scholarly journals Canopy uptake dominates nighttime carbonyl sulfide fluxes in a boreal forest

2017 ◽  
Vol 17 (18) ◽  
pp. 11453-11465 ◽  
Author(s):  
Linda M. J. Kooijmans ◽  
Kadmiel Maseyk ◽  
Ulli Seibt ◽  
Wu Sun ◽  
Timo Vesala ◽  
...  
Keyword(s):  
Boreal Forest ◽  
Stomatal Closure ◽  
Carbonyl Sulfide ◽  
Tracer Method ◽  
Dry Period ◽  
Canopy Layer ◽  
Canopy Uptake ◽  
Incomplete Closure ◽  
Chamber Measurements ◽  
Measurement Period

Abstract. Nighttime vegetative uptake of carbonyl sulfide (COS) can exist due to the incomplete closure of stomata and the light independence of the enzyme carbonic anhydrase, which complicates the use of COS as a tracer for gross primary productivity (GPP). In this study we derived nighttime COS fluxes in a boreal forest (the SMEAR II station in Hyytiälä, Finland; 61°51′ N, 24°17′ E; 181 m a.s.l.) from June to November 2015 using two different methods: eddy-covariance (EC) measurements (FCOS-EC) and the radon-tracer method (FCOS-Rn). The total nighttime COS fluxes averaged over the whole measurement period were −6.8 ± 2.2 and −7.9 ± 3.8 pmol m−2 s−1 for FCOS-Rn and FCOS-EC, respectively, which is 33–38 % of the average daytime fluxes and 21 % of the total daily COS uptake. The correlation of 222Rn (of which the source is the soil) with COS (average R2  =  0.58) was lower than with CO2 (0.70), suggesting that the main sink of COS is not located at the ground. These observations are supported by soil chamber measurements that show that soil contributes to only 34–40 % of the total nighttime COS uptake. We found a decrease in COS uptake with decreasing nighttime stomatal conductance and increasing vapor-pressure deficit and air temperature, driven by stomatal closure in response to a warm and dry period in August. We also discuss the effect that canopy layer mixing can have on the radon-tracer method and the sensitivity of (FCOS-EC) to atmospheric turbulence. Our results suggest that the nighttime uptake of COS is mainly driven by the tree foliage and is significant in a boreal forest, such that it needs to be taken into account when using COS as a tracer for GPP.

scholarly journals Canopy uptake dominates nighttime carbonyl sulfide fluxes in a boreal forest

2017 ◽  
Author(s):  
Linda M. J. Kooijmans ◽  
Kadmiel Maseyk ◽  
Ulli Seibt ◽  
Wu Sun ◽  
Timo Vesala ◽  
...  
Keyword(s):  
Boreal Forest ◽  
Stomatal Closure ◽  
Carbonyl Sulfide ◽  
Tracer Method ◽  
Dry Period ◽  
Canopy Layer ◽  
Night Time ◽  
Canopy Uptake ◽  
Incomplete Closure ◽  
Chamber Measurements

Abstract. Nighttime vegetative uptake of carbonyl sulfide (COS) can exist due to the incomplete closure of stomata and the light-independence of the enzyme carbonic anhydrase, which complicates the use of COS as a tracer for gross primary productivity (GPP). In this study we derived nighttime COS fluxes in a boreal forest (the SMEAR II station in Hyytiälä, Finland; 61°51′ N, 24°17′ E, 181 m ASL) from June to November 2015 using two different methods: eddy-covariance (EC) measurements (FCOS-EC) and the radon-tracer method (FCOS-Rn). The nighttime COS fluxes averaged over the whole measurement period were −8.1 ± 1.5 and −7.9 ± 3.8 pmol m−2 s−1 for FCOS-Rn and FCOS-EC, respectively, which is 38 % of the average daytime fluxes and 21 % of the total daily COS uptake. The correlation of 222Radon (of which the source is the soil) with COS (average R2 = 0.59) was lower than with CO2 (0.79), suggesting that the main sink of COS is not located at the ground. These observations are supported by soil chamber measurements that show that soil contributes to only 33 % of the total nighttime COS uptake. We found a decrease of COS uptake with decreasing night-time stomatal conductance and increasing VPD and air temperature, driven by stomatal closure in response to a warm and dry period in August. We also discuss the effect that canopy layer mixing can have on the radon-tracer method and the sensitivity of FCOS-EC to atmospheric turbulence. Our results suggest that the nighttime uptake of COS is mainly driven by the tree foliage and is significant in a boreal forest, such that it needs to be taken into account when using COS as a tracer for GPP.

