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Franks PJ, Herold N, Bonan GB, Oleson KW, Dukes JS, Huber M, Schroeder JI, Cox PM, Jones S. Land surface conductance linked to precipitation: Co-evolution of vegetation and climate in Earth system models. Glob Chang Biol 2024; 30:e17188. [PMID: 38462677 DOI: 10.1111/gcb.17188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Revised: 12/19/2023] [Accepted: 12/27/2023] [Indexed: 03/12/2024]
Abstract
Vegetation and precipitation are known to fundamentally influence each other. However, this interdependence is not fully represented in climate models because the characteristics of land surface (canopy) conductance to water vapor and CO2 are determined independently of precipitation. Working within a coupled atmosphere and land modelling framework (CAM6/CLM5; coupled Community Atmosphere Model v6/Community Land Model v5), we have developed a new theoretical approach to characterizing land surface conductance by explicitly linking its dynamic properties to local precipitation, a robust proxy for moisture available to vegetation. This will enable regional surface conductance characteristics to shift fluidly with climate change in simulations, consistent with general principles of co-evolution of vegetation and climate. Testing within the CAM6/CLM5 framework shows that climate simulations incorporating the new theory outperform current default configurations across several error metrics for core output variables when measured against observational data. In climate simulations for the end of this century the new, adaptive stomatal conductance scheme provides a revised prognosis for average and extreme temperatures over several large regions, with increased primary productivity through central and east Asia, and higher rainfall through North Africa and the Middle East. The new projections also reveal more frequent heatwaves than originally estimated for the south-eastern US and sub-Saharan Africa but less frequent heatwaves across east Europe and northeast Asia. These developments have implications for evaluating food security and risks from extreme temperatures in areas that are vulnerable to climate change.
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Affiliation(s)
- Peter J Franks
- School of Life and Environmental Sciences, The University of Sydney, Sydney, New South Wales, Australia
| | - Nicholas Herold
- School of Life and Environmental Sciences, The University of Sydney, Sydney, New South Wales, Australia
| | - Gordon B Bonan
- National Center for Atmospheric Research, Boulder, Colorado, USA
| | - Keith W Oleson
- National Center for Atmospheric Research, Boulder, Colorado, USA
| | - Jeffrey S Dukes
- Department of Global Ecology, Carnegie Institution for Science, Stanford, California, USA
| | - Matthew Huber
- Department of Earth, Atmosphere and Planetary Sciences, Purdue University, West Lafayette, Indiana, USA
| | - Julian I Schroeder
- Cell and Developmental Biology Department, University of California San Diego, San Diego, California, USA
| | - Peter M Cox
- Department of Mathematics and Statistics, University of Exeter, Exeter, UK
| | - Simon Jones
- Department of Mathematics and Statistics, University of Exeter, Exeter, UK
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Chi CJE, Zinsmeister D, Lai IL, Chang SC, Kuo YL, Burkhardt J. Aerosol Impacts on Water Relations of Camphor ( Cinnamomum camphora). Front Plant Sci 2022; 13:892096. [PMID: 35795349 PMCID: PMC9251497 DOI: 10.3389/fpls.2022.892096] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Accepted: 05/19/2022] [Indexed: 06/15/2023]
Abstract
Major parts of anthropogenic and natural aerosols are hygroscopic and deliquesce at high humidity, particularly when depositing to leaf surfaces close to transpiring stomata. Deliquescence and subsequent salt creep may establish thin, extraordinary pathways into the stomata, which foster stomatal uptake of nutrients and water but may also cause stomatal liquid water loss by wicking. Such additional water loss is not accompanied by a wider stomatal aperture with a larger CO2 influx and hypothetically reduces water use efficiency (WUE). Here, the possible direct impacts of aerosols on physical and physiological parameters of camphor (Cinnamomum camphora) were studied (i) in a greenhouse experiment using aerosol exclusion and (ii) in a field study in Taiwan, comparing trees at two sites with different aerosol regimes. Scanning electron microscopy (SEM) images showed that leaves grown under aerosol exclusion in filtered air (FA) were lacking the amorphous, flat areas that were abundant on leaves grown in ambient air (AA), suggesting salt crusts formed from deliquescent aerosols. Increasing vapor pressure deficit (VPD) resulted in half the Ball-Berry slope and double WUE for AA compared to FA leaves. This apparent contradiction to the wicking hypothesis may be due to the independent, overcompensating effect of stomatal closure in response to VPD, which affects AA more than FA stomata. Compared to leaves in a more polluted region in the Taiwanese Southwest, NaCl aerosols dominated the leaf surface conditions on mature camphor trees in Eastern Taiwan, while the considerably lower contact angles and the 2.5 times higher minimum epidermal conductances might have come from organic surfactants. Interpretations of SEM images from leaf surface microstructures should consider amorphous areas as possible indicators of aerosol deposition and other hygroscopic material. The amount and type of the material determine the resulting impacts on plant water relations, together with the surrounding atmosphere and ecophysiological traits.
