Fróðskaparrit - 01.01.2004, Qupperneq 236

234 ALTITUDINAL DISTRIBUTION OF PLANT COMMUNITIES IN THE FAROE ISLANDS
1991-1995).
The Racomitrium fasciculare-Alchemil-
la alpina community is not mentioned as a
community previously in the Faroe Islands,
but, nevertheless, the species Racomitrium
fasciculare is numerous in the vegetation
found on boulder fields in the Faroe Islands
(Hobbs and Averis, 1991). It is also numer-
ous in two vegetation types in mountainous
areas in Norway: Salix herbacea snow bed
vegetation, and moss snow bed vegetation
(Fremstad, 1997).
The Racomitrium lanuginosum-Salix
herbacea community is mainly restricted
to the arctic alpine region of Europe and
N. America (Wielgolaski, 1997). The Sa-
lix herbacea community is distributed in
the arctic area (Daniels, 1994) and also in
Fennoscandia and Iceland; Salix herbacea
is found in snow bed communities in high
alpine zones (Wielgolaski, 1997).
Low alpine vegetation zone
A characteristic of this zone is that the low-
er limit is set where Calluna vulgaris disap-
pears, but where Vaccinium myrtillus and
Empetrum nigrum are still dominant in one
of the three communities. The upper limit
of this zone is found where Vaccinium myr-
tillus disappears. The same species is also
used to define the upper limit of the low
alpine zone in Fennoscandia (Dahl, 1997).
This zone, as well as the temperate zone, is
heavily grazed.
The three communities in moist grass
vegetation: the Thymus praecox-Vaccin-
ium myrtillus community, the Narclus stric-
ta-Potentilla erecta community and the
Galium saxatilis-Anthoxanthum odoratum
community are all rich in moss species.
These communities are similar to the Fes-
tuca vivipara-Agrostis capillaris-Thymus
prciecox community (Hansen, 1967; Hobbs
and Averis, 1991), the Nardus stricta
community, and the Anthoxanthum odora-
tum-Agrostis capillaris community (Osten-
feld, 1905-1908) described from the Faroe
lslands.
Temperate vegetation zone
The characteristic species in this zone, such
as Calluna vulgaris, Polygala serpyllifolia,
Hypericum pulcrum, and Juncus squarro-
sus, are found in the cooler regions of the
northern hemisphere.
Dwarf shrub vegetation (.Empetrum ni-
grum-Calluna vulgaris community and
Calluna vulgaris-Nardus stricta commu-
nity) is restricted to south-facing transects.
On the north-facing slopes, moist grassland
vegetation penetrates down into the tem-
perate vegetation zone. This indicates that
these communities are at the limits of their
northern distribution area, and are more
common in warmer areas further south like
the Shetland Islands (Roper-Lindsay and
Say, 1986). The moist dwarf shrub heath,
which is similar to the damp heath in Nor-
way (Bocher, 1937), is distributed from
boreo-nemoral to the middle boreal regions
(Fremstad, 1997). The limited hours of
sunshine in combination with heavy graz-
ing could limit its distribution in the Faroe
Islands. The moist heath vegetalion type is
similar to the moist alpine coastal heath in
Norway, which is mostly distributed in the
northern boreal to low alpine zones (Frem-
stad, 1997).