ISSN 1239-6095 (print),   ISSN 1797-2469 (online)
© Boreal Environment Research 2009

Contents of Volume 14 Supplement A

Sorvari, S., Tikka, P. M., Niemelä, J., Raivio, K. & Korhonen-Kurki, K. 2009: Breaking the boundaries — multidisciplinary environmental research at the University of Helsinki. Boreal Env. Res. 14 (suppl. A): 1–4.
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Hari, P. & Nöjd, P. 2009: The effect of temperature and PAR on the annual photosynthetic production of Scots pine in northern Finland during 1906–2002. Boreal Env. Res. 14 (suppl. A): 5–18.
Abstract
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Hari, P., Hänninen, H., Berninger, F., Kolari, P., Nikinmaa, E. & Mäkelä, A. 2009: Predicting boreal conifer photosynthesis in field conditions. Boreal Env. Res. 14 (suppl. A): 19–28.
Abstract
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Nikula, S., Percy, K., Oksanen, E., Holopainen, T. & Manninen, S. 2009: Effects of elevated ozone on growth and foliar traits of European and hybrid aspen. Boreal Env. Res. 14 (suppl. A): 29–47.
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Huotari, J., Ojala, A., Peltomaa, E., Pumpanen, J., Hari, P. & Vesala, T. 2009: Temporal variations in surface water CO2 concentration in a boreal humic lake based on high-frequency measurements. Boreal Env. Res. 14 (suppl. A): 48–60.
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Hartikainen, H. & Kerko, E. 2009: Lead in various chemical pools in soil depth profiles on two shooting ranges of different age. Boreal Env. Res. 14 (suppl. A): 61–69.
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Hui, N., Selonen, S., Hanzel, J., Tuomela, M., Rainio, A., Kontio, H., Hakala, K., Lankinen, P., Steffen, K., Fingerroos, T., Strömmer, R., Setälä, H., Hatakka, A. & Romantschuk, M. 2009: Influence of lead on organisms within the detritus food web of a contaminated pine forest soil. Boreal Env. Res. 14 (suppl. A): 70–85.
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Järvi, J., Hannuniemi, H., Hussein, T., Junninen, H., Aalto, P. P., Hillamo, R., Mäkelä, T., Keronen, P., Siivola, E., Vesala, T. & Kulmala, M. 2009: The urban measurement station SMEAR III: Continuous monitoring of air pollution and surface–atmosphere interactions in Helsinki, Finland. Boreal Env. Res. 14 (suppl. A): 86–109.
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Toikka, A. 2009: Governance network structures and urban environmental policy making — a case study in Helsinki, Finland. Boreal Env. Res. 14 (suppl. A): 110–121.
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Hari, P. & Nöjd, P. 2009: The effect of temperature and PAR on the annual photosynthetic production of Scots pine in northern Finland during 1906–2002. Boreal Env. Res. 14 (suppl. A): 5–18.

The annual photosynthetic production of Scots pine (Pinus sylvestris) was simulated for 1906–2002 for a location in northern Finland. We used the PhenPhoto model, which combines two key features of photosynthesis: the response to instantaneous radiation and the acclimation to the annual cycle. The input data for the PhenPhoto model include instantaneous photosynthetically active radiation (PAR) and temperature. The PAR values were generated from existing weather data and the instantaneous temperatures were interpolated from daily maximum and minimum values. The simulated annual photosynthetic production was at a low level during the the first two decades of the 20th century. No trend was observed for 1920–2002. The standard deviation of the annual photosynthetic production was 11.3% of the mean for the period 1906–2002. There were large differences in springtime recovery of photosynthesis: in 1964 over 30% of annual photosynthetic production had accumulated by 10 June, while at the other extreme (1917) the percentage was only 3.5%. A comparison of the simulated photosynthetic production with tree-ring indices of Scots pine showed a rather similar pattern of high-frequency variation.
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Hari, P., Hänninen, H., Berninger, F., Kolari, P., Nikinmaa, E. & Mäkelä, A. 2009: Predicting boreal conifer photosynthesis in field conditions. Boreal Env. Res. 14 (suppl. A): 19–28.

Automatic continuous monitoring of shoot-level gas exchange and environmental factors in natural conditions provides an efficient but unexploited tool for testing the predictive power of plant photosynthesis models. We used automatically operated measurement chambers to monitor the CO2 exchange of Scots pine (Pinus sylvestris) shoots in Finnish Lapland near the timberline over two growing seasons, yielding a total of 90000 measurements. In this paper, we show that a recent ecophysiological model predicts the daily and seasonal pattern of photosynthesis with the unbiased percentages of explained variance of 90% and 92%, respectively, utilising temporally independent data. Our model combines the optimal stomatal control model of photosynthesis with a model of annual cycle of photosynthesis. The key feature for applications of the model is the temperature driven onset, acceleration and decline of photosynthesis. With these dynamics, the model provides a useful tool for analysing the effects of climate change on annual photosynthetic production in boreal conifers.
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Nikula, S., Percy, K., Oksanen, E., Holopainen, T. & Manninen, S. 2009: Effects of elevated ozone on growth and foliar traits of European and hybrid aspen. Boreal Env. Res. 14 (suppl. A): 29–47.

