The Botany of Iceland - 01.12.1930, Page 51
STUDIES ON THE VEGETATION OE ICELAND
41
Table 9 B.
Biological Spectra of the Mosathembur Vegetation.
1—11 correspond to 1—11 in table 9 A.
1 2 3 4 5 6 7 8 9 10 11
Poiuts sum 2(i8 212 192 212 344 208 184 304 268 256 120
Number of species 8 10 8 6 14 9 7 9 14 11 3
Density of species 2.7 2.1 1.9 2.1 3.4 2.1 1 8 3 0 2.7 2.6 1.2
A 77.6 79.2 72.9 64.2 77.9 94.2 95.7 78.9 89.6 93.8 100.0
E ... 22.4 20.8 27.1 35.8 22.1 5.8 4.3 21.1 10.4 6.3 0.0
a :i 47.8 67.9 54.2 50.9 55.8 92.3 91.3 71.1 80.6 79.7 100.0
A 2 26.9 9.4 18.8 13.2 18.6 1.9 4.3 7.9 9.0 14.1 »
A 1 3.0 1.9 * » 3.5 » » » » »
E 4 ... 20.9 13.2 25.0 26.4 18.6 5.8 4.3 11.8 7.5 4.7 »
E3 » » » » 1.2 > > » » » »
E2 1.5 7.5 2.1 9.4 2.4 » > 9.2 3.0 1.6 »
E 1 » » » » » > » » » » »
Ch 3.0 17.0 4.2 5.7 22.1 57.7 60.9 44.7 58.2 54.7 66.7
II .. . 56.7 24.5 45.8 39.6 39.5 3.8 4.3 17.1 9.0 15.6 »
< ’■ .. 40.3 58.5 50.0 54.7 38.4 38.5 34.8 38.2 32.8 29.7 33.3
HH » » » » » » » » » » »
Th .... » » » » » » » » » » »
mosathembur in Lýngdalur c. 200 m above sea level, 6—10 that
of Hrólfshólar c. 300 m above sea level, and No. 11 that of Thrasa-
horgir at a level of 400 m.
The phanerogamous vegetation is poor in species and open.
In 2.5 s(j. m on an average c. 10 species will occur with a density
of 2—3.
Biologically the mosathembur vegetation is remarkable bv its
bigh percentage of arctic, particularly high arctic, species, and more
especially liy its high G jiercentage.
In Lýngdalur, cf. Nos. 1—5, it is H and G that predominate,
while Ch is of minor importance. Here the dominant species are
Carex rigida, Polggonum viuiparum, Thalidum alpinum and Festuca
i’ubra. Iligher up, at Hrólfshólar, H gives place to Ch. Here Salix
herbacea is the most frequently occurring species. Everywhere
throughout the moss carpet tliis jilant sends up the tip of a branch
bearing two or lliree leaves, while the rest of the plant is buried