Greenhouse Gas Response to Simulated Precipitation Extremes in Alpine River Source Wetlands During the Growing Season
Against the backdrop of climate warming leading to an increase in extreme weather events, extreme precipitation events have become more frequent, and the impact of changes in precipitation on ecosystems cannot be ignored. There is a scarcity of field in situ observational data on greenhouse gas emis...
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| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2025-04-01
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| Series: | Atmosphere |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2073-4433/16/5/526 |
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| Summary: | Against the backdrop of climate warming leading to an increase in extreme weather events, extreme precipitation events have become more frequent, and the impact of changes in precipitation on ecosystems cannot be ignored. There is a scarcity of field in situ observational data on greenhouse gas emissions during the growing season for alpine wetlands, especially for alpine river source wetlands, which limits our understanding of the ability of alpine wetland ecosystems to convert between carbon sources and carbon sinks and also hinders our comprehension of the primary effects of extreme precipitation events on wetland ecosystems. In this study, we investigated the main greenhouse gas emission fluxes in two consecutive growing seasons (May to September) under the conditions of natural control (CK), 75% increase in precipitation (IP), and 75% decrease in precipitation (DP) through in situ field simulations of extreme precipitation in an alpine source wetland in the Qinghai Lake Basin of the Qinghai–Tibet Plateau. The results indicate the following: (1) The extreme precipitation increase (IP) treatment did not significantly increase CO<sub>2</sub> fluxes; it promoted CH<sub>4</sub> flux emissions by 168.2% and N<sub>2</sub>O flux emissions by 178.4% over the two growing seasons. The extreme precipitation decrease treatment had a non-significant impact on CO<sub>2</sub> fluxes; it inhibited CH<sub>4</sub> emission fluxes by 96.8% and promoted N<sub>2</sub>O emission fluxes by 137.8%. (2) During the growing season, CO<sub>2</sub> fluxes were 2.2% lower in the IP treatment than in the DP treatment under the two precipitation patterns; the CH<sub>4</sub> flux under the IP treatment is 84.1% higher than that under the DP treatment, and N<sub>2</sub>O fluxes were 43.8% lower in the IP treatment than in the DP treatment. CH<sub>4</sub> fluxes were the most sensitive to precipitation changes. (3) The extreme changes in precipitation were not the main influencing factor for CO<sub>2</sub> fluxes, while CH<sub>4</sub> fluxes were primarily affected by precipitation changes. (4) During the entire growing season, IP reduced the global warming potential (GWP) by 9.03%, and DP decreased GWP by 8.40%. These results suggest that the primary driver of CO<sub>2</sub> fluxes in alpine river source wetlands remains temperature factors; in scenarios where extreme climate events occur frequently, both extreme increases and decreases in precipitation have inhibitory effects on the global warming potential of alpine river source wetlands. |
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| ISSN: | 2073-4433 |