apparent dC / dN value. This model-enhanced analysis of the C and Ndep flux observations at the scale of the European network suggests a mean overall dC / dN response of forest lifetime C sequestration to Ndep of the order of 40–50 g (C) g−1 (N), which is slightly larger but not significantly different from the range of estimates published in the most recent reviews. Importantly, patterns of gross primary and net ecosystem productivity versus Ndep were non-linear, with no further responses at high Ndep levels (Ndep > 2.5–3 g (N) m−2 yr−1) partly due to large ecosystem N losses by leaching and gaseous emissions. The reduced increase in productivity per unit N deposited at high Ndep levels implies that the forecast increased Nr emissions and increased Ndep levels in large areas of Asia may not positively impact the continent's forest CO2 sink. The large level of unexplained variability in observed carbon sequestration efficiency (CSE) across sites further adds to the uncertainty in the dC / dN response.

Published
2019

32. Supplementary material to 'Carbon / nitrogen interactions in European forests and semi-natural vegetation. Part II: Untangling climatic, edaphic, management and nitrogen deposition effects on carbon sequestration potentials'

Author

Chris R. Flechard, Marcel van Oijen, David R. Cameron, Wim de Vries, Andreas Ibrom, Nina Buchmann, Nancy B. Dise, Ivan A. Janssens, Johan Neirynck, Leonardo Montagnani, Andrej Varlagin, Denis Loustau, Arnaud Legout, Klaudia Ziemblińska, Marc Aubinet, Mika Aurela, Bogdan H. Chojnicki, Julia Drewer, Werner Eugster, André-Jean Francez, Radosław Juszczak, Barbara Kitzler, Werner L. Kutsch, Annalea Lohila, Bernard Longdoz, Giorgio Matteucci, Virginie Moreaux, Albrecht Neftel, Janusz Olejnik, Maria J. Sanz, Jan Siemens, Timo Vesala, Caroline Vincke, Eiko Nemitz, Sophie Zechmeister-Boltenstern, Klaus Butterbach-Bahl, Ute M. Skiba, and Mark A. Sutton

Published
2019

33. Carbon / nitrogen interactions in European forests and semi-natural vegetation. Part I: Fluxes and budgets of carbon, nitrogen and greenhouse gases from ecosystem monitoring and modelling

Author

Chris R. Flechard, Andreas Ibrom, Ute M. Skiba, Wim de Vries, Marcel van Oijen, David R. Cameron, Nancy B. Dise, Janne F. J. Korhonen, Nina Buchmann, Arnaud Legout, David Simpson, Maria J. Sanz, Marc Aubinet, Denis Loustau, Leonardo Montagnani, Johan Neirynck, Ivan A. Janssens, Mari Pihlatie, Ralf Kiese, Jan Siemens, André-Jean Francez, Jürgen Augustin, Andrej Varlagin, Janusz Olejnik, Radosław Juszczak, Mika Aurela, Bogdan H. Chojnicki, Ulrich Dämmgen, Vesna Djuricic, Julia Drewer, Werner Eugster, Yannick Fauvel, David Fowler, Arnoud Frumau, André Granier, Patrick Gross, Yannick Hamon, Carole Helfter, Arjan Hensen, László Horváth, Barbara Kitzler, Bart Kruijt, Werner L. Kutsch, Raquel Lobo-do-Vale, Annalea Lohila, Bernard Longdoz, Michal V. Marek, Giorgio Matteucci, Marta Mitosinkova, Virginie Moreaux, Albrecht Neftel, Jean-Marc Ourcival, Kim Pilegaard, Gabriel Pita, Francisco Sanz, Jan K. Schjoerring, Maria-Teresa Sebastià, Y. Sim Tang, Hilde Uggerud, Marek Urbaniak, Netty van Dijk, Timo Vesala, Sonja Vidic, Caroline Vincke, Tamás Weidinger, Sophie Zechmeister-Boltenstern, Klaus Butterbach-Bahl, Eiko Nemitz, and Mark A. Sutton

Subjects
0106 biological sciences, 010504 meteorology & atmospheric sciences, 13. Climate action, 010604 marine biology & hydrobiology, 15. Life on land, 01 natural sciences, 0105 earth and related environmental sciences
Abstract

The impact of atmospheric reactive nitrogen (Nr) deposition on carbon (C) sequestration in soils and biomass of unfertilised, natural, semi-natural and forest ecosystems has been much debated. Many previous results of this dC / dN response were based on changes in carbon stocks from periodical soil and ecosystem inventories, associated with estimates of Nr deposition obtained from large-scale chemical transport models. This study and a companion paper (Flechard et al., 2019) strive to reduce uncertainties of N effects on C sequestration by linking multi-annual gross and net ecosystem productivity estimates from 40 eddy covariance flux towers across Europe to local measurement-based estimates of dry and wet Nr deposition from a dedicated collocated monitoring network. To identify possible ecological drivers and processes affecting the interplay between C and Nr inputs and losses, these data were also combined with in situ flux measurements of NO, N2O and CH4 fluxes, soil NO3− leaching sampling, as well as results of soil incubation experiments for N and greenhouse gas (GHG) emissions, surveys of available data from online databases and from the literature, together with forest ecosystem (BASFOR) modelling. Multi-year averages of net ecosystem productivity (NEP) in forests ranged from −70 to 826 g (C) m−2 yr−1 at total wet + dry inorganic Nr deposition rates (Ndep) of 0.3 to 4.3 g (N) m−2 yr−1; and from −4 to 361 g (C) m−2 yr−1 at Ndep rates of 0.1 to 3.1 g (N) m−2 yr−1 in short semi-natural vegetation (moorlands, wetlands and unfertilised extensively managed grasslands). The GHG budgets of the forests were strongly dominated by CO2 exchange, while CH4 and N2O exchange comprised a larger proportion of the GHG balance in short semi-natural vegetation. Nitrogen losses in the form of NO, N2O and especially NO3− were of the order of 10–20 % of Ndep at sites with Ndep 3 g (N) m−2 yr−1, indicating that perhaps one third of the sites were in a state of early to advanced N saturation. Net ecosystem productivity increased with Nr deposition up to 2–2.5 g (N) m−2 yr−1, with large scatter associated with a wide range in carbon sequestration efficiency (CSE, defined as the NEP / GPP ratio). At elevated Ndep levels (> 2.5 g (N) m−2 yr−1), where inorganic Nr losses were also increasingly large, NEP levelled off and then decreased. The apparent increase in NEP at low to intermediate Ndep levels was partly the result of geographical cross-correlations between Ndep and climate, indicating that the actual mean dC / dN response at individual sites was significantly lower than would be suggested by a simple, straightforward regression of NEP vs. Ndep.

