The Botany of Iceland - 01.12.1912, Side 85

MARINE ALGAL VEGETATION
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same figures as for E. Iceland, and on combining NW., SW. and
S. Iceland we get almost the same fignres as for SW. Iceland. E.
Iceland and N. Iceland have 101 species of red and brown algæ
collec.tively. Of these 8 (8 %) are arctic, 20 (20 %) subarctic (sub-
division I), 28 (27 %) subarctic (subdivision II), 17 (17 %) boreal-
arctic, 26 (26 %) cold-boreal and 2 (2 %) warm-boreal. NW., SW.
and S. Iceland have 131 species of red and brown algæ collectively.
Of tliese 3 (2%) are arctic, 20 (15%) subarctic (subdivision I), 29
(22 %) subarctic (subdivision II), 16 (12 %) boreal-arctie, 53 (41 %)
cold-boreal and 10 (8 °/o) warm-boreal.
As regards the components of the flora, both Iceland taken as
a whole, and SW. Iceland resemble Finmark; S. Iceland resembles
the Færöes and Nordland, and E. Iceland resembles the Wliite Sea.1
It is evidently not due to chance that the resemblance of the
floral districts happens thus. The situation of Iceland just soutli of
and at the boundary between the arctic and the cold-boreal districts
corresponds exactly with tlie situation of Nordland—Finmark;—White
Sea in relation to this boundary. Iceland and the White Sea are
at tlie boundary itself, and in Finmark it certainly will be possible
to distinguish parts of the coast with a similar mixed flora as in
N. and NW. Iceland; the southern part of Finmark will then be
sonietliing like SW. Iceland, while S. Iceland, as already mentioned,
corresponds with Nordland.
This comparison shows only the relation between the quanlity
of the species of the floral districts within the difierent groups, but
gives no information as to how far the species are common to all
those districts. Then it remains to be investigated how many species
Iceland lias in common with the other districts. At the present
time a comparison of tlie floras will, however, scarcely give any
satisfactory results, because all the districts in question are not
equally well-known. By future investigations a greater number of
species will unquestionably be found in the majority of the floral
districts, and the quantity of the species will thus be altered, but
the relation between the number of the species of the different
groups will, however, undoubtedly remain unaltered.
1 According to Börgesen and Jónsson (14) 52 species are known from the
White Sea, of which 3 (6 °/o) are arctic, 10 (19 °/o) subarctic (snbdivision I), 19
(37 °/o) subarctic (subdivision II), 8 (15 %>) boreal-arctic and 12 (23 %>) cold-boreal.
The subarctic species constitute 56 °/o of the entire number of species and the
character of tlie Ilora is consequently subarctic in the same degree as that of E
Iceland.