The Botany of Iceland - 01.12.1945, Blaðsíða 132

474
STEINDÓR STEINDÓRSSON
water are found here and there in the depressions. Otherwise the
ground is comparatively dry and sandy, in this respect differing very
much from the moraine in Kringilsárrani. Nowhere did I find the
Philonotis vegetation with Eriophorum Scheuchzeri and Carices men-
tioned from Kringilsárrani. As a whole this moraine is much more
sparsely covered with vegetation than the other one. The tufts of
vegetation are of low growth and scattered, and the whole vegetation
is, as it were, stunted. As in Kringilsárrani, hardly any moss vegetation
is found here. The dominant species are Poa alpina, Deschampsia
alpina, Festuca rubra, Saxifraga groenlandica, and Cerastium alpinum.
These are the pioneer species in the vegetation of the moraine, and
it is a little peculiar that the three pioneer species of the Kringilsárrani
moraine, Catabrosa algida, Draba rupestris, and Cerastium trigynum,
are entirely absent here. This is probably due to the much drier and
more sandy soil of this than of the other moraine, for moisture of the
soil is always required at any rate for the presence of Cdtabrosa and
Cerastium trigynum. As a whole the vegetation of this moraine bears
a close resemblance to that of the oldest part of the Kringilsárrani
moraine, which is only natural, the moraines being of almost the same
age. The whole vegetation from the terminal moraine to the edge of
the glacier is very uniform. Analyses 1-2 give a picture of the vegetation.
The four dominant species are mentioned above, the other species
present seem to be of more casual occurrence. The arctic plants indeed
constitute the majority, but are less predominant than in Kringilsár-
rani, and the Ch percentage is likewise lowest here. The spectra of
these analyses exhibit great similarity to analyses 4 and 5 from Krin-
gilsárrani. Analysis 3 was made on the sandy inner side of the morainic
ridge, where Equisetum arvense is completely dominant.
Analyses 4-6 were made on the morainic ridge so as to show a
transverse section of its vegetation and the zonation of the latter (see
Fig. 13). Analysis 6 was made at the foot of the ridge, on the side
turned away from the glacier. Taraxacum croceum dominates physiog-
nomically, but in addition Polygonum viviparum, Equisetum arvense,
Poa alpina, P. praitensis, and Phleum alpinum are conspicuous; Festuca
rubra is less conspicuous in spite of its high frequency number. In
analysis 5 the Gramineae are more conspicuous, but here the low
number of species and the density are remarkable. The locality is more
exposed than locality 6, the snow-covering is likewise very thin, and the
soil is drier. Analysis 4 was made on the side of the ridge facing the
glacier, i. e. the south-facing side. It is very similar to analysis 6.