Landscape patterns of CH 4 fluxes in an alpine tundra ecosystem

• Main Authors: West, A., Brooks, P., Fisk, M., Smith, L., Holland, E., Jaeger Iii, C., Babcock, S., Lai, R., Schmidt, S.
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: 1999
• Subjects: Tundra
• Online Access: http://hdl.handle.net/11858/00-001M-0000-000E-E1C8-2; http://hdl.handle.net/11858/00-001M-0000-000E-E1C7-4

We measured CH 4 fluxes from three major plant communities characteristic of alpine tundra in the Colorado Front Range. Plant communities in this ecosystem are determined by soil moisture regimes induced by winter snowpack distribution. Spatial patterns of CH 4 flux during the snow-free season corresponded roughly with these plant communities. In Carex- dominated meadows, which receive the most moisture from snowmelt, net CH 4 production occurred. However, CH 4 production in one Carex site (seasonal mean = +8.45 mg CH 4 m(-2) d(-1)) was significantly larger than in the other Carex sites (seasonal means = -0.06 and +0.05 mg CH 4 m(-2) d(-1)). This high CH 4 flux may have resulted from shallower snowpack during the winter. In Acomastylis meadows, which have an intermediate moisture regime, CH 4 oxidation dominated (seasonal mean = -0.43 mg CH 4 m(-2) d(-1)). In the windswept Kobresia meadow plant community, which receive the least amount of moisture from snowmelt, only CH 4 oxidation was observed (seasonal mean = - 0.77 mg CH 4 m(-2) d(-1)). Methane fluxes correlated with a different set of environmental factors within each plant community. In the Carex plant community, CH 4 emission was limited by soil temperature. In the Acomastylis meadows, CH 4 oxidation rates correlated positively with soil temperature and negatively with soil moisture. In the Kobresia community, CH 4 oxidation was stimulated by precipitation. Thus, both snow-free season CH 4 fluxes and the controls on those CH 4 fluxes were related to the plant communities determined by winter snowpack.We measured CH 4 fluxes from three major plant communities characteristic of alpine tundra in the Colorado Front Range. Plant communities in this ecosystem are determined by soil moisture regimes induced by winter snowpack distribution. Spatial patterns of CH 4 flux during the snow-free season corresponded roughly with these plant communities. In Carex-dominated meadows, which receive the most moisture from snowmelt, net CH 4 production occurred. However, CH 4 ...