Lappalainen, A., Tammi, J. & Puro-Tahvanainen, A. 2007: The effects of nickel smelters on water quality and littoral fish species composition in small watercourses in the border area of Finland, Norway and Russia. Boreal Env. Res. 12: 455–466.

The Pechenganickel smelters in Nikel and Zapoljarnyi, northwestern Kola Peninsula, have been among the world's largest point sources of SO₂, Ni and Cu emissions. In order to examine the effects of airborne emissions, the water quality of 35 small lakes and brooks in Finland, Norway and Russia, 1–50 km from the smelters, was surveyed, and fish of stony shores of these lakes and brooks were sampled by electrofishing in 2004 or 2005. The results demonstrated that in the study area the airborne emissions of the smelters have not caused any widespread damage to fish populations even in the most sensitive small waters. The small waters close to the smelters (roughly within a 10 km radius) are well buffered against the effects of high sulphate deposition. Extremely high concentrations of the heavy metals Ni and Cu, however, are a local threat to biota in small waters there, and a few lakes that have apparently lost their fish populations were found. In the border area of Russia, Norway and Finland, acidification is currently only a problem in some very small and sensitive waters located in the local highland areas, 15–50 km from the smelters. There, lakes with a low buffering capacity (alkalinity < 0.05 mmol l^–1) can be found and some fish populations, mainly minnows, have probably been lost. The SO₂ emissions from the smelters have declined to approximately one third of the maximum level in the late 1970s, and this can be seen in a general recovery of the buffering capacity of small lakes such as those in the Finnish border region, 40–50 km west of the smelters.

Rasmus, S., Grönholm, T., Lehning, M., Rasmus, K. & Kulmala, M. 2007: Validation of the SNOWPACK model in five different snow zones in Finland. Boreal Env. Res. 12: 467–488.

The performance of a snow pack structure model SNOWPACK was studied in five locations around Finland during two winters. Reasonable agreement between modelled and observed snow depth and snow pack structure evolution was found in all other locations except in coastal Santala. Agreement grew when going towards the north; better agreements were obtained during the early winter than during the melting period. Several test runs with changed input data were done for Hyytiälä. Water equivalent, temperature, grain form and grain size were the most sensitive of the model output quantities to changes in the input data. The use of measured precipitation instead of snow depth for driving the mass balance or the use of different radiation schemes had relatively large effects on the model output. Model sensitivity was high when many phase changes were involved such as during the melting phase in spring or in temperate climate zones.

Korkalainen, T. H. J., Laurén, A. M. & Kokkonen, T. S. 2007: A GIS-based analysis of catchment properties within a drumlin field. Boreal Env. Res. 12: 489–500.

When considering water protection, the spatial distribution of catchment properties is relevant, since the areas adjoining the water body contribute more to water quality than the remote areas near the water divide. This study presents an approach to describe catchments spatially; two-dimensional descriptions allow calculations of horizontally distributed properties of catchments as a function of distance to the water body by using the concept of the typical water flow path. The study area, situated in a drumlin field in central Finland, included 14 third-order catchments that were further divided into 782 head-water catchments using a 25 m x 25 m digital elevation model. For each head-water catchment, a typical water flow path with slope, elevation, length, relative width, and soil type was calculated. The flow path geometry was diverging towards the water body and there was a 25 m section with a gentle slope adjacent to the water body followed by a steeper slope. Mineral soils dominated throughout the typical water flow path. On the basis of the results, we proposed characteristics for an average head-water catchment with the following properties: area 109.1 ha and length of the water flow path 954 m with maximum elevation 11.5 m. The peatlands were concentrated within a distance of 50 m to the water body; the rest consisted of mineral soil. The results can be utilized, for example, in calculating the impacts of forest management practices on the quality of runoff water. The results offer a baseline for evaluating how typical previously studied catchments are in relation to larger catchment populations. They also enable a regional estimate of the distribution of the relative proportion of areas situated along the water flow path.

Benoy, G. A., Cash, K., Levesque, L., McCauley, E. & Wrona, F. 2007: Antecedent snow conditions affect water levels and plant biomass of a fen in the southern boreal forest: results from an experiment using mesocosms. Boreal Env. Res. 12: 501–513.

Biogeochemical processes in peatland environments, such as carbon sequestration and decomposition, are affected by variation in water supply. Across the boreal forest biome, climate change threatens to either alter rates of annual precipitation or skew the timing and ratio of rainfall and snowfall events. To simulate moisture variability during the ice-free season, cylindrical mesocosms (diameter 1.5 m) were installed in a southern boreal patterned fen in central Saskatchewan, Canada, to enable manipulations of antecedent snow conditions. The objectives of the study were to assess the utility of in situ mesocosms for peatland ecohydrology research and to test for effects of snow manipulations on fen plant communities. After spring thaw, initial water depths were greatest and dates of surface water disappearance were latest in the snow addition mesocosms, followed by the control and snow removal mesocosms. In contrast, maximum frost levels and frost disappearance dates in the snow addition mesocosms were intermediate to those of the control and snow removal mesocosms. Densification of snow during snow manipulation events is suggested to account for this confounding outcome. Of the nine plant taxa identified in the harvests of aboveground biomass from all mesocosms, buckbean (Menyanthes trifoliata) biomass was most strongly related to variation in surface water conditions. Climate conditions that favour persistence of either herbaceous- or graminoid-dominated communities will likely affect the carbon storage function of southern boreal fens.

Huttunen, A. 2007: Holocene vegetation history of the Riisitunturi fell area in NE Finland, traced by the palynostratigraphy of two disgenic upland lakes. Boreal Env. Res. 12: 515–534.

A palynological study of an upland lake was conducted in NE Finland to assess the timing of post-glacial vegetational phases as accurately as is possible with bulk samples of hard water-free, evenly deposited sediment. The studied lake, Kolmiloukkonen, as a reference site for the Kuusamo region, revealed an age of ca. 10580 cal. years BP for the beginning of the post-glacial period, ca. 9500–9200 calBP for the appearance of alder, ca. 5700 calBP for spruce by 1% of arboreal pollen, and ca. 3900 calBP for spruce rise. DCA ordination suggested rather stagnant plant communities in the mid-Holocene. Another lake from the mid-Holocene on top of a saddle mire in the oroboreal sparsely wooded heath was of secondary origin. Its sediment types and macrosubfossils showed an uncommon succession from heath forest to mire and finally to a water basin. The age of establishment of nearly open summits could not be pinpointed palynologically, however, some signals suggest a trend towards more open communities nearly 3000 calBP and about a millennium ago.