Published
2019

35. Increasing temperatures over an 18-year period shortens growing season length in a beech (Fagus sylvatica L.)-dominated forest

Author

Quentin Hurdebise, Caroline Vincke, Marc Aubinet, Bernard Heinesch, and UCL - SST/ELI/ELIE - Environmental Sciences

Subjects
0106 biological sciences, [SDV]Life Sciences [q-bio], Forest management, Eddy covariance, Growing season, Fagus sylvatica L, 010603 evolutionary biology, 01 natural sciences, Fagus sylvatica, Climate change, Phenological indicators, Beech, Ecology, biology, Phenology, Temperate forest, Forestry, phenological indicators, 15. Life on land, biology.organism_classification, Net ecosystem productivity, climate change, Agronomy, Productivity (ecology), 13. Climate action, Environmental science, 010606 plant biology & botany
Abstract

International audience; AbstractKey messageUsing long-term measurements in a mature beech (Fagus sylvatica L.)-dominated forest located in east Belgium, this paper showed that spring and autumn temperature increases during the last two decades led to an earlier end and a shortening of the growing season. These phenological shifts impact negatively but not significantly the forest annual net ecosystem productivity.ContextThe mechanisms controlling temperate forest phenology are not fully understood nor are the impacts of climate change and the consequences for forest productivity.AimsThe aim of this paper is to contribute to the understanding of how temperate forest phenology and net ecosystem productivity (NEP) interplay and respond to temperature and its evolution.MethodsIndicators of leaf phenology and productivity dynamics at the start and the end of the growing season, as well as combinations of these indicators (length of the growing season), were derived from a long-term (1997–2014) dataset of eddy covariance and light transmission measurements taken over a mature beech-dominated temperate forest.ResultsThe start and the end of the growing season were correlated to spring (and autumn, for the end) temperatures. Despite no trends in annual average temperatures being detected during the observation period, April and November temperatures significantly increased. As a result, an earlier but slower start and an earlier end, inducing a shorter length of the growing season, were observed over the studied period. The first shift positively impacts the mixed forest NEP but is mainly related to the presence of conifers in the subplot. The earlier end of the growing season, more related to beech phenology, negatively impacts the forest NEP. Overall, these two effects partially compensate each other, leading to a non-significant impact on NEP.ConclusionIncreasing temperatures over the 18-year studied period shortened the growing season length, without affecting significantly the mixed forest NEP. However, as beeches are only affected by the earlier end of the growing season, this suggests a phenologically driven beech productivity reduction in the forest.

Published
2019

36. Ancillary vegetation measurements at ICOS ecosystem stations

Author

Lutz Merbold, Manuel Acosta, Matthias Peichl, Bruce Osborne, Christine Moureaux, Pasi Kolari, Tanguy Manise, Leonardo Montagnani, Nina Buchmann, Marian Pavelka, Christine Metzger, Annalea Lohila, Mats Nilsson, Caroline Vincke, Dario Papale, Georg Wohlfahrt, Stefan Fleck, Eric Ceschia, Eeva-Stiina Tuittila, Tiphaine Tallec, Bert Gielen, Oliver Sonnentag, Denis Loustau, Radek Pokorny, Katja Klumpp, Sara Marañón-Jiménez, Nuria Altimir, Matthew Saunders, A. Cescatti, Kamel Soudani, Guillaume Simioni, Lukas Hörtnagl, Giorgio Matteucci, Department of Biology, University of Antwerp (UA), Global Change Research Institute CAS, Centre de Ciència i Tecnologia Forestal de Catalunya (CTFC), Department of Physics, Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), Institute for the Environment and Sustainability, Centre d'études spatiales de la biosphère (CESBIO), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Thuenen Institute of Forest Ecosystems, Partenaires INRAE, Unité Mixte de Recherche sur l'Ecosystème Prairial - UMR (UREP), Institut National de la Recherche Agronomique (INRA)-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS), Finnish Meteorological Institute (FMI), Interactions Sol Plante Atmosphère (UMR ISPA), Institut National de la Recherche Agronomique (INRA)-Ecole Nationale Supérieure des Sciences Agronomiques de Bordeaux-Aquitaine (Bordeaux Sciences Agro), Department of Applied Physics, Universidad de Huelva, Centre for Ecological Research and Forestry Applications (CREAF), Université de Liège, Consiglio Nazionale delle Ricerche (CNR), Mazingira Centre, International Livestock Research Institute, Karlsruhe Institute of Technology (KIT), Free University of Bolzano, Forest Services, Department of Forest Ecology and Management, Swedish University of Agricultural Sciences (SLU), University College Dublin (UCD), Department for Innovation in Biological, Agro-Food and Forest Systems, Tuscia University, School of Natural Sciences (Department of Botany), Trinity College Dublin, Ecologie des Forêts Méditerranéennes (URFM), Institut National de la Recherche Agronomique (INRA), Université Paris Saclay (COmUE), Department of Geography, Université Catholique de Louvain = Catholic University of Louvain (UCL), School of Forest Sciences, University of Eastern Finland, Earth and Life Institute [Louvain-La-Neuve] (ELI), Institute of Ecology, University of Innsbruck, UCL - SST/ELI - Earth and Life Institute, Global Change Research Centre (CzechGlobe), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Università degli studi della Tuscia [Viterbo], Leopold Franzens Universität Innsbruck - University of Innsbruck, and Department of Forest Sciences

Subjects
Peat, 010504 meteorology & atmospheric sciences, GRASSLAND, [SDV]Life Sciences [q-bio], Green Area Index, Eddy covariance, Soil Science, above-ground biomass, ICOS, litter biomass, protocol, 01 natural sciences, 114 Physical sciences, Protocol, Aboveground biomass, Litter biomass, CO2 EXCHANGE, Sampling design, ddc:550, PEATLAND, Ecosystem, SPATIAL VARIATION, aboveground biomass, Biology, 1172 Environmental sciences, 0105 earth and related environmental sciences, Water Science and Technology, Hydrology, Fluid Flow and Transfer Processes, Biomass (ecology), 4112 Forestry, FEN, CARBON-DIOXIDE EXCHANGE, LEAF-AREA INDEX, SEASONAL DYNAMICS, 04 agricultural and veterinary sciences, Vegetation, 15. Life on land, Earth sciences, 13. Climate action, Greenhouse gas, BALANCE, [SDE]Environmental Sciences, 040103 agronomy & agriculture, 0401 agriculture, forestry, and fisheries, RADIATION, Spatial variability, General Agricultural and Biological Sciences
Abstract

The Integrated Carbon Observation System is a Pan-European distributed research infrastructure that has as its main goal to monitor the greenhouse gas balance of Europe. The ecosystem component of Integrated Carbon Observation System consists of a multitude of stations where the net greenhouse gas exchange is monitored continuously by eddy covariance measurements while, in addition many other measurements are carried out that are a key to an understanding of the greenhouse gas balance. Amongst them are the continuous meteorological measurements and a set of non-continuous measurements related to vegetation. The latter include Green Area Index, aboveground biomass and litter biomass. The standardized methodology that is used at the Integrated Carbon Observation System ecosystem stations to monitor these vegetation related variables differs between the ecosystem types that are represented within the network, whereby in this paper we focus on forests, grasslands, croplands and mires. For each of the variables and ecosystems a spatial and temporal sampling design was developed so that the variables can be monitored in a consistent way within the ICOS network. The standardisation of the methodology to collect Green Area Index, above ground biomass and litter biomass and the methods to evaluate the quality of the collected data ensures that all stations within the ICOS ecosystem network produce data sets with small and similar errors, which allows for inter-comparison comparisons across the Integrated Carbon Observation System ecosystem network.

