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1. Global critical soil moisture thresholds of plant water stress

Author

Zheng Fu, Philippe Ciais, Jean-Pierre Wigneron, Pierre Gentine, Andrew F. Feldman, David Makowski, Nicolas Viovy, Armen R. Kemanian, Daniel S. Goll, Paul C. Stoy, Iain Colin Prentice, Dan Yakir, Liyang Liu, Hongliang Ma, Xiaojun Li, Yuanyuan Huang, Kailiang Yu, Peng Zhu, Xing Li, Zaichun Zhu, Jinghui Lian, and William K. Smith

Subjects
Science
Abstract

Abstract During extensive periods without rain, known as dry-downs, decreasing soil moisture (SM) induces plant water stress at the point when it limits evapotranspiration, defining a critical SM threshold (θcrit). Better quantification of θcrit is needed for improving future projections of climate and water resources, food production, and ecosystem vulnerability. Here, we combine systematic satellite observations of the diurnal amplitude of land surface temperature (dLST) and SM during dry-downs, corroborated by in-situ data from flux towers, to generate the observation-based global map of θcrit. We find an average global θcrit of 0.19 m3/m3, varying from 0.12 m3/m3 in arid ecosystems to 0.26 m3/m3 in humid ecosystems. θcrit simulated by Earth System Models is overestimated in dry areas and underestimated in wet areas. The global observed pattern of θcrit reflects plant adaptation to soil available water and atmospheric demand. Using explainable machine learning, we show that aridity index, leaf area and soil texture are the most influential drivers. Moreover, we show that the annual fraction of days with water stress, when SM stays below θcrit, has increased in the past four decades. Our results have important implications for understanding the inception of water stress in models and identifying SM tipping points.

Published
2024
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2. Large variations in afforestation-related climate cooling and warming effects across short distances

Author

Shani Rohatyn, Eyal Rotenberg, Fyodor Tatarinov, Yohay Carmel, and Dan Yakir

Subjects
Geology, QE1-996.5, Environmental sciences, GE1-350
Abstract

The time for the climatic benefits of afforestation via carbon-sequestration to offset the warming effects of reduced albedo and longwave radiation emission varies greatly across short distances, according to a study of paired forested and non-forested ecosystems along an aridity gradient.

Published
2023
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3. Bark Transpiration Rates Can Reach Needle Transpiration Rates Under Dry Conditions in a Semi-arid Forest

Author

Anna Lintunen, Yakir Preisler, Itay Oz, Dan Yakir, Timo Vesala, and Teemu Hölttä

Subjects
drought, embolism, irrigation experiment, lenticel, Pinus halepensis, stem respiration, Plant culture, SB1-1110
Abstract

Drought can cause tree mortality through hydraulic failure and carbon starvation. To prevent excess water loss, plants typically close their stomata before massive embolism formation occurs. However, unregulated water loss through leaf cuticles and bark continues after stomatal closure. Here, we studied the diurnal and seasonal dynamics of bark transpiration and how it is affected by tree water availability. We measured continuously for six months water loss and CO2 efflux from branch segments and needle-bearing shoots in Pinus halepensis growing in a control and an irrigation plot in a semi-arid forest in Israel. Our aim was to find out how much passive bark transpiration is affected by tree water status in comparison with shoot transpiration and bark CO2 emission that involve active plant processes, and what is the role of bark transpiration in total tree water use during dry summer conditions. Maximum daily water loss rate per bark area was 0.03–0.14 mmol m−2 s−1, which was typically ~76% of the shoot transpiration rate (on leaf area basis) but could even surpass the shoot transpiration rate during the highest evaporative demand in the control plot. Irrigation did not affect bark transpiration rate. Bark transpiration was estimated to account for 64–78% of total water loss in drought-stressed trees, but only for 6–11% of the irrigated trees, due to differences in stomatal control between the treatments. Water uptake through bark was observed during most nights, but it was not high enough to replenish the lost water during the day. Unlike bark transpiration, branch CO2 efflux decreased during drought due to decreased metabolic activity. Our results demonstrate that although bark transpiration represents a small fraction of the total water loss through transpiration from foliage in non-stressed trees, it may have a large impact during drought.

Published
2021
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4. Disentangling Soil, Shade, and Tree Canopy Contributions to Mixed Satellite Vegetation Indices in a Sparse Dry Forest

Author

Huanhuan Wang, Jonathan D. Muller, Fyodor Tatarinov, Dan Yakir, and Eyal Rotenberg

Subjects
semi-arid pine forest, mixed-pixel problem, soil disturbances, UAV multispectral data, image classification, canopy fraction, Science
Abstract

Remote sensing (RS) for vegetation monitoring can involve mixed pixels with contributions from vegetation and background surfaces, causing biases in signals and their interpretations, especially in low-density forests. In a case study in the semi-arid Yatir forest in Israel, we observed a mismatch between satellite (Landsat 8 surface product) and tower-based (Skye sensor) multispectral data and contrasting seasonal cycles in near-infrared (NIR) reflectance. We tested the hypothesis that this mismatch was due to the different fractional contributions of the various surface components and their unique reflectance. Employing an unmanned aerial vehicle (UAV), we obtained high-resolution multispectral images over selected forest plots and estimated the fraction, reflectance, and seasonal cycle of the three main surface components (canopy, shade, and sunlit soil). We determined that the Landsat 8 data were dominated by soil signals (70%), while the tower-based data were dominated by canopy signals (95%). We then developed a procedure to resolve the canopy (i.e., tree foliage) normalized difference vegetation index (NDVI) from the mixed satellite data. The retrieved and corrected canopy-only data resolved the original mismatch and indicated that the spatial variations in Landsat 8 NDVI were due to differences in stand density, while the canopy-only NDVI was spatially uniform, providing confidence in the local flux tower measurements.

Published
2022
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5. Large-scale semi-arid afforestation can enhance precipitation and carbon sequestration potential

Author

Gil Yosef, Robert Walko, Roni Avisar, Fedor Tatarinov, Eyal Rotenberg, and Dan Yakir

Subjects
Medicine, Science
Abstract

Abstract Afforestation is an important approach to mitigate global warming. Its complex interactions with the climate system, however, makes it controversial. Afforestation is expected to be effective in the tropics where biogeochemical and biogeophysical effects act in concert; however, its potential in the large semi-arid regions remains insufficiently explored. Here, we use a Global Climate Model to provide a process-based demonstration that implementing measured characteristics of a successful semi-arid afforestation system (2000 ha, ~300 mm mean annual precipitation) over large areas (~200 million ha) of similar precipitation levels in the Sahel and North Australia leads to the weakening and shifting of regional low-level jets, enhancing moisture penetration and precipitation (+0.8 ± 0.1 mm d−1 over the Sahel and +0.4 ± 0.1 mm d−1 over North Australia), influencing areas larger than the original afforestation. These effects are associated with increasing root depth and surface roughness and with decreasing albedo. This results in enhanced evapotranspiration, surface cooling and the modification of the latitudinal temperature gradient. It is estimated that the carbon sequestration potential of such large-scale semi-arid afforestation can be on the order of ~10% of the global carbon sink of the land biosphere and would overwhelm any biogeophysical warming effects within ~6 years.

Published
2018
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6. Assessing climatic benefits from forestation potential in semi-arid lands

Author

Shani Rohatyn, Eyal Rotenberg, Dan Yakir, and Yohay Carmel

Subjects
climate-change, afforestation, reforestation, drylands, semiarid, carbon, Environmental technology. Sanitary engineering, TD1-1066, Environmental sciences, GE1-350, Science, Physics, QC1-999
Abstract

Forestation actions are a major tool for both climate-change mitigation and biodiversity conservation. We address two weaknesses in this approach: the little attention given to the negative effects of reduced albedo associated with forestation in many regions, and ignoring the potential of drylands that account for 40% of the global potential land area for forestation. We propose an approach to identify suitable land for forestation and quantify its ‘net equivalent carbon stock change’ over 80 years of forest lifetime (NESC), accounting for both carbon sequestration and albedo changes. We combined remote-sensing tools with data-based estimates of surface parameters and with published climate matrices, to identify suitable land for forestation actions. We then calculated the cumulative (over 80 years) ‘net sequestration potential’ (ΔSP), the ‘emission equivalent of shortwave radiation forcing’ (EESF) due to changes in surface albedo, and, in turn, the combined NESC = ΔSP−EESF, of planting forests with >40% tree-cover. Demonstrating our approach in a large climatically diverse state (Queensland), we identified 14.5 million hectares of potential forestation land in its semi-arid land and show that accounting for the EESF, reduces the climatic benefits of the ΔSP by almost 50%. Nevertheless, it results in a total NESC of 0.72 Gt C accumulated by the end of the century, and 80 years of forestation cycle. This estimated NESC is equivalent to 15% of the projected carbon emissions for the same period in Queensland, for a scenario of no change in emission rates during that period. Our approach extends restoration efforts by identifying new land for forestation and carbon sequestration but also demonstrates the importance of quantifying the climatic value of forestation in drylands.

Published
2021
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7. Forest GPP Calculation Using Sap Flow and Water Use Efficiency Measurements

Author

Fyodor Tatarinov, Eyal Rotenberg, Dan Yakir, and Tamir Klein

Subjects
Biology (General), QH301-705.5
Abstract

This is a protocol to evaluate gross primary productivity (GPP) of a forest stand based on the measurements of tree’s sap flow (SF), 13C derived water use efficiency (WUE), and meteorological (met) data. GPP was calculated from WUE and stomatal conductance (gs), the later obtained from SF up-scaled from sampled trees to stand level on a daily time-scale and met data. WUE is obtained from 13C measurements in dated tree-ring wood and/or foliage samples. This protocol is based on the recently published study of Klein et al., 2016.

