The Botany of Iceland - 01.12.1930, Page 87
STUDIES ON THE VEGETATION OF ICELAND
77
Table 18. Biological Conditions in Mo, Flag, and Jaðar
at Björk (I) and Lækjamot (II). Cf. the text.
a Number of species Density of species Ch „ G Th
I. Moist mo 39.7 14.8 28.9 52.3 18.3 0.1
Flag 20.0 8.8 8.5 57.0 13.6 20.9
Jaðar 42.0 13.8 22.3 53 6 24.1 0.2
II. Moist mo 42.5 15.9 24.7 58.0 14.1 3,3
Flag mo 29.0 11.0 18.0 62.1 10.7 9.4
Mýri vegetation 33.0 11.2 12.5 39.9 45.9 2.1
b A E A 3 A 2 A 1 E 4 E3 E 2 E 1
I. Moist mo 39.3 60.7 19.3 9.6 10.4 32.6 10.8 16.8 0.5
Flag 52.8 47.2 36.1 165 0.1 18.1 27.7 1 1 0.3
Jaðar 35.6 64.4 15.0 8.2 12.5 35.8 13.5 14.9 0.3
II. Moist mo 56.5 43.5 32.6 15.9 8.0 22.6 10.2 8.8 2.0
FJag mo 63.3 36.7 41.5 21.8 » 12.3 22.9 1.7 >
Mýri vegetation .... 50.0 50.0 22.6 25.1 2.3 24.6 16 5 8.7
portion of Th, G, and H is no doubt directly dependent on the
comparatively strong desiccation of the flag in the summer.
On passing from the mo to the mýri on gently sloping ground,
in places where no flag vegetation has been developed, there will,
as will be shown in more detail later on, occur a decrease of the
Ch percentage and an increase of the H, Tli, and G percentages at
the level answering to the flag zone. Apart from the geophytes this
!S the same change as characterised the flag vegetation. Hence
the flag vegetation must not be regarded as such an
isolated phenomenon as its physiognomy and peculiar
biology would seera to suggest at a first glance, it must
be regarded as an extreme stage of development of those
conditions of environment wliich are found and act in
the stage of moisture with which the flag vegetation is
associated.
If we consider the species group spectrum, here, too, we shall
hnd a peculiar difference between the flag vegetation and the sur-
rounding types. The proportion of arctic plants is comparatively
high in the flag, and tliis is due to a rise in the A 3 and A 2 per-