Isoprene emission from a subarctic peatland under enhanced UV-B radiation.
Isoprene is a reactive hydrocarbon with an important role in atmospheric chemistry, and emissions from vegetation contribute to atmospheric carbon fluxes. The magnitude of isoprene emissions from arctic peatlands is not known, and it may be altered by increasing UV-B radiation. Isoprene emission was measured with the dynamic chamber method from a subarctic peatland under long-term enhancement of UV-B radiation targeted to correspond to a 20% loss in the stratospheric ozone layer. The site type of the peatland was a flark fen dominated by the moss Warnstorfia exannulata and sedges Eriophorum russeolum and Carex limosa. The relationship between species densities and the emission was also assessed. Isoprene emissions were significantly increased by enhanced UV-B radiation during the second (2004) and the fourth (2006) growing seasons under the UV-B exposure. Emissions were related to the density of E. russeolum. The dominant moss, W. exannulata, proved to emit small amounts of isoprene in a laboratory trial. Subarctic fens, even without Sphagnum moss, are a significant source of isoprene to the atmosphere, especially under periods of warm weather. Warming of the Arctic together with enhanced UV-B radiation may substantially increase the emissions.
Tiiva
Päivi
P
Department of Environmental Science, University of Kuopio, PO Box 1627, FI-70211 Kuopio, Finland.
Rinnan
Riikka
R
Department of Environmental Science, University of Kuopio, PO Box 1627, FI-70211 Kuopio, Finland.|Department of Terrestrial Ecology, Institute of Biology, University of Copenhagen, Øster Farimagsgade 2D, DK-1353 Copenhagen K, Denmark.
Faubert
Patrick
P
Department of Environmental Science, University of Kuopio, PO Box 1627, FI-70211 Kuopio, Finland.
Räsänen
Janne
J
Department of Environmental Science, University of Kuopio, PO Box 1627, FI-70211 Kuopio, Finland.
Holopainen
Toini
T
Department of Environmental Science, University of Kuopio, PO Box 1627, FI-70211 Kuopio, Finland.
Kyrö
Esko
E
Finnish Meteorological Institute, Arctic Research Center, FI-99600 Sodankylä, Finland.
Holopainen
Jarmo K
JK
Department of Environmental Science, University of Kuopio, PO Box 1627, FI-70211 Kuopio, Finland.
D001110:Arctic Regions; D019068:Bryopsida / Q000254:growth & development / Q000378:metabolism / Q000528:radiation effects; D002070:Butadienes / Q000032:analysis*; D002244:Carbon / Q000378:metabolism; D031255:Carex Plant / Q000254:growth & development / Q000378:metabolism / Q000528:radiation effects; D029785:Cyperaceae / Q000254:growth & development / Q000378:metabolism / Q000528:radiation effects; D017753:Ecosystem; D045782:Hemiterpenes / Q000032:analysis*; D010420:Pentanes / Q000032:analysis*; D011156:Population Density; D012987:Soil / Q000032:analysis*; D014466:Ultraviolet Rays
D002070:Butadienes; D045782:Hemiterpenes; D010420:Pentanes; D012987:Soil; C005059:isoprene; D002244:Carbon