The balance between methane emissions and uptake in a pond-grassland ecosystem: Evidence for high temperature-sensitivity of emissions
- Univ. of California, Irvine, CA (United States)
Methane emissions and uptake were studied in an annual grassland and in seasonally-flooded soils near a pond in California from 1991 to 1993. The pond margin emitted methane (0-229 mg CH{sub 4} m{sup -2} d{sup -1}). Uptake by the grasslands averaged -0.7 mg CH{sub 4} m{sup -2} d{sup -1}, and annual uptake was highly and positively correlated with soil carbon and nitrogen content (R{sup 2} = 0.97; n=5 sites) with no significant effect of sheep grazing. Field experiments were used to determine if emissions and uptake differed in their response to variation in temperature and moisture. Methane production and consumption responded differently to changes in temperature and moisture. Methane emissions were positively correlated with soil temperature, whereas methane uptake was not significantly related to temperature. The effective temperature response for emissions (e.g., Q{sub 10}) from locations with simultaneous production and consumption was much larger than the Q{sub 10} for production alone, a result with widespread implications. A model that incorporates both the differential effect of temperature on emissions and uptake, and the balance of production and consumption, predicts three times more change in global ecosystems emissions in response to warming than does a model that ignores these two features and includes only net methane release.
- OSTI ID:
- 95896
- Report Number(s):
- CONF-9507129-; ISSN 0012-9623; TRN: 95:004728-0164
- Journal Information:
- Bulletin of the Ecological Society of America, Vol. 76, Issue 2; Conference: 80. anniversary of the transdisciplinary nature of ecology, Snowbird, UT (United States), 30 Jul - 3 Aug 1995; Other Information: PBD: Jun 1995
- Country of Publication:
- United States
- Language:
- English
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