Differential responses to two heatwave intensities in a Mediterranean citrus orchard are identified by combining measurements of fluorescence and carbonyl sulfide (COS) and CO<sub>2</sub> uptake

Cochavi, Amnon; Amer, Madi; Stern, Rafael; Tatarinov, Fyodor; Migliavacca, Mirco; Yakir, Dan

doi:10.1111/nph.17247

Cited by 17 publications

(10 citation statements)

References 98 publications

(196 reference statements)

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“…The simulation of COS uptake is strongly coupled to GPP through g s and V max (which is included in g cos ) and therefore relies on the accuracy of these model parameters. However, several studies have shown that the ratio of COS to CO 2 deposition velocities (in the literature also called "leaf relative uptake") varies with temperature (Cochavi et al, 2021;Stimler et al, 2010) and humidity (Sun et al, 2018b;Kooijmans et al, 2019), in addition to the better known variability with light.…”

Section: Recommendations For Cos-specific Future Model Developmentmentioning

confidence: 99%

Evaluation of carbonyl sulfide biosphere exchange in the Simple Biosphere Model (SiB4)

Kooijmans

Cho

et al. 2021

Biogeosciences

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Abstract. The uptake of carbonyl sulfide (COS) by terrestrial plants is linked to photosynthetic uptake of CO2 as these gases partly share the same uptake pathway. Applying COS as a photosynthesis tracer in models requires an accurate representation of biosphere COS fluxes, but these models have not been extensively evaluated against field observations of COS fluxes. In this paper, the COS flux as simulated by the Simple Biosphere Model, version 4 (SiB4), is updated with the latest mechanistic insights and evaluated with site observations from different biomes: one evergreen needleleaf forest, two deciduous broadleaf forests, three grasslands, and two crop fields spread over Europe and North America. We improved SiB4 in several ways to improve its representation of COS. To account for the effect of atmospheric COS mole fractions on COS biosphere uptake, we replaced the fixed atmospheric COS mole fraction boundary condition originally used in SiB4 with spatially and temporally varying COS mole fraction fields. Seasonal amplitudes of COS mole fractions are ∼50–200 ppt at the investigated sites with a minimum mole fraction in the late growing season. Incorporating seasonal variability into the model reduces COS uptake rates in the late growing season, allowing better agreement with observations. We also replaced the empirical soil COS uptake model in SiB4 with a mechanistic model that represents both uptake and production of COS in soils, which improves the match with observations over agricultural fields and fertilized grassland soils. The improved version of SiB4 was capable of simulating the diurnal and seasonal variation in COS fluxes in the boreal, temperate, and Mediterranean region. Nonetheless, the daytime vegetation COS flux is underestimated on average by 8±27 %, albeit with large variability across sites. On a global scale, our model modifications decreased the modeled COS terrestrial biosphere sink from 922 Gg S yr−1 in the original SiB4 to 753 Gg S yr−1 in the updated version. The largest decrease in fluxes was driven by lower atmospheric COS mole fractions over regions with high productivity, which highlights the importance of accounting for variations in atmospheric COS mole fractions. The change to a different soil model, on the other hand, had a relatively small effect on the global biosphere COS sink. The secondary role of the modeled soil component in the global COS budget supports the use of COS as a global photosynthesis tracer. A more accurate representation of COS uptake in SiB4 should allow for improved application of atmospheric COS as a tracer of local- to global-scale terrestrial photosynthesis.

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Section: Recommendations For Cos-specific Future Model Developmentmentioning

confidence: 99%

Evaluation of carbonyl sulfide biosphere exchange in the Simple Biosphere Model (SiB4)

Kooijmans

Cho

et al. 2021

Biogeosciences

View full text Add to dashboard Cite

show abstract

“…The modeled COS uptake is strongly coupled to GPP. However, several studies have shown that the ratio of COS to CO2 deposition velocities (in literature also called the leaf relative uptake ratio) varies with temperature (Cochavi et al, 2021;Stimler et al, 2010) and humidity (Sun et al 2018;Kooijmans et al 2019), in addition to the better known variability with light. The temperature response of the COS uptake is currently taken from Vmax and is scaled with an empirical temperature function (Eq.…”

Section: Recommendations For Cos-specific Future Model Developmentmentioning

confidence: 99%

Evaluation of carbonyl sulfide biosphere exchange in the Simple Biosphere Model (SiB4)

