Carbonyl sulfide (COS) as a tracer for canopy photosynthesis, transpiration and stomatal conductance: potential and limitations†

Wohlfahrt, Georg; Brilli, Federico; Hörtnagl, Lukas; Xu, Xiangde; Bingemer, Heinz; Hansel, Armin; Loreto, Francesco

doi:10.1111/j.1365-3040.2011.02451.x

Cited by 97 publications

(137 citation statements)

References 48 publications

Supporting

Mentioning

114

Contrasting

Order By: Relevance

“…Indeed, the uptake rate of OCS by foliage is strongly related to GPP (SandovalSoto et al, 2005;Stimler et al, 2010) or more generally to the rate of CO 2 transfer into foliage (e.g. Seibt et al, 2010;Wohlfahrt et al, 2011). This is because both OCS and CO 2 molecules diffuse into foliage through the same stomatal pores and through mesophyll cells, where they are rapidly hydrated in an enzymatic reaction with carbonic anhydrase (CA) (Protoschill-Krebs and Kesselmeier, 1992).…”

Section: J Ogée Et Al: a New Mechanistic Framework To Predict Ocs Fmentioning

confidence: 99%

A new mechanistic framework to predict OCS fluxes from soils

Ogée¹,

et al. 2016

View full text Add to dashboard Cite

Abstract.Estimates of photosynthetic and respiratory fluxes at large scales are needed to improve our predictions of the current and future global CO 2 cycle. Carbonyl sulfide (OCS) is the most abundant sulfur gas in the atmosphere and has been proposed as a new tracer of photosynthetic gross primary productivity (GPP), as the uptake of OCS from the atmosphere is dominated by the activity of carbonic anhydrase (CA), an enzyme abundant in leaves that also catalyses CO 2 hydration during photosynthesis. However soils also exchange OCS with the atmosphere, which complicates the retrieval of GPP from atmospheric budgets. Indeed soils can take up large amounts of OCS from the atmosphere as soil microorganisms also contain CA, and OCS emissions from soils have been reported in agricultural fields or anoxic soils. To date no mechanistic framework exists to describe this exchange of OCS between soils and the atmosphere, but empirical results, once upscaled to the global scale, indicate that OCS consumption by soils dominates OCS emission and its contribution to the atmospheric budget is large, at about one third of the OCS uptake by vegetation, also with a large uncertainty. Here, we propose a new mechanistic model of the exchange of OCS between soils and the atmosphere that builds on our knowledge of soil CA activity from CO 2 oxygen isotopes. In this model the OCS soil budget is described by a first-order reaction-diffusion-production equation, assuming that the hydrolysis of OCS by CA is total and irreversible. Using this model we are able to explain the observed presence of an optimum temperature for soil OCS uptake and show how this optimum can shift to cooler temperatures in the presence of soil OCS emission. Our model can also explain the observed optimum with soil moisture content previously described in the literature as a result of diffusional constraints on OCS hydrolysis. These diffusional constraints are also responsible for the response of OCS uptake to soil weight and depth observed previously. In order to simulate the exact OCS uptake rates and patterns observed on several soils collected from a range of biomes, different CA activities had to be invoked in each soil type, coherent with expected physiological levels of CA in soil microbes and with CA activities derived from CO 2 isotope exchange measurements, given the differences in affinity of CA for both trace gases. Our model can be used to help upscale laboratory measurements to the plot or the region. Several suggestions are given for future experiments in order to test the model further and allow a better constraint on the large-scale OCS fluxes from both oxic and anoxic soils.

show abstract

Section: J Ogée Et Al: a New Mechanistic Framework To Predict Ocs Fmentioning

confidence: 99%

A new mechanistic framework to predict OCS fluxes from soils

Ogée¹,

et al. 2016

View full text Add to dashboard Cite

show abstract

“…For soil fluxes, underpressure seems more problematic than overpressure, because it would siphon up the soil pore air that is usually enriched in CO 2 by a few orders of magnitude. To prevent pressure-related flux biases, we set the inlet flow slightly higher than the outlet flow, with the small residual flow (approximately 0.1 slpm) equilibrated through a vent at the top of the chamber (Xu et al, 2006). The residual flow that was dissipated would not affect the mass balance calculation, because fluxes were always calculated using the flow rates measured at the inlet.…”

Section: Methodsmentioning

confidence: 99%

“…Because of the irreversible COS hydrolysis in leaves, COS is taken up concurrently with CO 2 through stomata and is not emitted back from leaves (Sandoval-Soto et al, 2005;Stimler et al, 2010). This allows COS to serve as a tracer with which to quantify terrestrial photosynthesis independently from respiration (Montzka et al, 2007;Campbell et al, 2008;Seibt et al, 2010;Wohlfahrt et al, 2012;Asaf et al, 2013;Berry et al, 2013;Billesbach et al, 2014;Maseyk et al, 2014).…”

mentioning

confidence: 99%

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

et al. 2018

View full text Add to dashboard Cite

Abstract. Soil is a major contributor to the biosphereatmosphere 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 CO 2 , 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 CO 2 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 : CO 2 and CO : CO 2 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.

show abstract

“…It has a greenhouse gas effect based on absorption of far-infrared radiation (Brühl et al, 2012). OCS is also found as a potential trace gas, other than carbon dioxide, that could provide independent information about carbon cycle processes (Montzka et al, 2007;Campbell et al, 2008;Suntharalingam et al, 2008;Wohlfahrt et al, 2012;Blonquist et al, 2011;Berry et al, 2013). For example, recent work by Campbell et al (2008) suggests that carbonyl sulfide is a good photosynthetic tracer.…”

Section: Introductionmentioning

confidence: 99%

Characterization of Aura TES carbonyl sulfide retrievals over ocean

et al. 2014

View full text Add to dashboard Cite

Abstract. We present a description of the NASA Aura Tropospheric Emission Spectrometer (TES) carbonyl sulfide (OCS) retrieval algorithm for oceanic observations, along with evaluation of the biases and uncertainties using aircraft profiles from the HIPPO (HIAPER Pole-to-Pole Observations) campaign and data from the NOAA Mauna Loa site. In general, the OCS retrievals (1) have less than 1.0 degree of freedom for signals (DOFs), (2) are sensitive in the mid-troposphere with a peak sensitivity typically between 300 and 500 hPa, (3) but have much smaller systematic errors from temperature, CO 2 and H 2 O calibrations relative to random errors from measurement noise. We estimate the monthly means from TES measurements averaged over multiple years so that random errors are reduced and useful information about OCS seasonal and latitudinal variability can be derived. With this averaging, TES OCS data are found to be consistent (within the calculated uncertainties) with NOAA ground observations and HIPPO aircraft measurements. TES OCS data also captures the seasonal and latitudinal variations observed by these in situ data.

show abstract

Carbonyl sulfide (COS) as a tracer for canopy photosynthesis, transpiration and stomatal conductance: potential and limitations†

Cited by 97 publications

References 48 publications

A new mechanistic framework to predict OCS fluxes from soils

A new mechanistic framework to predict OCS fluxes from soils

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

Characterization of Aura TES carbonyl sulfide retrievals over ocean

Contact Info

Product

Resources

About