Published
2018

37. Quantifying the effect of forest age in annual net forest carbon balance

Author

Bart Kruijt, Martin Herold, Christopher M Gough, Andrej Varlagin, Katerina Havrankova, Rainer Steinbrecher, Jan G. P. W. Clevers, Simon Besnard, Lukas Hörtnagl, Martin Jung, Alexander Knohl, Alessandro Cescatti, Asko Noormets, Anders Lindroth, Jiquan Chen, Markus Reichstein, Nina Buchmann, Olivier Roupsard, Caroline Vincke, Beverly E. Law, Sytze de Bruin, Nuno Carvalhais, M. Altaf Arain, Lenka Krupkova, Andrew Black, Ankur R. Desai, Max Planck Society, Wageningen University and Research Centre (WUR), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA), McMaster University, Faculty of Land and Food Systems, University of British Columbia (UBC), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), European Commission, Michigan State University [East Lansing], Michigan State University System, Department of Atmospheric and Oceanic Sciences [Madison], University of Wisconsin-Madison, Department of Biology, University of Antwerp (UA), Czech Academy of Sciences [Prague] (CAS), Bioclimatology, Georg-August-University = Georg-August-Universität Göttingen, Wageningen Environmental Research (Alterra), College of Forestry, Oregon State University (OSU), Department of Physical Geography and Ecosystem Science, Lund University [Lund], Department of Forestry and Environmental Resources, North Carolina State University [Raleigh] (NC State), University of North Carolina System (UNC)-University of North Carolina System (UNC), Department of Ecosystem Science and Management, Pennsylvania State University (Penn State), Penn State System-Penn State System, Ecologie fonctionnelle et biogéochimie des sols et des agro-écosystèmes (UMR Eco&Sols), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut de Recherche pour le Développement (IRD)-Institut National de la Recherche Agronomique (INRA)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad), Karlsruhe Institute of Technology (KIT), A.N. Severtsov Institute of Ecology and Evolution, Russian Academy of Sciences [Moscow] (RAS), Earth and Life Institute‐Environmental Sciences, Université Catholique de Louvain = Catholic University of Louvain (UCL), Ministry of Education, Youth and Sports of the Czech Republic within the National Sustainability Programme I (NPU I), grant number LO1415, BACI project and the Independent Monitoring Project, NOVA grant UID/AMB/04085/2013, GlobBiomass project., Georg-August-University [Göttingen], Lund University, and Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)

Subjects
0106 biological sciences, [SDV.SA]Life Sciences [q-bio]/Agricultural sciences, 010504 meteorology & atmospheric sciences, Climate, F62 - Physiologie végétale - Croissance et développement, Eddy covariance, 01 natural sciences, Laboratory of Geo-information Science and Remote Sensing, K01 - Foresterie - Considérations générales, ddc:550, Net ecosystem production, carbon cycle, eddy covariance, net ecosystem production, empirical modelling, forest age, climate, soil properties, General Environmental Science, Abiotic component, Vegetal Biology, Biosphere, Carbon cycle, PE&RC, Agricultural sciences, Physiologie végétale, Forêt, accroissement forestier, modèle empirique, Empirical modelling, ecosystem approaches [EN], F40 - Écologie végétale, P40 - Météorologie et climatologie, Aménagement forestier, Forest management, 010603 evolutionary biology, Fertilité du sol, production primaire nette, [SDV.BV]Life Sciences [q-bio]/Vegetal Biology, Laboratorium voor Geo-informatiekunde en Remote Sensing, Ecosystem, Modélisation environnementale, écosystème forestier, 0105 earth and related environmental sciences, empirical modeling, WIMEK, Forest age, Renewable Energy, Sustainability and the Environment, Public Health, Environmental and Occupational Health, 15. Life on land, Soil properties, eddy covariance, net ecosystem production, Earth sciences, Disturbance (ecology), 13. Climate action, Environmental science, age de la foret, Water Systems and Global Change, Spatial variability, Physical geography, Cycle du carbone, Sciences agricoles, Biologie végétale
Abstract

Forests dominate carbon (C) exchanges between the terrestrial biosphere and the atmosphere on land. In the long term, the net carbon flux between forests and the atmosphere has been significantly impacted by changes in forest cover area and structure due to ecological disturbances and management activities. Current empirical approaches for estimating net ecosystem productivity (NEP) rarely consider forest age as a predictor, which represents variation in physiological processes that can respond differently to environmental drivers, and regrowth following disturbance. Here, we conduct an observational synthesis to empirically determine to what extent climate, soil properties, nitrogen deposition, forest age and management influence the spatial and interannual variability of forest NEP across 126 forest eddy-covariance flux sites worldwide. The empirical models explained up to 62% and 71% of spatio-temporal and across-site variability of annual NEP, respectively. An investigation of model structures revealed that forest age was a dominant factor of NEP spatio-temporal variability in both space and time at the global scale as compared to abiotic factors, such as nutrient availability, soil characteristics and climate. These findings emphasize the importance of forest age in quantifying spatio-temporal variation in NEP using empirical approaches. ISSN:1748-9326 ISSN:1748-9318

Published
2018

38. Towards long-term standardised carbon and greenhouse gas observations for monitoring Europe's terrestrial ecosystems: a review

