Rit (Vísindafélag Íslendinga) - 01.06.1975, Page 39

the undular ridges than in the hollows. The flói is so wet that
water floods it almost constantly, which always shows in footprints.
Apart from the character species there are hardly more than
hvo others which may be described as constant, i.e. Calamagrostis
iteglecta and Polygonum viviparum. The latter, however, is by no
tneans a regular flói plant, but it has a very wide amplitude with
fespect to moisture, since it can grow in the driest gravel flats as
well as in the wettest flói tracts, so that it would seem to be as
'widely distributed in lowland areas as in the highest mountain
districts or unto the upper limit of vegetation.
Calamagrostis neglecta on the other hand is a wetland species
and it often occurs in the flói area. I will deal with it later on,
particularly in connection with pioneer sociations. Salix glauca
occurs frequently in this sociation. It is a common plant in flói
and mýri vegetation in mountainous districts, but more seldom seen
in lowland mire sociations, and it does not appear to be vulnerable
to soil moistm'e. This agrees with what Nordhagen says about the
naountain willow species in Norway: “Fjellvieartene er gode skil-
iearter mellem forbunnets subalpine associationer og lavlandsfor-
tunn”. (Nordhagen, 1943, p. 484) Eriophorum Scheuchzeri occurs
in several places where the flói approximates the pioneer sociations
°f the flæðimýri. The species are few and little variation in the
spectrum. The A group is high here, as was to be expected in
highland vegetation, and hemicryptophytes also have a higher ratio
than was to be expected on the basis of the moisture content of the
s°il and the high HH percentage.
The following should be noted in connection with individual
analyses:
Analyses 6-7 are from Eyjabakkar, but 8-11 from Kýhngar. The
same applies to these observations sites, i.e. that they were formed
in a manner which differs from what normally holds true of flói
areas, since they are in effect delta formations (alluvials) and
should accordingly rather belong to the flæðimýn (alluvial mire).
On the other hand these areas all have the characteristics of the
flói vis á vis vegetation and surface, so that I have included them
here. Analysis 12 is taken in Síðumannaafréttur from a flói with
ridges. The ridges are quite dense and about 75 cm. high with a
steep erosion side facing fhe slope. Above them are level plains,
39