Jari Huttunen , Hannu Nykänen, Jukka Turunen, Olli Nenonen, Pertti Martikainen

Typpioksiduulivirrat suunnitellun Vuotoksen tekojärven alueen soilta

Huttunen J., Nykänen H., Turunen J., Nenonen O., Martikainen P. Typpioksiduulivirrat suunnitellun Vuotoksen tekojärven alueen soilta.

Tiivistelmä

Nitrous oxide (N2O) fluxes were measured on ten natural minerotrophic peatlands in an area planned for a hydroelectric reservoir (Vuotos) in northern Finland. The mean N2O fluxes from the sites with mean water tables from –25 to 3.4 cm (negative below the peat surface) ranged from –30 to 230 µg m–2 d–1 during summer 1994. At the driest site, the herb-grass spruce mire with the mean water table at –38 cm, the mean summertime N2O emission was 940 µg m-2 d-1 in 1994, attributable to the increased N2O release at low peat temperatures in autumn. A similar increase in the N2O emissions was not found in 1995, as the measurements were finished before the peat started to freeze. The mean N2O fluxes at the sites correlated negatively with the mean water table levels. The peatlands in the northern boreal zone are unlikely important sources of atmospheric N2O in their natural state. The planned reservoir would barely have large long-term N2O emissions from the pelagic zone, but the importance of temporally flooded areas in the postflood N2O release is uncertain similar to the short-term emissions following the flooding.

Avainsanat
global change; Northern boreal peatlands; climate warming; flooding; greenhouse gas emission; hydro dam

Vastaanotettu 31.10.2017 Julkaistu 1.1.2002

Katselukerrat 3431

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