We studied growth and foliar responses of two clones of both European aspen (Populus tremula) and hybrid aspen (P. tremula x P. tremuloides) to elevated O3 (45 ppb, 14-h mean) over one growing season using a free-air fumigation system in central Finland. All clones exhibited O3-specific foliar injury and accelerated leaf senescence under elevated O3. Yet, exposure to 1.5 x ambient O3 had only minor effects on the growth and biomass production of clones grown under optimal nutrient and water supply, and no O3 effects on leaf morphology were observed. Slower-growing European aspen was more sensitive to elevated O3 than hybrid aspen. Exposure to O3 decreased the root/stem ratio (–11%) and leaf N concentration (–9%) of European aspen. Inter- or intraspecific differences in the O3 sensitivity of the trees could not be explained by stomatal conductance, but some xeromorphic leaf traits were related to increased susceptibility to O3. Intraspecific differences in the O3 sensitivity have implications e.g. for nurseries producing commercial tree material.
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Huotari, J., Ojala, A., Peltomaa, E., Pumpanen, J., Hari, P. & Vesala, T. 2009: Temporal variations in surface water CO2 concentration in a boreal humic lake based on high-frequency measurements. Boreal Env. Res. 14 (suppl. A): 48–60.

We measured surface water CO2 concentrations continuously at three different depths to reveal the seasonal, daily and diel CO2 dynamics of a steeply stratified pristine, spring- meromictic, humic lake during April 2005–October 2006. The lake was supersaturated with CO2 most of the time and was a net source of CO2 to the atmosphere. The stability of stratification and the depth of water column mixing strongly controlled the surface water CO2 concentrations. Surface water concentrations as high as 195 µmol l–1 were measured when mixing extended to deep waters during spring ice breakup and autumn turnover. The concentrations were near the level of atmospheric equilibrium, about 15 µmol l–1, during periods of high stability. The yearly CO2 fluxes to the atmosphere were 3.7 and 2.5 mol m–2 in 2005 and 2006, respectively.
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Hartikainen, H. & Kerko, E. 2009: Lead in various chemical pools in soil depth profiles on two shooting ranges of different age. Boreal Env. Res. 14 (suppl. A): 61–69.

We investigated the distribution of pellet-derived lead (Pb) in various chemical pools within soil depth profiles in a new and an old clay pigeon shooting range to assess its tendency for mobility. The results showed that the pellets weathered slowly: about 10% of metallic Pb had been released over 16–37 years. Nevertheless, the resulting Pb concentrations in the soil largely exceeded the upper guideline value defined as contaminated on grounds of ecological risk. The operational fractionation analysis produced a useful, although tentative, insight into the environmental fate of Pb. In the acid forest soil of the ranges studied, organic matter seemed to act as a primary sink for Pb but became a mobile carrier with increasing Pb load. Generally, the residual fraction (including oxide-bound Pb) predominated in the mineral soil layers. The estimated average migration rate was roughly 2–3 mm a year. The abnormally high Pb concentrations in the control area outside the shooting ranges suggest that environmental risks are not limited only to pellet-shot-fall areas.
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Hui, N., Selonen, S., Hanzel, J., Tuomela, M., Rainio, A., Kontio, H., Hakala, K., Lankinen, P., Steffen, K., Fingerroos, T., Strömmer, R., Setälä, H., Hatakka, A. & Romantschuk, M. 2009: Influence of lead on organisms within the detritus food web of a contaminated pine forest soil. Boreal Env. Res. 14 (suppl. A): 70–85.

The shooting range site at Hälvälä in southern Finland is heavily contaminated by lead pellets. Still, the appearance of the forest is not visibly changed. Lead contamination strongly decreased the amount of enchytraeid worms, while reporter bacteria showed no or very minor decrease in viability. The bioavailability of lead in the soil was measured to be low, which was verified by the very low water extractability of lead. Nevertheless, the frequency of lead resistant cultivable bacteria was elevated, and the bacterial community composition in lead contaminated soil was altered. Some enzymes of litter decomposing fungi isolated from Hälvälä also showed an elevated lead tolerance, though generally their activity was highly variable and in some cases lead enhanced enzyme production of a fungus. In conclusion, our results point to a low acute toxicity of lead, but to a risk of deleterious long term effects in a pine forest environment.
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Järvi, J., Hannuniemi, H., Hussein, T., Junninen, H., Aalto, P. P., Hillamo, R., Mäkelä, T., Keronen, P., Siivola, E., Vesala, T. & Kulmala, M. 2009: The urban measurement station SMEAR III: Continuous monitoring of air pollution and surface–atmosphere interactions in Helsinki, Finland. Boreal Env. Res. 14 (suppl. A): 86–109.

We present results from the air pollution and turbulent exchange measurements made at the urban measurement station SMEAR III in Helsinki, Finland. First measurements at the station started in August 2004 and since then more measurements have gradually been added. We analyze data until June 2007. Temporal variations and dependencies between the size-fractionated particle number concentrations (both fine and coarse particle concentrations), gas concentrations (O3, NOx, CO and SO2), turbulent fluxes of momentum, sensible and latent heat and CO2, and meteorological variables were studied. Most of the air pollutants and turbulent fluxes showed distinct annual and diurnal variation closely related to the local combustion sources (especially traffic) and the amount of available solar radiation. Ultrafine particles showed the most explicit dependence on traffic and traffic-related pollutants, while larger particles were more affected by the meteorological conditions. The surface fluxes were strongly affected by the specific conditions in urban environment.
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Toikka, A. 2009: Governance network structures and urban environmental policy making — a case study in Helsinki, Finland. Boreal Env. Res. 14 (suppl. A): 110–121.

This paper describes changes in local environmental governance through the framework of governance. Governance literature states that policy making has moved from a centralized governmental process to an open negotiation involving various actors from both public and private sectors. The changes affect both the decision-making processes and policy focus, as measured by the issue areas included. The analysis is based on the City of Helsinki. The data used consists of 75 interviews with organizational representatives, as well as archival data. Descriptive measures of social network analysis are used to describe the links between the network and the policy decisions.
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