Published
2017
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8. Ecophysiological adjustments of a pine forest to enhance early spring activity in hot and dry climate

Author

Huanhuan Wang, Anatoly Gitelson, Michael Sprintsin, Eyal Rotenberg, and Dan Yakir

Subjects
adjustments, Aleppo pine, Monteith assumption, optimum time, photoprotection, semi-arid forest, Environmental technology. Sanitary engineering, TD1-1066, Environmental sciences, GE1-350, Science, Physics, QC1-999
Abstract

Climate change can impose large offsets between the seasonal cycle of photosynthesis and that in solar radiation and temperature which drive it. Ecophysiological adjustments to such offsets in forests growing under hot and dry conditions are critical for maintaining carbon uptake and survival. Here, we investigate the adjustments that underlie the unusually short and intense early spring productive season, under suboptimal radiation and temperature conditions in a semi-arid pine forest. We used eddy covariance flux, meteorological, and close-range sensing measurements, together with leaf chlorophyll content over four years in a semi-arid pine forest to identify the canopy-scale ecophysiological adjustments to the short active season, and long seasonal drought. The results reveal a range of processes that intricately converge to support the early spring peak (March) in photosynthetic activity, including peaks in light use efficiency, leaf chlorophyll content, increase in the absorption of solar radiation, and high leaf scattering properties (indicating optimizing leaf orientation). These canopy-scale adjustments exploit the tradeoffs between the yet increasing temperature and solar radiation, but the concurrently rapidly diminishing soil moisture. In contrast, during the long dry stressful period with rapidly declining photosynthesis under high and potentially damaging solar radiation, physiological photoprotection was conferred by strongly relaxing the early spring adjustments. The results provide evidence for canopy-scale ecophysiological adjustments, detectable by spectral measurements, that support the survival and productivity of a pine forest under the hot and dry conditions, which may apply to large areas in the Mediterranean and other regions in the next few decades due to the current warming and drying trends.

Published
2020
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9. Long-term fluxes of carbonyl sulfide and their seasonality and interannual variability in a boreal forest

Author

Lenka Foltýnová, David R. Nelson, Kukka-Maaria Kohonen, Markku Kulmala, Ivan Mammarella, Timo Vesala, Pasi Kolari, Arnaud P. Praplan, Mark S. Zahniser, Linda M. J. Kooijmans, Dan Yakir, Jaana Bäck, Viikki Plant Science Centre (ViPS), Institute for Atmospheric and Earth System Research (INAR), Micrometeorology and biogeochemical cycles, Ecosystem processes (INAR Forest Sciences), Department of Forest Sciences, and Forest Ecology and Management

Subjects
Biosphere model, 11832 Microbiology and virology, 4112 Forestry, Atmospheric Science, Phenology, Vapour Pressure Deficit, Eddy covariance, Evergreen, Seasonality, Luchtkwaliteit, 15. Life on land, Atmospheric sciences, medicine.disease, 11831 Plant biology, 114 Physical sciences, Air Quality, Boreal, Photosynthetically active radiation, 13. Climate action, 1181 Ecology, evolutionary biology, medicine, Environmental science, Life Science
Abstract

The seasonality and interannual variability of terrestrial carbonyl sulfide (COS) fluxes are poorly constrained. We present the first easy-to-use parameterization for the net COS forest sink based on the longest existing eddy covariance record from a boreal pine forest, covering 32 months over 5 years. Fluxes from hourly to yearly scales are reported, with the aim of revealing controlling factors and the level of interannual variability. The parameterization is based on the photosynthetically active radiation, vapor pressure deficit, air temperature, and leaf area index. Wavelet analysis of the ecosystem fluxes confirmed earlier findings from branch-level fluxes at the same site and revealed a 3 h lag between COS uptake and air temperature maxima at the daily scale, whereas no lag between radiation and COS flux was found. The spring recovery of the flux after the winter dormancy period was mostly governed by air temperature, and the onset of the uptake varied by 2 weeks. For the first time, we report a significant reduction in ecosystem-scale COS uptake under a large water vapor pressure deficit in summer. The maximum monthly and weekly median COS uptake varied by 26 % and 20 % between years, respectively. The timing of the latter varied by 6 weeks. The fraction of the nocturnal uptake remained below 21 % of the total COS uptake. We observed the growing season (April–August) average net flux of COS totaling −58.0 g S ha−1 with 37 % interannual variability. The long-term flux observations were scaled up to evergreen needleleaf forests (ENFs) in the whole boreal region using the Simple Biosphere Model Version 4 (SiB4). The observations were closely simulated using SiB4 meteorological drivers and phenology. The total COS uptake by boreal ENFs was in line with a missing COS sink at high latitudes pointed out in earlier studies.

Published
2022

10. The three major axes of terrestrial ecosystem function

Author

Georg Wohlfahrt, Sebastian Wolf, David Martini, Alexander Knohl, Micol Rossini, Dennis D. Baldocchi, Nuno Carvalhais, Talie Musavi, Tarek S. El-Madany, Ulisse Gomarasca, Ankur R. Desai, Matthias Forkel, Dario Papale, Marcos Fernández-Martínez, Jens Kattge, Jacob A. Nelson, Michael J. Liddell, Peter B. Reich, Guido Kraemer, Christopher M. Gough, Miguel D. Mahecha, Mathias Göckede, Hiroki Ikawa, Elise Pendall, Ivan A. Janssens, Rune Christiansen, Jiquan Chen, Craig Macfarlane, Alessandro Cescatti, Andreas Ibrom, Leonardo Montagnani, Marta Galvagno, T. Andrew Black, Michael Bahn, Sönke Zaehle, Giorgio Matteucci, Dan Yakir, Russell L. Scott, Silvia Caldararu, Jürgen Knauer, Markus Reichstein, Ulrich Weber, Richard P. Phillips, Cinzia Panigada, Mirco Migliavacca, Ian J. Wright, Jonas Peters, Beverly E. Law, Josep Peñuelas, Martha M. Farella, Arnaud Carrara, Eyal Rotenberg, Ivan Mammarella, Gianluca Filippa, Xuanlong Ma, Hideki Kobayashi, Jamie Cleverly, Oscar Perez-Priego, Edoardo Cremonese, Peter D. Blanken, Karen Anderson, Martin Jung, Clément Stahl, Daniel E. Pabon-Moreno, Damien Bonal, Nina Buchmann, Trevor F. Keenan, Institute for Atmospheric and Earth System Research (INAR), Micrometeorology and biogeochemical cycles, Migliavacca, M, Musavi, T, Mahecha, M, Nelson, J, Knauer, J, Baldocchi, D, Perez-Priego, O, Christiansen, R, Peters, J, Anderson, K, Bahn, M, Black, T, Blanken, P, Bonal, D, Buchmann, N, Caldararu, S, Carrara, A, Carvalhais, N, Cescatti, A, Chen, J, Cleverly, J, Cremonese, E, Desai, A, El-Madany, T, Farella, M, Fernandez-Martinez, M, Filippa, G, Forkel, M, Galvagno, M, Gomarasca, U, Gough, C, Gockede, M, Ibrom, A, Ikawa, H, Janssens, I, Jung, M, Kattge, J, Keenan, T, Knohl, A, Kobayashi, H, Kraemer, G, Law, B, Liddell, M, Ma, X, Mammarella, I, Martini, D, Macfarlane, C, Matteucci, G, Montagnani, L, Pabon-Moreno, D, Panigada, C, Papale, D, Pendall, E, Penuelas, J, Phillips, R, Reich, P, Rossini, M, Rotenberg, E, Scott, R, Stahl, C, Weber, U, Wohlfahrt, G, Wolf, S, Wright, I, Yakir, D, Zaehle, S, and Reichstein, M

Subjects
010504 meteorology & atmospheric sciences, Range (biology), General Science & Technology, Climate, Ecosystem ecology, Biome, Datasets as Topic, 01 natural sciences, 114 Physical sciences, Article, Carbon Cycle, 03 medical and health sciences, Water Cycle, SDG 13 - Climate Action, Ecosystem, Biology, 030304 developmental biology, 0105 earth and related environmental sciences, SDG 15 - Life on Land, 0303 health sciences, Principal Component Analysis, Multidisciplinary, Ecology, Humidity, ecosystem ecology, Vegetation, 15. Life on land, Carbon Dioxide, Plants, Arid, Productivity (ecology), Biogeography, 13. Climate action, Ecosystem function, terrestrial biomes, productivity, vegetation structure, water-use efficiency, carbon-use efficiency, Environmental science, Terrestrial ecosystem, Engineering sciences. Technology
Abstract

The leaf economics spectrum1,2 and the global spectrum of plant forms and functions3 revealed fundamental axes of variation in plant traits, which represent different ecological strategies that are shaped by the evolutionary development of plant species2. Ecosystem functions depend on environmental conditions and the traits of species that comprise the ecological communities4. However, the axes of variation of ecosystem functions are largely unknown, which limits our understanding of how ecosystems respond as a whole to anthropogenic drivers, climate and environmental variability4,5. Here we derive a set of ecosystem functions6 from a dataset of surface gas exchange measurements across major terrestrial biomes. We find that most of the variability within ecosystem functions (71.8%) is captured by three key axes. The first axis reflects maximum ecosystem productivity and is mostly explained by vegetation structure. The second axis reflects ecosystem water-use strategies and is jointly explained by variation in vegetation height and climate. The third axis, which represents ecosystem carbon-use efficiency, features a gradient related to aridity, and is explained primarily by variation in vegetation structure. We show that two state-of-the-art land surface models reproduce the first and most important axis of ecosystem functions. However, the models tend to simulate more strongly correlated functions than those observed, which limits their ability to accurately predict the full range of responses to environmental changes in carbon, water and energy cycling in terrestrial ecosystems7,8., Three key axes of variation of ecosystem functional changes and their underlying causes are identified from a dataset of surface gas exchange measurements across major terrestrial biomes and climate zones.

