Rit (Vísindafélag Íslendinga) - 01.06.1975, Side 57

flói, but in parts of the country it extends over wide areas not least
of which are lower heaths, e.g. Mosfellsheiði, the flói tracts to
the south of Kaldidalur, the heaths between Borgarfjörður and
Húnaþing and Fljótsheiði in Þingeyjarsýsla. Carex rostrata always
characterizes the vegetation, although it has less covering than the
other character species of the sociation. The reason for this is its
height, and the fact that it is the coarsest of those carices which
accompany it, and its bluegreen colour, which sets it apart from
the colours of the other species. In this survey one sociation of the
C. rostrata flói is ahsent, i.e. the pure C. rostrata sociation, which
only occurs in pond fringes and lakc inlets and may therefore be
included with aquatic growth proper. There C. rostrata reaches its
maximum height, often more than one metre and proportionately
stout as well. These vegetative belts correspond to the Magnocari-
céta in Europe. Out from this belt the flói proper commences, some-
times a C. rostrata flói, but more often an Eriophorum flói.
Topography in the C. rostrata flói differs in several respects from
that of the Eriophorum flói, the main difference being that here
the flói slopes somewhat, so that it in this respect approximates the
mýri in some places. As a result the ground water does not stagnate
as it does in the Eriophorum flói. On the other hand, it is wet, and
I think that it never really dries out in summer, at least I have
not seen any signs thereof. The surface of the C. rostrata flói is
often pattemed with low mounds. Moss vegetation is abundant,
richer and more continuous than in the Eriophorum flói, but at
the same time the phanerogamous covering becomes more sparse,
and the withered tangles of the Eriophorum flói are not much in
evidence. No statement will be made on peat formation, but I be-
lieve that it is slight. Nor will anything be said about the vulnera-
bility of the C. rostrata flói to changes in the ground water level,
but I believe, however, that it tolerates an increase in moisture
content better than the Eriophorum flói. It is more closely related
to the Eriophorum flói than the C. Lyngbyei flói, since Eriophorum
is frequent here.
The C. rostrata flói is richer in species than the Eriophorum flói.
Ori the basis of its species nothing is to be determined about its
acidity, since the majority of the common species of this type seems
to be indifferent in this respect. No oligotrophic species is among
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