Carlsson, R. 2000. The distribution of the gastropods Theodoxus fluviatilis (L.) and Potamopyrgus antipodarum (Gray) in lakes on the Åland Islands, southwestern Finland. Boreal Env. Res. 5: 187–195.
Abstract
Full text (pdf format)
Ferm, M., Westling, O. & Hultberg, H. 2000. Atmospheric deposition of base cations, nitrogen and sulphur in coniferous forests in Sweden — a test of a new surrogate surface. Boreal Env. Res. 5: 197–207.
Abstract
Full text (pdf format)
Tkatcheva, V., Holopainen, I. J. & Hyvärinen, H. 2000. Heavy metals in perch (Perca fluviatilis) from the Kostomuksha region (North-western Karelia, Russia). Boreal Env. Res. 5: 209–220.
Abstract
Full text (pdf format)
Andersson, L. & Lepistö, A. 2000. Annual variability of nitrogen concentrations and export from forested catchments: A consequence of climatic variability, sampling strategies or human interference? Boreal Env. Res. 5: 221–233.
Abstract
Full text (pdf format)
Kotta, J., Kotta, I. & Viitasalo, I. 2000. Effect of diffuse and point source nutrient supply on the low diverse macrozoobenthic communities of the northern Baltic Sea. Boreal Env. Res. 5: 235–242.
Abstract
Full text (pdf format)
Ojala, A. E. K., Saarinen, T. & Salonen, V.-P. 2000. Preconditions for the formation of annually laminated lake sediments in southern and central Finland. Boreal Env. Res. 5: 243–255.
Abstract
Full text (pdf format)
Aamlid, D., Vassilieva, N., Aarrestad, P.A., Gytarsky, M. L., Lindmo, S., Karaban, R., Korotkov, V., Rindal, T., Kuzmicheva, V. & Venn, K. 2000. The ecological state of the ecosystems in the border areas between Norway and Russia. Boreal Env. Res. 5: 257–278.
Abstract
Full text (pdf format)
Carlsson, R. 2000. The distribution of the gastropods Theodoxus fluviatilis (L.) and Potamopyrgus antipodarum (Gray) in lakes on the Åland Islands, southwestern Finland. Boreal Env. Res. 5: 187–195.
Ferm, M., Westling, O. & Hultberg, H. 2000. Atmospheric deposition of base cations, nitrogen and sulphur in coniferous forests in Sweden — a test of a new surrogate surface. Boreal Env. Res. 5: 197–207.
Tkatcheva, V., Holopainen, I. J. & Hyvärinen, H. 2000. Heavy metals in perch (Perca fluviatilis) from the Kostomuksha region (North-western Karelia, Russia). Boreal Env. Res. 5: 209–220.
Andersson, L. & Lepistö, A. 2000. Annual variability of nitrogen concentrations and export from forested catchments: A consequence of climatic variability, sampling strategies or human interference? Boreal Env. Res. 5: 221–233.
Kotta, J., Kotta, I. & Viitasalo, I. 2000. Effect of diffuse and point source nutrient supply on the low diverse macrozoobenthic communities of the northern Baltic Sea. Boreal Env. Res. 5: 235–242.
Ojala, A. E. K., Saarinen, T. & Salonen, V.-P. 2000. Preconditions for the formation of annually laminated lake sediments in southern and central Finland. Boreal Env. Res. 5: 243–255.
Aamlid, D., Vassilieva, N., Aarrestad, P.A., Gytarsky, M. L., Lindmo, S., Karaban, R., Korotkov, V., Rindal, T., Kuzmicheva, V. & Venn, K. 2000. The ecological state of the ecosystems in the border areas between Norway and Russia. Boreal Env. Res. 5: 257–278.
On the Åland Islands, surrounded by the brackish Baltic Sea, the two species Theodoxus fluviatilis (L.) and Potamopyrgus antipodarum (Gray) are common and widespread. T. fluviatilis was found in lakes where the hardness values were below 3 °dH. P. antipodarum was found in four lakes at sea level and in two additional lakes of older age (higher elevation). On the Åland Islands the short distances from the lakes to the sea are advantageous for the transportation of snails, provided the lakes are connected to the sea through open ditches where fish wander or active colonization is possible. T. fluviatilis appears to be absent in Finnish lakes and P. antipodarum has previously not been encountered in Finnish lakes. The absence of the species in Finnish mainland lakes may be due to too high contents of humic substances and too low calcium values.
