POLLEN DIAGRAM
In the pollen diagram arboreal taxa (
AP)
dominate with 70-90% (Fig. 3).
The main forest coniferous and deciduous trees are present -
Pinus diploxylon-
type (
P. mugo
and
P. sylvestris), Pinus рейсе, Picea, Abies, Fagus, Quercus,
Carpinus,
etc. This presumes a realtively young age of the core analysed. The
subdivision of the pollen diagram into two zones (Smr-1 and Smr-2) is based
mainly on the changes in the behaviour of the pollen presence of
Pinus
diploxylon-type, Pinus рейсе, Picea
and
Abies.
At the transition to zone Smr-
2 the quantity of deciduous tree pollen declines.
LPAZ Smr-1 (140-55 cm)
Pollen of
Pinus diploxylon-typQ
prevails with ca 40 %. A slight decrease to
20-25 % is observed for the interval 100-55 cm. Pollen of
Pinus рейсе
shows
a tendency of increase from 10 to 20 %.
Abies
is comparatively well represented
with up to 10 %, together with
Fagus
5-7 % and
Picea
3-5 %. Pollen of
Quercus robur-
type and
Q. cerris-
type reaches 3-5
%.
Low percentages are
recorded for
Corylus, Carpinus, Acer
and
Humulus/Cannabis.
In this zone the
highest frequences of Poaceae up to 20 %,
Artemisia
up to 10 %, Cichoriaceae,
Ranunculus
and
Rumex
pollen are established. Pollen of
Secale
and spores of
Polypodiaceae are also quite common.
The vegetation reconstruction for this zone reveals dominance of communities
of
Pinus mugo
in the subalpine zone, and wide distribution of mixed coniferous
forests with
Pinus рейсе, Pinus sylvestris
and
Picea abies
on the northern
approaches to the lake. The find of
Fagus
pollen demonstrates its good
capacity of upslope transport from mid-altitudes and testifies to the wider past
distribution of
Fagus
in the vicinity of the Rila Monastery, an area where the
best preserved old beech forests in this part of the mountain are found
nowadays. Silver fir
{Abies alba
) has occupied the lower part of the coniferous
belt. Nowadays vast monodominant or mixed communities of
Abies alba
are
growing in the valley of the Rilska Reka river at 1400-1600 m. At low altitudes
the tree vegetation was represented by mixed oak forests.
In general, the herb pollen types identified
{NAP),
reflect the vegetation
pattern around the sampling site by that time, being composed of various
representatives of Poaceae, Asteraceae, Brassicaceae, Ranunculaceae and
Caryophyllaceae species. The regular presence of pollen of anthropogenic
indicators
{Plantago lanceolata, Rumex, Scleranthus)
and of cereals
{Secale)
is
indicative of well-pronounced human interference, seasonal livestock-breeding
on the high pasture land and crop production in the foothills.
The time interval for this zone is determined by comparison with the pollen
diagram from the near-by Lake Ostrezko-2 ( То п к о v, M a r i n o v a , in press).
In particular, the decline of
Abies
and the rise of
Picea
in Lake Osrezko-2 were
dated at 1290+/-40 yrs. В. P. This age can be also accepted for the zone
11
Электронная Научная СельскоХозяйственная Библиотека