Due to joint investigations permanent sample plots for long-term observations of the environmental changes were set up on both sides of the Russian-Norwegian border. Changes of species diversity of forest vegetation (trees, bushes, herbs, mosses and lichens) were investigated. Their vital status, growth rate, morphology, production and chemical composition were studied. Changes of the acidity, cation exchangeable properties, nutrition status and heavy metal accumulation in soils as well as the mechanisms of their interactions were investigated. Heavy metal accumulation in wildlife animals was also studied. Preliminary borders of the area of "Pechenganickel" smelter's possible influence on the environment were revealed and the methodology for forest ecosystems' state assessments was developed.

The limits of tolerance of the most sensitive components of forest ecosystems were estimated and critical levels of sulphur dioxide concentrations in the ambient air were set.

Soil buffer capacity and its susceptibility to acidification were estimated both in field conditions and laboratory experiments. The weathering rate as the key long-term process of proton consumption was assessed with the PROFILE model on the base of detail study of soil mineralogy and texture. Critical loads of acid deposition were calculated by the simple balance method and mapped for soils both in the study area and the Kola Peninsula. Long-term changes of forest soils in response to several deposition scenarios were predicted with the SMART model.

• Aamlid, D. 1990. Some ongoing monitoring activities concerning air pollution and effects on forests in Pasvik, Finnmark country of Norway. In: K.Kinnunen and M. Varmola (eds.). Effects of Air Pollutants and Acidification in Combination with Climatic Factors on Forests, Soils, and Waters in Northern Fennoscandia. Rep. from a workshop, Rovaniemi, Finland 17-19 October 1988. NORD 1990: 20, pp. 171-177.
• Aamlid, D. 1993. Symptoms of sulphur dioxide injuries on some boreal plants. In: Jalkanen, R.and Aalto, T. (Eds.), Forest Pathological Research in Northern Forests with Special Reference to Abiotic Stress Factors. Extended SNS meeting in forest pathology in Lapland, Finland, 3-7 August 1992. MetsÄntutkimuslaitoksen Tiedonantoja.
• Aamlid, D. 1994. Forurensninger i skog. Analyser av nedbor pa intensivt overvakete forskningsflater i 1993. (Pollution in forests. Analyses of precipitation at intensively monitored research plots in Norway in 1993). Rapp. Skogforsk. 19/94: pp. 1-21 (in Norwegian).
• Aamlid, D. 1995. Heavy metals in Salix leaves. In: Effects of air pollutants on terrestrial ecosystems in the border area between Norway and Russia. Proceedings from the second symposium, Svanvik, Norway, 3-5.10.94. Ed. by LÜbersli, E. and Venn, K. Trondheim. pp. 73-75.
• Aamlid, D. 1995. Air pollution impact on forest ecosystems in South-Varanger, Finnmark, Norway. In: Effects of air pollutants on terrestrial ecosystems in the border area between Norway and Russia. Proceedings from the second symposium, Svanvik, Norway, 3-5.10.94. Ed. by LÜbersli, E. and Venn, K. Trondheim. pp. 94-102.
• Aamlid, D. and I. Skogheim. 1993. Nickel, kopper og andre metaller i multer og blÅbÔr fra SÜr-Varanger, 1992 (Nickel, copper and other metals in berries of cloudberry (Rubus chamaemorus) and bilberry (Vaccinium myrtillus) from South Varanger, north-east Norway, 1992). In: Norwegian. Rapp. Skogforsk 14/93: pp. 1-15 (in Norwegian).
• Aamlid, D., TÜmmervik, H., Gytarsky, M., Karaban', R., Venn, K., Rindal, T., Vassilieva, N., Koptsik, G.and LÜbersli E. 1995. Determination of exceedance of critical levels in the border area between Norway and Russia. In: Effect of Air Pollutants on Terrestrial Ecosystems in the Border Area between Norway and Russia. Proceedings from the second symposium, Svanvik, Norway, 3-5 October 1994. pp. 19-24.
• Aamlid, D. and K. Venn. 1992. Monitoring of forest vegetation in eastern Finnmark, Norway. - Crown density and crown colour 1988-1991. In: E. Tikkanen, M. Varmola and T. Katermaa (eds.), Symposium on the State of the Environment and Environmental Monitoring in Northern Fennoscandia and the Kola Peninsula. October 6-8 1992. Arctic Centre Publications 4. Rovaniemi, pp. 200-203.
• Aamlid, D. and K. Venn. 1993. Methods of monitoring the effects of air pollution on forest and vegetation of eastern Finnmark, Norway. Norwegian Journal of Agricultural Sciences 7: pp. 71-87.
