The Botany of Iceland - 01.12.1930, Page 78

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H.M0LHOLM HANSEN
Table 15b.
Biological Spectra of the Jailar- and Mvri Vegetation.
1 2 3 4 5 i 6 7 8 9 10 11
Points sum 1370 1404 1352 1360 1408 1076 752 1004 1076 888 1032
Number of species 38 42 42 39 38 34 19 21 23 16 35
Density of species 13.8 14.0 13.5 13.6 14.1 10.8 7.5 10.0 10.8 8.9 10.3
A 42 7 34.8 36 4 33.8 39.8 47.2 50.0 52.6 51.7 40.5 40.7
57.3 65.2 63.6 66.2 60.2 52.8 50.0 47.4 48.3 59.5 59.3
A 3 20.1 15.4 14.5 13.2 15.3 21 2 16.5 17.5 160 10 4 10.1
A 2 12 2 6.8 9.5 10.6 11.6 16.7 16.5 23.9 24.5 16.2 18.2
A 1 10.5 12.5 12.4 10.0 12.8 9.3 17.0 11.2 11.2 14.0 12.4
E 4 30.2 39.3 32.2 45.3 39.8 32.7 36.2 33.9 32.0 41.9 39.9
E 3 15.4 14.2 12.7 18.8 16.8 16.4 13.8 13.5 16.4 16.2 14.0
E 2 11.6 11.7 18.0 2.1 3.6 3,7 i > > > 1.4 5.4
E 1 > > 0.6 > > > > > » » >
Ch 12 2 27.6 16.9 21.5 ; 28.7 18.6 29.3 30.7 27.5 36.0 29.5
H 52.9 45.3 61.8 38.8 29.8 34.2 7.4 15.9 15.2 2.3 15.9
g ; 33.7 24.2 21.0 31.5 33.8 40.9 60.1 47.8 47.6 48.6 41.9
HH 0.9 2 0 0.3 8.2 7.7 5.9 3.2 5.6 9.7 13.1 12.8
Th 0.3 0.3 > j > | > 0.4 > » > | >
common to the dry and the + moist Cyperaceae mýri. Carex Goode-
noughii, C. chordorrhiza, and C. rariflora, hesides Eriophorum poly-
stachipim. Common to all tliree formations are Empetrum nigrum,
Vaccinium uliginosum, Salix phglicifolia, Polygonum viviparum, and
Thalictrum alpinum.
The Betula nana Mv'ri. Table 15 A—B, 7—11.
in this formation the change from jaðar to Salix mýri lias pro-
gressed still further. The number and density of the species is
appreciably diminished. H have decreased considerably and G
have attained a maximum. The Ch and HH percentages have also
risen. The species group spectrum has likewise undergone a change.
The quantity of A species has increased somewhat, and in the A
subgroups tliere is displacement from A 3 to A 2 and A 1. The E
subgroups show a displacement in the direction of E 4.
Physiognomically chamaephytes and Cyperaceae are dominant,
thus of chamaephytes especially Betula nana, Vaccinium uliginosum,