The retreat of pine forest in Finnish Lapland since the Holocene climatic optimum: a general discussion with radiocarbon evidence from subfossil pines

Abstract

Literature data on the retreat of the pine forest in Northern Fennoscandia are presented to cover the period from the early 19th century onwards, i.e. since the first reliable observations were made. These data are compared with radiocarbon datings of 44 samples from subfossil pines found at or beyond the present limit of pine forest. The trees had usually been preserved best in moist surroundings, the majority of the trunks and stumps having been recovered from small lakes or wet paludified depressions. Although the dates are scattered over a wide period of time, from about 7000 B.P. up to recent times, there is a concentration around 4000‑6000 B.P. sufficient to suggest that pine forest grew beyond the present limit during the Holocene climatic optimum. The most pronounced retreat in the forest limit since that time is recorded in Enontekiö, in the western part of Finnish Lapland. The results fit well with existing pollen records, which indicate that pine spread to Lapland around 8500‑7500 B.P. and achieved its maximum distribution in the period 7500‑5000 B.P., gradually retreating since then, due to the deteriorating climate.