• Aarrestad, P.A. and Aamlid, D. 1995. Field vegetation monitoring in South-Varanger, Finnmark, Norway. In: Effects of air pollutants on terrestrial ecosystems in the border area between Norway and Russia. Proceedings from the second symposium, Svanvik, Norway, 3-5.10.94. Ed. by LÜbersli, E. and Venn, K. Trondheim. pp. 112-116.
• Acid Deposition and Forest Soils. Nikonov V.V. and G.N. Koptsik (eds.). 1999. Apatity. 325 p. (In Russian).
• Effects of Air Pollutants on Terrestrial Ecosystems in the Border Area between Russia and Norway. Kismul, V., J. Jerre and E. LÜbersli (eds.). 1992. Proceedings from the First Symposium. Svanvik, Norway, 18-20 March 1992. SFT Document 92: 04. 220 p.
• Effects of Air Pollutants on Terrestrial Ecosystems in the Border Area between Russia and Norway. LÜbersli, E. and K. Venn (eds.). 1995. Proceedings from the second symposium, Svanvik, Norway, 3-5 October 1994. Research Report for Directorate for Nature Management in cooperation with Norwegian Pollution Control Authority. Trondheim. 140 p.
• Gytarsky, M.L., Karaban, R.T., Nazarov, I.M., Sysygina, T.I. and Chemeris, M.V. 1995. Monitoring of forest ecosystems in the Russian Subarctic: effects of industrial pollution. The Science of the Total Environment 164: pp. 57-68.
• Johansen, M.E., TÜmmervik, H., Guneriussen and Pedersen, J.P. 1995. Using a geographic information system (ARC/INFO) to integrate remote sensed and in-situ data in an analisis of the air pollution effects on terretsrial ecosystems in the border areas between Norway and Russia. In: Effects of air pollutants on terrestrial ecosystems in the border area between Norway and Russia. Proceedings from the second symposium, Svanvik, Norway, 3-5.10.94. Ed. by LÜbersli, E. and Venn, K. Trondheim. pp. 120-130.
• Karaban, R.T. and M.L. Gytarsky. 1995. Studies of precipitation contamination levels over the north-western forests of Russia subject to emissions from the two nickel smelters. Water, Air and Soil Pollution 85: pp. 2071-2076.
• Koptsik, G. 1995. Forest soil response on air pollution in the north-western part of Kola Peninsula. In: Proc. of 10th World Clean Air Congress. Helsinki. pp. 419-422.
• Koptsik, G. and D. Aamlid. 1995. Effects of soil contamination on forest status near a nickel smelter. In: Biogeochemistry of Trace Elements. Proc. of 3th Int. Conf. Paris.
• Koptsik, G. and S. Koptsik. 1995. Critical loads of acid deposition for forest ecosystems in the Kola Peninsula. Water, Air and Soil Pollution 85: pp. 2553-2558.
• Koptsik, G. and S. Koptsik. 1995. Assessment of critical loads of acidity for soils in the Kola Peninsula. In: Effect of Air Pollutants on Terrestrial Ecosystems in the Border Area between Norway and Russia. Proceedings from the second symposium, Svanvik, Norway, 3-5 October 1994. pp. 124-132.
• Koptsik, G., Koptsik, S. and Silaeva, E. 1995. The contribution of organic matter to buffering of acid deposition by forest soils in the Kola Peninsula. In: Organic-Mineral Interactions in Soils and Sediments. University of Newcastle upon Tyne, UK. p. 36.
• Koptsik, G. and I. Mukhina. 1995. Effects of acid deposition on acidity and exchangeable cations in podzols of the Kola Peninsula. Water, Air and Soil Pollution 85: pp. 1209-1214.
• Koptsik, G. and Niedbaiev, N.P. 1992. Effect of atmospheric deposition on forest soils in the Northwestmost part of Kola Peninsula. In: Effect of Air Pollutants on Terrestrial Ecosystems in the Border Area between Russia and Norway. Proceedings from the first symposium, Svanvik, Norway. 18-20.03.1992. pp. 48-55.
• Koptsik, G. and Silaeva, E. 1994. Buffering of acid deposition by forest soil. In: EERO Symposium on Chemical Risk Assessment: New Approaches and Opportunities. 13-17 September p. 6. Moscow.
• Koptsik, G. and Silaeva, E. 1996. Buffering capacity of forest litters to acid atmospheric precipitation. Eurasian Soil Science 28 (10): pp. 124-136.
• Koptsik, G., Silaeva, E., Mukhina, I. and Nedbaev, N. 1995. Forest soil buffering to acid deposition. In: Effect of Air Pollutants on Terrestrial Ecosystems in the Border Area between Norway and Russia. Proceedings from the second symposium, Svanvik, Norway, 3-5 October 1994. pp. 36-44.