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Affiliation(s)
- Chia-Ju Ellen Chi
- Institute of Crop Science and Resource Conservation, University of Bonn, Bonn, Germany
| | - Daniel Zinsmeister
- Institute of Crop Science and Resource Conservation, University of Bonn, Bonn, Germany
| | - I-Ling Lai
- Graduate Institute of Bioresources, National Pingtung University of Science and Technology, Pingtung, Taiwan
| | - Shih-Chieh Chang
- Department of Natural Resources and Environmental Studies, Center for Interdisciplinary Research on Ecology and Sustainability, National Dong Hwa University, Hualien, Taiwan
| | - Yau-Lun Kuo
- Department of Forestry, National Pingtung University of Science and Technology, Pingtung, Taiwan
| | - Jürgen Burkhardt
- Institute of Crop Science and Resource Conservation, University of Bonn, Bonn, Germany
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Franks PJ, Bonan GB, Berry JA, Lombardozzi DL, Holbrook NM, Herold N, Oleson KW. Comparing optimal and empirical stomatal conductance models for application in Earth system models. Glob Chang Biol 2018; 24:5708-5723. [PMID: 30218538 DOI: 10.1111/gcb.14445] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Revised: 08/23/2018] [Accepted: 08/29/2018] [Indexed: 05/27/2023]
Abstract
Earth system models (ESMs) rely on the calculation of canopy conductance in land surface models (LSMs) to quantify the partitioning of land surface energy, water, and CO2 fluxes. This is achieved by scaling stomatal conductance, gw , determined from physiological models developed for leaves. Traditionally, models for gw have been semi-empirical, combining physiological functions with empirically determined calibration constants. More recently, optimization theory has been applied to model gw in LSMs under the premise that it has a stronger grounding in physiological theory and might ultimately lead to improved predictive accuracy. However, this premise has not been thoroughly tested. Using original field data from contrasting forest systems, we compare a widely used empirical type and a more recently developed optimization-type gw model, termed BB and MED, respectively. Overall, we find no difference between the two models when used to simulate gw from photosynthesis data, or leaf gas exchange from a coupled photosynthesis-conductance model, or gross primary productivity and evapotranspiration for a FLUXNET tower site with the CLM5 community LSM. Field measurements reveal that the key fitted parameters for BB and MED, g1B and g1M, exhibit strong species specificity in magnitude and sensitivity to CO2 , and CLM5 simulations reveal that failure to include this sensitivity can result in significant overestimates of evapotranspiration for high-CO2 scenarios. Further, we show that g1B and g1M can be determined from mean ci /ca (ratio of leaf intercellular to ambient CO2 concentration). Applying this relationship with ci /ca values derived from a leaf δ13 C database, we obtain a global distribution of g1B and g1M , and these values correlate significantly with mean annual precipitation. This provides a new methodology for global parameterization of the BB and MED models in LSMs, tied directly to leaf physiology but unconstrained by spatial boundaries separating designated biomes or plant functional types.
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Affiliation(s)
- Peter J Franks
- School of Life and Environmental Sciences, The University of Sydney, Sydney, New South Wales, Australia
| | - Gordon B Bonan
- National Center for Atmospheric Research, Boulder, Colorado
| | - Joseph A Berry
- Department of Global Ecology, Carnegie Institution for Science, Stanford, California
| | | | - N Michele Holbrook
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, Massachusetts
| | - Nicholas Herold
- School of Life and Environmental Sciences, The University of Sydney, Sydney, New South Wales, Australia
| | - Keith W Oleson
- National Center for Atmospheric Research, Boulder, Colorado
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Urban J, Ingwers M, McGuire MA, Teskey RO. Stomatal conductance increases with rising temperature. Plant Signal Behav 2017; 12:e1356534. [PMID: 28786730 PMCID: PMC5616154 DOI: 10.1080/15592324.2017.1356534] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Accepted: 07/05/2017] [Indexed: 05/02/2023]
Abstract
Stomatal conductance directly modifies plant water relations and photosynthesis. Many environmental factors affecting the stomatal conductance have been intensively studied but temperature has been largely neglected, even though it is one of the fastest changing environmental variables and it is rising due to climate change. In this study, we describe how stomata open when the temperature increases. Stomatal conductance increased by ca 40% in a broadleaf and a coniferous species, poplar (Populus deltoides x nigra) and loblolly pine (Pinus taeda) when temperature was increased by 10 °C, from 30 °C to 40 °C at a constant vapor pressure deficit of 1 kPa. The mechanism of regulating stomatal conductance by temperature was, at least partly, independent of other known mechanisms linked to water status and carbon metabolism. Stomatal conductance increased with rising temperature despite the decrease in leaf water potential, increase in transpiration, increase in intercellular CO2 concentration and was decoupled from photosynthesis. Increase in xylem and mesophyll hydraulic conductance coming from lower water viscosity may to some degree explain temperature dependent opening of stomata. The direct stomatal response to temperature allows plants to benefit from increased evaporative cooling during the heat waves and from lower stomatal limitations to photosynthesis but they may be jeopardized by faster depletion of soil water.
