Rit (Vísindafélag Íslendinga) - 01.06.1975, Side 153

few in number, and the A and C percentage are high. The socia-
tion occurs on drier ground than sociation 88. Both sociations are
probahly stages in a succession from damp and which phases into
heath vegetation.
91. J. balticus — Festuca rubra — Carex maritima sociation
This sociation is closely connected with sociations 88 and 89, hut
more particularly with sociation 88, the only difference between
them being that here Salix glauca has disappeared. The soil is
sandy and somewhat moister than where sociation 88 occurs. Moss
vegetation is almost nonexistent. This sociation is mostly encoun-
tered in the highland and I have descrihed it in my paper 1945
pp. 405—406. I have, however, observed it at Meðalland where it
clearly occurs as a vegetation in a succession from a lake on the
sands down to the shoreline. In the immediate vicinity of the lake
there is an Agrostis stolonifera-Ranunculus reptans sociation which
is then replaced by a Calamagrostis neglecta, but this Juncus so-
ciation constitutes the third and final stage. Here the number of
species has increased from the preceding stages, hut the most im-
portant new feature is the appearance of J. balticus and C. maritima.
92. J. balticus — Festuca rubra — Equisetum pratense sociation
(Tab. XXI A-B 3)
Only one ohservation is available here, from Skógar in Eyjafjöll,
at an altitude of about 150 m. The analysis is taken from a depres-
sion in a broad patch of vegetation which is heavily ravaged hy
erosion and blown sand. This is obviously a mire in the process of
desiccation. The sociation has a large number of species, and it is
the only jaðar sociation where Equisetum pratense occurs. The H
percentage reaches its maximum in the J. balticus jaðar, which
mdicates close affinity to grassfield which is the adjacent vegeta-
tion type.
I have observed the same sociation at Mógilsá in Kjósarsýsla in a
mire which was beginning to dry out owing to drainage. A large num-
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