Rit (Vísindafélag Íslendinga) - 01.06.1939, Page 26

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no. 11 the angelica-clusters with Archangelica officinalis
Hoffm., Cochlearia officinalis L., Matricaria inodora L. var.
phæocephala Rupr. and Rhodiola rosea L.
The spread of the arctic plants reaches its maximum in
the gravel 46,3 %, and so diminishes over the peat and
blómlendi formations and is lowest in the puffin-colony
0 %, to rise after in the angelica clusters to 22,9 %. Arch-
angelica is an arctic plant and under these conditions
grows very luxuriantly.
Otherwise E 4 has the greatest distribution of any
species, and spreads the more as the plant-formation is
more specialised.
The behaviour of E 1 is peculiar, it is not found in the
highly specialised plant-formations, but seems to be ac-
cording to the number of species as it is highest in the
blómlendi 24,2 %, and is also rather high in the lava
13,9 %. It is clearly to be seen from this that E 1 is the
species of the dry in summer, shallow soil, gravelly but
yet moss-covered, areas.
Ch. seem to some extent to accompany the arctic plants
and to be the typical life-form of the gravel and peat-
formations, and they are therefore more apt to react to
the soil than to the climate, cf. p. 24 Peat-formation.
Hemicryptophytes and Geophytes are altogether in-
different, save in the sandy, mossless soil, and there, as in
the reclaimed sand and the angelica clusters, the Geo-
phytes are not at home.
The Therophytes are most prominent in the plant-forma-
tions of the E 4 species, but in inverse ratio with E 1,
otherwise one would expect E 1 and Th would corres-
pond better. But if one investigates better it appears that
the distribution of the Th life-form in the sand is a speci-
alisation phenomenon due to the very loose soil, cf. p. 18,
Vegetation of the sand. On the other hand in the bird-
colony the distribution of the Th life-form seems to be
due only to excessive manuring — phenomenal — and the