Skógræktarritið - 15.05.2001, Síða 139

NATALIA E. KOROLEVA
Mountain Birch Forests of
Murmansk Province, Russia
SAMANTEKT
í þessari grein er fjallað um veðurfar, landslag, jarðgrunn, jarðveg og
gróður í birkiskógum í Múrmanskhéraði, öðru nafni Kolaskaga. Ilm-
bjarkarskógar þekja 20% af Kolaskaga, þ.m.t. stóran hluta Iáglendis
bæði norðan- og sunnanmegin, og mynda vel afmarkað belti milli
barrskógarins og túndrunnar í fjalllendi á miðjum skaganum. Birki-
skógarnir flokkast í tvær megingerðir: 1) þar sem lyngtegundir eru
ríkjandi í botngróðri ásamt fléttum og mosum, sem er oft á fremur
þurru og rýru landi og 2) þar sem jurtir eru ríkjandi í botngróðri, oftast
á rakari og frjósamari svæðum. Fjórir undirflokkar eru af .lyng’skógum,
tveir af .jurta’skógum og einn lendir þar á milli. .Lyng’skógarnir eru oft
gisnir og trén smávaxin, margstofna og kræklótt en á frjósamara landi
verður skógurinn þéttari og trén stærri og beinvaxnari. Fjallað er um
áhrif mengunar, sinuelda, hreindýrabeitar og traðks á skógana.
Introduction
Birch forests occupy about 20%
of the Murmansk Province cover-
ing a large area of the plains and
low mountain areas and forming
a well-defined narrow band
between coniferous (pine and
spruce) forests and tundra in
high mountains. A narrow zone
of birch forest fringes the eastern
and south-eastern maritime part
of the Kola Peninsula, mainly on
the coastal slopes, and bordering
with seashore heathlands, and
coniferous forests and peat bogs
- from the inland countryside.
The aims of this study are:
- to survey mountain birch forest
ecosystems in the Murmansk
area, being the most north-east-
ern area of Fennoscandia;
- to present results of classifica-
tion of plant communities, and
- to assess the human impact.
Geology, geomorphology and
soils.
The area of study covers most of
province's mountains and north
shore of the White Sea. As far as
geomorphology is concerned, the
study area is subdivided into two
remarkably different sections -
the west and the east. The west-
ern part is sharply rugged, with
mountains attaining 800 - 1200
m, the most prominent being the
Sal’nye Tundry, Chuna-tundra,
Monche-tundra, Khibinskie and
Lovozerskie mountains. Because
of recent glaciation, the moun-
tains have flat surfaces and steep
slopes, with well-developed
glacial morainic deposits. The
eastern part has a landscape
consisting of a range of low
uplands (the collective name is
Keyvy) situated in the central
part of peninsula, which decline
gradually towards the Southeast.
The parent rocks in the birch
forest area are of various struc-
tures and composition
(Geologicheskoe..., 1958). Sub-
maritime birch forests are locat-
ed on maritime sediments.
Mountain birch forests grow on
multiform bedrocksfgranite,
gneiss, granulites, and shist)
which has been subject to basic
and ultrabasic random intrusion.
As a result of glaciation, quater-
nary morainic deposits almost
entirely cover the bedrock, and
soils derived from these are char-
acterised by sandy texture with a
lot of stone and gravel in the soil
profile.
Podzolic soils prevail in all the
birch forests of Murmansk
Province, but owing to rich par-
ent bedrocks in the Khibiny and
Lovozersky mountains and par-
ticular climatic conditions (more
rainfall and snow cover, and a
longer growing season) the pod-
zol layer formation is reduced.
This soil, called Al-Fe humic pod-
zol, has a relatively high humus
content in its mineral layers,
amounting to as much as 5,8% in
the illuvial horizon, whereas the
SKÓGRÆKTARRITIÐ 2001 l.tbl.
137