The Botany of Iceland - 01.12.1945, Blaðsíða 55

THE VEGETATION OF CENTRAL ICELAND
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is found as small patches in a mosaic of closely related associations near
brooks and rivers. Analyses 1-3 are from Arnardalur, 4 from Hvan-
nalindir.
5. Calamagrostis neglecta—Eriophorum polystachyum—Salix gla\uca-
Ass. (Tab. IV, 5).
This association has only been found in Kringilsárrani and is no
doubt of very rare occurrence. Its species composition and biological
spectra remind one of association 4, but its physiognomy resembles
that of association 3. Furthermore it grows in similar localities, sloping
ground with large mossy cushions. The analysis was taken near analysis
IV, 6 and should perhaps be regarded as a variant of association 3,
only growing in more sandy soil than the latter.
6. Carex Goodenoughii—Salix glauca-Ass. (Tab. IV. A-B, 7).
Dominant in this association, besides the character species, is Poly-
gonum viviparum. The association has only been found in small patch-
es in Fragidalur in the immediate vicinity of the C. Goodenoughii flói.
It forms a kind of transition to the Salix jaðar or to the pure Salix
heath. The surface is knolly and slightly inclined. The A-groups do-
minate over the E-groups. G and Gh are the most prominent life-forms.
7. Carex Goodenoughii—Equisetum palustre—Salix glauca-Ass.
(Tab. IV. A-B, 8; Tab. VI. A-B, 1-2).
As shown by the analyses, we are here concerned with two variants.
Analyses VI, 1-2 show Carex rigida and C. rariflora to be very pre-
dominant, whereas IV, 8 shows that Vaccinium uliginosum is among
the dominants. Otherwise the association is characterised by a high
E percentage. G is the dominant life-form, but the Ch percentage also
attains a relative maximum in this association. Analysis IV, 8 is from
Fagridalur, where the association is fairly widely distributed on the
lower parts of the slightly sloping mountain sides. Analyses VI, 1-2 are
from Síðumannaafrjettur, where the association likewise exhibits a
fairly wide distribution. Otherwise it was not observed in the highland.
In spite of the considerable altitudinal difference between these two
localities—Fagridalur lies about 200 m above Síðumannaafrjettur—the
character species of the association show a surprisingly good agreement