• Koptsik, G., Sokolova, T.A. and Terekhin, V.G. 1992. Estimation of forest soil buffering to acid deposition. In: Effect of Air Pollutants on Terrestrial Ecosystems in the Border Area between Russia and Norway. Proceedings from the first symposium, Svanvik, Norway. 18-20.03.1992. pp. 177-184.
• Koptsik, G. and Teveldal, S. 1995. The main mineralogy in 9 profiles from Kola (6) and Finnmark (3). Norwegian Forest Research Institute. NISK Report. 78 p.
• Koptsik, G., Teveldal, S., Aamlid, D. and Venn, K. 1999. Calculations of weathering rate and soil solution chemistry for forest soils in the Norwegian-Russian border area with the Profile model. Applied Geochemistry 14(2): pp. 95-107.
• Lukina, N. and V. Nikonov. 1995. Acidity of podzolic soils subjected to sulphur pollution near a Cu-Ni smelter at the Kola Peninsula. Water, Air and Soil Pollution 85: pp. 1057-1062.
• Lukina, N. and V. Nikonov. 1996. Biogeochemical Cycles in the Northern Forests Subjected to Air Pollution, Part 1-2. Apatity, Kola Science Centre, RAS. 410 p. (In Russian).
• Lukina, N., Nikonov, V. and Raitio, H. 1995. The foliar chemical composition of Scots pine in the Cu-Ni smelter surroundings on the Kola peninsula. In: Effects of air pollutants on terrestrial ecosystems in the border area between Norway and Russia. Proceedings from the second symposium, Svanvik, Norway, 3-5.10.94. Ed. by LÜbersli, E. and Venn, K. Trondheim. pp. 47-53.
• Nikonov, V. and N. Lukina. 1994. Forest biogeochemical function on the northern tree line. Apatity. 314 p. (in Russian).
• Nikonov, V. and Lukina, N. 1995. Acidity and nutritional status in pine forest soil in the Pechenganikel company surroundings. In: Effects of air pollutants on terrestrial ecosystems in the border area between Norway and Russia. Proceedings from the second symposium, Svanvik, Norway, 3-5.10.94. Ed. by LÜbersli, E. and Venn, K. Trondheim. pp. 36-46.
• Solheim, H. and Aamlid, D. 1993. Possible influence of air pollution on endophytic fungi in Norway spruce needles. In: Forest pathological research in northern forests with a special reference to abiotic stress factors. Extended SNS meeting in forest pathology in Lapland, Finland, 3-7 August, 1992. Ed. by Jalkanen, R., Aaito, T. and Lahti, M.L. The Finnish Forest Research Institute, Department of Forest Ecology, Rovaniemi. pp. 108-118.
• Steinnes, E., Glesne, O., Lukina, N. and Nikonov, V. 1995. Soil plant systems in the border area between Norway and Russia. In: Effects of air pollutants on terrestrial ecosystems in the border area between Norway and Russia. Proceedings from the second symposium, Svanvik, Norway, 3-5.10.94. Ed. by LÜbersli, E. and Venn, K. Trondheim. pp. 14-15.
• TÜmmervik, H., Johansen, B.E. and Pedersen, J.P. 1995. Multitemporal Landsat image data for mapping the effects of air pollution on vegetation in the Kirkenes-Pechenga area in the period 1973-1988. In: Effects of air pollutants on terrestrial ecosystems in the border area between Norway and Russia. Proceedings from the second symposium, Svanvik, Norway, 3-5.10.94. Ed. by LÜbersli, E. and Venn, K. Trondheim. pp. 117-119.
• TÜmmervik, H., Skevik, K. 1995. Chlorophyll fluorescence measurements on several plant plant species in different air pollution affected sites in Varanger, Northen Norway, compared with remote sensing data. In: Effects of air pollutants on terrestrial ecosystems in the border area between Norway and Russia. Proceedings from the second symposium, Svanvik, Norway, 3-5.10.94. Ed. by LÜbersli, E. and Venn, K. Trondheim. pp. 131-135.
• Vassilieva, N., Gytarsky, M. and Karaban, R. 1995. Changes of the dominant species of epiphytic lichens and the ground vegetation cover in the forests subject to "Pechenganikel" smelter impact. In: Effects of air pollutants on terrestrial ecosystems in the border area between Norway and Russia. Proceedings from the second symposium, Svanvik, Norway, 3-5.10.94. Ed. by LÜbersli, E. and Venn, K. Trondheim. pp. 103-111.