Published
2021
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11. Covariations between plant functional traits emerge from constraining parameterization of a terrestrial biosphere model

Author

Georg Wohlfahrt, Marc Peaucelle, Damiano Gianelle, Nicolas Delpierre, Dan Yakir, Philippe Ciais, Timo Vesala, Sylvain Kuppel, Eric Dufrêne, Mark A. Sutton, Thomas Kolb, Nicolas Vuichard, Cédric Bacour, Andreas Ibrom, Ladislav Šigut, Lutz Merbold, Sebastian Wolf, Leonardo Montagnani, Anders Lindroth, Nina Buchmann, Jiquan Chen, Carsten Gruening, Josep Peñuelas, Luca Belelli Marchesini, Tomomichi Kato, Stefano Minerbi, Andrej Varlagin, Beverly E. Law, Ivan Mammarella, Cristina Gimeno-Colera, Ankur R. Desai, Richard Joffre, Nicolas Viovy, Lukas Hörtnagl, Carole Helfter, Peter D. Blanken, 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), NOVELTIS [Sté], 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), Modélisation des Surfaces et Interfaces Continentales (MOSAIC), Global Ecology Unit CREAF-CEAB-CSIC, Universitat Autònoma de Barcelona (UAB), Vrije Universiteit Amsterdam [Amsterdam] (VU), Institute of Agricultural Sciences [Zürich], Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), Department of Environmental Sciences [Toledo USA], University of Toledo, Ecologie Systématique et Evolution (ESE), Université Paris-Sud - Paris 11 (UP11)-AgroParisTech-Centre National de la Recherche Scientifique (CNRS), Department of Atmospheric and Oceanic Sciences [Madison], University of Wisconsin-Madison, Centro di Ecologia Alpina, Fondazione Edmund Mach - Edmund Mach Foundation [Italie] (FEM), Joint Research Centre, Edinburgh Research Station, Centre for Ecology and Hydrology, Swiss Federal Institute of Technology, Danmarks Tekniske Universitet = Technical University of Denmark (DTU), Centre d’Ecologie Fonctionnelle et Evolutive (CEFE), Université Paul-Valéry - Montpellier 3 (UPVM)-Institut National de la Recherche Agronomique (INRA)-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), Hokkaido University [Sapporo, Japan], Department of Physical Geography and Ecosystem Science [Lund], Lund University [Lund], Department of Physics [Helsinki], Falculty of Science [Helsinki], Helsingin yliopisto = Helsingfors universitet = University of Helsinki-Helsingin yliopisto = Helsingfors universitet = University of Helsinki, Institute of Agricultural Sciences, Ecole Polytechnique Fédérale de Zurich, Provincia Autonoma di Bolzano Servizi Forestali, Servizi Forestali, Provincia Autonoma di Bolzano, Agenzia per l'Ambiente, Department of Physics [Montréal], McGill University = Université McGill [Montréal, Canada], A.N. Severtsov Institute of Ecology and Evolution, Russian Academy of Sciences [Moscow] (RAS), Department of Physics, Institute of Ecology, Leopold Franzens Universität Innsbruck - University of Innsbruck, Kiel University, Weizmann Institute of Science [Rehovot, Israël], 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), Vrije universiteit = Free university of Amsterdam [Amsterdam] (VU), Technical University of Denmark [Lyngby] (DTU), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-Institut National de la Recherche Agronomique (INRA)-Université Paul-Valéry - Montpellier 3 (UPVM)-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 de Recherche pour le Développement (IRD [France-Sud]), University of Helsinki-University of Helsinki, University of Innsbruck, Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS), Universitat Autònoma de Barcelona [Barcelona] (UAB), VU University Amsterdam, Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology in Zürich [Zürich] (ETH Zürich), Université Paul-Valéry - Montpellier 3 (UM3)-Institut National de la Recherche Agronomique (INRA)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-École pratique des hautes études (EPHE)-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), Hokkaido University, McGill University, A.N.Severtsov Institute of Ecology and Evolution, and Weizmann Institute of Science

Subjects
0106 biological sciences, Biosphere model, Optimization, Eddy covariance, Atmospheric sciences, 010603 evolutionary biology, 01 natural sciences, Ecology and Environment, Terrestrial model, Data assimilation, FluxNet, Ecosystem model, Settore BIO/07 - ECOLOGIA, ORCHIDEE, Plant functional traits, Ecosystem, Plant acclimatation, Ecology, Evolution, Behavior and Systematics, ComputingMilieux_MISCELLANEOUS, SDG 15 - Life on Land, [SDV.EE]Life Sciences [q-bio]/Ecology, environment, Global and Planetary Change, Ecology, 010604 marine biology & hydrobiology, Biosphere, 15. Life on land, Assimilation, Trait, Environmental science, Plant acclimation
Abstract

Aim: The mechanisms of plant trait adaptation and acclimation are still poorly understood and, consequently, lack a consistent representation in terrestrial biosphere models (TBMs). Despite the increasing availability of geo-referenced trait observations, current databases are still insufficient to cover all vegetation types and environmental conditions. In parallel, the growing number of continuous eddy-covariance observations of energy and CO2 fluxes has enabled modellers to optimize TBMs with these data. Past attempts to optimize TBM parameters mostly focused on model performance, overlooking the ecological properties of ecosystems. The aim of this study was to assess the ecological consistency of optimized trait-related parameters while improving the model performances for gross primary productivity (GPP) at sites.Location: Worldwide. Time period: 1992–2012. Major taxa studied: Trees and C3 grasses. Methods: We optimized parameters of the ORCHIDEE model against 371 site-years of GPP estimates from the FLUXNET network, and we looked at global covariation among parameters and with climate. Results: The optimized parameter values were shown to be consistent with leaf-scale traits, in particular, with well-known trade-offs observed at the leaf level, echoing the leaf economic spectrum theory. Results showed a marked sensitivity of trait-related parameters to local bioclimatic variables and reproduced the observed relationships between traits and climate. Main conclusions: Our approach validates some biological processes implemented in the model and enables us to study ecological properties of vegetation at the canopy level, in addition to some traits that are difficult to observe experimentally. This study stresses the need for: (a) implementing explicit trade-offs and acclimation processes in TBMs; (b) improving the representation of processes to avoid model-specific parameterization; and (c) performing systematic measurements of traits at FLUXNET sites in order to gather information on plant ecophysiology and plant diversity, together with micro-meteorological conditions.

Published
2019
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12. Mortality versus survival in drought‐affected Aleppo pine forest depends on the extent of rock cover and soil stoniness

Author

José M. Grünzweig, Nir Her, Lisa Wingate, Tamir Klein, Shani Rohatyn, Itzhak Moshe, Jérôme Ogée, Fyodor Tatarinov, Yakir Preisler, Dan Yakir, Eyal Rotenberg, Didier Bert, Weizmann Institute of Science [Rehovot, Israël], The Hebrew University of Jerusalem (HUJ), Biodiversité, Gènes & Communautés (BioGeCo), Institut National de la Recherche Agronomique (INRA)-Université de Bordeaux (UB), 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), KKL, and Partenaires INRAE

Subjects
0106 biological sciences, surface rock cover, [SDV]Life Sciences [q-bio], semi-arid, stoniness, 15. Life on land, Biology, Soil type, biology.organism_classification, 010603 evolutionary biology, 01 natural sciences, Permanent wilting point, tree rings, Agronomy, Aleppo Pine, Dry season, Soil water, [SDE]Environmental Sciences, Yatir Forest, Soil horizon, soil moisture, Water content, Ecology, Evolution, Behavior and Systematics, 010606 plant biology & botany, Transpiration
Abstract

Drought‐related tree mortality had become a widespread phenomenon in forests around the globe. This process leading to these events and its complexity is not fully understood. Trees in the dry timberline are exposed to ongoing drought, and the available water for transpiration in the soil can determine their survival chances. Recent drought years led to 5%–10% mortality in the semi‐arid pine forest of Yatir (Israel). The distribution of dead trees was, however, highly heterogeneous with parts of the forest showing >80% dead trees (D plots) and others with mostly live trees (L plots). At the tree level, visible stress was associated with low pre‐dawn leaf water potential at the dry season (−2.8 MPa vs. −2.3 MPa in non‐stressed trees), shorter needles (5.5 vs. 7.7 mm) and lower chlorophyll content (0.6 vs. 1 mg/g dw). Trends in tree‐ring widths reflected differences in stress intensity (30% narrower rings in stressed compared with unstressed trees), which could be identified 15–20 years prior to mortality. At the plot scale, no differences in topography, soil type, tree age or stand density could explain the mortality difference between the D and L plots. It could only be explained by the higher surface rock cover and in stoniness across the soil profile in the L plots. Simple bucket model simulations using the site’s long‐term hydrological data supported the idea that these differences could result in higher soil water concentration (m³/m³) in the L plots and extend the time above wilting point by several months across the long dry season. Accounting for subsurface heterogeneity may therefore critical to assessing stand‐level response to drought and projecting tree survival, and can be used in management strategies in regions undergoing drying climate trends. A plain language summary is available for this article.

