The Botany of Iceland - 01.12.1945, Page 91

THE VEGETATION OF CENTRAL ICELAND
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The spectrum of the flora in the areas investigated is as follows:
A 66.6 Ch 23.9 G 12.6 Th 3.8
E 33-4 H 55.3 HH 4.4
A comparison with the flora spectrum shows no small disagreement
in the proportions of the species groups, the snow-patch spectrum hav-
ing a much lower A percentage than that of the area investigated; on
the other hand, there is surprisingly good agreement with the life-form
spectra; the Ch percentage is somewhat lower in the snow-patch spec-
trum than in the flora spectrum, but the H, G, and Th percentages
are all a little higher in the snow-patch spectrum than in the flora
spectrum. HH are lacking in the snow-patch.
I have pointed out here some facts concerning the snow-patch
vegetation. I am aware, however, that many problems still await their
solution, and that a satisfactory solution can only be arrived at by means
of systematic measurements of the depth of the snow, preferably in
several parts of the country, along with the botanical investigation.
5. THE HEATH SERIES
To the heath series I refer such formations as are found on dry
soil and in which the vegetation is fairly closed and neither stones nor
the bare ground are conspicuous in the physiognomy. The heath series
is divided into two formations, dwarf shrub heath (Runnaheiði) and
Grimmia heath (Mosaþemba). Several earlier authors have used these
terms for the same or closely related formations; however, I propose
to use the names in a special sense here, so that the term h e a t h is
only used for the alpine formations, whereas the corresponding lowland
formation will be called by the Icelandic name Mó, as done by M 0 1-
h o 1 m H a n s e n and several other authors. The vegetations of these
two communities, the heath and the mó, are very closely related, and
many of the species are common to both. While the mó is, as a rule,
knolly, and even with big knolls, the surface of the heath is either level
or with quite small knolls; since, moreover, the name heath (heiði) in
some parts of the country has been applied to such land, I think it
appropriate to apply it to this alpine formation.
The series here called heath series by me is equivalent to the heath
or heath series of several Scandinavian authors. I may quote here