Publication Date:
2018-03-09
Description:
Carbonyl sulfide (OCS) has recently emerged as a tracer for terrestrial carbon uptake. While physiological studies relating OCS fluxes to leaf stomatal dynamics have been established at leaf and branch scales and incorporated in global carbon cycle models, the quantity of data from ecosystem-scale field studies remains limited. In this study we employ established theoretical relationships to infer ecosystem-scale OCS uptake from concentration measurements. OCS uptake was found to scale with independent measurements of CO2 fluxes over a 60-m-tall old-growth forest in the Pacific Northwestern U.S. (45°49′13.76′′N; 121°57′06.88′′) at hourly and monthly timescales across the growing season in 2015. OCS fluxes tracked changes in soil moisture, and were strongly influenced by the fraction of downwelling diffuse light. Fluxes were also strongly affected by sequential heat waves during the growing season. Our results bolster previous evidence that ecosystem OCS uptake is strongly related to stomatal dynamics, and measuring this gas improves constraints on estimating photosynthetic rates at the ecosystem scale.
Print ISSN:
1810-6277
Electronic ISSN:
1810-6285
Topics:
Biology
,
Geosciences