Epsilon Archive for Student Projects

Abstract

Since 1921 the Białowieża National Park (BNP)/Poland strictly protects one of the best
preserved ancient lowland forests of the European temperate zone, with many stands close to
natural character. Within the reserve, old Pinus sylvestris trees grow on fertile soils in a mixed
deciduous forest (oak-lime-hornbeam forest Tilio-Carpinetum) with a very rich and dense
field layer. This study will explore the features of P. sylvestris trees and if this earlysuccessional
species is able to regenerate and establish under such habitat conditions as
present today. On three such Tilio-Carpinetum typicum study areas (in total 230 ha) 723 P.
sylvestris trees were inventoried and mapped during transect walks over site type gradients.
Mean tree density for all sites was low with 3,1/ha. 70% of alive trees had a DBH of 46-89
cm (μ= 64,5) and 50% of alive trees were ≥30 m in height. 85% of all trees were estimated to
be ≥100-250 years old, none alive tree younger than 50 years. Fire scarred were 18,4% of all
Scots pines recorded, half of those additionally modified by chipping for wood splints, beehive
caves or axe cutting by people (CMTs). These marks are undoubtedly signs of past
anthropogenic utilization impact on appearance and history of the studied forest stands. At
least 52 pine trees were multiple fire-scarred, with a range of 2-10 fire events counted.
Maximum height for open fire scars was 320 cm. There was no single P. sylvestris seedling or
sapling found during the regeneration inventories in June 2010. Not even where better light
conditions or soil disturbances with a reduced field layer coverage occurred. Due to
similarities to Scots pine in its ecology Pedunculate oak (Quercus robur L.) was included in
the macro-scale regeneration inventory: seedling/sapling density ranged between sites from 1
to 89,1 oak individuals/ha. In the micro-scale regeneration inventory, Acer platanoides,
followed by Tilia cordata, Fraxinus excelsior and Carpinus betulus seedlings was the tree
species with the highest frequency. In the sapling stage instead, the dominant abundance of
Norway maple was followed by hornbeam and Ulmus spp. In sum 28 dead Scots pines were
cored for age determination: the oldest tree on the study sites germinated in 1637, 1642 and
1728 respectively. Overall about 15 irrregular regeneration pulses could be detected from the
samples for the time period 1637-1852. A share of 33% of all estimated germination dates
falls within a 15-year interval, stretching from 1767 to 1782. Longer fire-free periods, e.g.
after a likely fire in 1777, allowed Scots pine to recruit and to be resistant enough to survive
following fires, as those dated from scars during the 19th century, namely in 1822, 1833, 1851
and 1861. Fire could serve as one hypothetic explanation (besides eutrophication) for the
appearance of P. sylvestris in richer habitats in BNP, formerly promoted by people in the
region due to traditional forest utilization. The diminishing influence of man in BNP may
cause the depression in regeneration of short lived pioneers and climax, light demanding tree
species like Pedunculate oak and Scots pine.