The Botany of Iceland - 01.12.1930, Síða 170
160
H. M0LHOI.M HANSEN
by means of Raunkiær’s circling method, the flora lists of the in-
dividual random samples will furnish a point of departure for the
consideration of this subject.
This question, as well as the others referred to above, I have,
however, been obliged to leave for future consideration, partly for
lack of time, partly for want of suitable inaterial. A few more
questions, thus some investigations on the acidity of some types of
Icelandic vegetation, and some reflections on the relation between
plant geography and farming, will be dealt with briefly below.
Determinations of the acidity of the soil were made simultane-
ously with the investigation of the vegetation. The mode of proce-
dure in taking samples of the soil and determining the degree of
acidity was that described by Carsten Olsen (1921). For practical
reasons tlie investigation was only made at Bjork, on Lýngdalsheiði,
and on Arnarvatnsheiði.
For the various types of vegetation in the above-mentioned
localities the acidity expressed in pH was as follow's:
At Bjork
Elyna mo 6.5, 6.5 average 6.5
Arctostaphylos mo 6.5, 6.5, 6.4 — 6.5
Calluna-Empetrum mo . 6.4, 6.3 — 6.4
Jaðar 6.0, 6.0 — 6.0
Salix mýri 6.0, 5.7, 5.7 — 5.8
Betula nana mýri 5.7, 5.6, 5.2, 5.2 — 5.4
Koenigia flag 6.6, 6.3 — 6.5
On Lýngdalsheiði
Mosathembur 6.5, 6.4, 6.3, 6.3 — 6.4
Melar 6.3, 6.3, 6.2, 6.2 — 6.3
Mo 6.4, 6.4, 6.4, 6.4, 6.3 — 6.3
» 6.2, 6.2, 6.2. 6.2
Valllendi 6.3, 6.2, 6.1, 6.1, 5.7 — 6.1
Jaðar 6.0 — 6.0
Salix mýri 5.3 — 5.3
Betula nana mýri 5.3, 5.1, 5.1, 5.0, 5.0, 4.8, 4.8 — 5.0
Geiri 6.1, 6.1, 6.0 — 6.1
On Arnarvatnsheiði
Melar 6.9, 6.8, 6.7, 6.6, 6.6 — 6.7
The level mo 6.8, 6.8, 6,4, 6.3, 6.2 — 6.5