scholarly journals Supplementary material to "Canopy uptake dominates nighttime carbonyl sulfide fluxes in a boreal forest"

2017 ◽  
Author(s):  
Linda M. J. Kooijmans ◽  
Kadmiel Maseyk ◽  
Ulli Seibt ◽  
Wu Sun ◽  
Timo Vesala ◽  
...  
Keyword(s):  
Boreal Forest ◽  
Carbonyl Sulfide ◽  
Canopy Uptake ◽  
Supplementary Material

scholarly journals Stomatal control of leaf fluxes of carbonyl sulfide and CO<sub>2</sub> in a <i>Typha</i> freshwater marsh

2018 ◽  
Vol 15 (11) ◽  
pp. 3277-3291 ◽  
Author(s):  
Wu Sun ◽  
Kadmiel Maseyk ◽  
Céline Lett ◽  
Ulli Seibt
Keyword(s):  
Stomatal Closure ◽  
Carbonyl Sulfide ◽  
Co2 Assimilation ◽  
Stomatal Resistance ◽  
Freshwater Marsh ◽  
Co2 Uptake ◽  
Stomatal Control ◽  
Environmental Controls ◽  
High Vapor ◽  
Assimilation Capacity

Abstract. Carbonyl sulfide (COS) is an emerging tracer to constrain land photosynthesis at canopy to global scales, because leaf COS and CO2 uptake processes are linked through stomatal diffusion. The COS tracer approach requires knowledge of the concentration normalized ratio of COS uptake to photosynthesis, commonly known as the leaf relative uptake (LRU). LRU is known to increase under low light, but the environmental controls over LRU variability in the field are poorly understood due to scant leaf scale observations. Here we present the first direct observations of LRU responses to environmental variables in the field. We measured leaf COS and CO2 fluxes at a freshwater marsh in summer 2013. Daytime leaf COS and CO2 uptake showed similar peaks in the mid-morning and late afternoon separated by a prolonged midday depression, highlighting the common stomatal control on diffusion. At night, in contrast to CO2, COS uptake continued, indicating partially open stomata. LRU ratios showed a clear relationship with photosynthetically active radiation (PAR), converging to 1.0 at high PAR, while increasing sharply at low PAR. Daytime integrated LRU (calculated from daytime mean COS and CO2 uptake) ranged from 1 to 1.5, with a mean of 1.2 across the campaign, significantly lower than the previously reported laboratory mean value (∼ 1.6). Our results indicate two major determinants of LRU – light and vapor deficit. Light is the primary driver of LRU because CO2 assimilation capacity increases with light, while COS consumption capacity does not. Superimposed upon the light response is a secondary effect that high vapor deficit further reduces LRU, causing LRU minima to occur in the afternoon, not at noon. The partial stomatal closure induced by high vapor deficit suppresses COS uptake more strongly than CO2 uptake because stomatal resistance is a more dominant component in the total resistance of COS. Using stomatal conductance estimates, we show that LRU variability can be explained in terms of different patterns of stomatal vs. internal limitations on COS and CO2 uptake. Our findings illustrate the stomata-driven coupling of COS and CO2 uptake during the most photosynthetically active period in the field and provide an in situ characterization of LRU – a key parameter required for the use of COS as a photosynthetic tracer.

scholarly journals Soil fluxes of carbonyl sulfide (COS), carbon monoxide, and carbon dioxide in a boreal forest in southern Finland

2018 ◽  
Vol 18 (2) ◽  
pp. 1363-1378 ◽  
Author(s):  
Wu Sun ◽  
Linda M. J. Kooijmans ◽  
Kadmiel Maseyk ◽  
Huilin Chen ◽  
Ivan Mammarella ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Soil Respiration ◽  
Boreal Forest ◽  
Boreal Forests ◽  
Carbonyl Sulfide ◽  
Co2 Flux ◽  
Growing Season ◽  
Uptake Rates ◽  
Scots Pine Forest ◽  
Microbial Groups