Kooijmans

Cho

et al. 2021

Preprint

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Abstract. The uptake of carbonyl sulfide (COS) by terrestrial plants is linked to photosynthetic uptake of CO2 by a shared diffusion pathway. Applying COS as a photosynthesis tracer in models requires an accurate representation of biosphere COS fluxes, but these models have not been extensively evaluated against field observations of COS fluxes. In this paper, the COS flux as simulated by the Simple Biosphere Model, version 4 (SiB4) is updated with the latest mechanistic insights and evaluated with site observations from different biomes: one evergreen needleleaf forest, two deciduous broadleaf forests, three grasslands, and two crop fields spread over Europe and North America. To account for the effect of atmospheric COS mole fractions on COS biosphere uptake, we replaced the fixed COS mole fraction originally used in SiB4 with spatially and temporally varying COS mole fraction fields. The lower COS mole fractions in the late growing season reduces COS uptake rates in agreement with observations. We also replaced the empirical soil COS uptake model in SiB4 with a mechanistic model that represents both uptake and production of COS in soils, which improves the match with observations over agricultural fields and fertilized grassland soils. SiB4 was capable of simulating the diurnal and seasonal variation of COS fluxes in the boreal, temperate and Mediterranean region. The daytime vegetation COS flux is on average 8 ± 27 % underestimated, albeit with large variability across sites. On a global scale, our model modifications caused a drop in the COS biosphere sink from 922 Gg S yr−1 in the original SiB4 model to 753 Gg S yr−1 in the updated version. The largest drop in fluxes was driven by lower atmospheric COS mole fractions over regions with high productivity, which highlights the importance of accounting for variations in atmospheric COS mole fractions. The change to a different soil model, on the other hand, had a relatively small effect on the global biosphere COS sink. The small role of the modeled soil component in the COS budget supports the use of COS as a global photosynthesis tracer.

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“…(2018) and Cochavi et al. (2021) during heat waves, in a Mediterranean pine forest and citrus orchard, respectively.…”

Section: Conclusion and Outlooksmentioning

confidence: 97%

Carbon and Water Fluxes of the Boreal Evergreen Needleleaf Forest Biome Constrained by Assimilating Ecosystem Carbonyl Sulfide Flux Observations

et al. 2023

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Gross primary production (GPP) by boreal forests is highly sensitive to environmental changes. However, GPP simulated by land surface models (LSMs) remains highly uncertain due to the lack of direct photosynthesis observations at large scales. Carbonyl sulfide (COS) has emerged as a promising proxy to improve the representation of GPP in LSMs. Because COS is absorbed by vegetation following the same diffusion pathway as CO2 during photosynthesis and not emitted back to the atmosphere, incorporating a mechanistic representation of vegetation COS uptake in LSMs allows using COS observations to refine GPP representation. Here, we perform ecosystem COS flux and GPP data assimilations to constrain the COS‐ and GPP‐related parameters in the ORCHIDEE LSM for boreal evergreen needleleaf forests (BorENF). Assimilating ecosystem COS fluxes at Hyytiälä forest increases the simulated net ecosystem COS uptake by 14%. This increase largely results from changes in the internal conductance to COS, highlighting the need to improve the representation of COS internal diffusion and consumption. Moreover, joint assimilation of ecosystem COS flux and GPP at Hyytiälä improves the simulated latent heat flux, contrary to the GPP‐only data assimilation, which fails to do so. Finally, we scaled this assimilation framework up to the boreal region and find that the joint assimilation of COS at Hyytiälä and GPP fluxes at 10 BorENF sites increases the modeled vegetation COS uptake up to 18%, but not GPP. Therefore, this study encourages the use of COS flux observations to inform GPP and latent heat flux representations in LSMs.

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Differential responses to two heatwave intensities in a Mediterranean citrus orchard are identified by combining measurements of fluorescence and carbonyl sulfide (COS) and CO₂ uptake

Cited by 17 publications

References 98 publications

Evaluation of carbonyl sulfide biosphere exchange in the Simple Biosphere Model (SiB4)

Evaluation of carbonyl sulfide biosphere exchange in the Simple Biosphere Model (SiB4)

Evaluation of carbonyl sulfide biosphere exchange in the Simple Biosphere Model (SiB4)

Carbon and Water Fluxes of the Boreal Evergreen Needleleaf Forest Biome Constrained by Assimilating Ecosystem Carbonyl Sulfide Flux Observations

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Differential responses to two heatwave intensities in a Mediterranean citrus orchard are identified by combining measurements of fluorescence and carbonyl sulfide (COS) and CO2 uptake

Cited by 17 publications

References 98 publications

Evaluation of carbonyl sulfide biosphere exchange in the Simple Biosphere Model (SiB4)

Evaluation of carbonyl sulfide biosphere exchange in the Simple Biosphere Model (SiB4)

Evaluation of carbonyl sulfide biosphere exchange in the Simple Biosphere Model (SiB4)

Carbon and Water Fluxes of the Boreal Evergreen Needleleaf Forest Biome Constrained by Assimilating Ecosystem Carbonyl Sulfide Flux Observations

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Differential responses to two heatwave intensities in a Mediterranean citrus orchard are identified by combining measurements of fluorescence and carbonyl sulfide (COS) and CO₂ uptake