Published
2019
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13. Soil-atmosphere exchange of carbonyl sulfide in Mediterranean citrus orchard

Author

Fulin Yang, Rafat Qubaja, Fyodor Tatarinov, Rafael Stern, and Dan Yakir

Subjects
complex mixtures
Abstract

Carbonyl sulfide (COS) is used as a as a tracer of CO2 exchange at the ecosystem and larger scales. The robustness of this approach depends on knowledge of the soil contribution to the ecosystem fluxes, which is uncertain at present. We assessed the spatial and temporal variations of soil COS and CO2 fluxes in the Mediterranean citrus orchard combining surface flux chambers and soil concentration gradients. The spatial heterogeneity in soil COS exchange indicated net uptake below and between trees of up to −4.6 pmol m−2 s−1, and net emission in exposed soil between rows, of up to +2.6 pmol m−2 s−1, with weighted mean uptake values of −1.10 ± 0.10 pmol m−2 s−1. Soil COS concentrations decreased with soil depth from atmospheric levels of ~ 450 to ~ 100 ppt at 20 cm depth, while CO2 concentrations increased from ~ 400 to ~ 5000 ppm. COS flux estimates from the soil concentration gradients were, on average, −1.02 ± 0.26 pmol m−2 s−1, consistent with the chamber measurements. A soil COS flux algorithm driven by soil moisture and temperature (5 cm depth) and distance from the nearest tree, could explain 75 % of variance in soil COS flux. Soil relative uptake, the normalized ratio of COS to CO2 fluxes was, on average −0.37 and showed a general exponential response to soil temperature. The results indicated that soil COS fluxes at our study site were dominated by uptake, with relatively small net fluxes compared to both soil respiration and reported canopy COS fluxes. Such result should facilitate the application of COS as a powerful tracer of ecosystem CO2 exchange.

Published
2018

14. Assessing a New Clue to How Much Carbon Plants Take Up

Author

Yuting Wang, Sinikka T. Lennartz, Philippe Peylin, Georg Wohlfahrt, Nicola J. Blake, Le Kuai, Donald R. Blake, J. Stinecipher, Timo Vesala, Max Berkelhammer, Ian Baker, U. Seibt, Mary E. Whelan, Joseph A. Berry, J. F. Campbell, Huilin Chen, Stephen A. Montzka, Sauveur Belviso, Timothy W. Hilton, Kadmiel Maseyk, Jürgen Kesselmeier, Dan Yakir, Stephen Sitch, 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), Modélisation des Surfaces et Interfaces Continentales (MOSAIC), 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), ICOS-RAMCES (ICOS-RAMCES), Isotope Research, 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
0301 basic medicine, [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, 010504 meteorology & atmospheric sciences, Ecology, chemistry.chemical_element, 15. Life on land, Photosynthesis, 01 natural sciences, Carbon cycle, 03 medical and health sciences, chemistry.chemical_compound, 030104 developmental biology, chemistry, 13. Climate action, Environmental protection, Carbon dioxide, Assessment methods, General Earth and Planetary Sciences, Environmental science, Climate model, Ecosystem, [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment, Carbon, 0105 earth and related environmental sciences, Carbonyl sulfide
Abstract

International audience; Current climate models disagree on how much carbon dioxide land ecosystems take up for photosynthesis. Tracking the stronger carbonyl sulfide signal could help. Measuring carbonyl sulfide in the atmosphere may be a way to track terrestrial photosynthesis, potentially filling in a critical gap in current climate models. This alpine study area near Boulder, Colo., where the carbonyl sulfide signal was first detected 10 years ago, is part of the NOAA air monitoring network. Credit: B. Bowman

Published
2017
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15. Variation of net primary productivity and its drivers in China's forests during 2000–2018.

Author

Ji, Yuhe, Zhou, Guangsheng, Luo, Tianxiang, Dan, Yakir, Zhou, Li, and Lv, Xiaomin

Subjects
BROADLEAF forests, TRENDS, TREND analysis
Abstract

Background: Net primary productivity (NPP) in forests plays an important role in the global carbon cycle. However, it is not well known about the increase rate of China's forest NPP, and there are different opinions about the key factors controlling the variability of forest NPP. Methods: This paper established a statistics-based multiple regression model to estimate forest NPP, using the observed NPP, meteorological and remote sensing data in five major forest ecosystems. The fluctuation values of NPP and environment variables were extracted to identify the key variables influencing the variation of forest NPP by correlation analysis. Results: The long-term trends and annual fluctuations of forest NPP between 2000 and 2018 were examined. The results showed a significant increase in forest NPP for all five forest ecosystems, with an average rise of 5.2 gC·m− 2·year− 1 over China. Over 90% of the forest area had an increasing NPP range of 0–161 gC·m− 2·year− 1. Forest NPP had an interannual fluctuation of 50–269 gC·m− 2·year− 1 for the five major forest ecosystems. The evergreen broadleaf forest had the largest fluctuation. The variability in forest NPP was caused mainly by variations in precipitation, then by temperature fluctuations. Conclusions: All five forest ecosystems in China exhibited a significant increasing NPP along with annual fluctuations evidently during 2000–2018. The variations in China's forest NPP were controlled mainly by changes in precipitation. [ABSTRACT FROM AUTHOR]

Published
2020
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16. Biogeochemical factors contributing to enhanced carbon storage following afforestation of a semi-arid shrubland

Author

Ilya Gelfand, Dan Yakir, Y. Fried, José M. Grünzweig, and EGU, Publication

Subjects
Mediterranean climate, Biogeochemical cycle, Tree allometry, lcsh:Life, Carbon sequestration, [SDU.ASTR] Sciences of the Universe [physics]/Astrophysics [astro-ph], Shrubland, lcsh:QH540-549.5, Afforestation, Ecosystem, Ecology, Evolution, Behavior and Systematics, Earth-Surface Processes, geography, geography.geographical_feature_category, Ecology, [SDU.OCEAN] Sciences of the Universe [physics]/Ocean, Atmosphere, Soil organic matter, lcsh:QE1-996.5, [SDU.ENVI] Sciences of the Universe [physics]/Continental interfaces, environment, lcsh:Geology, lcsh:QH501-531, Agronomy, [PHYS.ASTR.CO] Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], [SDU.STU] Sciences of the Universe [physics]/Earth Sciences, Environmental science, lcsh:Ecology
Abstract

Ecosystems in dry regions are generally low in productivity and carbon (C) storage. We report, however, large increases in C sequestration following afforestation of a semi-arid shrubland with Pinus halepensis trees. Using C and nitrogen (N) inventories, based in part on site-specific allometric equations, we measured an increase in the standing ecosystem C stock from 2380 g C m−2 in the shrubland to 5840 g C m−2 in the forest after 35 years, with no significant change in N stocks. Carbon sequestration following afforestation was associated with increased N use efficiency as reflected by an overall increase in C/N ratio from 7.6 in the shrubland to 16.6 in the forest. The C accumulation rate in the forest was particularly high for soil organic C (SOC; increase of 1760 g C m−2 or 50 g C m−2 yr−1), which was associated with the following factors: 1) Analysis of a small 13C signal within this pure C3 system combined with size fractionation of soil organic matter indicated a significant addition of new SOC derived from forest vegetation (68% of total forest SOC) and a considerable portion of the old original shrubland SOC (53%) still remaining in the forest. 2) A large part of both new and old SOC appeared to be protected from decomposition as about 60% of SOC under both land-use types were in mineral-associated fractions. 3) A short-term decomposition study indicated decreased decomposition of lower-quality litter and SOC in the forest, based on reduced decay rates of up to 90% for forest compared to shrubland litter. 4) Forest soil included a significant component of live and dead roots (12% of total SOC). Our results suggest a role for increased N use efficiency, enhanced SOC protection and reduced decomposition rates in the large C sequestration potential following afforestation in semi-arid regions. These results are particularly relevant in light of persistent predictions of drying trends in the Mediterranean and other regions.