Author

Tiphaine Tallec, Arnaud Carrara, Ralf Kiese, Juha-Pekka Tuovinen, Mika Aurela, Olaf Kolle, Bernard Heinesch, Sébastien Gogo, Annalea Lohila, Maarten Op de Beeck, Nina Buchmann, Nicola Arriga, Hans Peter Schmid, Jukka Pumpanen, Ladislav Šigut, Meelis Mölder, Lilian Joly, Lukas Hörtnagl, Giorgio Matteucci, Leonardo Montagnani, Anders Lindroth, Hanna Silvennoinen, Robert Clement, Eric Ceschia, George Burba, Matthias Peichl, Bruce Osborne, Ana López-Ballesteros, B. Longdoz, Thomas Grünwald, Domenico Vitale, Rainer Steinbrecher, Andrea Pitacco, Lukas Siebicke, Mikaell Ottosson Löfvenius, Peter Waldner, Pasi Kolari, Marion Schrumpf, Alexander Graf, Tuomas Laurila, Oliver Sonnentag, Gianluca Filippa, Daniel Berveiller, Jouni Heiskanen, Michael P. Jones, Marc Aubinet, Sébastien C. Biraud, Mathias Herbst, Philip Meier, Mirco Migliavacca, Marian Pavelka, Per Weslien, Roland Fuß, Bert Gielen, Kamel Soudani, Mari Pihlatie, Radek Pokorný, Manuel Acosta, Simone Mereu, Mats Nilsson, Achim Grelle, Caroline Vincke, Guillaume Simioni, Patrick M. Crill, Leif Klemedtsson, Christine Moureaux, Natascha Kljun, Stefan Metzger, Christian Brümmer, Lutz Merbold, Katja Klumpp, Matthias Mauder, Christine Herschlein, Claudy Jolivet, Simone Sabbatini, Patrice Soulé, Mireille Barbaste, Céline Ratié, Edoardo Cremonese, Patrik Vestin, Nicolas Saby, Patrick Gross, Penélope Serrano Ortiz, Hakima Boukir, Giacomo Nicolini, Stefan Fleck, Sune Linder, Pavel Sedlák, Sami Haapanala, Gaëlle Vincent, David R. Nelson, Werner L. Kutsch, Edward Ayres, Lisa Wingate, Nuria Altimir, Anne De Ligne, Andreas Ibrom, Marilyn Roland, Eeva-Stiina Tuittila, Timothy Brown, Corinna Rebmann, Eiko Nemitz, Sara Maraňón Jiménez, Koen Hufkens, Andrew S. Kowalski, Ivan Mammarella, Timo Vesala, Sigrid Dengel, Eva Darenova, Markus Hehn, Anne Thimonier, Mark S. Zahniser, Matthew Saunders, John Grace, Georg Wohlfahrt, A. Cescatti, Ute Skiba, Dominique Arrouays, Petra D'Odorico, Olli Peltola, Daniela Franz, Tanguy Manise, Gerardo Fratini, Thunen Institute of Climate-Smart Agriculture, Czech Academy of Sciences [Prague] (CAS), Institute for Atmosphere and Earth System Research/ Physics, Partenaires INRAE, Centre de Ciència i Tecnologia Forestal de Catalunya (CTFC), University of Antwerp (UA), InfoSol (InfoSol), Institut National de la Recherche Agronomique (INRA), Université de Liège, Finnish Meteorological Institute (FMI), National Ecological Observatory Network, Science Office (NEON), Trinity College Dublin, Unité de service et de recherches en analyses végétales et environnementales (USRAVE), Ecologie Systématique et Evolution (ESE), Université Paris-Sud - Paris 11 (UP11)-AgroParisTech-Centre National de la Recherche Scientifique (CNRS), Lawrence Berkeley National Laboratory [Berkeley] (LBNL), Australian National University (ANU), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), LI-COR Biosciences, University of Nebraska [Lincoln], University of Nebraska System, Centro de Estudios Ambientales del Mediterraneo, European Commission, Centre d'études spatiales de la biosphère (CESBIO), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), University of Edinburgh, Environmental Protection Agency of Aosta Valley, Stockholm University, Thunen Institute of Forest Ecosystems, Thünen Institute, Interactions Sol Plante Atmosphère (UMR ISPA), Institut National de la Recherche Agronomique (INRA)-Ecole Nationale Supérieure des Sciences Agronomiques de Bordeaux-Aquitaine (Bordeaux Sciences Agro), Unité Mixte de Recherche sur l'Ecosystème Prairial - UMR (UREP), Institut National de la Recherche Agronomique (INRA)-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS), Ecologie des Forêts Méditerranéennes (URFM), University of Nebraska–Lincoln, Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), and Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)

Subjects
Oobservational network, 010504 meteorology & atmospheric sciences, ICOS, GHG exchange, carbon cycle, [SDV]Life Sciences [q-bio], ICOS, GHG exchange, carbon cycle, standardised monitoring, observational network, climate change, Climate change, Eddy covariance, 01 natural sciences, Atmospheric Sciences, Carbon cycle, standardised monitoring, 11. Sustainability, Forest ecology, Sampling design, ddc:550, SDG 13 - Climate Action, Ecosystem, Biology, standardized protocols, 0105 earth and related environmental sciences, SDG 15 - Life on Land, business.industry, Environmental resource management, Agronomy & Agriculture, 04 agricultural and veterinary sciences, Vegetation, 15. Life on land, Earth sciences, climate change, 13. Climate action, Greenhouse gas, [SDE]Environmental Sciences, 040103 agronomy & agriculture, observational network, 0401 agriculture, forestry, and fisheries, ddc:640, Terrestrial ecosystem, business
Abstract

Research infrastructures play a key role in launching a new generation of integrated long-term, geographically distributed observation programmes designed to monitor climate change, better understand its impacts on global ecosystems, and evaluate possible mitigation and adaptation strategies. The pan-European Integrated Carbon Observation System combines carbon and greenhouse gas (GHG; CO2, CH4, N2O, H2O) observations within the atmosphere, terrestrial ecosystems and oceans. High-precision measurements are obtained using standardised methodologies, are centrally processed and openly available in a traceable and verifiable fashion in combination with detailed metadata. The Integrated Carbon Observation System ecosystem station network aims to sample climate and land-cover variability across Europe. In addition to GHG flux measurements, a large set of complementary data (including management practices, vegetation and soil characteristics) is collected to support the interpretation, spatial upscaling and modelling of observed ecosystem carbon and GHG dynamics. The applied sampling design was developed and formulated in protocols by the scientific community, representing a trade-off between an ideal dataset and practical feasibility. The use of open-access, high-quality and multi-level data products by different user communities is crucial for the Integrated Carbon Observation System in order to achieve its scientific potential and societal value.

Published
2018

39. Evapotranspiration assessment of a mixed temperate forest by four methods: Eddy covariance, soil water budget, analytical and model

Author

André Granier, Marc Aubinet, Caroline Vincke, Rémy Soubie, Bernard Heinesch, Université Catholique de Louvain (UCL), Université de Liège, Ecologie et Ecophysiologie Forestières [devient SILVA en 2018] (EEF), Institut National de la Recherche Agronomique (INRA)-Université de Lorraine (UL), and Université Catholique de Louvain = Catholic University of Louvain (UCL)

Subjects
0106 biological sciences, Atmospheric Science, 010504 meteorology & atmospheric sciences, [SDV]Life Sciences [q-bio], Eddy covariance, Interception loss, Atmospheric sciences, 01 natural sciences, Water balance, Fagus sylvatica, Sap flow, Evapotranspiration, Forest ecology, Beech, 0105 earth and related environmental sciences, Hydrology, Global and Planetary Change, biology, Forestry, 15. Life on land, biology.organism_classification, Soil water, Mixed stand, Environmental science, Interception, Soil water budget modeling, Agronomy and Crop Science, 010606 plant biology & botany
Abstract