Back to the top
Dry deposition of base cations, nitrate, as well as particulate ammonium, and sulphate in coniferous forests was measured using a surrogate surface in combination with net throughfall measurements at 11 sites in southern Sweden. The measurement technique involved monitoring gaseous pollutants with diffusive samplers and assuming common dry deposition rates on forest and the surrogate surface. The dry deposition of base cations was important as compared to the wet deposition at all coastal (windy) sites. Correlations of the internal fluxes of potassium and calcium were identified with regard to the deposition of reduced nitrogen compounds and sulphur dioxide respectively. In addition, the results outline the significance of dry deposition compared to wet deposition and trends relating to the net throughfall of nitrogen compounds. The net throughfall of nitrogen compounds was often negative, but approached the estimated dry deposition with increasing load.
Back to the top
The Kostomuksha mining plant (KMP, Republic of Karelia, Russia), which is an important producer of iron pellets, is situated in the upper part of the Kenti–Kento lake–river system. In this water system, Lake Kostomuksha drains its waters through a chain of small lakes into the larger Lake Kuito and on to the White Sea. Effluents from the mining plant have been deposited in Lake Kostomuksha since 1982. For this study, samples of perch (Perca fluviatilis) were obtained from three metal-contaminated lakes with different pollutant concentrations downstream from Lake Kostomuksha. The concentrations of heavy metals (Hg, Cd, Cu, Zn, Ni and Cr) in fish liver and muscle were analysed. Concentrations of Hg, Ni and Cr (1.13, 0.09 and 0.08 ug g–1 dry weight, respectively) in fish liver from the studied lakes were higher than those in the control lake, Kamennoe (0.43, < 0.001, < 0.001 ug g–1), which is not directly influenced by the KMP. In the uppermost lake, Poppalijärvi, the concentration of Hg in perch muscle and liver was > 1.0 ug g–1 dry weight. Compared to the control lake, the electron microscope study of liver tissue from perch in this lake showed an increase in the distance between hepatocytes, a decrease in the number of nuclear pores and the smallest mitochondria of all the lakes studied.
Back to the top
This study was based on the data from 18 years of monitoring in six forested catchments. The aim was to find links between annual estimates of export and concentrations of NO3-N and organic N and hydroclimatological factors, sampling strategy and human interference. A topography-based wetness index was used to assess whether the effects of forestry activities depended on prevailing wetness conditions. For organic N, annual runoff was the main explaining factor in three catchments. The flow condition during sampling was for organic N the main explaining factor in three and for NO3-N in one catchment. Effects of clear-cutting of 14% in one catchment were observed. For organic N, the model could be improved by considering clear-cutting in wet areas only. The southernmost catchment, but also the northernmost catchment with the lowest deposition, showed links to atmospheric deposition, demonstrating that deposition can cause a significant direct response in streamwater concentrations in nutrient-poor catchments.
Back to the top
Soft bottom macrozoobenthic communities from the coastal sea area of Helsinki (south Finland) and Saaremaa Island (west Estonia) were compared in order to evaluate the effects of diffuse and point source nutrient supply. The coastal sea area of Helsinki receives a moderate load of municipal sewage water and the latter is ranked among the most undisturbed ecosystems in the northern Baltic Sea. The species composition and dominance structure were similar in both the studied areas indicating that different sources of eutrophication (i.e. local or basin wide) have similar consequences for the macrozoobenthic communities. However, functional diversity was higher in the Saaremaa area as the higher share of herbivores and suspension feeders were found in the area.
Back to the top
The geological and geomorphological settings of annually laminated sediments in Finnish boreal lakes in southern and central Finland were investigated. The purpose of the study was to identify the key sedimentary environmental factors of the morphometric features and catchment sediment types that control varve deposition in lakes. Altogether nearly 300 lakes were surveyed, of which 180 basins were cored. 35 of the cored lakes were found to contain partially laminated and 13 completely laminated sediments. Statistical analyses of the lake dataset, which also includes 15 previously located lakes composing varved sediments, show that two groups of lakes are more favourable for the formation of varves than others. The first group includes the majority of previously located varved lakes and is characterized by small-sized, relatively deep basins in glaciofluvial deposits. The second group is characterized by fairly equal proportions of till, bedrock and fine-grained sediment in the catchment, and it is more dependent on the shape of the catchment and basin itself than maximum depth and lake area. These lakes are located in the distal part of Younger Dryas end moraines or in the areas of ancient lake complexes or ice-lakes, and commonly comprise clastic-organic laminae couplets.
Back to the top
e established to perform a long-term study of effects of air pollution on pine forest ecosystems along a pollution gradient in the border areas between Norway and Russia. The main pollution source is a nickel smelter. Several methods and analyses were used to investigate different compartments of this northern boreal forest ecosystem. The differences in ecological condition and diversity observed among the research sites are probably due to the air pollution load in the area. The elevated concentrations of Ni and Cu detected in plant tissues, the reduced lichen vegetation on stems and on the forest floor, and the reduced or absent moss vegetation are the most obvious impacts in the investigated area.
Back to the top