Plant growth form more important than temperature in controlling CH{sub 4} flux in Alaskan tundra communities

Journal Article · Fri Sep 01 04:00:00 EDT 1995 · Bulletin of the Ecological Society of America

OSTI ID:107149

Verville, J H; Chapin, III, F S; Hobbie, S E ^[1]

---

1. Univ. of California, Berkeley, CA (United States)

We conducted species removals, vegetation and soil transplants, and air temperature manipulations in Alaskan wet meadow and upland tussock tundra communities to determine the relative importance of vegetation type and environmental variables in controlling CH{sub 4} flux. Removal of sedges in the wet meadow community significantly decreased CH{sub 4} flux, while moss removal had no significant effects on emissions. At 15 cm depth, pore water CH{sub 4} concentrations were higher in sedge removals, relative to control plots, suggesting that sedges contribute to CH{sub 4} emissions by transporting CH{sub 4} from anaerobic soil to the atmosphere, rather than by promoting methanogenesis. In reciprocal ecosystem transplants between the wet meadow and upland tussock tundra communities, CH{sub 4} flux was higher in the wet meadow site, but was unrelated to transplant origin. Soil temperature, thaw depth, and water table depth were correlated with CH{sub 4} flux, but their relative importance on a local level varied throughout the season. Plastic greenhouses placed over the wet meadow species removal plots increased soil moisture and air and soil temperatures, but did not affect CH{sub 4} flux. These results suggest that future changes in CH{sub 4} flux in response to climatic change will be more strongly mediated by large-scale changes in soil moisture and vegetation than by direct temperature effects on CH{sub 4} emissions.

• OSTI ID: 107149
• Report Number(s): CONF-9507129--
• Journal Information: Bulletin of the Ecological Society of America, Journal Name: Bulletin of the Ecological Society of America Journal Issue: 3 Vol. 76; ISSN BECLAG; ISSN 0012-9623
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
AMBIENT TEMPERATURE
ECOLOGICAL CONCENTRATION
EMISSION
METHANE
MORPHOLOGY
PLANTS
RESPONSE MODIFYING FACTORS
TUNDRA