In forest ecosystems, assessment of evapotranspiration fluxes (ET) and distinction of its components, i.e. tree transpiration (T), rainfall interception (I), and soil plus understory evapotranspiration (ETu), are a major issue. At the Vielsalm Terrestrial Observatory in Belgium (VTO, Integrated Carbon Observation System network, ICOS), covered by a mixed forest of broadleaved (mainly Fagus sylvatica L.) and coniferous species (mainly Pseudotsuga menziesii [Mirb.] Franco), the water vapor fluxes have been continuously measured by eddy covariance since 1996, without distinction of its components. Widely validated for CO2 fluxes, water vapor fluxes measured by eddy covariance still lack validation, particularly in mixed and/or heterogeneous stands. During 2010–2011, three other methods to assess ET were implemented, in order to inter-validate them and to disentangle species specific ET into its components. These methods were: (i) the analytical method which relies on measurement of each elementary flux, i.e. tree transpiration, interception loss and evapotranspiration of soil plus understory (ETA); (ii) the soil water budget method (ETS) and (iii) modeling of stand ET (ETM). Our results showed that during dry foliage conditions, stand T + ETu estimated by the analytical method or model were in very good agreement with eddy covariance ET measurements. Interception loss measured was 14% and 30% of rainfall (P) for beech and Douglas-fir respectively, leading to 19% for the whole stand. Beech interception being quite low, ETA for the stand is probably slightly underestimated. Over 2010 and 2011, the mean seasonal value of ET was 1.9 mm d−1, considering all the methods. The four methods gave close estimates, with maximum deviations from the mean being of 12%, and uncertainties, while remaining acceptable (maximum 26% with analytical method) overlap between methods. Regardless of methods, flux measurements during rainy conditions were more complex to characterize. A slight underestimation of ET by the eddy covariance method was observed at different time step, in comparison to the others implemented methods. On an annual scale, the forest water balance model estimates (BILJOU©; ETM) were similar in beech (68% of potential evapotranspiration, PET) and Douglas-fir sub-stands (72% of PET), despite their differences in phenology and water use patterns. Low differences were also observed between species in the water flux partitioning, with modeled ET composed of ca. 58%, 33% and 9% of T, I and ETu respectively on the annual timescale (2010–2011).

Published
2016

40. Modelling the mortality of Hylotrupes bajulus (L.) larvae exposed to anoxic treatment for disinfestation of wooden art objects

Author

Patrick Bogaert, Erika Rabelo, Jean-Marc Henin, Caroline Vincke, Géraud de Streel, Emmanuelle Mercier, and Benoît Jourez

Subjects
0106 biological sciences, Larva, biology, Ecology, Treatment duration, Petri dish, fungi, Forestry, Plant Science, biology.organism_classification, 01 natural sciences, Anoxic waters, Industrial and Manufacturing Engineering, law.invention, Toxicology, 010602 entomology, law, General Materials Science, Hylotrupes, 010606 plant biology & botany
Abstract

Experiments were conducted to quantify the effect of several variables on the mortality of insects exposed to an anoxic treatment in order to generate a model linking mortality to these variables. This study aims to explore the possible interest of using such a model to determine the characteristics of treatment (especially duration) needed to guarantee insect mortality with a given level of probability. Trials were performed on Hylotrupes bajulus larvae, which is a widespread species known for its high tolerance to anoxic conditions. The studied variables are the initial mass of the larvae, the treatment temperature (21, 30 and 40 °C), the treatment duration (four durations for each temperature tested) and whether the larva is held in wood or in a petri dish (directly exposed to anoxic atmosphere) during the experiment. It was found that, while the last variable is not correlated with mortality, treatment duration and temperature are significantly and positively correlated with it. Larvae with higher body mass were also shown to have a better resistance to the treatment. Based on these results, a model including insect initial mass, treatment temperature and duration, together with the interaction between these two variables, was determined. This relatively simple model appeared to be a useful tool in overcoming the difficulty in defining the modalities for anoxic treatment in order to reach a given level of mortality.

Published
2016

41. Concentrations and distributions of Al, Ca, Cl, K, Mg and Mn in a Scots pine forest in Belgium

Author

Jordi Vives i Batlle, May Van Hees, Sienke Gielen, Caroline Vincke, and Hildergarde Vandenhove

Subjects
0106 biological sciences, Radionuclide, biology, Chemistry, Ecological Modeling, Pine tree, Scots pine, Fractionation, 010501 environmental sciences, biology.organism_classification, 01 natural sciences, Suberin, Environmental chemistry, Botany, Phloem transport, Cycling, 010606 plant biology & botany, 0105 earth and related environmental sciences
Abstract

A Pinus sylvestris stand located in Mol, Belgium was studied for its content of six elements: Ca, K, Mg, Al, Cl and Mn. A fractionation of tree components was carried out into 8 classes (heart and sapwood, inner and outer bark, living branches, twigs and young/old needles) and their element contents were measured. Comparisons were made between the different compartments in terms of absolute and relative element contents. Quantitatively, Ca and K are the main elements: in young needles, Ca + K reach 83% of the elements’ whole stock. The wood compartments (heartwood + sapwood) have generally low element content, as does the outer bark except for Ca (which is bound to suberin) and Al, possibly from atmospheric clay deposition. The inner bark, twigs and needles have high element contents possibly linked to high symplasmic content. The Inner bark shows high Ca and K contents as these elements are involved in phloem transport. Positive correlations were found between Ca and Al, Mn and Cl, K and Cl and K and Mn, attributed to similarity in chemical and biological function. A simple empirical compartment model was developed to derive numerically the transfer rates that reproduce the element distribution within tree compartments. The calculated mass flows appear to be within range of the limited data available from other pine tree studies. This study highlights the potential for coupling of specific elements (including radionuclides) to Ca, K, Mg, Al, Cl and Mn in context of vegetation modelling, by assuming that these elements follow the same pathways. We found indication that 36Cl, 90Sr and 137Cs (environmentally important from the perspective of nuclear power and waste management) can be coupled to Cl, Ca and K fluxes within the tree, increasing the understanding of the cycling of radionuclides in a forest ecosystem.

