Rit (Vísindafélag Íslendinga) - 01.08.1930, Side 11

11
TABLE III.
BIOLOGICAL SPECTRA OF HEATHER AND GRIMMIA HEATH-
VEGETATION.
H Ch H G HH Th
Heather-land .. .. . 45 22,5 60,0 15,6 „ 1
Grimmia heath. . . . 27 44,4 40,7 7,4 » 7,4
A E A3 Aa A3 E< Es E2 Ei
Heather-land . . .. . 42,0 57,8 24,4 6,7 11,1 22,2 13,4 17,8 4,4
Grimmia heath. . . . 74,0 26,0 44,4 11,1 18,5 14,8 n 7,4 3,7
On comparing the forestland and the Orimmia heath one
can see how much higher the Ch percentage and the A group
is in the Grimmia heath (cf. tables II. and III.). The Grimmia
heath is characterized by the Ch vegetation and the Northern
plants. The result is the same according to H. M. H.’s obser-
vations on Lyngdalsheiði, yet there is the difference that the
G percentage is much higher on Lyngdalsheiði than here. It
must be taken into account that it is impossible to make a
direct comparison, as I couldn’t circle the Grimmia heath
near Asólfsstaðir.
There is no distinct boundary between the Grimmia heath
vegetation and the heather-vegetation. The moss gradually
decreases, the vegetation-carpet becomes more uniform, and
the silvery greyish colour of Grimmia disappears before the
brown colour of Elyna Bellardi and Juncus trifidus, which
are character-plants here, and give the land its colour. On
approaching the lowland the species of grass become more
and more dominant. The boundaries between Grimmia heath
and heather lie, I think, in the altitude of ab. 250 metres, or
a bit lower than the highest forest-boundary, for the forest
reaches probably the altitude of ab. 280—300 metres.
A Planllist over the Heather-Iand.
H Anihoxanthum odoratum. . E3 G Carex rigida . . A3
H . E2 H . . A3
H canina . E3 Ch Empetrum nigrum .. Er
Ch Armeria vulgaris . A3 G Equisetum arvense .. . . . . Eí
H Carex capallaris . A3 G pratense.... . . E2