Published
2007

17. Interpreting canopy development and physiology using the EUROPhen camera network at flux sites

Author

Juan Alberto Porcar Castell, Dan Yakir, Olaf Kolle, James I. L. Morison, Bernard Genty, Lukas Hörtnagl, Alexander Knohl, Pasi Kolari, Richard Joffre, Werner Eugster, Cristina Gimeno, Christophe Moisy, Bernard Heinesch, Lisa Wingate, Edoardo Cremonese, Tatsuro Nakaji, Werner L. Kutsch, Christine Moreaux, Barbara Köstner, Bert Gielen, Manuela Balzarolo, Dominique Guyon, Marta Galvagno, Thomas Grünwald, Georg Wohlfahrt, Janne Levula, Anders Lindroth, Toshie Mizunuma, Dario Papale, Georg Charles, Jean-Marc Ourcival, Mirco Migliavacca, Andreas Ibrom, Matthew Wilkinson, Tanguy Manise, Eero Nikinmaa, Gianluca Filippa, Katja Klumpp, Margareta Hellström, Andres Plaza-Aguilar, Hella Ellen Ahrends, John Grace, Jérôme Ogée, Jin-Hong Guan, Bernard Longdoz, Michael Sprintsin, Department of Forest Sciences, Department of Physics, Eero Nikinmaa / Principal Investigator, Viikki Plant Science Centre (ViPS), Ecosystem processes (INAR Forest Sciences), Micrometeorology and biogeochemical cycles, and Forest Ecology and Management

Subjects
Canopy, Hydrology, 4112 Forestry, Phenology, education, Growing season, Vegetation, 15. Life on land, Evergreen, Atmospheric sciences, 114 Physical sciences, Deciduous, 13. Climate action, Environmental science, Ecosystem, Segmented regression
Abstract

Plant phenological development is orchestrated through subtle changes in photoperiod, temperature, soil moisture and nutrient availability. Presently, the exact timing of plant development stages and their response to climate and management practices are crudely represented in land surface models. As visual observations of phenology are laborious, there is a need to supplement long-term observations with automated techniques such as those provided by digital repeat photography at high temporal and spatial resolution. We present the first synthesis from a growing observational network of digital cameras installed on towers across Europe above deciduous and evergreen forests, grasslands and croplands, where vegetation and atmosphere CO2 fluxes are measured continuously. Using colour indices from digital images and using piecewise regression analysis of time-series, we explored whether key changes in canopy phenology could be detected automatically across different land use types in the network. The piecewise regression approach could capture the start and end of the growing season, in addition to identifying striking changes in colour signals caused by flowering and management practices such as mowing. Exploring the dates of green up and senescence of deciduous forests extracted by the piecewise regression approach against dates estimated from visual observations we found that these phenological events could be detected adequately (RMSE < 8 and 11 days for leaf out and leaf fall respectively). We also investigated whether the seasonal patterns of red, green and blue colour fractions derived from digital images could be modelled mechanistically using the PROSAIL model parameterised with information of seasonal changes in canopy leaf area and leaf chlorophyll and carotenoid concentrations. From a model sensitivity analysis we found that variations in colour fractions, and in particular the late spring "green hump" observed repeatedly in deciduous broadleaf canopies across the network, are essentially dominated by changes in the respective pigment concentrations. Using the model we were able to explain why this spring maximum in green signal is often observed out of phase with the maximum period of canopy photosynthesis in ecosystems across Europe. Coupling such quasi-continuous digital records of canopy colours with co-located CO2 flux measurements will improve our understanding of how changes in growing season length are likely to shape the capacity of European ecosystems to sequester CO2 in the future.

Published
2015

19. Atmospheric turbulence triggers pronounced diel pattern in karst carbonate geochemistry

Author

Yves Goddéris, J. Schott, R. Van Grieken, Francisco Domingo, Philippe Ciais, Andrew S. Kowalski, Penélope Serrano-Ortiz, Dan Yakir, Ivan A. Janssens, Enrique P. Sánchez-Cañete, Sergio Sanchez-Moral, Soledad Cuezva, Bernard Longdoz, Marilyn Roland, Carolina Cardell, Department of Biology (University of Antwerp), University of Antwerp (UA), Estación Experimental de Zonas Aridas, Consejo Superior de Investigaciones Científicas [Spain] (CSIC), Centro Andaluz de Medio Ambiente (CEAMA), Universidad de Granada (UGR), Departamento de Fisica Aplicada [Granada], Géosciences Environnement Toulouse (GET), Centre National de la Recherche Scientifique (CNRS)-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Recherche pour le Développement (IRD)-Centre National d'Études Spatiales [Toulouse] (CNES), Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS), Departamento de Ciencias de la Tierra y del Medio Ambiente [Universidad de Alicante], Universidad de Alicante, Museo Nacional de Ciencias Naturales, Ecologie et Ecophysiologie Forestières [devient SILVA en 2018] (EEF), Institut National de la Recherche Agronomique (INRA)-Université de Lorraine (UL), Weizmann Institute of Science, Universiteit Antwerpen [Antwerpen], Departamento de Mineralogia y Petrologia [Granada], Institute for Promotion of Innovation through Science and Technology in Flanders (IWT-Vlaanderen), Spanish Ministry of Science and Innovation, Spanish Ministry of Science and Innovation, research programme Juan de la Cierva, Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), 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), 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), ICOS-ATC (ICOS-ATC), 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), Weizmann Institute of Science [Rehovot, Israël], Universidad de Alicante. Departamento de Ciencias de la Tierra y del Medio Ambiente, Petrología Aplicada, Universidad de Granada = University of Granada (UGR), 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 de Recherche pour le Développement (IRD)-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), 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)-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), Museo Nacional de Ciencias Naturales [Madrid] (MNCN), and Universiteit Antwerpen = University of Antwerpen [Antwerpen]

Subjects
010504 meteorology & atmospheric sciences, [SDV]Life Sciences [q-bio], Karst carbonate geochemistry, lcsh:Life, Weathering, UNSATURATED ZONE, 010501 environmental sciences, Atmospheric sciences, 01 natural sciences, DESERT, Atmosphere, chemistry.chemical_compound, DISSOLUTION, lcsh:QH540-549.5, ROCK FRAGMENTS, Ecosystem, Precipitation, Biology, Ecology, Evolution, Behavior and Systematics, 0105 earth and related environmental sciences, Earth-Surface Processes, WATER-VAPOR ADSORPTION, Diel pattern, Physics, SPAIN, lcsh:QE1-996.5, 04 agricultural and veterinary sciences, Soil carbon, 15. Life on land, CO2 FLUX, NET ECOSYSTEM, SOIL CARBON, DIOXIDE, lcsh:Geology, Chemistry, lcsh:QH501-531, Outgassing, Oceanography, chemistry, 13. Climate action, Atmospheric turbulence triggers, 040103 agronomy & agriculture, 0401 agriculture, forestry, and fisheries, Carbonate, Terrestrial ecosystem, lcsh:Ecology, Geology, Petrología y Geoquímica
Abstract

CO2 exchange between terrestrial ecosystems and the atmosphere is key to understanding the feedbacks between climate change and the land surface. In regions with carbonaceous parent material, CO2 exchange patterns occur that cannot be explained by biological processes, such as disproportionate outgassing during the daytime or nighttime CO2 uptake during periods when all vegetation is senescent. Neither of these phenomena can be attributed to carbonate weathering reactions, since their CO2 exchange rates are too small. Soil ventilation induced by high atmospheric turbulence is found to explain atypical CO2 exchange between carbonaceous systems and the atmosphere. However, by strongly altering subsurface CO2 concentrations, ventilation can be expected to influence carbonate weathering rates. By imposing ventilation-driven CO2 outgassing in a carbonate weathering model, we show here that carbonate geochemistry is accelerated and does play a surprisingly large role in the observed CO2 exchange pattern of a semi-arid ecosystem. We found that by rapidly depleting soil CO2 during the daytime, ventilation disturbs soil carbonate equilibria and therefore strongly magnifies daytime carbonate precipitation and associated CO2 production. At night, ventilation ceases and the depleted CO2 concentrations increase steadily. Dissolution of carbonate is now enhanced, which consumes CO2 and largely compensates for the enhanced daytime carbonate precipitation. This is why only a relatively small effect on global carbonate weathering rates is to be expected. On the short term, however, ventilation has a drastic effect on synoptic carbonate weathering rates, resulting in a pronounced diel pattern that exacerbates the non-biological behavior of soil–atmosphere CO2 exchanges in dry regions \mbox{with carbonate soils}., M. Roland was granted by the Institute for Promotion of Innovation through Science and Technology in Flanders (IWT-Vlaanderen). I. A. Janssens and R. Van Grieken acknowledge the Research Foundation – Flanders (FWO). P. Serrano-Ortiz is funded by a postdoctoral fellowship from the Spanish Ministry of Science and Innovation. S. Cuezva was funded by a postdoctoral fellowship from the Spanish Ministry of Science and Innovation, research programme Juan de la Cierva.

Published
2013
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21. The impact of soil microorganisms on the global budget of δ18O in atmospheric CO2

Author

Behzad Mortazavi, Bernard Genty, Kadmiel Maseyk, Lisa Wingate, Ilja M. Reiter, Elise Pendall, Dan Yakir, Margaret M. Barbour, Matthias Cuntz, Philippe Peylin, Régis Burlett, Jee H. Shim, John Grace, John B. Miller, Jérôme Ogée, Maurizio Mencuccini, Ulli Seibt, John Hunt, Écologie fonctionnelle et physique de l'environnement (EPHYSE), Institut National de la Recherche Agronomique (INRA), School of GeoSciences, University of Edinburgh, Max Planck Institute for Biogeochemistry (MPI-BGC), Max-Planck-Gesellschaft, Biologie cellulaire et moléculaire des plantes et des bactéries (BCMPB), Université de la Méditerranée - Aix-Marseille 2-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Biogéochimie et écologie des milieux continentaux (Bioemco), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut de Recherche pour le Développement (IRD)-Institut National de la Recherche Agronomique (INRA)-Université Pierre et Marie Curie - Paris 6 (UPMC)-AgroParisTech-Centre National de la Recherche Scientifique (CNRS), Université Pierre et Marie Curie - Paris 6 (UPMC), Weizmann Institute of Science [Rehovot, Israël], Department of Botany, University of Wyoming (UW), Manaaki Whenua – Landcare Research [Lincoln], Department of Biological Sciences, University of Alabama [Tuscaloosa] (UA), Dauphin Island Sea Lab, University of South Alabama, 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), Modélisation des Surfaces et Interfaces Continentales (MOSAIC), 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), National Oceanic and Atmospheric Administration (NOAA), Cooperative Institute for Research in Environmental Sciences (CIRES), University of Colorado [Boulder]-National Oceanic and Atmospheric Administration (NOAA), Colorado State University [Fort Collins] (CSU), Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de la Méditerranée - Aix-Marseille 2, École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut National de la Recherche Agronomique (INRA)-Université Pierre et Marie Curie - Paris 6 (UPMC)-AgroParisTech-Centre National de la Recherche Scientifique (CNRS), 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
cycle du carbone, 010504 meteorology & atmospheric sciences, δ18O, cycle de l'eau, Climate Change, [SDE.MCG]Environmental Sciences/Global Changes, Population, carbonic anhydrase, water cycle, Photosynthesis, 01 natural sciences, Models, Biological, Atmosphere, chemistry.chemical_compound, Flux (metallurgy), carbon cycle, education, Milieux et Changements globaux, isotope, Soil Microbiology, 0105 earth and related environmental sciences, Carbonic Anhydrases, education.field_of_study, Multidisciplinary, Chemistry, oxygen isotopes, 04 agricultural and veterinary sciences, Carbon Dioxide, terrestrial biosphere, 13. Climate action, Environmental chemistry, Soil water, Carbon dioxide, Physical Sciences, 040103 agronomy & agriculture, 0401 agriculture, forestry, and fisheries, Seasons, Soil microbiology
Abstract

