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The Arctic is one of the regions most sensitive to global warming, for which climate and environmental proxy archives are largely insufficient. Arctic driftwood provides a unique resource for research into the circumpolar entanglements of terrestrial, coastal and marine factors and processes – past, present, future. Here, first dendrochronological and wood anatomical insights into 639 Arctic driftwood samples are presented. Samples were collected across northern Norway (n =430) and north-western Iceland (n =209) in 2022. The overall potentials and limitations of Arctic driftwood to improve tree-ring chronologies from the boreal forest, and to reconstruct changes in sea ice extent and ocean current dynamics are discussed. Finally, the role driftwood has possibly played for Arctic settlements in the past hundreds of years is examined. [ABSTRACT FROM AUTHOR]

The research was conducted in selected 80- to 110-year-old spruce stands in the south-eastern part of the Českomoravská Upland at altitudes from 350 m a.s.l. to 465 m a.s.l. The regional standard tree-ring chronology shows very low increments for years 1974, 1976 and 1992. After 1992, there is a sharp rise in increments with a climax in 1997. Afterwards, increments gradually decrease, reaching minima in 2003 and 2008. The years with low increments were also confirmed by the analysis of negative pointer years when over 80% of the analysed trees responded by a sharp decrease in increment, mainly in years 1976 and 1992. We can usually find values of monthly precipitation or monthly temperature average which can explain or help explain these falls in the radial growth. The correlations of diameter increments with average monthly precipitation gain only positive statistically significant values, namely for the months of May, June, July and August of the particular year. The correlations of diameter increments with average monthly temperatures gain only negative statistically significant values, namely for the months of June, July and September of the previous year and January and August of the particular year. In the examined area there is a significant negative correlation between average temperatures and monthly precipitation in July, August and September. The results of the habitual diagnostics show that with respect to the climatic conditions the health condition of the monitored stands is relatively good. On average, the defoliation does not exceed the values ascertained in different territories of the Czech Republic. [ABSTRACT FROM AUTHOR]

The aims of the study were to determine the effect of temperatures and precipitation on the ring width and to compare the results with the results of previous studies conducted in other mountain ranges of the Czech Republic. The research was performedin the central part of the Ceskomoravská Uplandin the vicinity of Herálec municipality in selected 70- up to 110-year-old spruce stands at altitudes from 680ma.s.l. to 779 m a.s.l. Measuring of tree-ring widths and synchronization of individual ring series were conducted in PAST4. The age trend was removed by ARSTAN and climatic effects were modelled in Dendro Clim 2002. The correlation of tree-ring width with monthly precipitation is positive and statistically significant for July of the previous year andfor the entire summer periodfrom June to September of the current year. The correlation of tree-ring width with mean monthly temperatures is negative andstatistically significant for July and Septem - ber andpositive andstatistically significant for October of the previous year. Negative correlation was also foundfor temperatures of the entire summer periodfrom June to September of the previous year. The regional tree-ring chronology mainly shows two periods of highly reduced increment: from 1992 to 1996 and from 2003 to the end of the analysed period. The results thus confirm the hypothesis that the tree-ring width is in positive correlation with summer precipitation andnegative correlation with summer temperatures. Also the results of the habitual diagnostics have shown a relatively low degree of crown transformation which indicates a weak or short-term stress load. [ABSTRACT FROM AUTHOR]

Driftwood supply was a pivotal factor for the Norse expansion in medieval times and still exhibits an essential resource for Arctic settlements. The physical causes and societal consequences of long-term changes in the distribution of Arctic driftwood are, however, poorly understood. Here, we use dendrochronology to reconstruct the age and origin of 289 driftwood samples that were collected at remote shorelines in northeast Iceland. Based on 240 reference tree-ring width chronologies from the boreal forest zone, and an overall provenance success of 73%, we show that most of the driftwood is pine and larch from the Yenisei catchment in central Siberia. Our study reveals an abrupt decline in the amount of driftwood reaching Iceland since the 1980s, which is corroborated by the experience of local farmers and fishers. Despite the direct and indirect effects of changes in both, logging activity across Siberia as well as Arctic Ocean currents, the predicted amount of sea-ice loss under anthropogenic global warming is likely to terminate Iceland's driftwood supply by 2060 CE. • Driftwood was and is the most important resource for all Arctic settlements. • Most of the Icelandic driftwood originates from the Yenisei catchment in central Siberia. • An abrupt decline in the amount of Icelandic driftwood supply occurred in the 1980s. • Icelandic driftwood supply will cease under predicted sea-ice loss by 2060 CE. [ABSTRACT FROM AUTHOR]