Jökull - 01.12.1993, Side 26

Species/Genera Sampling site (Fig. 1) Time span No. of trees Intemal correlation Origin
Iceland 1 Pinus silvestris C 1748-1973 15 0.673 Yenisey river
Iceland 2 Pinus silvestris B and C 1820-1977 5 0.608 White Sea, Arkhangelsk
Iceland 3 Pinus silvestris B and C 1777-1948 3 0.613 White Sea, Murmansk
Iceland 4 Picea sp. B and C 1811-1982 7 0.567 White Sea, Aikhangelsk
Iceland 5 Larix sp. B and C 1-224 Tree rings 7 0.520 East of Ural
Greenland 1 Pinus silvestris D 1884-1961 2 0.680 White Sea, Arkhangelsk
Greenland 2 Picea sp. D 1850-1930 3 0.503 White Sea, Aikhangelsk
Iceland: Strandir (B) Iceland: Langanes (C) Iceland: Reykjanes (A) Iceland total Greenland: Scoresby Sund (D)
Pinus 29 (71 %) 171 (68 %) 32 (64 %) 232 (68 %) 9 (36 %)
Picea 3(7%) 42 (17 %) 8 (16 %) 53 (15 %) 10 (40 %)
Larix 7 (17 %) 33 (13 %) 11 (20 %) 51 (15 %) 4 (16 %)
broadleaf trees 2(5%) 5 ( 2%) 0 7(2%) 2(8%)
Total 41 251 51 343 25
Table 3. Dated and undated
driftwood mean curves from
this study. — Samantekt á
meðaltölum árhringja í reka-
viði frá Islandi og Grœn-
landi.
Table 4. Distribution of the
driftwood taxa collected in
Iceland and Greenland.
— Tíðni mismunandi viðar-
tegunda í reka á Islandi og
Grœnlandi.
SPECIES DISTRIB UTION AND ORIGIN
The distribution of the driftwood taxa from the
sampling sites (A,B,C,D) are shown in Table 4 and
summarised in the last column. The collections are
all dominated by coniferous trees, indicating that they
originate from boreal forest regions. If the species
distribution is compared with the forest composition
of the boreal forests of Russia (including Siberia)
where Picea and Pinus dominate the western parts
of the forests and Larix the eastern parts (Figure 4),
it can be concluded that the Larix driftwood origi-
nates from the eastern boreal forests of Russia, while
the Pinus and Picea samples originate from western
Russia. As illustrated in Table 3 the collection from
Greenland (D), although small, indicates that the tree
species composition differs from that on Iceland, par-
ticularly in the amount of Picea. This might be due to
input from the North American rivers (catchment area,
Mackenzie, Canada and Yukon, Alaska is dominated
by Picea) draining into the Arctic Ocean (Figure 4).
Dendrochronological studies on driftwood from Baf-
fin Island point in the same direction (Eggertsson and
Laeyendecker, submitted).
DENDROCHRONOLOGICALINVESTIGATIONS
Of the Pinus samples from Langanes (Figure 1 ;C
Table 4), 92 could be synchronised as one group, 54%
of the total Pinus samples from that locality. They
therefore originate from the "same" area. Out of those
15 were used to build a mean tree-ring curve for Pi-
24 JÖKULL, No. 43, 1993