TABLE 108. 
STUDIES ON THE VEGETATION OF ICELAND 
1 2 3 4 5 6 7 
SPORES SUM ois cross ss ae 412 692 580 320 220 688 940 
Eirsmber of species... ....- 14 20 22 15 13 14 29 
Density Of SDECIES.......... 4.1 6.9 5.8 3'2 PER, 6.9 9.4 
REE OP AE 62.1 56.6 75.2 72.5 | 50.9 52.9 54.5 
EN PN 37.9 43.4 24.8 27.5 49.1 47.1 45.5 
ET TON See Gear 40.8 32.9 52.4 50.0 23.6 PT (oS 28.5 
2 LS pelo ois s'dis-clsers, © anaraeie.e 19.4 19.7 19.3 15.0 107 25.6 17.4 
a D3 OSes 1.9 | 4.0 3.4 179 14.5 » 8.5 
ers 'e aj sae ale a she sites une 23.3 33.5 Dell 25.0 34.5 aia 29.8 
LE: Le SR EN 6 vero: Re 14.6 9.8 2 € 25 14.5 9.9 12.8 
RS dan so see >. » > » > » PE] 
u ees Sistas > | > » > > 0.9 
nee conso e 28.2 | 45.1 42.8 31.5 45.5 55.2 47.3 
ee eens 53.4 | 42.2 45.5 43.8 54.5 33.1 44.6 
ee EEE 18.5 | 1257 313157) 18.8 > 11.6 8.1 
HH else unless @ 610 6 set. « © 0.8 6, 0e, > > » > > > » 
nus > > > > > > > 
Biological Spectra of the Melar Vegetation. 
45 
ences in the vegetation, but owing to the small part played by the 
vegetation in the appearance of the landscape it is difficult to form 
an idea as to how much this is the case. It is easiest to ascertain 
the connection between the vegetation and the age of the area as 
melar soil. On recently denuded patches hardly any plants are seen, 
whereas a good deal are seen to have immigrated at a somewhat 
later stage. Fig. 5 shows such a melar vegetation near Hrölfshölar, 
and table 10 A 1 and 4—5 give the circling results for this and 
similar localities on Lyngdalsheidi. The density of species is still 
rather low, 2—4, in spite of the comparatively high number of spe- 
cies, c. 15. Of life forms H and Ch are almost the sole prevailing 
ones. The most conspicuous species are Thymus serpyllum, Salix 
herbacea, Armeria, Silene acaulis, Cerastium alpinum, and Arabis 
petræa; of herbaceous plants Juncus trifidus, Luzula spicata, Poly- 
gonum viviparum, Agrostis canina, Festuca ovina, and F. rubra are 
met with. 
On still older stretches of melar not only the vegetation but 
also the character of the soil have undergone change. The soil 