Improved global estimates of terrestrial photosynthesis and respiration are critical for predicting the rate of change in atmospheric CO 2 . The oxygen isotopic composition of atmospheric CO 2 can be used to estimate these fluxes because oxygen isotopic exchange between CO 2 and water creates distinct isotopic flux signatures. The enzyme carbonic anhydrase (CA) is known to accelerate this exchange in leaves, but the possibility of CA activity in soils is commonly neglected. Here, we report widespread accelerated soil CO 2 hydration. Exchange was 10–300 times faster than the uncatalyzed rate, consistent with typical population sizes for CA-containing soil microorganisms. Including accelerated soil hydration in global model simulations modifies contributions from soil and foliage to the global CO 18 O budget and eliminates persistent discrepancies existing between model and atmospheric observations. This enhanced soil hydration also increases the differences between the isotopic signatures of photosynthesis and respiration, particularly in the tropics, increasing the precision of CO 2 gross fluxes obtained by using the δ 18 O of atmospheric CO 2 by 50%.

Published
2009
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22. The triple isotopic composition of oxygen in leaf water and its implications for quantifying biosphere productivity

Author

Dan Yakir, Eugeni Barkan, Boaz Luz, Amaelle Landais, 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), Glaces et Continents, Climats et Isotopes Stables (GLACCIOS), 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), The Hebrew University of Jerusalem (HUJ), Department of Environmental Sciences and Energy Research [Rehovot], Weizmann Institute of Science [Rehovot, Israël], 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
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, 010504 meteorology & atmospheric sciences, δ18O, Climate change, Biosphere, Vegetation, 15. Life on land, 010502 geochemistry & geophysics, Oxygen cycle, Atmospheric sciences, 01 natural sciences, Atmosphere, 13. Climate action, Greenhouse gas, Climatology, Environmental science, [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, Transpiration
Abstract

Publisher Summary Among the main processes that affect global climate changes, are the interactions between the atmosphere and biosphere. Climatic conditions control the biosphere productivity and, in turn, vegetation strongly influences climate through the emission and consumption of greenhouse gases and through the terrestrial albedo. The only effective way to understand these interactions is based on examination of the past climate changes and the associated biosphere evolution. This chapter describes some of the basic principles underlying the mass-dependent and mass-independent fractionation in the oxygen cycle. It then details how the change in the global oxygen-based biosphere productivity can be inferred from the past changes in the triple isotopic composition of O2. The necessity to know precisely the relationship between δ17O and δ18O during leaf transpiration, is emphasized. The results of the experimental studies on transpiration isotope effects that include— variations along a leaf, daily variations, the influence of plant species, and the effects of environmental and climatic conditions— are reported. Finally, these results are used to perform a global budget of the three isotopes of oxygen in the atmosphere and show the implications for the estimate of the ratio between the last glacial maximum (LGM) and the present-day oxygen biosphere productivities.

Published
2007
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23. The triple isotopic composition of oxygen in leaf water

Author

Dan Yakir, Amaelle Landais, Boaz Luz, Eugeni Barkan, Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), 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), Glaces et Continents, Climats et Isotopes Stables (GLACCIOS), 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), The Hebrew University of Jerusalem (HUJ), Institute of Earth Sciences, The Hebrew University in Jerusalem, A. Safra Campus, 91904, Jerusalem, Israel, Department of Mathematics (Weizmann Institute of Science), Weizmann Institute of Science [Rehovot, Israël], 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), and 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)

Subjects
Hydrology, [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, 010504 meteorology & atmospheric sciences, Isotope, Chemistry, Analytical chemistry, chemistry.chemical_element, 15. Life on land, 010502 geochemistry & geophysics, Photosynthesis, 01 natural sciences, Oxygen, Ice core, Geochemistry and Petrology, Relative humidity, Cycling, [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment, Stratosphere, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, Transpiration
Abstract

The isotopic composition of atmospheric O2 depends on the rates of oxygen cycling in photosynthesis, respiration, photochemical reactions in the stratosphere and on d 17 O and d 18 O of ocean and leaf water. While most of the factors affecting d 17 O and d 18 O of air O2 have been studied extensively in recent years, d 17 O of leaf water—the substrate for all terrestrial photosynthesis—remained unknown. In order to understand the isotopic composition of atmospheric O2 at present and in fossil air in ice cores, we studied leaf water in field experiments in Israel and in a European survey. We measured the difference in d 17 O and d 18 O between stem and leaf water, which is the result of isotope enrichment during transpiration. We calculated the slopes of the lines linking the isotopic compositions of stem and leaf water. The obtained slopes in ln(d 17 O + 1) vs. ln(d 18 O + 1) plots are characterized by very high precision (� 0.001) despite of relatively large differences between duplicates in both d 17 O and d 18 O (0.02–0.05&). This is so because the errors in d 18 O and d 17 O are mass-dependent. The slope of the leaf transpiration process varied between 0.5111 ± 0.0013 and 0.5204 ± 0.0005, which is considerably smaller than the slope linking liquid water and vapor at equilibrium (0.529). We further found that the slope of the transpiration process decreases with atmospheric relative humidity (h) as 0.522–0.008 · h, for h in the range 0.3–1. This slope is neither influenced by the plant species, nor by the environmental conditions where plants grow nor does it show strong variations along long leaves.

Published
2006
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24. Towards a standardized processing of net ecosystem exchange measured with eddy covariance technique : algorithms and uncertainly estimation

Author

Dario Papale, R. Valentini, Marc Aubinet, E. Canfora, Christian Bernhofer, Bernard Longdoz, Timo Vesala, Dan Yakir, Markus Reichstein, Werner L. Kutsch, Serge Rambal, Division of Atmospheric Sciences and Geophysics (Department of Physics) (-2009), Ecosystem processes (INAR Forest Sciences), Micrometeorology and biogeochemical cycles, Department of Forest Science and Environment, Max-Planck-Institut für Biogeochemie (MPI-BGC), Faculté des Sciences Agronomiques, Dept. of Meteorology, Institute of Hydrology and-Meteorology, Ecologie et Ecophysiologie Forestières [devient SILVA en 2018] (EEF), Institut National de la Recherche Agronomique (INRA)-Université de Lorraine (UL), Centre d’Ecologie Fonctionnelle et Evolutive (CEFE), Institut de Recherche pour le Développement (IRD [France-Sud])-Centre National de la Recherche Scientifique (CNRS)-École pratique des hautes études (EPHE)-Université de Montpellier (UM)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro)-Institut National de la Recherche Agronomique (INRA)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-Université Paul-Valéry - Montpellier 3 (UM3), Department of Physical Sciences [Helsinki], University of Helsinki, Dept. of Environmental Sciences and Energy Research, Weizmann Institute of Science, Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-Institut National de la Recherche Agronomique (INRA)-Université Paul-Valéry - Montpellier 3 (UPVM)-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 de Recherche pour le Développement (IRD [France-Sud]), Weizmann Institute of Science [Rehovot, Israël], Tuscia University, Max Planck Institute for Biogeochemistry (MPI-BGC), Max-Planck-Gesellschaft, Université de Liège, Technische Universität Dresden = Dresden University of Technology (TU Dresden), Centre National de la Recherche Scientifique (CNRS), Université Paul-Valéry - Montpellier 3 (UPVM)-Institut National de la Recherche Agronomique (INRA)-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), and Helsingin yliopisto = Helsingfors universitet = University of Helsinki

Subjects
european database of the eddy covariance measurements, 010504 meteorology & atmospheric sciences, Meteorology, net ecosystem exchange, Heuristic (computer science), Biome, lcsh:Life, Eddy covariance, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, Atmospheric sciences, 01 natural sciences, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], FluxNet, lcsh:QH540-549.5, [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment, Ecology, Evolution, Behavior and Systematics, 0105 earth and related environmental sciences, Earth-Surface Processes, eddy covariance technique, [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, Data processing, algorithm, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], lcsh:QE1-996.5, Primary production, Biosphere, 04 agricultural and veterinary sciences, 15. Life on land, terrestrial ecosystem respiration, gross primary production, [SDV.BBM.BC]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Biomolecules [q-bio.BM], lcsh:Geology, lcsh:QH501-531, 13. Climate action, 040103 agronomy & agriculture, co2, 0401 agriculture, forestry, and fisheries, Environmental science, Terrestrial ecosystem, lcsh:Ecology, measurement
Abstract

