This study revealed a significant reduction in tree growth across northern Fennoscandia following the 1600 AD eruption of Huaynaputina in Peru, the most powerful volcanic event in South America over the past two millennia. In the analysis, we utilized six tree-ring chronologies, which included the Finnish super-long chronology (5634 BC–2004 AD), the Kola Peninsula chronology (1445–2004 AD), and historical chronologies derived from old wooden churches in Finnish Lapland and Karelia, Russia. Using a superposed epoch analysis across these chronologies revealed a significant 24% (p < 0.01) decline in tree-ring growth in 1601 compared to the previous six years. The northernmost records, the Finnish super-long chronology (72%, p < 0.001) and the Sodankylä Old Church chronology (67%, p < 0.001), showed the most pronounced decreases. Statistical analysis confirmed significant (p < 0.05) similarities in tree-ring responses across all chronologies from 1601 to 1608. These findings underscore the reliability of using the 1600 Huaynaputina eruption as a chronological marker for dating historic wooden churches in northern Fennoscandia that were likely built between the late 17th and early 18th centuries. Additionally, analyzing church wood may provide insights into past climate patterns and environmental conditions linked to the eruption.

A 105-year chronology (AD 1917–2021) was developed from mountain birch (Betula pubescens Ehrh.) from beyond the coniferous treeline on the Kola Peninsula in Northwestern Russia (68.86 N, 34.69 E). A total of 22 trees were cored, including the oldest living mountain birch of 105 years old. The highest correlations occurred for the May temperature (r = 0.39, p < 0.01) and July sunshine duration (r = −0.39, p < 0.05). The increase in radial growth in May seemed to be caused by snowmelt giving rise to soil temperature, which can lead to a resumption in radial growth after winter dormancy. The negative correlation with the July sunshine duration seemed to be connected to changes in the spectral composition of solar radiation in the red to far-red ratio in the end of the polar day in July. The application of wavelet coherency revealed a significant (>95%) connection between the radial growth of B. pubescens, and solar activity in frequency bands encompassed the main solar cycles: 5.5 years (the second harmonic of the Schwabe cycle), 11 years (the Schwabe cycle) and 22 years (the Hale cycle). The results show that the northernmost birch trees in Europe are suited for tree-ring research. This allows us to expand the area of dendrochronological research further beyond the conifer treeline above the Polar Circle.

The article discusses the findings from monitoring sites of accumulated environmental damage (AED) along the East Murman coastline. The area surveyed includes the mouth of the Kharlovka River estuary, which is near the Seven Islands Archipelago within the Kandalaksha State Nature Reserve. During a thorough engineering and environmental assessment of the region, an inventory of AED sites was conducted, along with an evaluation of the amount of accumulated waste and an analysis of pollutant levels in the soil. The survey revealed six unauthorized waste disposal sites, primarily consisting of fuel and lubricant containers and scrap metal. Soil testing at two locations within the Barents Sea’s water protection zone indicated significant contamination with oil products, while the levels of metals (Zn, Cd, Pb, Cu) were found to be acceptable. The analysis of soil conditions revealed that degradation within the Kharlovka River estuary began during the operation of a fuel and lubricants storage facility in the area. At the time of the assessment, over a third of the surveyed area lacked a fertile soil layer, and the remaining soil and vegetation were sparse. The degree of contamination by oil products requires the implementation of highly efficient soil remediation methods.