Published
2016

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

Author

Christian Brümmer, Bart Kruijt, Arne Poyda, Bert Gielen, Giovanni Manca, Marilyn Roland, Janina Klatt, Michal Heliasz, Jan Holst, Caroline Vincke, Corinna Rebmann, Meelis Mölder, Natalia Kowalska, Nadia Vendrame, Jinshu Chi, Nina Buchmann, Andreas Ibrom, Jiří Dušek, Stephan Weber, Lenka Foltýnová, Tarek S. El-Madany, Ladislav Šigut, Joachim Ingwersen, Alexander Graf, Mika Korkiakoski, Franziska Koebsch, Frédéric Bornet, Anne De Ligne, Denis Loustau, Eugénie Paul-Limoges, Mats Nilsson, Christophe Chipeaux, Eeva-Stiina Tuittila, Christian Wille, Torsten Sachs, Pascal Kremer, Shiva Ghiasi, Matthias Peichl, Gerald Jurasinski, Harry Vereecken, Matthias Mauder, Mana Gharun, Patrizia Ney, Thomas Grünwald, Hans-Dieter Wizemann, Pia Gottschalk, Marius Schmidt, Vincenzo Magliulo, Edoardo Cremonese, Joël Léonard, Ivan Mammarella, Anne Klosterhalfen, Mirco Migliavacca, Nicola Arriga, Silvano Fares, Milan Fischer, Matthias Cuntz, Andrej Varlagin, Alexander Knohl, Christian Bernhofer, Bernard Longdoz, Ingo Völksch, Frederik Schrader, Günther Heinemann, Sébastien Lafont, Nicolas Brüggemann, Heye Bogena, Bernard Heinesch, Jan Konopka, Matthias Zeeman, Johan Neirynck, Andrea Pitacco, Lukas Siebicke, Lukas Hörtnagl, SILVA (SILVA), AgroParisTech-Université de Lorraine (UL)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), French National Research Agency (ANR)ANR-11-LABX-0002-01ANR-16-SUMF-0001-01Alexander von Humbold Stiftung (MaNiP) Federal Ministry of Education & Research (BMBF)01LN1313AGerman Federal Ministry of Food and Agriculture BMEL (ERA-NET FACCE ERAGAS) German Research Foundation (DFG)BE1721/23PAK 346FOR 1695INST 186/1118-1 FUGGGIP Ecofor SOERE F-ORE-T Finnish Center of Excellence 307331FWOG0H3317NHelmholtz Association HGF (TERENO) VH-NG-821Hainich National Park Horizon 2020 696356ICOS-FINLAND 281255Kempe Foundation SMK-1743Knut & Alice Wallenberg Foundation2015.0047Max-Planck Institute for Biogeochemistry Russian Foundation for Basic Research (RFBR)19-0401234-aSwiss National Science Foundation (SNSF)ICOS-CH Phase 2 20FI20_173691InnoFarm 407340_172433European Commission (SUPER-G) European Commission (RINGO) European Commission (ERA-NET Sumforest) 606803Service Public de Wallonie (DGO6) 1217769SustES CZ. 02.1.01/0.0/0.0/16_019/0000797CzeCOS LM2015061Swedish Research CouncilSwedish Research Council Formas201601289942-2015-49University of Padua CDPA148553, Ludwig-Maximilians University Munich, ∗Agrosphere (IBG-3), Institute of Bio- and Geosciences, Forschungszentrum Jülich GmbH, Jülich, Germany, Institute of Bio- and Geosciences [Jülich] (IBG), Forschungszentrum Jülich GmbH | Centre de recherche de Juliers, Helmholtz-Gemeinschaft = Helmholtz Association-Helmholtz-Gemeinschaft = Helmholtz Association-Forschungszentrum Jülich GmbH | Centre de recherche de Juliers, Helmholtz-Gemeinschaft = Helmholtz Association-Helmholtz-Gemeinschaft = Helmholtz Association, Department of Biology, University of Antwerp (UA), Institute of Hydrology and Meteorology [Dresden], Technische Universität Dresden = Dresden University of Technology (TU Dresden), Agrosphere, IBG-3, Transfrontalière BioEcoAgro (Transfrontalière BioEcoAgro), Université d'Artois (UA)-Université de Liège-Université de Picardie Jules Verne (UPJV)-Université du Littoral Côte d'Opale (ULCO)-Université de Lille-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Helmholtz-Gemeinschaft = Helmholtz Association, Thünen Institute of Climate-Smart Agriculture, Department of Environmental Systems Science [ETH Zürich] (D-USYS), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), Department of Forest Ecology and Management, Swedish University of Agricultural Sciences (SLU), Interactions Sol Plante Atmosphère (UMR ISPA), Ecole Nationale Supérieure des Sciences Agronomiques de Bordeaux-Aquitaine (Bordeaux Sciences Agro)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Federal Ministry of Education & Research (BMBF)01LN1313AGerman Federal Ministry of Food and Agriculture BMEL (ERA-NET FACCE ERAGAS) German Research Foundation (DFG)BE1721/23PAK 346FOR 1695INST 186/1118-1 FUGGGIP Ecofor SOERE F-ORE-T Finnish Center of Excellence 307331FWOG0H3317NHelmholtz Association HGF (TERENO) VH-NG-821Hainich National Park Horizon 2020 696356ICOS-FINLAND 281255Kempe Foundation SMK-1743Knut & Alice Wallenberg Foundation2015.0047Max-Planck Institute for Biogeochemistry Russian Foundation for Basic Research (RFBR)19-0401234-aSwiss National Science Foundation (SNSF)ICOS-CH Phase 2 20FI20_173691InnoFarm 407340_172433European Commission (SUPER-G) European Commission (RINGO) European Commission (ERA-NET Sumforest) 606803Service Public de Wallonie (DGO6) 1217769SustES CZ. 02.1.01/0.0/0.0/16_019/0000797CzeCOS LM2015061Swedish Research CouncilSwedish Research Council Formas201601289942-2015-49University of Padua CDPA148553, ANR-16-SUMF-0001,ForRISK,Forest density reduction to minimize the vulnerability of Norway spruce and silver fir to extreme drought – a risk assessment(2016), ANR-11-LABX-0002,ARBRE,Recherches Avancées sur l'Arbre et les Ecosytèmes Forestiers(2011), Ludwig-Maximilians University [Munich] (LMU), Transfrontalière BioEcoAgro - UMR 1158 (BioEcoAgro), Université d'Artois (UA)-Université de Liège-Université de Picardie Jules Verne (UPJV)-Université du Littoral Côte d'Opale (ULCO)-Université de Lille-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-JUNIA (JUNIA), and Université catholique de Lille (UCL)-Université catholique de Lille (UCL)

Subjects
Peat, 010504 meteorology & atmospheric sciences, Forests, Atmospheric sciences, 01 natural sciences, Evapotranspiration, water-use efficiency, SDG 15 - Life on Land, Environmental Sciences (social aspects to be 507), Articles, 04 agricultural and veterinary sciences, Grassland, Droughts, Europe, Meteorology and Atmospheric Sciences, [SDE]Environmental Sciences, eddy-covariance, Terrestrial ecosystem, SDG 6 - Clean Water and Sanitation, General Agricultural and Biological Sciences, Farms, net carbon uptake, Climate Change, evapotranspiration, Eddy covariance, heat flux, Sensible heat, General Biochemistry, Genetics and Molecular Biology, ddc:570, Latent heat, eddy covariance, energy balance, Water-use efficiency, Biology, 0105 earth and related environmental sciences, WIMEK, Atmosphere, Global warming, 15. Life on land, 13. Climate action, Wetlands, 040103 agronomy & agriculture, 0401 agriculture, forestry, and fisheries, Environmental science, Water Systems and Global Change, Human medicine
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 CO 2 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 CO 2 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’.