Eddy covariance technique to measure CO2, water and energy fluxes between biosphere and atmosphere is widely spread and used in various regional networks. Currently more than 250 eddy covariance sites are active around the world measuring carbon exchange at high temporal resolution for different biomes and climatic conditions. In this paper a new standardized set of corrections is introduced and the uncertainties associated with these corrections are assessed for eight different forest sites in Europe with a total of 12 yearly datasets. The uncertainties introduced on the two components GPP (Gross Primary Production) and TER (Terrestrial Ecosystem Respiration) are also discussed and a quantitative analysis presented. Through a factorial analysis we find that generally, uncertainties by different corrections are additive without interactions and that the heuristic u(*)-correction introduces the largest uncertainty. The results show that a standardized data processing is needed for an effective comparison across biomes and for underpinning interannual variability. The methodology presented in this paper has also been integrated in the European database of the eddy covariance measurements. Eddy covariance technique to measure CO2, water and energy fluxes between biosphere and atmosphere is widely spread and used in various regional networks. Currently more than 250 eddy covariance sites are active around the world measuring carbon exchange at high temporal resolution for different biomes and climatic conditions. In this paper a new standardized set of corrections is introduced and the uncertainties associated with these corrections are assessed for eight different forest sites in Europe with a total of 12 yearly datasets. The uncertainties introduced on the two components GPP (Gross Primary Production) and TER (Terrestrial Ecosystem Respiration) are also discussed and a quantitative analysis presented. Through a factorial analysis we find that generally, uncertainties by different corrections are additive without interactions and that the heuristic u(*)-correction introduces the largest uncertainty. The results show that a standardized data processing is needed for an effective comparison across biomes and for underpinning interannual variability. The methodology presented in this paper has also been integrated in the European database of the eddy covariance measurements. Eddy covariance technique to measure CO2, water and energy fluxes between biosphere and atmosphere is widely spread and used in various regional networks. Currently more than 250 eddy covariance sites are active around the world measuring carbon exchange at high temporal resolution for different biomes and climatic conditions. In this paper a new standardized set of corrections is introduced and the uncertainties associated with these corrections are assessed for eight different forest sites in Europe with a total of 12 yearly datasets. The uncertainties introduced on the two components GPP (Gross Primary Production) and TER (Terrestrial Ecosystem Respiration) are also discussed and a quantitative analysis presented. Through a factorial analysis we find that generally, uncertainties by different corrections are additive without interactions and that the heuristic u(*)-correction introduces the largest uncertainty. The results show that a standardized data processing is needed for an effective comparison across biomes and for underpinning interannual variability. The methodology presented in this paper has also been integrated in the European database of the eddy covariance measurements.

Published
2006
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25. Reviews and Syntheses: Carbonyl Sulfide as a Multi-scale Tracer for Carbon and Water Cycles.

Author

Whelan, Mary E., Lennartz, Sinikka T., Gimeno, Teresa E., Wehr, Richard, Wohlfahrt, Georg, Yuting Wang, Kooijmans, Linda M. J., Hilton, Timothy W., Belviso, Sauveur, Peylin, Philippe, Commane, Róisín, Wu Sun, Huilin Chen, Le Kuai, Mammarella, Ivan, Maseyk, Kadmiel, Berkelhammer, Max, King-Fai Li, Dan Yakir, and Zumkehr, Andrew

Subjects
CARBONYL compounds, PHOTOSYNTHESIS, CARBONIC anhydrase, CARBON cycle, HYDROLOGIC cycle
Abstract

For the past decade, observations of carbonyl sulfide (OCS or COS) have been investigated as a proxy for carbon uptake by plants. OCS is destroyed by enzymes that interact with CO2 during photosynthesis, namely carbonic anhydrase (CA) and RuBisCO, where CA is the more important. The majority of sources of OCS to the atmosphere are geographically separated from this large plant sink, whereas the sources and sinks of CO2 are co-located in ecosystems. The drawdown of OCS can therefore be related to the uptake of CO2 without the added complication of co-located emissions comparable in magnitude. Here we review the state of our understanding of the global OCS cycle and its applications to ecosystem carbon cycle science. OCS uptake is correlated well to plant carbon uptake, especially at the regional scale. OCS can be used in conjunction with other independent measures of ecosystem function, like solar-induced fluorescence and carbon and water isotope studies. More work needs to be done to generate global coverage for OCS observations and to link this powerful atmospheric tracer to systems where fundamental questions concerning the carbon and water cycle remain. [ABSTRACT FROM AUTHOR]

Published
2017
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26. Pan-European d13C values of air and organic matter from forest ecosystems

Author

Catarina Mata, Dalibor Janouš, Alessandro Cescatti, Barbara Marcolla, Cathy Kurz Besson, Timo Vesala, Robert Clement, Kevin Black, João Pereira, Patrick Gross, Zuzana Rosova, Ivan A. Janssens, Mari Pihlatie, Thomas Grünwald, Katarina Havrankova, Andrea Scartazza, Francesca Ponti, Deborah Hemming, Régis Burlett, Nina Buchmann, Alexander Knohl, Bruce Osborne, André Granier, Mika Aurela, Tuomas Laurila, Giorgio Matteucci, Barbara K Östner, Andrew S. Kowalski, Per Ambus, Eddy Moors, John Moncrieff, Kim Pilegaard, Federica Rossi, and Dan Yakir

Subjects
0106 biological sciences, Delta, Ecosystem respiration, 010504 meteorology & atmospheric sciences, Vapour Pressure Deficit, d13C, Atmospheric sciences, 01 natural sciences, soil respiration, tree-ring cellulose, Soil respiration, Alterra - Centre for Water and Climate, Environmental Chemistry, below-ground carbon, Organic matter, Ecosystem, fossil-fuel co2, Wageningen Environmental Research, 0105 earth and related environmental sciences, General Environmental Science, Stable isotopes, sampling-network, chemistry.chemical_classification, Hydrology, Global and Planetary Change, ecosystem carbon budget, atmospheric co2, environmental-regulation, CO(2) fluxes, isotopic discrimination, ecosystem respiration, stable isotopes, Ecology, δ13C, Soil organic matter, root respiration, 15. Life on land, dioxide emissions, Carboeuroflux, CO2 fluxes, chemistry, 13. Climate action, Environmental science, 010606 plant biology & botany, Alterra - Centrum Water en Klimaat, carbon-isotope discrimination
Abstract

We present carbon stable isotope, delta(13)C, results from air and organic matter samples collected during 98 individual field campaigns across a network of Carboeuroflux forest sites in 2001 (14 sites) and 2002 (16 sites). Using these data, we tested the hypothesis that delta(13)C values derived from large-scale atmospheric measurements and models, which are routinely used to partition carbon fluxes between land and ocean, and potentially between respiration and photosynthesis on land, are consistent with directly measured ecosystem-scale delta(13)C values. In this framework, we also tested the potential of delta(13)C in canopy air and plant organic matter to record regional-scale ecophysiological patterns. Our network estimates for the mean delta(13)C of ecosystem respired CO(2) and the related 'discrimination' of ecosystem respiration, delta(er) and Delta(er), respectively, were -25.6 +/- 1.9 parts per thousand and 17.8 +/- 2.0 parts per thousand in 2001 and -26.6 +/- 1.5 parts per thousand and 19.0 +/- 1.6 parts per thousand in 2002. The results were in close agreement with delta(13)C values derived from regional-scale atmospheric measurement programs for 2001, but less so in 2002, which had an unusual precipitation pattern. This suggests that regional-scale atmospheric sampling programs generally capture ecosystem delta(13)C signals over Europe, but may be limited in capturing some of the interannual variations. In 2001, but less so in 2002, there were discernable longitudinal and seasonal trends in delta(er). From west to east, across the network, there was a general enrichment in (13)C (similar to 3 parts per thousand and similar to 1 parts per thousand for the 2 years, respectively) consistent with increasing Gorczynski continentality index for warmer and drier conditions. In 2001 only, seasonal (13)C enrichment between July and September, followed by depletion in November (from about -26.0 parts per thousand to -24.5 parts per thousand to -30.0 parts per thousand), was also observed. In 2001, July and August delta(er) values across the network were significantly related to average daytime vapor pressure deficit (VPD), relative humidity (RH), and, to a lesser degree, air temperature (T(a)), but not significantly with monthly average precipitation (P(m)). In contrast, in 2002 (a much wetter peak season), delta(er) was significantly related with T(a), but not significantly with VPD and RH. The important role of plant physiological processes on delta(er) in 2001 was emphasized by a relatively rapid turnover (between 1 and 6 days) of assimilated carbon inferred from time-lag analyses of delta(er) vs. meteorological parameters. However, this was not evident in 2002. These analyses also noted corresponding diurnal cycles of delta(er) and meteorological parameters in 2001, indicating a rapid transmission of daytime meteorology, via physiological responses, to the delta(er) signal during this season. Organic matter delta(13)C results showed progressive (13)C enrichment from leaves, through stems and roots to soil organic matter, which may be explained by (13)C fractionation during respiration. This enrichment was species dependent and was prominent in angiosperms but not in gymnosperms. delta(13)C values of organic matter of any of the plant components did not well represent short-term delta(er) values during the seasonal cycle, and could not be used to partition ecosystem respiration into autotrophic and heterotrophic components.

