Zhang, Q., Gradinger, R. & Spindler, M. 1999. Experimental study on the effect of salinity on growth rates of Arctic-sea-ice algae from the Greenland Sea. Boreal Env. Res. 4: 1–8.
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Bobyrev, A. & Kriksunov, E. 1999. Environmental effects on the recruitment dynamics of coregonids from the Petchora River. Boreal Env. Res. 4: 9–17.
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Vallius, H. & Leivuori, M. 1999. The distribution of heavy metals and arsenic in recent sediments in the Gulf of Finland. Boreal. Env. Res. 4: 19–29.
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Edén, P., Weppling, K. & Jokela, S. 1999. Natural and land-use induced load of acidity, metals, humus and suspended matter in Lestijoki, a river in western Finland. Boreal Env. Res. 4: 31–43.
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Kolström, M. & Pitkänen, S. 1999. Effect of forest management on alpha diversity of ground vegetation in boreal forests: a model approach. Boreal Env. Res. 4: 45–54.
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Kukkonen, J., Salmi, T., Saari, H., Konttinen, M. & Kartastenpää, R. 1999. Review of urban air quality in Finland. Boreal Env. Res. 4: 55–65.
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Kozlov, M.V., Zvereva, E.L. & Niemelä, P. 1999. Effects of soil quality and air pollution on the rooting and survival of Salix borealis cuttings. Boreal Env. Res. 4: 67–76.
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Wulff, A., Anttonen, S., Pellinen, R., Savonen, E.-M., Sutinen, M.-L., Heller, W., Sandermann, H. Jr. & Kangasjärvi, J. 1999. Birch (Betula pendula Roth.) responses to high UV-B radiation. Boreal Env. Res. 4: 77–88.
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Venäläinen, A., Rontu, L. & Solantie, R. 1999. On the influence of peatland draining on local climate. Boreal Env. Res. 4: 89–100.
Abstract
Full text (pdf format)
Zhang, Q., Gradinger, R. & Spindler, M. 1999. Experimental study on the effect of salinity on growth rates of Arctic-sea-ice algae from the Greenland Sea. Boreal Env. Res. 4: 1–8.
Bobyrev, A. & Kriksunov, E. 1999. Environmental effects on the recruitment dynamics of coregonids from the Petchora River. Boreal Env. Res. 4: 9–17.
Vallius, H. & Leivuori, M. 1999. The distribution of heavy metals and arsenic in recent sediments in the Gulf of Finland. Boreal. Env. Res. 4: 19–29.
Edén, P., Weppling, K. & Jokela, S. 1999. Natural and land-use induced load of acidity, metals, humus and suspended matter in Lestijoki, a river in western Finland. Boreal Env. Res. 4: 31–43.
Kolström, M. & Pitkänen, S. 1999. Effect of forest management on alpha diversity of ground vegetation in boreal forests: a model approach. Boreal Env. Res. 4: 45–54.
Kukkonen, J., Salmi, T., Saari, H., Konttinen, M. & Kartastenpää, R. 1999. Review of urban air quality in Finland. Boreal Env. Res. 4: 55–65.
Kozlov, M.V., Zvereva, E.L. & Niemelä, P. 1999. Effects of soil quality and air pollution on the rooting and survival of Salix borealis cuttings. Boreal Env. Res. 4: 67–76.
Wulff, A., Anttonen, S., Pellinen, R., Savonen, E.-M., Sutinen, M.-L., Heller, W., Sandermann, H. Jr. & Kangasjärvi, J. 1999. Birch (Betula pendula Roth.) responses to high UV-B radiation. Boreal Env. Res. 4: 77–88.
Venäläinen, A., Rontu, L. & Solantie, R. 1999. On the influence of peatland draining on local climate. Boreal Env. Res. 4: 89–100.
An Arctic bottom ice algal community collected from a pack ice floe in the Greenland Sea in autumn 1995 was cultured at 10 salinities ranging from 4.0 to 90.8 PSU for 19 days. Growth of species was determined by microscopical analysis of samples taken every 3 to 5 days. During the experiment the abundance of the algae increased over a wide salinity range from 4.0 to 74.0 PSU, but decreased at the highest salinity (90.8). Maximum growth rates were 0.29 d–1 for the entire ice algal community and 0.42 d–1 for individual taxa. The final composition of the algal communities varied with salinities. Phytoflagellates and Chaetoceros spp. were most abundant at low salinities (<= 12.2), while pennate diatoms of the genus Nitzschia were the dominant algae at higher salinities.
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Stock-recruitment processes in four coregonid species, Coregonus lavaretus pidschian, C. peled, C. albula maris-albi and C. autumnalis, from the Petchora River were investigated. The dynamics of density-independent mortality for the 0-group of each species were reconstructed using stock-recruitment models and compared with environmental factors including average monthly water surface temperature, average monthly water level, monthly total length of open sunshine, ice thickness during winter months, and date of steady ice cover setting. The results of a stepwise variable selection analysis showed that 68.7% to 95.1% of the recruitment variability is due to perturbations in environmental conditions. The primary factor influencing pre-recruitment mortality is insolation. Less important, but still significant, factors are water temperature and water level.