Published
2020

43. Low topographic positions enhance woody vegetation stability in the Ferlo (Senegalese Sahel)

Author

Morgane Dendoncker, Caroline Vincke, and UCL - SST/ELI/ELIE - Environmental Sciences

Subjects
Sylviculture, Pastoralism, Population, Distribution (economics), Sahel, medicine, Regeneration, education, Regeneration (ecology), Ecology, Evolution, Behavior and Systematics, Deep well, Earth-Surface Processes, education.field_of_study, Ecology, business.industry, Geography, Topogra^hy, Field inventory, Threatened species, Species richness, medicine.symptom, Scale (map), Vegetation (pathology), business, Tree
Abstract

Woody vegetation provides multiple services to the pastoralists in the Sahel and since the drought of 1972–1984, concerns have been raised about its persistence. Some studies have observed a decline in tree density and specific richness while others have reported a greening at a larger scale. In this study, an extensive field inventory was carried out around two deep wells in the Ferlo (Senegal). The influence of topography and proximity of deep wells on woody vegetation density, diversity and regeneration was studied. An analysis of the size class distribution was carried out to gain insight into the population dynamics of some species. This study highlights the key role of low topographic positions in favouring woody vegetation establishment with a higher species richness and a greater density. The remoteness of deep wells seems to have no effect on these variables. The instability of several tree species populations was evident from the size class analysis. As large trees play an important role in hosting regeneration, the persistence of the current woody vegetation is threatened. Given the positive impact of depressions on woody vegetation, further research should focus on these topographic features and their role as central pieces in a potential management plan.

Published
2020

44. A gendered pipeline typology in academia

Author

Bernard Fusulier, Farah Dubois-Shaik, and Caroline Vincke

Subjects
Typology, ComputingMilieux_THECOMPUTINGPROFESSION, business.industry, Comparative method, media_common.quotation_subject, Perspective (graphical), Institution, Sociology, Public relations, business, Pipeline (software), media_common
Abstract

This chapter proposes a typology of gendered pipelines that provides a multi-level, multi-dimensional and comparative analytical framework of leaky pipelines and interrelated phenomena across six European countries (Belgium, Iceland, Italy, the Netherlands, Slovenia and Switzerland) and research institutions. In line with previous studies, we intend to establish that women’s moving away or being distanced from scientific or academic paths leading to higher positions does not happen that easily; a composite view of causes and effects on the “leaky pipeline” is needed. Whereas the data collected in various national and organisational contexts focusing on the disappearance of women while climbing the career ladder provides us with a rich and comparative approach enlarging the research perspective on “gendered pipelines”, what we propose is a typology of “gendered pipelines”. This allows us to identify a range of costs of gendered pipelines on three entity levels (Science/Institution/Individual) as well as three ideal-typical “career paths, organisations and experiences”, which have been variously gender-impacted.

Published
2018

45. Soil-meteorological measurements at ICOS monitoring stations in terrestrial ecosystems

Author

Leif Klemedtsson, Simone Mereu, Marian Pavelka, Caroline Vincke, Matthew Saunders, Leonardo Montagnani, Maarten Op de Beeck, Mats Nilsson, Bert Gielen, Christine Moureaux, Lukas Hörtnagl, Penélope Serrano-Ortiz, Manuel Acosta, Lutz Merbold, Anne De Ligne, Edward Ayres, and Sara Marañón-Jiménez

Subjects
010504 meteorology & atmospheric sciences, Soil heat flux density, Climate change, 04 agricultural and veterinary sciences, Atmospheric sciences, Soil water content, 01 natural sciences, Physics::Geophysics, Water table depth, Plant science, Soil temperature, ICOS, Greenhouse gas, 040103 agronomy & agriculture, 0401 agriculture, forestry, and fisheries, Terrestrial ecosystem, Astrophysics::Earth and Planetary Astrophysics, Biology, Physics::Atmospheric and Oceanic Physics, 0105 earth and related environmental sciences
Abstract

The Integrated Carbon Observation System is a pan-European research infrastructure providing standardized, long-term observations of greenhouse gas concentrations and earth-atmosphere greenhouse gas interactions. The terrestrial component of Integrated Carbon Observation System comprises a network of monitoring stations in terrestrial ecosystems where the principal activity is the measurement of ecosystem-atmosphere fluxes of greenhouse gases and energy by means of the eddy covariance technique. At each station a large set of ancillary variables needed for the interpretation of observed fluxes and for process studies is additionally monitored. This set includes a subset of variables that describe the thermal and moisture conditions of the soil and which are here conveniently referred to as soil-meteorological variables: soil temperature, volumetric soil water content, water table depth, and soil heat flux density. This paper describes the standard methodology that has been developped for the monitoring of these variables at the ecosystem stations.

Published
2018

46. Linking Forest Cover to Water Quality: A Multivariate Analysis of Large Monitoring Datasets

Author

Adrien Michez, Delphine Brogna, Sander Jacobs, Marc Dufrêne, Nicolas Dendoncker, Caroline Vincke, and UCL - SST/ELI/ELIE - Environmental Sciences

Subjects
Multivariate statistics, lcsh:Hydraulic engineering, 010504 meteorology & atmospheric sciences, Geography, Planning and Development, 010501 environmental sciences, Forests, redundancy analysis, 01 natural sciences, Biochemistry, Wallonia, physico-chemical water qualitu, lcsh:Water supply for domestic and industrial purposes, land cover, Belgium, Agricultural land, water framework directive, physico-chemical water quality, Water Science and Technology, agriculture, Agriculture, Management, Policy, Water Framework Directive, Land cover, Physico-chemical water quality, Aquatic Science, Environment, land use, forests, monitoring network, lcsh:TC1-978, Spatial analysis, 0105 earth and related environmental sciences, Hydrology, lcsh:TD201-500, Land use, Redundancy analysis, Environmental science, Water framework directive, Cover (algebra), Physical geography, Water quality, Monitoring network
Abstract

Forested catchments are generally assumed to provide higher quality water. However, this hypothesis must be validated in various contexts as interactions between multiple land use and land cover (LULC) types, ecological variables and water quality variables render this relationship highly complex. This paper applies a straightforward multivariate approach on a typical large monitoring dataset of a highly managed and densely populated area (Wallonia, Belgium; 10-year dataset), quantifying forest cover effects on nine physico-chemical water quality variables. Results show that forest cover explains about one third of the variability of water quality and is positively correlated with higher quality water. When controlling for spatial autocorrelation, forest cover still explains 9% of water quality. Unlike needle-leaved forest cover, broad-leaved forest cover presents an independent effect from ecological variables and explains independently 4.8% of water quality variability while it shares 5.8% with cropland cover. This study demonstrates clear independent effects of forest cover on water quality, and presents a method to tease out independent LULC effects from typical large multivariate monitoring datasets. Further research on explanatory variables, spatial distribution effects and water quality datasets could lead to effective strategies to mitigate pollution and reach legal targets.

