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The sun's activity role in climate change has become a topic of debate. According to data from the IPCC, the global average temperature has shown an increasing trend since 1850, with an average increase of 0.06 °C/decade. Our analysis of summer temperature records from five weather stations in northern Fennoscandia (65°–70.4° N) revealed an increasing trend, with a range of 0.09 °C/decade to 0.15 °C/decade. However, due to the short duration of instrumental records, it is not possible to accurately assess and predict climate changes on centennial and millennial timescales. In this study, we used the Finnish super-long (~7600 years) tree-ring chronology to create a climate prediction for the 21st century. We applied a method that combines a long short-term memory (LSTM) neural network with the continuous wavelet transform and wavelet filtering in order to make climate change predictions. This approach revealed a significant decrease in tree-ring growth over the near term (2063–2073). The predicted decrease in tree-ring growth (and regional temperature) is thought to be a result of a new grand solar minimum, which may lead to Little Ice Age-like climatic conditions. This result is significant for understanding current climate processes and assessing potential environmental and socio-economic risks on a global and regional level, including in the area of the Arctic shipping routes. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

The use of rare earth elements (REE) in diverse areas of the world economy (e.g., industry, agriculture, medicine) has been significantly increased during the last decades. The mineral loparite can be considered as one of the REE sources along with bastnasite, monazite, and xenotime. The only active deposit of loparite ores in Russia is located at Kola Peninsula, northwestern Russia. The mining and processing of loparite are carried out at Lovozersky Mining and Processing Plant (MPP). In this study microfungal species isolated from the Lovozersky MPP's loparite ore concentration tailings, were studied. Based on morphological markers, a total of 15 species from nine genera have been isolated and identified. Two most dominant fungal species (Geomyces vinaceus and Penicillium simplicissimum) and two non-dominant (Aspergillus niveoglaucus and Pseudogymnoascuc pannorum), were tested in vitro on their tolerance/resistance to lanthanides (Nd and Ce). For comparison, microfungal strain Cadophora malorum, that is not isolate, was also tested. As the result, the most tolerant to both elements was P. simplicissimum which continued to grow at highest (500 mg/l) REE concentrations. Another dominant isolate G. vinaceus proved to be tolerant only to Nd and more sensitive to Ce. Our results indicate that P. simplicissimum has the potential to recover REEs such as Ce and Nd from the loparite ore concentration tails. The results obtained may be useful in order to evaluate the potential of the isolated P. simplicissimum in REE bioleaching. [ABSTRACT FROM AUTHOR]

The use of trace rare metals and rare-earth elements (REEs) in diverse areas of the world economy (e.g. agronomy, medicine, industry) has significantly increased during the last decades. At present, the information on the ecotoxicological effects of these elements is scarce and contradictory. This study aims to evaluate the ecotoxicity of 15 REEs (Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Dy, Ho, Er, Tm, Yb, and Lu) and 3 trace rare metals (Ga, Ge, and In) to ciliates Paramecium bursaria, which are a symbiosis of Paramecium and green algae Chlorella. Median lethal concentrations (12-h LC50) were assessed in P. bursaria cells at 12 h of exposure. A bioassay method based on galvanotaxis was used to explore the toxicity of non-lethal concentrations of cerium chloride to P. bursaria cells. The results showed a significant inhibition of galvanotactic migration of P. bursaria by CeCl3 in the presence of an electric field. This preliminary work aimed to evaluate the sensitivity of P. Bursaria to trace metals and REEs. [ABSTRACT FROM AUTHOR]