Rit (Vísindafélag Íslendinga) - 01.06.1975, Page 33

large stretohes of land. It occurs exclusively in very wet tracts,
where the water level is approximately constant throughout the
summer. The surface is altogether level, but mound ridges do
occur. There is very little moss. As the table shows, no other so-
ciation of the flói is so poor in species as this one, which has only
1-6 species per analysis. The sole accompanying species are Carex
chordoirhiza and Carex limosa, and the latter might indicate that
ihe flói is unusually acid. Although this sociation is not common
m larger areas, it occurs in small patches throughout the country.
In the highland and in the lowland as well it occurs in various
places as a narrow fringe along ponds and pools. In the lowland
Carex nigra and even C. Bigelowii often replace it, and on lower
uioors also Carex rostrata. A significant difference is that when
this fringe is covered with Carices there is no difference between
the soil level and that of the lake itself, hut the E. sociation is al-
ways at a slightly higher location and it occasionally comes close
to forming a low ridge in the shore of the lake, which has been
formed by plant rests and current. In such places Eriophorum
augustifolium obtains maximum growth.
The biological spectrum is homogeneous, as may generally be
oxpected. Geophytes almost exclusively dominate and the same
applies to the southem species, the E. group. Analysis no. 4 is
tttuque, since it is taken rather high above sea level, and therefore
tt mdicates a vast increase in the percentage of nordic plants, the
A group.
2. Eriophorum angustifolium — Carex nigra sociation
(Tab. Ix A-B, 1-4)
The table material presented here includes 4 analyses, all from
Flói, where this sociations was widely distributed before irrigation
aud later drainage of the land was started. Little probably remains
°f it now. Apart from the character species Carex saxatilis and
Carex chordorrhiza are widely distributed, and there is thus a close
relationship among these three sociations, i.e. no. 2, 3 and 4, so
fhat they might conceivably be joined in one.
Among other species which occur noticeably in individual ana-
lyses Juncus alpinus, Carex Lyngbyei and Calamagrostis neglecta
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