Summary A sediment core recovered from Poteryanny Zub Lake on the Kola Peninsula of Russia (68°48′91″ N, 35°19′32″ E) provides fossil pollen and stomate evidence for Pinus sylvestris treeline development and movement. The site today lies in birch forest tundra, approximately 25 km north of the pine treeline and 90 km south of the Murman Coast. The record begins approximately 10 050 14C years before present (bp). The post‐glacial tundra, typified by various herbaceous taxa and Artemisia, was followed by Betula‐dominated woodland forest with Polypodiaceae‐Gramineae pollen types. Such vegetation assemblages are not analogous to any in the western Kola Peninsula today. Stomate evidence demonstrates that Pinus sylvestris immigrated to the study site as early as 8150 14C bp. Pine forest probably expanded northwards from sparse or small disjunct populations, which established c. 1000 14C bp before the expansion evident in the pollen and wood macrofossil records (7200 14C bp). Betula and other shrub and herb taxa declined at this time, possibly as a result of shading by the pine canopy. The presence of fossil Pinus sylvestris stomates and wood, together with AP : NAP ratios, indicates that the pine treeline was some 100 km north of its present position by the end of the middle Holocene warming (7000–6000 14C bp). This places it near the Barents Sea coast, currently tundra vegetation. An approximate 2 °C increase in regional summer temperatures would be necessary to move the treeline to the present‐day coastline. From 6000 14C bp the pine treeline gradually retreated southward to its present modern position. Birch woodland has grown at the site since c. 3000 14C bp.

Radiocarbon dates were obtained from 24 samples of Pinus sylvestris L. (Scots pine) wood recovered from sites beyond the modern conifer tree-line on the Kola Peninsula of Russia. Twenty-one of the samples came from the shallow waters and eroding peats at the edges of two small lakes at 68°439N, 35°109E, located north of the modern conifer tree-line. Three samples came from a small pond located above the modern elevational limits of Pinus sylvestris at 68°259N, 35°199E. The radiocarbon dates indicate that pine trees grew approximately 20 km north of the mapped modern limits of the species from 6680 BP to 3830 BP. Pine trees were also growing some 40 m above their modern elevational limits between 5890 BP and 3450 BP. Nineteen of the samples date from 6680 BP to 5070 BP, suggesting that the density of trees north of the modern tree-line was greatest between 7000 and 5000 BP. The timing of tree-line advance and greatest density on the Kola Peninsula are in agreement with the results of similar studies from northern Fennoscandia which indicate that maximum northern and elevational extension of tree-line occurred between 7000 BP and 4000 BP. The general agreement between tree-line reconstructions suggests that the climatic changes that promoted mid-Holocene tree-line extension along the North Atlantic margins in northern Fennoscandia propagated eastward to the Kola Peninsula. The late timing of initial pine expansion on the Kola and in adjacent northern Fennoscandia remains problematic and may relate to lower winter insolation, temperature regimes in the adjacent oceans or slow rates of migration.

We present two new quantitative July mean temperature (Tjul) reconstructions from the Arctic tree-line region in the Kola Peninsula in north-western Russia. The reconstructions are based on fossil pollen records and cover the Younger Dryas stadial and the Holocene. The inferred temperatures are less reliable during the Younger Dryas because of the poorer fit between the fossil pollen samples and the modern samples in the calibration set than during the Holocene. The results suggest that the Younger Dryas Tjulin the region was 8.0–10.0°C, being 2.0–3.0°C lower than at present. The Holocene summer temperature maximum dates to 7500–6500 cal yr BP, with Tjulabout 1.5°C higher than at present. These new records contribute to our understanding of summer temperature changes along the northern-European tree-line region. The Holocene trends are consistent in most of the independent records from the Fennoscandian–Kola tree-line region, with the beginning of the Holocene thermal maximum no sooner than at about 8000 cal yr BP. In the few existing temperature-related records farther east in the Russian Arctic tree line, the period of highest summer temperature begins already at about 10,000 cal yr BP. This difference may reflect the strong influence of the Atlantic coastal current on the atmospheric circulation pattern and the thermal behaviour of the tree-line region on the Atlantic seaboard, and the more direct influence of the summer solar insolation on summer temperature in the region east of the Kola Peninsula.

Potential linkages between volcanic activity and a 403-year record of Pinus sylvestris L. (Scots pine) growth and summer temperatures estimated from tree-ring widths are evaluated from an Arctic tree-line site on the Kola Peninsula, northwestern Russia. The joint occurrence of volcanic eruptions and severe negative ring-width values is more than four times that expected by chance. A composite average of temperatures indicates that a 0.72°C temperature reduction is typical for the year immediately following volcanic eruptions, while tree growth is reduced for up to two decades. The Greenland Ice Sheet Project 2 (GISP2) volcanic sulphate record shows a small but significant correlation with summer temperatures. Volcanic aerosols originating at low and middle latitudes appear to cause the greatest ring-width reduction and cooling.