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A large number of sediment samples representing most of the active mud accumulation areas of the Gulf of Finland were studied for total cadmium, chromium, lead, mercury, arsenic, copper and zinc. The highest concentrations of metals were found in sediment surfaces in the easternmost part of the Gulf, which is influenced by the inflow of the Neva river and the loads of the city of St. Petersburg. Vyborg Bay and the Kymi River also clearly affect the off-shore sea bottom. The vertical distributions determined in four sediment cores show for all metals overall decreasing concentrations towards the surface of the sediment cores, which in part indicates decreased load of metals. Evidently levels of copper, lead and mercury are still decreasing, while cadmium and arsenic levels are slowly increasing in the eastern Gulf of Finland. From the mean sedimentation rate of wet suspended particulate matter (SPM) and dry weight of the surficial sediment, an annual accumulation of 8.7 × 106 t a–1 of SPM was estimated for the Gulf. With that estimate the annual total accumulation of elements into the sediments was calculated. The annual accumulations of cadmium and lead are clearly higher in the Gulf of Finland than in the Gulf of Bothnia. Accumulation of the other metals is somewhat higher in the Gulf of Finland, while the accumulation of arsenic is clearly lower, only one fifth of that in the Gulf of Bothnia.
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Lestijoki, a river in western Finland, runs through areas with abundant peatlands and acid sulphate (AS) soils, which cause water quality problems. A natural population of sea trout (Salmo trutta m. trutta (L.)) and other valuable species still exist in the river, but the declining water quality is a serious threat to their survival. The AS soils and the peatlands cause a natural high load of acidity, metals, humus and suspended matter. This load is enhanced by human activities such as agriculture and draining, being 2–5 times higher than in Fennoscandian streams in general. During high flow, the load reaches levels deleterious for many species. The results of several large water quality surveys and routine monitoring show that low pH in Lestijoki (min. 4.9) and the feeder streams (min. 4.4), together with high metal contents (e.g., max. Fe 7.3 and 5.8 mg l–1, respectively) and high amounts of humic and suspended matter, occasionally cause conditions where reproduction failures of fish occur. The acidity and metal load from subsurface drained AS soils is especially deleterious for the biological conditions in the main stream.
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The effect of various forest management types on the alpha diversity of ground vegetation was studied with an ecological simulation model. With this model, stand characteristics were simulated during different management programmes and were then used to calculate the diversity of the ground vegetation. Alpha diversity was expressed as Simpson's reciprocal, which was estimated using stand attributes. The diversity model was estimated using generalised linear models (GLMs). The significant variables in the diversity model were site type, stage of development (clearcut area or other), stand basal area and proportions of pine, aspen and willow as number of stems. In alternative management programmes, the type, interval and intensity of thinning were varied. In managed forests, the most intensive thinning produced the highest diversity of ground vegetation during a rotation. Differences in the diversity of ground vegetation between management programmes were, however, small.
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We present a review of the air quality in Finnish cities and towns, based on the data from urban measurement networks. The data were compiled from 42 Finnish cities and towns, from measurements conducted in 1990–1993. These data show that the newly-introduced (1996) national air quality guidelines have been fairly often exceeded in urban areas, most commonly for particulate matter, both PM10 and total suspended particles (TSP). Some exceedances have also occurred for NO2 and CO, at sites with high traffic densities. Some TSP values in the largest cities in Finland are exceptionally high, caused by the resuspension of dust from street surfaces. However, the European Union air quality limit values were only exceeded at one measurement station for TSP in 1990, 1991 and 1992. We also analysed seasonal variation of the guideline exceedings.
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The rooting and survival of Salix borealis cuttings were studied in the surroundings of the Severonikel smelter (Kola Peninsula, NW Russia). In favourable habitats (birch and willow-dominated secondary communities), 22% of the 120 cuttings were successfully established, and 89% of the established cuttings survived up to the fourth year after planting. Cutting survival and vigour were affected by both soil quality and air pollution level. Cutting mortality during the two first weeks after planting depended on soil contamination; in metal-polluted soils it was seven times as high as in clean soils. The detrimental effects of ambient sulphur dioxide became visible after four weeks, whereas survival at the end of the growing season was almost exclusively determined by the nutritional quality of the soil. Cuttings from female genets were more resistant to pollutants than cuttings from male genets; cuttings from the unpolluted site were more tolerant of metals than cuttings from the heavily polluted site. The leaf size of the surviving cuttings was independent of soil, water or air contamination. These preliminary findings seem to indicate that cuttings of S. borealis can be used for the partial revegetation of industrial barrens even at high emission levels.
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Responses of European silver birch seedlings to highly enhanced levels of UV-B radiation (14.4 or 22.5 kJ m–2 d–1 UV-BBE) were studied in a glasshouse experiment. Visible symptoms, membrane lipid composition, secondary metabolites, mRNA levels of chalcone synthase (Chs), localisation of Chs mRNA and leaf structure were analysed. Interveinal chlorosis and asymmetric leaves were induced by UV-B. A significant UV-B -induced increase in 18:2 fatty acid of both glycolipids and phospholipids was detected. UV-B dependent increase in accumulation of a quercetin-3-glycoside and three other compounds, as well as a transient increase in Chs mRNA levels are indicative of induced biosynthesis of flavonoids. In situ experiments showed that mRNA of Chs was mainly found in the upper mesophyll and vascular bundle tissues. Structural observations showed injuries caused by high irradiances. At the light microscopy level there was first a reduction in palisade parenchyma and later a more dense structure of spongy parenchyma cells. Electron microscopy demonstrated an increase in vacuolar membrane whorls and dark bodies, occurrence of lipid material and darkened chloroplast stroma in mesophyll cells. However, results also indicated that Betula pendula is capable of inducing defence reactions such as biosynthesis of flavonoids even at very high UV-B radiation.
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In no other country has the draining of peatland taken place to such a large extent as in Finland. According to earlier studies based on an analysis of observed temperatures, this draining has lowered the night-time minimum temperatures in heavily-drained regions. In the present study, we simulated the cooling effect using the HIRLAM numerical weather prediction model. When simulated wet and dry peat conditions were compared in a late summer clear and calm case leading to night frost, the drop in local night-time minimum temperatures reached ten degrees. The difference in temperature was caused mainly by the change in the soil heat flux.
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