STUDIES ON THE VEGETATION OF ICELAND 11 
TABLE 9B. 
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 
Pormts sum"... - 268 | 212 | 192 | 212 | 344 || 208 | 184 | 304 | 268 | 256 | 120 
Number of species 8 10 8 6 14 9 7 9 14} il 3 
Density of species | 2.7| 2.1| 1.9| 21| 3.4| 21|j 18) 30| 27} 2.6] 1.2 
2 See eee 77.6 79.2 72.9 64.2 77.9 94.2 95.7 78.9 89.6 93.8 100.0 
So Se ac 22.4 | 20.8 | 27.1) 35.8| 22.1] 5.8| 4.3) 21.1) 10.4| 6.3] 0.0 
Beet... le. 47.8 67.9 54.2 50.9 55.8 92.3 91.3 71.1 80.6 79.7 100.0 
EEE 26.9| 9.41 18.8| 13.21 18.61 19| 43! 7.9|. 9.0. 14.1 
2 EST 30 9 > » 3.5 > > > 
Een 20.9| 13.2) 25.0| 26.4| 18.6) 5.8) 43) 11.8] 7.5| 4.7 > 
2 SRE eee » > > > 1.2 > > > > 
er 1.5) 7.51 2:1) 9:4) 724 mt 19:2) 3101" 1-6 
E 1 ss... 2 > > » > » > > > > 
D 3.0| 17.0 4.2) 5.7| 22.1) 57.7| 60.9| 44.7| 58.2 | 54.7 66.7 
Se 56.7 | 24.5 45.8 39.6) 39.5 38 43 17.1 9.0| 15.6 > 
0. 40.3 58.5 50.0 54.7 38.4 38.5 34.8 38.2 32.8 29.7 33.3 
CE REPARER RP > > » > | > » » > > » y 
Be. er > » > | » » > > > | > > 
mosathembur in Lyngdalur c. 200 m above sea level, 6—10 that 
of Hrölfshölar c. 300 m above sea level, and No. 11 that of Thrasa- 
borgir at a level of 400 m. 
The phanerogamous vegetation is poor in species and open. 
In 2.5 sq. m on an average c. 10 species will occur with a density 
of 2—3. 
Biologically the mosathembur vegetation is remarkable by its 
high percentage of arctic, particularly high arctic, species, and more 
especially by its high G percentage. 
In Lyngdalur, cf. Nos. 1—5, it is H and G that predominate, 
while Ch is of minor importance. Here the dominant species are 
Carex rigida, Polygonum viviparum, Thalictum alpinum and Festuca 
rubra. Higher up, at Hrölfshölar, H gives place to Ch. Here Salix 
herbacea is the most frequently occurring species. Everywhere 
throughout the moss carpet this plant sends up the tip of a branch 
bearing two or three leaves, while the rest of the plant is buried 
