Rit (Vísindafélag Íslendinga) - 01.06.1975, Side 65

sociations are closely related, and there is little difference in topo-
graphy, so that for the time being it is most proper not to differ-
entiate between them. Yet, it may be asserted that the main so-
ciation is in the wettest areas and where a typical C. chordorrhiza
flói occurs.
33. C. chordorrhiza — C. limosa sociation
(Tab. VI A-B 12-13 and Tab. Vly A-B 1-7)
Analysis VI 12 is from Fljótsdalsheiði made in close proximity
to C. rostrata — C. chordorrhiza sociation Tab. VI 5-6. A close
relationship is involved, and it is doubtful whether this sociation
should be differentiated from the former, since it only grows in
srnall patches interwoven with the other. It is difficult to establish
a difference in biological conditions, except that the C. chordorrhiza
flói contains more clay (rauði), and it is rootrotted with bald patches
■where the soil is bare.
Analysis VI. 13 is from Vopnafjörður, taken in an extensive flói
tract at Hofsárbakkar. The terrain is level, clay is abundant in the
soil, but sand at greater depths, because the base layer is formed
by river deposits. The rootrot is therefore less pronounced than in
12. C. limosa is very conspicuous in covering.
At this point I wish to interject a description of a C. chordoirhiza
flói at Hagi on Barðaströnd, although an analysis is not available.
The flói occurs in a flói tract, which has been described earlier in
dealing with sociation 7. In the lowest and wettest parts of the
flói a pure C. chordorrhiza develops together with all the charac-
teristics of this sociation, little moss, rootrot, and bald patches. Also
noticeable are C. rostrata, C. rariflora and sparse C. limosa and C.
panicea.
Analysis Vly is from Straumfjarðartunga at Snæfellsnes, where
the sociation is quite widely distributed, but 2—7 are all from Fljóts-
dalshérað, Hjaltastaðablá and its vicinity. Analyses 2-3 are from
the wettest flói area, where it is muddy with an abundance of red
day. C. chordorrhiza dominates there, so that all the other species
combined do not reach a higher covering level than grade 1 accord-
Jng to the Hult-Sernander Scale. The surface is quite level. In bogs
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