Greinar (Vísindafélag Íslendinga) - 01.01.1942, Blaðsíða 19

Í5
ferent from those usually obtaining where valllendi vege-
tation grows. The shelter is good here and the depth of
snow probably great compared with the rest of the island.
There is some moisture in the slope, penetrating down to
it from a boggy strip of land above it. Puffins have dug
burrows in the slope and it gets some manure from them
and, indeed, it has about the most luxuriant growth on the
island with the exception of the cultivated meadow. Pat-
ches like this slope are to be found in many places on the
cliffs but not elsewhere. In addition to the characteristic
species, Ranunculus acer and Taraxacum acromaurum are
so conspicuous as to make it almost a flowering meadow
(blómlendi). In none of the other Associations which are
rich in C. rigida is the A% as low as here, or 23.8%. The
H% is here comparatively high. It is the only valllendi-
Association in the island where Ch is entirely absent.
5. C. rigida — Juncus trifidus — Ass. (Table III, 5).
The analysis was made on the top of a very dry mound in
the south of the island. There this Association is found
under conditions very like Ass. 3. These two Associations
alternate on the driest mound tops. In addition to the
characteristic species, Poa pratensis is very conspicuous.
H is the dominant life form.
6. C. rigida — Agrostis canina — Ass. (Table III, 6).
The analysis was made on the curve of the side of a mound
near III, 5. This Association forms in this place a belt
round the mound, whereas Ass. 5 covers the top of the
mound. This Association is found all over the island in
such belts, cf. diagram, or on the tops of lower mounds
where neither Kobresia nor Juncus trifidus grows. I con-
sider that this Association is the most common one in the
valllendi. H is the dominant life form although the G% is
also rather high.
7. Festuca rubra — Poa pratensis — Armeria vulga-
ris — Ass. (Table III, 7). The analysis was made on the
side of a very sunny mound right at the south of the is-
land. There this Association is to be found in small patches
where there is most sun and it grows right down to the