Radiocarbon-Dated Subfossil Pines from Finnish Lapland

Abstract

A total of 64 subfossil pine samples from the pine tree limit zone or beyond the present limit of pine in Finnish Lapland have been 14C dated. Ten new dates from the Enontekio region in northwestern Finnish Lapland are reported in the present paper. The majority of the dates from that region falls between approx. 6000 and 4000 B.P., showing that the pine area reached its maximum extent during that period. The dates from Inari and Utsjoki in the northernmost part of Finland are scattered between a few hundred and about 7000 years B.P., indicating that the retreat of the pine limit was a gradual process. Pine reached its maximum distribution during the postglacial climatic optimum, when the outermost occurrences were far beyond its present limit. The slow climatic deterioration since about 5000 B.P. has been the main reason for the decline of northernmost pine forests. The present material does not allow oscillations in the pine limit to be detected, but presumbly some variations did occur within the general long-term cooling trend. Radiocarbon-dated subfossil pines from Finnish Lapland It has been known for a long time that subfossil pine stumps and trunks are to be found beyond the present pine limit in Fennoscandia, the first detailed descriptions having been made during the last century and at the beginning of this century (e.g. Sandberg 1898, Fellman 1906, Juul 1925, see Eronen 1979). The ages of the finds could only be estimated very roughly, however, before the invention of the radiocarbon method. The earliest 14C dates for subfossil pines were obtained from stumps found above the present pine limit on the Swedish fells (G. Lundqvist 1959), since when a large body of dates from comparable material has accumulated in Sweden (G. Lundqvist 1962, J. Lundqvist 1969, 1973, Karlen 1976, Kullman 1980). 14C dates for subfossil pines from Norway have been reported and described by Moe (1979), Hafsten (1981), and Selsing and Wishman (1984). The first radiocarbon dates from Finnish Lapland were published by Salmi (1970) and Lappalainen (1970). Dates are now available for a large number of specimens (Eronen 1979, Eronen and Hyvarinen 1982) and 10 new ones are reported in this paper. New '4C dates for subfossil pines: site descriptions All the pine dates related to postglacial tree-line changes in Finnish Lapland are listed in Table 1. Detailed descriptions of the earlier finds can be found in the references included in the table. Dated pine remains from three sites in Enonteki6 are described here. (The locations of these sites are marked on the map (Fig. 1) in Eronen and Hyvarinen 1982). Site: Ainavarppijirvi, 68° 41' 40 N, 20° 26' E. Finnish national grid reference 762350, 51825/21, 405 m above sea level. Enonteki6, topographic map 1:100000, sheet 1832. A small lake with many pine trunks and stumps on the bottom. Samples taken by wading in the lake. Ainavarppijarvi I: Only the stumps and lower part of the trunk preserved. The sample was taken from the trunk about 0.5 m above the base. Approx. the 90 innermost rings were dated: 5460±140 B.P. Hel-1518. Ainavarppijarvi II: Sample collected by Heikki Uotila. Only the stump had been preserved and could be used for dating. Approx. the 60 innermost rings were dated: 5690±140 B.P. Hel-1519. Ainavarppijarvi III: Sample collected by Heikki Uotila. Only the stump had been preserved and could be used for dating. Approx. the 60 innermost rings were dated: 5700±140 B.P. Hel1520. Ainavarppijiarvi IV: The trunk had been preserved, a sample from which was taken about 1.3 m above the base. Approx. the 30 innermost rings were dated: 5900±140 B.P. Hel-1521. Ainavarppijdrvi V: The trunk had been preserved, a sample from which was taken about 1.3 m above the base. Approx. the 50 innermost rings were dated: 5690±120 B.P. Hel-1522. All the above subfossil pines were found lying on the mud or partly buried in it in shallow nearshore water in Lake Ainavarppijarvi. Site: Ldntinen (= Western) Ladnajdrvi, 68° 42' 40 N, 21° 30' 35 E. Finnish national grid reference 762540, 52060/21,480 m above sea level. Enontekio, topographic map 1:100000, sheet 1832. A small lake with several subfossil pine trunks on the bottom. Western Ladnajdrvi I: A trunk about 6 m long lying in water of depth approx. 1.5 m below the shore bank. The trunk broke as it was being moved and only the upper part could be lifted from the water. The sample was taken by Heikki Uotila from about 2.5 m Geografiska Annaler * 69 A (1987) · 2 297 This content downloaded from 207.46.13.145 on Wed, 27 Apr 2016 05:49:17 UTC All use subject to http://about.jstor.org/terms