178 
TABLE 38. 
H. MØLHOLM HANSEN 
Species-group spectra and biological spectra of the different types of 
Vegetation on Iceland, based upon statistical investigations. 
ss... 
ss... 
EORMYrIeE 0e | 
Bien (01a ee ele a aie) nie 
Number of 
Localities 
examined 
CRC || 
Points-sum 
| 2568 
10658 | 2 
43908 
‚10140 | 
15240 
| 4180 
1740 
5592 
404 
| 4092 
Number of 
species 
|| Density of 
115374 | : 
| 4852 | 
species 
> 
6.8 | 72 | 28 
113.3 | 53 47 
13.2 47 53 |: 
9.449 | 51 | 
8.3144 56 | 
1.9 | 28 | 72 
8.6 | 28 | 72 
| 
| 
2.0 14 86 
9.9 | 58 42 
6.925 | 75 | 16 
23183 17 
114 
22 
17 | 
r 
[9] 
| 11.0 37 | 63 | 23 
| 14 | 
38 
18 
|| 
E |A 3/A 2/A 1|E4 E3 E2 E1 Ch 
eat] 
| G HH | Th 
| | 
| | a | NE En 
13) 1/14| 1) 4) »|27|40|33| » | > 
6124| 410.5 0.147 11), (ae 
| 9|27|10| 90.5131 16) » [0.5 
1031|12)1010.1)18'53|28| ı | 1 
9/38/12] 1| >»|24|21/49| 5 |02 
525/21 11| >| 8/28. 58) 6| 1 
20137|136| »| »| 2 76 10| > 
4124 26 | 13 |1.1 | 34 16| » |0.1 
4/22 37/11] 312 7216| >| 3 
| | | 
»/21)65| » | »|| »/11)18) » | 7 
» 115,25 1.4 0.1/13 6012) > | 15 
9|20|1836| 213 /67|20| > | 1 
| | | Il | 
5. The low temperature in winter being the factor which has 
the greatest bearing on the vegetation, a natural system of the Ice- 
landic types of vegetation, i.e. a system in which the factors are 
given in the order of their degree of importance for the vegetation, 
must give as the first principle of division the conditions of snow- 
covering, as the next, the conditions of moisture, and so forth. 
Hence, the types of vegetation investigated in this treatise must 
be ranged in the following order. 
I. Vegetation bare of snow. 
1. Soil covered with moss 
2. Soil covered with gravel 
II. Vegetation with normal snow-covering. 
1. Soil dry 
2. Soil moderately moist 
a. Soil covered with vegetation, level 
b. Soil covered with vegetation, knolly 
c. Soil bare, with smallknolls 
Mosathembur (moss 
heath, Grimmia heath) 
Melar (fell field) 
Mo 
Valllendi 
Jadar (grass mo) 
Flag (clayey flats) 
