Plant Production, Decomposition, and Carbon Efflux in a Subarctic Patterned Fen

作者：Tim R. Moore · 发表于：Arctic and Alpine Research · 年份：1989 · DOI：10.2307/1551627 · 被引用次数：60 · 研究领域：Peatlands and Wetlands Ecology、Geology and Paleoclimatology Research、Fire effects on ecosystems

Measurements of plant biomass and primary productivity, plant-tissue decomposition, and gas flux were made at sites representing strings, flarks, and pools in a strongly patterned fen near Schefferville, northern Quebec. Biomass and production were strongly related to the position of the water table, with biomass ranging from an average of 190 g m-2 on the strings to 7 g m-2 in the pools. Scirpus cespitosus shoots and Chamaedaphne calyculata leaves decomposed slowly at both string and pool sites, losing 25 to 35% of their mass after 3 yr. In contrast, Menyanthes trifoliata, characteristic of the deeper pools, lost 80%7 of its mass after 3 yr. Carbon dioxide dominated the gas flux at the string site, but there were significant fluxes of methane at the flark and pool sites (7-8 g m-2 yr-'). A carbon budget, based on production and gas flux, suggested that the string site gained carbon at about 40 g m-2 yr-', whereas the flark site (with the water surface very close to the peat surface) lost about 15 g m-2 yr-' and the pool site (with the water surface about 25 cm above the peat surface) showed a very small loss (about 2 g m-2 yr-'). The results show that differential rates of plant production, combined with differences in the rates of plant tissue decomposition and methane efflux, contribute to the expansion of the flark/pool morphology at the present time.