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Affiliation(s)
- Josef Urban
- Department of Forest Botany, Dendrology and Geobiocenology, Mendel University in Brno, Czech Republic
- Siberian Federal University, Krasnoyarsk, Russia
| | - Miles Ingwers
- Institute of Plant Breeding, Genetics and Genomics, University of Georgia, Athens, GA, USA
| | - Mary Anne McGuire
- Daniel B. Warnell School of Forestry and Natural Resources, University of Georgia, Athens, Georgia, USA
| | - Robert O. Teskey
- Daniel B. Warnell School of Forestry and Natural Resources, University of Georgia, Athens, Georgia, USA
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Huang MX, Wang J, Tang JZ, Yu Q, Zhang J, Xue QY, Chang Q, Tan MX. [Suitability of four stomatal conductance models in agro-pastoral ecotone in North China: A case study for potato and oil sunflower.]. Ying Yong Sheng Tai Xue Bao 2016; 27:3585-3592. [PMID: 29696856 DOI: 10.13287/j.1001-9332.201611.033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
The suitability of four popular empirical and semi-empirical stomatal conductance models (Jarvis model, Ball-Berry model, Leuning model and Medlyn model) was evaluated based on para-llel observation data of leaf stomatal conductance, leaf net photosynthetic rate and meteorological factors during the vigorous growing period of potato and oil sunflower at Wuchuan experimental station in agro-pastoral ecotone in North China. It was found that there was a significant linear relationship between leaf stomatal conductance and leaf net photosynthetic rate for potato, whereas the linear relationship appeared weaker for oil sunflower. The results of model evaluation showed that Ball-Berry model performed best in simulating leaf stomatal conductance of potato, followed by Leuning model and Medlyn model, while Jarvis model was the last in the performance rating. The root-mean-square error (RMSE) was 0.0331, 0.0371, 0.0456 and 0.0794 mol·m-2·s-1, the normalized root-mean-square error (NRMSE) was 26.8%, 30.0%, 36.9% and 64.3%, and R-squared (R2) was 0.96, 0.61, 0.91 and 0.88 between simulated and observed leaf stomatal conductance of potato for Ball-Berry model, Leuning model, Medlyn model and Jarvis model, respectively. For leaf stomatal conductance of oil sunflower, Jarvis model performed slightly better than Leuning model, Ball-Berry model and Medlyn model. RMSE was 0.2221, 0.2534, 0.2547 and 0.2758 mol·m-2·s-1, NRMSE was 40.3%, 46.0%, 46.2% and 50.1%, and R2 was 0.38, 0.22, 0.23 and 0.20 between simulated and observed leaf stomatal conductance of oil sunflower for Jarvis model, Leuning model, Ball-Berry model and Medlyn model, respectively. The path analysis was conducted to identify effects of specific meteorological factors on leaf stomatal conductance. The diurnal variation of leaf stomatal conductance was principally affected by vapour pressure saturation deficit for both potato and oil sunflower. The model evaluation suggested that the stomatal conductance models for oil sunflower are to be improved in further research.
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Affiliation(s)
- Ming Xia Huang
- College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China
| | - Jing Wang
- College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China
| | - Jian Zhao Tang
- College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China
| | - Qiang Yu
- State Key Laboratory of Soil Erosion and Dryland Farming on Loess Plateau, Institute of Soil and Water Conservation, Northwest A&F University, Yangling 712100, Shaanxi, China
| | - Jun Zhang
- College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China
| | - Qing Yu Xue
- Tianjin Climate Center, Tianjin 300074, China
| | - Qing Chang
- College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China.,Shanxi Meteorological Service Centre, Taiyuan 030002, China
| | - Mei Xiu Tan
- College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China
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