Published
2017

47. Farmlands Feature Greater Woody Cover than Savannas in Semi-Arid West Africa

Author

Feng Tian, Morgane Dendoncker, Cheikh Mbow, K. A. Melocik, Martin Brandt, Caroline Vincke, John L. David, Rasmus Fensholt, Pierre Hiernaux, Laurent Kergoat, Compton J. Tucker, Ole Mertz, Kjeld Rasmussen, Xiaoye Tong, and Stefanie M. Herrmann

Subjects
environmental_sciences, 0106 biological sciences, 2. Zero hunger, Human environment, 010504 meteorology & atmospheric sciences, Land use, Agroforestry, Forestry, 15. Life on land, 010603 evolutionary biology, 01 natural sciences, Arid, West africa, Geography, Feature (computer vision), Woody cover, 0105 earth and related environmental sciences
Abstract

Woody vegetation in farmland acts as a carbon sink and provides ecosystem services for local people, but no macro-scale assessments of the impact of management and climate on woody cover exists for drylands. Here we make use of very high spatial resolution satellite imagery to derive wall-to-wall woody cover patterns in tropical West African drylands. In arid and semi-arid Sahel, areas of more people are associated with more trees: mean woody cover is greater in farmlands (12%) than in savannas (6%), and likewise it is higher close to villages than further away. In sub-humid savannas of West Africa, woody cover is generally above 20% and decreases with increasing population density, but remains around 15% in farmlands, independent of rainfall. In the region as a whole, rainfall, terrain and soil are the most important (80%) determinants of woody cover, while management factors play a smaller (20%) role. We conclude that agricultural expansion cannot generally be claimed to cause woody cover losses, and that observations in Sahel contradict simplistic ideas of a high negative correlation between population density and woody cover.

Published
2017
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48. Characterization of black locust (Robinia pseudoacacia L.) heartwood extractives: identification of resveratrol and piceatannol

Author

Benoît Jourez, Stéphane Kohnen, Yves-Jacques Schneider, Thérèse Sergent, Cécile Beauve, and Caroline Vincke

Subjects
chemistry.chemical_classification, Piceatannol, biology, Flavonoid, Robinia, Forestry, Plant Science, Resveratrol, biology.organism_classification, Industrial and Manufacturing Engineering, Dihydrorobinetin, chemistry.chemical_compound, Nutraceutical, chemistry, Botany, Natural source, General Materials Science, Food science, Locust
Abstract

Robinia pseudoacacia L. heartwood is characterized by a very high natural durability. However, a significant difference was observed between the mature and juvenile heartwood, the latter presenting less durability against fungi decay, which could be attributed to lower extractive content. In order to elucidate this idea, extractives from mature and juvenile heartwoods of black locust trees were investigated. Results showed that extractive and phenolic contents were higher in mature than in juvenile heartwoods. The identification of phenolic compounds by UPLC–DAD–MS/MS revealed, for the first time, the presence of resveratrol and piceatannol. These two stilbenes as well as the flavonoid dihydrorobinetin were present at the highest level in mature heartwood, and as they are known antifungals, they could account for the great durability of mature heartwood. The stilbenes were detected in significant amounts particularly in mature heartwood where piceatannol reached a level tenfold higher than that reported for Japanese knotweed roots, the primary natural source of these stilbenes, whereas resveratrol level was comparable with reported values. As resveratrol and piceatannol receive increasing demand for nutraceutical, cosmetic and, possibly, pharmaceutical purposes, due to their beneficial health effects, this study underlines the use of R. pseudoacacia as a promising sustainable and economical source of resveratrol and piceatannol.

Published
2014

49. Sap flux density and stomatal conductance of European beech and common oak trees in pure and mixed stands during the summer drought of 2003

Author

Caroline Vincke, Mathieu Jonard, François Jonard, Quentin Ponette, and Frédéric André

Subjects
Stomatal conductance, Horticulture, biology, Fagus sylvatica, Vapour Pressure Deficit, Environmental science, Growing season, Quercus petraea, Leaf area index, biology.organism_classification, Beech, Water content, Water Science and Technology
Abstract

Sap flux density of European beech and common oak trees was determined from sap flow measurements in pure and mixed stands during the summer drought of 2003. Eight trees per species and per stand were equipped with sap flow sensors. Soil water content was monitored in each stand at different depths by using time-domain reflectometry (TDR). Leaf area index and vertical root distribution were also investigated during the growing season. From sap flux density (SFD) data, mean stomatal conductance of individual trees (Gs) was calculated by inverting the Penman–Monteith equation. Linear mixed models were developed to analyse the effects of species and stand type (pure vs. mixed) on SFD and Gs and on their sensitivity to environmental variables (vapour pressure deficit (D), incoming solar radiation (RG), and relative extractable water (REW)). For reference environmental conditions, we did not find any tree species or stand type effects on SFD. The sensitivity of SFD to D was higher for oak than for beech in the pure stands (P < 0.0001) but the mixing of species reduced it for oak and increased it for beech, so that the sensitivity of SFD to D became higher for beech than for oak in the mixed stand (P < 0.0001). At reference conditions, Gs was significantly higher for beech compared to oak (2.1 and 1.8 times in the pure and mixed stand, respectively). This was explained by a larger beech sapwood-to-leaf area ratio compared to oak. The sensitivity of Gs to REW was higher for beech than for oak and was ascribed to a higher vulnerability of beech to air embolism and to a more sensitive stomatal regulation. The sensitivity of beech Gs to REW was lower in the mixed than in the pure stand, which could be explained by a better sharing of the resources in the mixture, by facilitation processes (hydraulic lift), and by a rainfall partitioning infavour of beech.

Published
2011

50. Long term dynamics and structure of woody vegetation in the Ferlo (Senegal)

Author

M. Grouzis, I. Diedhiou, and Caroline Vincke

Subjects
Topography, education.field_of_study, Drought, Ecology, Population, Species diversity, Soil quality, Trees, Ecological indicator, Ferlo, Sahel, Land use, Environmental science, Ecosystem, Species richness, education, Ecology, Evolution, Behavior and Systematics, Balanites aegyptiaca, Earth-Surface Processes, Woody plant
Abstract

This study analyzes the evolution of the woody vegetation structure in the Ferlo (Senegal) from 1976 to 1995 on a site not much influenced by human pressure (Fete-Ole), to characterize the long-term effects of drought. In 1995, we measured ecological indicators related to the woody population, differentiating species, and we compared them with data collected on the same site in 1976 and 1983. To document the combined effects of drought and anthropogenic factors on the woody plant vegetation, we measured the same indicators at increasing distances from a borehole and we compared them with the Fete-Ole data. The two study sites confirmed the degradation of the woody cover and highlighted the importance of soil quality in the resilience of these ecosystems: in both sites, the topographic elements significantly influenced density, diversity, regeneration and mortality, with a contraction of the vegetation in depressions. Results at Fete-Ole showed a decline of the woody cover over the 1976-1995 period coupled with an increase of Sahelian species like Boscia senegalensis, Balanites aegyptiaca and Calotropis procera. The floristic richness, density and regeneration showed an average increase with distance to borehole, confirming the anthropogenic pressure on the woody plant population. (C) 2009 Elsevier Ltd. All rights reserved.

Published
2010

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