Abstract. Soil is a major contributor to the biosphere–atmosphere exchange of carbonyl sulfide (COS) and carbon monoxide (CO). COS is a tracer with which to quantify terrestrial photosynthesis based on the coupled leaf uptake of COS and CO2, but such use requires separating soil COS flux, which is unrelated to photosynthesis, from ecosystem COS uptake. For CO, soil is a significant natural sink that influences the tropospheric CO budget. In the boreal forest, magnitudes and variabilities of soil COS and CO fluxes remain poorly understood. We measured hourly soil fluxes of COS, CO, and CO2 over the 2015 late growing season (July to November) in a Scots pine forest in Hyytiälä, Finland. The soil acted as a net sink of COS and CO, with average uptake rates around 3 pmol m−2 s−1 for COS and 1 nmol m−2 s−1 for CO. Soil respiration showed seasonal dynamics controlled by soil temperature, peaking at around 4 µmol m−2 s−1 in late August and September and dropping to 1–2 µmol m−2 s−1 in October. In contrast, seasonal variations of COS and CO fluxes were weak and mainly driven by soil moisture changes through diffusion limitation. COS and CO fluxes did not appear to respond to temperature variation, although they both correlated well with soil respiration in specific temperature bins. However, COS : CO2 and CO : CO2 flux ratios increased with temperature, suggesting possible shifts in active COS- and CO-consuming microbial groups. Our results show that soil COS and CO fluxes do not have strong variations over the late growing season in this boreal forest and can be represented with the fluxes during the photosynthetically most active period. Well-characterized and relatively invariant soil COS fluxes strengthen the case for using COS as a photosynthetic tracer in boreal forests.

scholarly journals Hydrogen soil deposition at an urban site in Finland

2009 ◽  
Vol 9 (21) ◽  
pp. 8559-8571 ◽  
Author(s):  
M. Lallo ◽  
T. Aalto ◽  
J. Hatakka ◽  
T. Laurila
Keyword(s):  
Deposition Velocity ◽  
Photochemical Reactions ◽  
Urban Site ◽  
Two Dimensional ◽  
Tracer Method ◽  
Closed Chamber ◽  
Radon Exhalation ◽  
Radon Exhalation Rates ◽  
Soil Deposition ◽  
Chamber Measurements

Abstract. Hydrogen deposition velocities (vd) were estimated by field chamber measurements and model simulations. A closed-chamber method was used for soil deposition studies in Helsinki, Finland, at an urban park inhabited by broad-leaved trees. Radon tracer method was used to estimate the vd in nighttime when photochemical reactions were minimal and radon gas was concentrated in the shallow boundary layer due to exhalation from soil. A two-dimensional atmospheric model was used for the calculation of respective vd values and radon exhalation rates. The vd and radon exhalation rates were lower in winter than in summer according to all methods. The radon tracer method and the two-dimensional model results for hydrogen deposition velocity were in the range of 0.13 mm s−1 to 0.93 mm s−1 (radon tracer) and 0.12 mm s−1 to 0.61 mm s−1 (two-dimensional). The soil chamber results for vd were 0.00 mm s−1 to 0.70 mm s−1. Both models and chamber measurements revealed a relation between one week cumulative rain sum and deposition velocity. When precipitation events occurred a few days before the chamber measurements, lower vd values were observed. A snow cover also lowered vd.

scholarly journals Consumption of atmospheric carbonyl sulfide by coniferous boreal forest soils

1999 ◽  
Vol 104 (D9) ◽  
pp. 11569-11576 ◽  
Author(s):  
Jeffrey S. Simmons ◽  
Leif Klemedtsson ◽  
Hans Hultberg ◽  
Mark E. Hines
Keyword(s):  
Boreal Forest ◽  
Forest Soils ◽  
Carbonyl Sulfide ◽  
Coniferous Boreal Forest

scholarly journals Supplementary material to "Long-term fluxes of carbonyl sulfide and their seasonality and interannual variability in a boreal forest"

