Sari Juutinen

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We have examined how some major catchment disturbances may affect the aquatic greenhouse gas fluxes in the boreal zone, using gas flux data from studies made in 1994-1999 in the pelagic regions of seven lakes and two reservoirs in Finland. The highest pelagic seasonal average methane (CH(4)) emissions were up to 12 mmol x m(-2) x d(-1) from eutrophied lakes(More)
Methane (CH4) emissions from boreal wetlands show considerable seasonal variation, including small winter emissions. We addressed the seasonality of CH4-producing microbes by comparing archaeal communities and the rates and temperature response of CH4 production in a boreal fen at three key phases of growing season and in winter. Archaeal community analysis(More)
Anthropogenic nitrogen (N) loading has the potential to affect plant community structure and function, and the carbon dioxide (CO2) sink of peatlands. Our aim is to study how vegetation changes, induced by nutrient input, affect the CO2 exchange of a nutrient-limited bog. We conducted 9- and 4-year fertilization experiments at Mer Bleue bog, where we(More)
To study vegetation feedbacks of nutrient addition on carbon sequestration capacity, we investigated vegetation and ecosystem CO2 exchange at Mer Bleue Bog, Canada in plots that had been fertilized with nitrogen (N) or with N plus phosphorus (P) and potassium (K) for 7-12 years. Gross photosynthesis, ecosystem respiration, and net CO2 exchange were measured(More)
 Short-term (3–6 days) and long-term (27 days) laboratory experiments were carried out to determine the distribution of assimilated C in the system Phragmites australis (common reed)-waterlogged fen soil after 14C pulse labelling. The investigated system of fen plants and anaerobic organic soil showed different patterns of assimilated 14C distribution when(More)
Plants in nutrient-poor environments typically have low foliar nitrogen (N) concentrations, long-lived tissues with leaf traits designed to use nutrients efficiently, and low rates of photosynthesis. We postulated that increasing N availability due to atmospheric deposition would increase photosynthetic capacity, foliar N, and specific leaf area (SLA) of(More)
The contribution of Phragmites australis (Cav.) Trin. ex Steud. (common reed) litter as an origin of CH4-C was studied in a microcosm experiment. 14C-labelled, dried and ground P. australis root and shoot litter was buried in waterlogged, planted or non-planted fen microcosms. The evolution of 14CO2 and 14CH4 from the pots was monitored during the 35-day(More)
Aerosol samples have been studied under different background conditions using gamma-ray coincidence and low-background gamma-ray singles spectrometric techniques with High-Purity Germanium detectors. Conventional low-background gamma-ray singles counting is a competitive technique when compared to the gamma-gamma coincidence approach in elevated background(More)
The rotational band structure of the Z=104 nucleus (256)Rf has been observed up to a tentative spin of 20ℏ using state-of-the-art γ-ray spectroscopic techniques. This represents the first such measurement in a superheavy nucleus whose stability is entirely derived from the shell-correction energy. The observed rotational properties are compared to those of(More)
R. D. Page,1 L. Bianco,1 I. G. Darby,1 J. Uusitalo,2 D. T. Joss,1,3 T. Grahn,1,2 R.-D. Herzberg,1 J. Pakarinen,1,2 J. Thomson,1 S. Eeckhaudt,2 P. T. Greenlees,2 P. M. Jones,2 R. Julin,2 S. Juutinen,2 S. Ketelhut,2 M. Leino,2 A.-P. Leppänen,2 M. Nyman,2 P. Rahkila,2 J. Sarén,2 C. Scholey,2 A. Steer,2 M. B. Gómez Hornillos,3 J. S. Al-Khalili,4 A. J. Cannon,4(More)