Precipitation changes regulate the annual methane uptake in a temperate desert steppe

A - Papers appearing in refereed journals

Yue, P., Zuo, X., Li, K., Li, X., Wang, S. and Misselbrook, T. H. 2021. Precipitation changes regulate the annual methane uptake in a temperate desert steppe. Science of the Total Environment. 804 (15 January 2022), p. 150172. https://doi.org/10.1016/j.scitotenv.2021.150172

AuthorsYue, P., Zuo, X., Li, K., Li, X., Wang, S. and Misselbrook, T. H.
Abstract

Desert soils are an important sink of atmospheric methane (CH4) and regulate the global CH4 budget. However, it is still unclear how CH4 fluxes respond to precipitation changes in desert-steppe soils. Therefore, a two-year in situ control experiment was conducted to investigate the effect of precipitation changes on CH4 uptake in desert steppe of Inner Mongolia in northwest China and its driving mechanism. The result showed that this desert steppe was an important sink of CH4. with an annual uptake of 2.93 (2.64-322) kg C ha(-1). It was found that CH4 uptake was reduced significantly for decreasing precipitation, especially in spring and summer. In contrast, an increasing trend of CH4 uptake was observed for increasing precipitation, although it was not statistically significant. Further analyses found that CH4 uptake was more sensitive to decreasing precipitation than increasing precipitation. This may be mainly due to the fact that only moderate water-filled pore space (WFPS) induced by precipitation promoted CH4 uptake, while too-high (>32%) or too-low WFPS inhibited its uptake. A structural equation model showed that the copy number of the pmoA functional gene was the most important factor affecting CH4 uptake. In contrast, soil moisture had a very important indirect effect on CH4 uptake, mainly through significantly affected soil porosity, the above-ground plant biomass and NO3--N content, further affected CH4 uptake. Overall. CH4 sinks in desert steppe was still mainly controlled by methane-oxidizing bacteria containing the key functional gene pmoA and WFPS. Therefore, precipitation plays an important role in regulating the intensity of CH4 sinks in desert steppe, while it is worth noting that too-little precipitation will significantly weaken CH4 sinks.

KeywordsPrecipitation changes; Methane flux; Functional genes; Temperate desert steppe
Year of Publication2021
JournalScience of the Total Environment
Journal citation804 (15 January 2022), p. 150172
Digital Object Identifier (DOI)https://doi.org/10.1016/j.scitotenv.2021.150172
Open accessPublished as non-open access
FunderBiotechnology and Biological Sciences Research Council
Funder project or codeS2N - Soil to Nutrition - Work package 2 (WP2) - Adaptive management systems for improved efficiency and nutritional quality
Output statusPublished
Publication dates
Online08 Sep 2021
Publication process dates
Accepted02 Sep 2021
PublisherElsevier Science Bv
ISSN0048-9697

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