Rit (Vísindafélag Íslendinga) - 01.06.1975, Side 104

covering although this was not to be gathered from the topographi-
cal characteristics.
As for the biological spectrum it is most important to note that
A group constitutes a clear majority here, as may be expected in
a highland sociation; the Ch percentage is high everywhere, but
otherwise the life forms are fairly evenly distributed between Ch,
H and G. The G percentage, however, is normally highest. There
are, however, considerable fluctuations in the percentages. The
topography is characterised by a highly patterned surface, some-
what sloping, but relatively dry. The moss vegetation is invari-
ably abundant; Sphagnum in the dampest areas and Rhacomitriinn
in the driest parts. The main vegetative difference between mounds
and hollows is the occurrence of moss on the mounds, causing the
phanerogamous vegetation to be more sparse there than in the
hollows. The phanerogams, however, are fairly evenly distributed
on mounds and in hollows. Analysis 19 is in some respects unique.
It was taken at Egilsáfangi in Kaldidalur in a mire-borderland on
a strip between mire and heath. The ground is patterned and dry.
Rhacomitrium is conspicuous and covers approximately 40%. Pha-
nerogams occurring there, but missing elsewhere are Vaccinium
uliginosum and Juncus trifidus. The latter is almost as conspicuous
in physiognomy as C. Bigelowii. This observation indicates close
relationship to the Scandinavian C. Bigelowii heath. I observed a
closely related variant in the vicinity of Djúpivogur. There C.
Bigelowii and Juncus balticus were dominant species and Rha-
comitrium was most conspicuous in physiognomy.
Analysis 10 is from the mountain above Staður in Reykjanes at
an altitude of approximately 300 m above sea level. The area is
coarse-patterned, but relatively dry. There the sociation is exten-
sively distributed, but it never has large, continuous coverage.
Analyses 11-13 are from the Snæfell highland at an altitude of
4-500 m above sea level; the sociation is widely distributed there,
and also on Jökuldalsheiði. Analysis 14 is from Síðumannaafréttur
where the sociation does not cover continuous areas anywhere.
Analyses 15-18 are from Holtavörðuheiði and the eastern part of
Tröllakirkja (altitude 400-490 m.) In 15 Sphagnum was con-
spicuous and in 17 there was so much Polygonum viviparum that
it characterised the vegetation together with C. Bigelowii. The so-
104