Advanced

Carbon dioxide balance of a fen ecosystem in northern Finland under elevated UV-B radiation

Haapala, Jaana K.; Morsky, Sami K.; Saarnio, Sanna; Rinnan, Riikka LU ; Suokanerva, Hanne; Kyro, Esko; Latola, Kirsi; Martikanen, Pertti J.; Holopainen, Toini and Silvola, Jouko (2009) In Global Change Biology 15(4). p.943-954
Abstract
The effect of elevated UV-B radiation on CO2 exchange of a natural flark fen was studied in open-field conditions during 2003-2005. The experimental site was located in SodankylA in northern Finland (67 degrees 22'N, 26 degrees 38'E, 179 m a.s.l.). Altogether 30 study plots, each 120 cm x 120 cm in size, were randomly distributed between three treatments (n=10): ambient control, UV-A control and UV-B treatment. The UV-B-treated plots were exposed to elevated UV-B radiation level for three growing seasons. The instantaneous net ecosystem CO2 exchange (NEE) and dark respiration (R-TOT) were measured during the growing season using a closed chamber method. The wintertime CO2 emissions were estimated using a gradient technique by analyzing the... (More)
The effect of elevated UV-B radiation on CO2 exchange of a natural flark fen was studied in open-field conditions during 2003-2005. The experimental site was located in SodankylA in northern Finland (67 degrees 22'N, 26 degrees 38'E, 179 m a.s.l.). Altogether 30 study plots, each 120 cm x 120 cm in size, were randomly distributed between three treatments (n=10): ambient control, UV-A control and UV-B treatment. The UV-B-treated plots were exposed to elevated UV-B radiation level for three growing seasons. The instantaneous net ecosystem CO2 exchange (NEE) and dark respiration (R-TOT) were measured during the growing season using a closed chamber method. The wintertime CO2 emissions were estimated using a gradient technique by analyzing the CO2 concentration in the snow pack. In addition to the instantaneous CO2 exchange, the seasonal CO2 balances during the growing seasons were modeled using environmental data measured at the site. In general, the instantaneous NEE at light saturation was slightly higher in the UV-B treatment compared with the ambient control, but the gross photosynthesis was unaffected by the exposure. The R-TOT was significantly lower under elevated UV-B in the third study year. The modeled seasonal (June-September) CO2 balance varied between the years depending on the ground water level and temperature conditions. During the driest year, the seasonal CO2 balance was negative (net release of CO2) in the ambient control and the UV-B treatment was CO2 neutral. During the third year, the seasonal CO2 uptake was 43 +/- 36 g CO2-C m(-2) in the ambient control and 79 +/- 45 g CO2-C m(-2) in the UV-B treatment. The results suggest that the long-term exposure to high UV-B radiation levels may slightly increase the CO2 accumulation to fens resulting from a decrease in microbial activity in peat. However, it is unlikely that the predicted development of the level of UV-B radiation would significantly affect the CO2 balance of fen ecosystems in future. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
stratospheric ozone depletion, seasonal CO2 balance, peatland ecosystem, CO2 exchange, flark fen, ultraviolet-B
in
Global Change Biology
volume
15
issue
4
pages
943 - 954
publisher
Wiley-Blackwell
external identifiers
  • wos:000263752300014
  • scopus:61549111306
ISSN
1354-1013
DOI
10.1111/j.1365-2486.2008.01785.x
language
English
LU publication?
yes
id
d29a0036-6881-43b2-9c9d-d7cc24c233c0 (old id 1371147)
date added to LUP
2009-05-08 12:24:38
date last changed
2017-04-02 03:31:50
@article{d29a0036-6881-43b2-9c9d-d7cc24c233c0,
  abstract     = {The effect of elevated UV-B radiation on CO2 exchange of a natural flark fen was studied in open-field conditions during 2003-2005. The experimental site was located in SodankylA in northern Finland (67 degrees 22'N, 26 degrees 38'E, 179 m a.s.l.). Altogether 30 study plots, each 120 cm x 120 cm in size, were randomly distributed between three treatments (n=10): ambient control, UV-A control and UV-B treatment. The UV-B-treated plots were exposed to elevated UV-B radiation level for three growing seasons. The instantaneous net ecosystem CO2 exchange (NEE) and dark respiration (R-TOT) were measured during the growing season using a closed chamber method. The wintertime CO2 emissions were estimated using a gradient technique by analyzing the CO2 concentration in the snow pack. In addition to the instantaneous CO2 exchange, the seasonal CO2 balances during the growing seasons were modeled using environmental data measured at the site. In general, the instantaneous NEE at light saturation was slightly higher in the UV-B treatment compared with the ambient control, but the gross photosynthesis was unaffected by the exposure. The R-TOT was significantly lower under elevated UV-B in the third study year. The modeled seasonal (June-September) CO2 balance varied between the years depending on the ground water level and temperature conditions. During the driest year, the seasonal CO2 balance was negative (net release of CO2) in the ambient control and the UV-B treatment was CO2 neutral. During the third year, the seasonal CO2 uptake was 43 +/- 36 g CO2-C m(-2) in the ambient control and 79 +/- 45 g CO2-C m(-2) in the UV-B treatment. The results suggest that the long-term exposure to high UV-B radiation levels may slightly increase the CO2 accumulation to fens resulting from a decrease in microbial activity in peat. However, it is unlikely that the predicted development of the level of UV-B radiation would significantly affect the CO2 balance of fen ecosystems in future.},
  author       = {Haapala, Jaana K. and Morsky, Sami K. and Saarnio, Sanna and Rinnan, Riikka and Suokanerva, Hanne and Kyro, Esko and Latola, Kirsi and Martikanen, Pertti J. and Holopainen, Toini and Silvola, Jouko},
  issn         = {1354-1013},
  keyword      = {stratospheric ozone depletion,seasonal CO2 balance,peatland ecosystem,CO2 exchange,flark fen,ultraviolet-B},
  language     = {eng},
  number       = {4},
  pages        = {943--954},
  publisher    = {Wiley-Blackwell},
  series       = {Global Change Biology},
  title        = {Carbon dioxide balance of a fen ecosystem in northern Finland under elevated UV-B radiation},
  url          = {http://dx.doi.org/10.1111/j.1365-2486.2008.01785.x},
  volume       = {15},
  year         = {2009},
}