Greinar (Vísindafélag Íslendinga) - 01.01.1967, Blaðsíða 59

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third association is to be found: the Angelica clusters.
This area is rather easily reached from the sea, but in
general it is difficult to reach such associations which are
situated on shelves and in niches on the cliff face. Hvann-
hilla slopes diagonally up the rock from the sea. At its
lower extremity there is little vegetation; then comes a
grass slope with a composition similar to that of the puf-
fin colony (Table IV, Bjarnarey 7). The Angelica cluster
is at the top of the incline and extending down by the
cliff for a short distance. This covers an area of 420 sq. m.
The dominant species Archangelica officinalis was ex-
tremely luxuriant, about 120 cm high and with a coverage
of 51%. Its associated species, consisted of Matricaria
maritima 12% and Stellaria media 14% which are the
undergrowth and Festuca rubra 13%, which grows on the
margins, while bare patches measured 10% (Table IV,
Bjarnarey 8). The soil of the Angelica clusters was some-
what gravelly and fairly wet, for water drips constantly
down the rock. Fulmar frequent this area in particular,
supplying natural fertilizer. The Angelica clusters conse-
quently could be named the fulmar colony vegetation.
Raunkiaer frequency-measurements were taken here for
comparison with those of B. Johnsen of 33 years earlier
(Table V, Bjarnarey 3, ’66 and Bjarnarey 1, ’33). Here
some changes in distribution seem to have taken place.
Three species — Ranunculus acris, Sedum roseum and
Cochlearia officinalis — have disappeared, and other as-
sociated species become less frequent. Beside this, the
Angelica appears to have thinned somewhat during the
33 years between measurements.
Álsey
Álsey is the third island in size, or about 0.25 sq. km.
It is very precipitous, surrounded by cliff on all sides ex-
cept the northern. There is no level ground on the island
except at its extreme summit, where there is a patch of
dry meadow iand. This is very small in extent. The domi-
nating species of the dry meadow land are Festuca rubra