2021 ◽  
Author(s):  
Timo Vesala ◽  
Kukka-Maaria Kohonen ◽  
Arnaud P. Praplan ◽  
Linda M. J. Kooijmans ◽  
Lenka Foltýnová ◽  
...  
Keyword(s):  
Boreal Forest ◽  
Interannual Variability ◽  
Carbonyl Sulfide ◽  
Supplementary Material

scholarly journals Hydrogen soil deposition at an urban site in Finland

2009 ◽  
Vol 9 (4) ◽  
pp. 14873-14899 ◽  
Author(s):  
M. Lallo ◽  
T. Aalto ◽  
J. Hatakka ◽  
T. Laurila
Keyword(s):  
Deposition Velocity ◽  
Atmospheric Model ◽  
Photochemical Reactions ◽  
Urban Site ◽  
Two Dimensional ◽  
Tracer Method ◽  
Closed Chamber ◽  
Radon Exhalation ◽  
Soil Deposition ◽  
Chamber Measurements

Abstract. Hydrogen deposition velocities (v_d) were estimated by field chamber measurements and model simulations. A closed-chamber method was used for soil deposition studies in Helsinki, Finland, at an urban park inhabited by broad-leaved trees. Radon tracer method was used to estimate the v_d in nighttime when photochemical reactions were minimal and radon gas was concentrated to shallow boundary layer due to exhalation from soil. A two-dimensional atmospheric model was used for calculation of respective v_d values and radon exhalation rate. v_d and radon exhalation rates were lower in winter than in summer according to all methods. The radon tracer method and two-dimensional model results for hydrogen deposition velocity were in the range of 0.13 mm s−1 to 0.90 mm s−1 (radon tracer) and 0.12 mm s−1 to 0.61 mm s−1 (two-dimensional). The soil chamber results for v_d were 0.00 mm s−1 to 0.70 mm s−1. Both models and chamber measurements revealed relation between one week cumulative rain sum and deposition velocity. Lower v_d values were usually measured in high soil moisture conditions. Precipitation occurring a few days before chamber measurements decreased v_d values. The snow cover also lowered v_d.

scholarly journals Soil fluxes of carbonyl sulfide (COS), carbon monoxide, and carbon dioxide in a boreal forest in southern Finland

2017 ◽  
Author(s):  
Wu Sun ◽  
Linda M. J. Kooijmans ◽  
Kadmiel Maseyk ◽  
Huilin Chen ◽  
Ivan Mammarella ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Soil Respiration ◽  
Boreal Forest ◽  
Carbonyl Sulfide ◽  
Co2 Flux ◽  
Growing Season ◽  
Natural Environments ◽  
Uptake Rates ◽  
Scots Pine Forest ◽  
Microbial Groups

Abstract. Soil is a major contributor to the biosphere–atmosphere exchange of carbonyl sulfide (COS) and carbon monoxide (CO). COS is used to improve constraints on terrestrial photosynthesis based on the link between leaf uptake of COS and of CO2, but this use requires the soil COS flux to be well quantified. For CO, soil is a main sink in natural environments that influences the tropospheric CO budget. We measured soil fluxes of COS, CO, and CO2 hourly over the 2015 late growing season in a Scots pine forest in Hyytiälä, Finland. The soil acted as a net sink of COS and CO. Average uptake rates were around 3 pmol m−2 s−1 for COS, and 1 nmol m−2 s−1 for CO, respectively. Soil respiration showed seasonal dynamics controlled by soil temperature, peaking in late August and September with fluxes around 4 μmol m−2 s−1 and dropping to 1–2 μmol m−2 s−1 in October. In contrast, seasonal variations of COS and CO fluxes were weak and mainly driven by soil moisture changes through diffusion limitation. COS and CO fluxes did not appear to respond to temperature, although they both correlated well with soil respiration in specific temperature bins. We found that COS : CO2 and CO : CO2 flux ratios were modulated by temperature, possibly indicating shifts in active COS and CO-consuming microbial groups. Our results show that soil COS and CO uptake do not have strong variations over the late growing season in the boreal forest, and can be well described during the photosynthetically most active period. Well characterized and relatively invariant soil COS fluxes strengthen the case for using COS as a tracer for photosynthesis in this globally important biome.

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