Skógræktarritið - 15.05.2001, Blaðsíða 141

Fig. 1 TWINSPAN dendrogram of all stands of mountain birch forests, showing indicator species.
Cla ran
Emp herm
Corn sue
Ger sylv
Gymn dry
Iletr niv
Jnn bor
Sol v-a
Trie eur
Led pal
jEqui syf
Sal glau
Sorb auc
Des fle
I: Arctostaphylos uva-ursi type
II: Empetrum - Flavocetraria type
III: Empetrum - Cladina type
IV: Empetrum - Hylocomium type
V: Empetrum - Cornus type
VI: Equisetum sylvaticum type
VII: Cicerbita alpina type
Cla ran Cladina rangiferina Soli v-a Solidago virgaurea Arc u-u Arctostaphylos uva-ursi
Emp herm Empetrum hermaphroditum Led pal Ledum palustre Vac myr Vaccinium myrtillus
Com sue Cornus suecica Equ syl Equisetum sylvaticum Hyl spl Hylocomium splendens
Gymn dry Gymnocarpium dryopteris Sali gla Salix glauca Pol viv Polygonum viviparum
Cetr niv Flavocetraria nivalis Sorb auc Sorbus aucuparia Ver alb Veratrum album
Linn bor Linnaea borealis Des fle Deschampsia flexuosa Sali gla Salix glauca
Trie eur Trientalis europaea Cla gra Cladonia gracilis Cic alp Cicerbita alpina
Ger sylv Geranium sylvaticum
the field layer and the ground
layer is poorly developed. The
Equisetum sylvaticum type compris-
es fresh meadow birch forests
situated in ravines, on moist
slopes in mountains, and on
seashore terrains. The Cicerbita
alpina type comprises more
humid birch forests, situated
mainly in mountains, near
brooks and springs.
Whereas birch forests of
Fennoscandia form oroarctic
(mountain), arctic and maritime
timberlines (Hamet-Ahti, 1963,
Ahti et al., 1968), in Murmansk
Province most birch forests form
only the oroarctic timberline.
They are common on extensive
plains in central and western
parts of the province at altitudes
of 150-350 m a.s.l., where
lichenous, mossy, heath forests
prevail. Fresh heath and meadow
birch forests are common in high
mountains of the province, and
are associated with springs and
brooks. Meadow and heath sub-
maritime birch forests are practi-
cally absent from the Barents Sea
coast and occur only on the
White Sea coast as a rather nar-
row zone, where they are found
at elevations from 20 to 50 m
a.s.l.
Human impact.
In Murmansk Province, birch
forests cover a large area that
varies considerably with regard
to local population density and
level of industrial development,
that determines the character
and pressure of antropogenic
impact. The most populated and
most industrial sectors are in the
central part, situated along the
Petersburg-Murmansk road, and
in the north-western part. The
eastern part of Murmansk
Province is almost uninhabited,
with the main pasture area of
reindeer husbandry located
there.
Industrial pollution. industrial
development in Murmansk
Province started in the 1930’s,
and nowadays numerous plants
and ore mines cause essential
damage to biota. Fertilizers, etc.
are produced from apatite ores in
the Khibiny mountains. Copper-
nickel smelters produce copper,
nickel and cobalt and waste
gases containing sulphur dioxide
and dust are considered to be
the major damaging factors caus-
ing deforestation around
Monchegorsk, Nikel and
Zapoljarnyi. Wastes from the alu-
minium plant in Kandalaksha
and ore-developing factories in
Kovdor and Olenegorsk are
lower, but contribute much to
tree-line ecosystem degradation
in neighboring mountains.
Fires and Felling usually accom-
pany the industrial impact over-
all in causing forest degradation.
Although the felling is of minor
occurrence in the timberline
area, ground fires almost entirely
(and sometimes repeatedly)
cover areas adjoining industrial
centers. They can have a dramat-
ic effect, when the ground layer
and litter burn, bare soil slips
downhill to reveal the moraine
horizon. This leads to complete
ecosystem degradation, and fires
SKÓGRÆKTARRITIÐ 2001 l.tbl.
139