Published
2005
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27. On the separation of net ecosystem exchange into assimilation and ecosystem respiration: review and improved algorithm

Author

Katka Havránková, Thomas Grünwald, Timo Vesala, Annalea Lohila, Alexander Knohl, Marc Aubinet, Franco Miglietta, Nina Buchmann, A. Granier, Denis Loustau, Eva Falge, Tilden P. Meyers, Francesco Primo Vaccari, Dennis D. Baldocchi, Jukka Pumpanen, Eyal Rotenberg, Tuomas Laurila, Hannu Ilvesniemi, María José Sanz, Dalibor Janouš, John Tenhunen, Christian Bernhofer, Dario Papale, Tagir G. Gilmanov, Jean-Marc Ourcival, Giorgio Matteucci, Dan Yakir, Riccardo Valentini, Paul Berbigier, Serge Rambal, G. Seufert, Markus Reichstein, Tuscia University, University of Bayreuth, University of California [Berkeley], University of California, Université de Liège, Unité de bioclimatologie, Institut National de la Recherche Agronomique (INRA), Technische Universität Dresden = Dresden University of Technology (TU Dresden), Max Planck Institute for Biogeochemistry (MPI-BGC), Max-Planck-Gesellschaft, South Dakota State University (SDSTATE), Unité d'écophysiologie forestière, Czech Academy of Sciences [Prague] (CAS), Finnish Forest Research Institute, Finnish Meteorological Institute (FMI), Écologie fonctionnelle et physique de l'environnement (EPHYSE), Institute for Environment and Sustainability of the JRC, Partenaires INRAE, National Oceanic and Atmospheric Administration (NOAA), Consiglio Nazionale delle Ricerche (CNR), Centre d’Ecologie Fonctionnelle et Evolutive (CEFE), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-Institut National de la Recherche Agronomique (INRA)-Université Paul-Valéry - Montpellier 3 (UPVM)-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 de Recherche pour le Développement (IRD [France-Sud]), University of Helsinki, Weizmann Institute of Science [Rehovot, Israël], and Centro de Estudios Ambientales del Mediterraneo

Subjects
Mediterranean climate, 010504 meteorology & atmospheric sciences, ecosystem respiration, [SDE.MCG]Environmental Sciences/Global Changes, Eddy covariance, Atmospheric sciences, 01 natural sciences, computational methods, FluxNet, eddy covariance, Environmental Chemistry, Ecosystem, 0105 earth and related environmental sciences, General Environmental Science, carbon balance, Global and Planetary Change, Ecology, 04 agricultural and veterinary sciences, 15. Life on land, Evergreen forest, Deciduous, Boreal, 13. Climate action, 040103 agronomy & agriculture, temperature sensitivity of respiration, 0401 agriculture, forestry, and fisheries, Environmental science, gross carbon uptake, Ecosystem respiration
Abstract

International audience; This paper discusses the advantages and disadvantages of the different methods that separate net ecosystem exchange (NEE) into its major components, gross ecosystem carbon uptake (GEP) and ecosystem respiration (Reco). In particular, we analyse the effect of the extrapolation of night-time values of ecosystem respiration into the daytime; this is usually done with a temperature response function that is derived from long-term data sets. For this analysis, we used 16 one-year-long data sets of carbon dioxide exchange measurements from European and US-American eddy covariance networks. These sites span from the boreal to Mediterranean climates, and include deciduous and evergreen forest, scrubland and crop ecosystems. We show that the temperature sensitivity of Reco, derived from long-term (annual) data sets, does not reflect the short-term temperature sensitivity that is effective when extrapolating from night- to daytime. Specifically, in summer active ecosystems the long-term temperature sensitivity exceeds the short-term sensitivity. Thus, in those ecosystems, the application of a long-term temperature sensitivity to the extrapolation of respiration from night to day leads to a systematic overestimation of ecosystem respiration from halfhourly to annual time-scales, which can reach 425% for an annual budget and which consequently affects estimates of GEP. Conversely, in summer passive (Mediterranean) ecosystems, the long-term temperature sensitivity is lower than the short-term temperature sensitivity resulting in underestimation of annual sums of respiration. We introduce a new generic algorithm that derives a short-term temperature sensitivity of Reco from eddy covariance data that applies this to the extrapolation from night- to daytime, and that further performs a filling of data gaps that exploits both, the covariance between fluxes and meteorological drivers and the temporal structure of the fluxes. While this algorithm should give less biased estimates of GEP and Reco, we discuss the remaining biases and recommend that eddy covariance measurements are still backed by ancillary flux measurements that can reduce the uncertainties inherent in the eddy covariance data.

Published
2005
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28. Natural Abundance Carbon Isotope Composition of Isoprene Reflects Incomplete Coupling between Isoprene Synthesis and Photosynthetic Carbon Flow

Author

Dan Yakir and Hagit P. Affek

Subjects
Physiology, chemistry.chemical_element, Plant Science, Photosynthesis, chemistry.chemical_compound, Cytosol, Hemiterpenes, Rhamnus alaternus, Fosfomycin, Pentanes, Botany, Genetics, Butadienes, Isoprene, Carbon Isotopes, Myrtus communis, biology, Atmosphere, Metabolism, Carbon Dioxide, Darkness, biology.organism_classification, Mucuna, Carbon, Myrtus, Plant Leaves, Glucose, Rhamnus, chemistry, Isotopes of carbon, Carbon dioxide, Glycolysis, Research Article
Abstract

Isoprene emission from leaves is dynamically coupled to photosynthesis through the use of primary and recent photosynthate in the chloroplast. However, natural abundance carbon isotope composition (δ13C) measurements in myrtle (Myrtus communis), buckthorn (Rhamnus alaternus), and velvet bean (Mucuna pruriens) showed that only 72% to 91% of the variations in the δ13C values of fixed carbon were reflected in the δ13C values of concurrently emitted isoprene. The results indicated that 9% to 28% carbon was contributed from alternative, slow turnover, carbon source(s). This contribution increased when photosynthesis was inhibited by CO2-free air. The observed variations in the δ13C of isoprene under ambient and CO2-free air were consistent with contributions to isoprene synthesis in the chloroplast from pyruvate associated with cytosolic Glc metabolism. Irrespective of alternative carbon source(s), isoprene was depleted in 13C relative to mean photosynthetically fixed carbon by 4‰ to 11‰. Variable13C discrimination, its increase by partially inhibiting isoprene synthesis with fosmidomicin, and the associated accumulation of pyruvate suggested that the main isotopic discrimination step was the deoxyxylulose-5-phosphate synthase reaction.

Published
2003

29. Bulk carbon, oxygen, and hydrogen stable isotope composition of recent resins from amber-producing Hymenaea.

Author

Arie Nissenbaum, Dan Yakir, and Jean H. Langenheim

Subjects
HYMENAEA, ANGIOSPERMS, CAESALPINIACEAE, PHANEROGAMS
Abstract

Resins of Hymenaea, an angiosperm tree genus known to be a copious resin producer and a major source of amber since the Oligo-Miocene, were collected from a wide range of tropical environments from Latin America and Africa, and analyzed for their carbon, hydrogen, and oxygen stable isotope composition. The average value for d 13C in the resins was found to be -27.0±1.3‰, which is very similar to the values reported for resins in other studies. d 18? values for the Hymenaea resins averaged +11.2±1.6‰, or about 20‰ more depleted than normal plant cellulose. dD values of the resins ranged from -196 to -319‰, with an average of -243±30‰. Rough estimates suggest a fractionation of -200 to -210‰ between the resins and the environmental water. This value is similar to the -200‰ value observed for the fractionation between other plant lipids and environmental water. The present study suggests that the stable isotope composition of fossil resins (amber) has the potential to provide information on ancient environmental waters. [ABSTRACT FROM AUTHOR]

Published
2005

30. Amber, Resinite, and Fossil Resins

Author

KEN B. ANDERSON, JOHN C. CRELLING, Jean H. Langenheim, Arie Nissenbaum, Dan Yakir, Scott A. Stout, Tatsushi Murae, Shuji Shimokawa, A. Aihara, David J. Clifford, Patrick G. Hatcher, Edith C. Stout, Curt W. Beck, Barbara Kosmowska-Ceranowicz, P. F. van Bergen, M. E. Collinson, A. C. Scott, J. W. de Leeuw, Ben A. LePage, Joseph B. Lambert, Suzanne C. Johnson, George O. Poinar, David A. Grimaldi, S. M. Halpine, Xueyun S. Wang, Hendrik N. Poinar, Jeffrey L. Bada, Richard Dutta, Harold H. Schobert, Q. Yu, L. Li, J. D. Miller, KEN B. ANDERSON, JOHN C. CRELLING, Jean H. Langenheim, Arie Nissenbaum, Dan Yakir, Scott A. Stout, Tatsushi Murae, Shuji Shimokawa, A. Aihara, David J. Clifford, Patrick G. Hatcher, Edith C. Stout, Curt W. Beck, Barbara Kosmowska-Ceranowicz, P. F. van Bergen, M. E. Collinson, A. C. Scott, J. W. de Leeuw, Ben A. LePage, Joseph B. Lambert, Suzanne C. Johnson, George O. Poinar, David A. Grimaldi, S. M. Halpine, Xueyun S. Wang, Hendrik N. Poinar, Jeffrey L. Bada, Richard Dutta, Harold H. Schobert, Q. Yu, L. Li, and J. D. Miller

Subjects
Resins, Fossil--Congresses, Amber--Congresses, Resinite--Congresses, Organic geochemistry--Congresses
Published
1995

Catalog

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