This is an early access version, the complete PDF, HTML, and XML versions will be available soon.
Methane Flux Responses to Warming and Inundation in the Qinghai Lake Littoral Wetland
by
, ,
Hairui Zhao
1,2,3,
Ziwei Yang
2,3,4,
Yanfen Yang
2,3,4,
Mingzhu Cao
2,3,4,
Yuyu Ma
2,3,4,
Chen Chen
2,3,4,
Shuchang Zhu
2,3,4 and
Kelong Chen
2,3,4,* 1
School of Life Sciences, Qinghai Normal University, Xining 810008, China
2
Key Laboratory of Natural Geography and Environmental Processes of Qinghai Province, Xining 810008, China
3
Key Laboratory of Qinghai-Tibet Plateau Surface Process and Ecological Conservation, Ministry of Education, Qinghai Normal University, Xining 810008, China
4
School of Geographical Sciences, Qinghai Normal University, Xining 810008, China
*
Author to whom correspondence should be addressed.
Biology 2026, 15(11), 840; https://doi.org/10.3390/biology15110840
Submission received: 28 April 2026
/
Revised: 23 May 2026
/
Accepted: 25 May 2026
/
Published: 27 May 2026
(This article belongs to the Section Ecology)
Simple Summary
Global warming and altered flooding patterns significantly affect methane emissions from alpine wetlands. This study conducted a one-year experiment in the Qinghai Lake littoral wetland with warming and different inundation depths to explore their interactive effects on methane fluxes. The results showed that under flooding alone, methane emissions peaked in autumn. Warming not only changed the seasonal pattern of emissions but also caused anomalously high emissions in winter. Warming combined with deep flooding enhanced emissions in summer and autumn but suppressed them in winter. Soil carbon and nitrogen components were closely related to methane emissions, but this relationship was only significant in autumn. Overall, the interaction between warming and flooding on methane emissions is strongly season-specific, and autumn is a key window for carbon-nitrogen coupling driving methane emissions. Future climate warming and hydrological extremes may further increase the risk of methane release from littoral wetlands.
Abstract
This study investigated the interactive effects of warming and inundation on methane (CH4) fluxes and soil physicochemical mechanisms in the littoral wetland of Qinghai Lake. Soil samples were collected from the Bird Island littoral wetland. Eight treatments were established: natural control (CK), different inundation depths (S0, S10, S20), warming alone (ZWCK), and warming combined with inundation (ZW0, ZW10, ZW20). CH4 fluxes were measured over one year using an ABB LGR analyzer. Principal component analysis (PCA) and Mantel tests were used to identify environmental drivers. The main findings are as follows: (1) Under different water level treatments, CH4 fluxes showed a unimodal seasonal pattern, peaking in autumn. Warming and the interactive treatments shifted the emission pattern to bimodal or multimodal and significantly increased emission intensity. The warming-alone group had the highest annual emission, with anomalously high winter emission (47.683 μg·m−2·h−1). Under the ZW20 treatment, emissions were synergistically enhanced in summer and autumn but turned to suppression in winter. (2) PCA showed that the carbon nitrogen pool (70.5%) and the salinity pH gradient (14.9%) were the main drivers of soil variation. The interactive effects on carbon-nitrogen dynamics shifted with season: warming promoted accumulation in spring; warming with shallow inundation retained carbon-nitrogen in summer, but deep inundation caused loss; warming with deep inundation formed a nutrient center in autumn; inundation dominated accumulation in winter, while warming increased loss. (3) Mantel tests showed that carbon-nitrogen components were highly correlated across seasons, but were strongly and positively correlated with CH4 flux only in autumn (Mantel’s r ≥ 0.4, p < 0.05), indicating autumn as the key window. These findings provide important insights into carbon cycling processes and regulatory mechanisms of alpine wetlands under future climate change scenarios.
