@article{gledocs_11858_9373,
author = {Komiya, Shujiro and Yazaki, Tomotsugu and Kondo, Fumiyoshi and Katano, Kentaro and Lavric, Jost V. and McTaggart, Iain and Pakoktom, Tiwa and Siangliw, Meechai and Toojinda, Theerayut and Noborio, Kosuke},
title = {Stable Carbon Isotope Studies of CH4 Dynamics Via Water and Plant Pathways in a Tropical Thai Paddy: Insights Into Diel CH4 Transportation},
year = {2020},
volume = {125},
number = {9},

abstract = {Separate evaluation of methane (CH4) emission dynamics (e.g., oxidation, production, and transportation) at the soil-plant-atmosphere and soil-water-atmosphere interfaces has been limited in tropical rice paddies, but it is crucial for comprehending the entire CH4 cycles. We investigated CH4 oxidation, production, and transportation through plant and water pathways during the reproductive stage in a tropical Thailand rice paddy field using natural abundance carbon stable isotope ratios (δ13CH4 and δ13CO2). Mass balance equations using δ13CH4 and δ13CO2 in soil gases indicated that CH4 oxidation in the planted soil exceeded those in the interrow soil due to oxygen supply through rice roots. In addition, at 1–11 cm depth acetate fermentation was the dominant process in the planted soil, whereas in the interrow soil the dominant process was H2/CO2 reduction. The water pathway showed a significant negative correlation between CH4 flux and released δ13CH4 over 24 hr, driven by a diel change in episodic ebullition, steady ebullition, and diffusion, all due to diel changes in soil temperature and atmospheric pressure. In contrast, the plant pathway showed a significant positive relationship between CH4 flux and emitted δ13CH4 throughout one day. A comparison of the diel change in emitted δ13CH4 between the water and plant pathways showed that the rice plants transported CH4 in soil bubbles without any large isotopic fractionation. The diel change in the plant-mediated CH4 transportation was mainly controlled by diel changes in soil bubble expansion and CH4 diffusion through plants, which were probably regulated by diel changes in soil temperature and atmospheric pressure.},
note = { \url {http://resolver.sub.uni-goettingen.de/purl?gldocs-11858/9373}},
}