Oak coppices in Prykarpattja and their spatial structure

Abstract

The oak (Quercus robur L.) is one of the most emission species from genus
“Oak” (Quercus L.). It has very wide natural habitat in European continent owing
to high tolerance to humidity and temperature. Oak is good growing in semi
humid natural conditions of Western Europe and bearing continental climate in
Eastern Europe (Stoyko S., 2009).
Oak coppices were territorial and cenosis undergo changes in flat and low
mountain areas. The main problems of its degradation are intensive exploitation
last three centuries and insufficiently attention to oak’s regeneration. All these
were caused to simplification of form, structure and rare of oak stands and oak
coppice especially. As result were formed stands with structure, which aren’t
agree with ecological demands (Smirnova O., 1994).
The modern level of forestry in oak’s stands is oriented to receive largest
volume of high quality wood with shortest period of growing. Accordingly the
ways of increasing of productivity in oak’s stands are principal task of foresters.
But it caused contrary situations when in oak’s area were cultivating low/middle
quality wood species with short period of growing. In edge of forest were kept
some specific oak’s stands (coppices) with exclusive crown and stem forming.
These stands are naming oak’s coppices, which structure is mostly forming
accordingly to influence of agriculture closeness, grazing and recreation site
location.
Accordingly to forest data base, at 2011 in Prykarpattja were 108 336 ha of
oak’s stands, most of them (83%) were high productivity stands. Forestry
activities in these stands are oriented mostly for high productivity forest with a lot
of stems per ha. So in low productivity with small numbers of stems stands were excluded from some activities. These stands are mostly locate close to
settlements and have little rectangular or rounded area (2-3 ha).
The aim of research is to evaluate spatial structure and species composition
of oak’s coppice.
Research methods. Remote sensing data allowed receiving some
objective information about spatial structure of oak’s coppice in Prykarpattja. In
particular were used Landsat-8 data for photointerpretation of 3 research zones
with possible growing coppices. Additionally were used cartography materials
from forestry.
Based on extracted zones were conducted land investigation and chosen 5
areas (sample plots) for research. For biometrics estimation were measured
trees on 3 rectangular (100×100 m) sample plots and calculated main taxation
indexes. For this were used common silviculture and taxation techniques (Buzikin
A. et al., 2009, Smirnova O. et al., 1994, Danchuk O. et al., 2007, Chirici G. et al.,
2012, Commarmot B. et al., 2013, Donnelly K.P., 1978). For obtaining positions
of sample plots were used GPS-receivers. The main taxation indexes were
obtaining with Field-Map technology, in particular stand composition, absolute
stand density, volume of growing stock, vertical and horizontal structure et al.
The spatial structure was estimated with Cox index, Angle index and
Shannon-Wiener index (diversity index) (Boyko S. et al., 2011, Kudejarov V. et
al., 2007, Pretzsch H., 2001).
Results and discussion. It is distinguish 3 components of spatial structure
(vertical and horizontal structure, abundance of tree species per ha).
The vertical structure was analyzed using measured trees height for all
species on sample plots and divided on different tree levels. According to
selected tree levels were calculated percentages of different levels.
Based on trees amount we investigated, that the highest level occupy 15-
30%, middle level – 20-40%, lowest level accordingly 30-45%.
The main taxation indexes are presenting in article. The species
compositions on sample plots are presented different species, mostly oak (7-10
units in composition). In different level the oak is presented from 3 to 10 units, the
lowest level is composed mostly from softwood species, for example asp, willow and alder. The total volume of oak’s coppices are from 100 to 220 cubic meter
per ha, where oak makes 70-90%.
Knowledge formation processes of horizontal structure are given possibility
to determine the effectiveness of application of forest potential, the level of
interspecific competition and space familiarization. The competition for space and
resources is important factor in horizontal structure (Boyko S., 2011, Manoylo V.,
2011).
Based on calculated different indexes (Angle index, Clark-Evans index and
in Donnelly modification) we can affirm, that in oak’s coppices are prevailing
random location type with big gaps. This type is typical for all diameter groups (all
levels), but for group with diameter less than 20 cm (mostly it is lowest level) the
location type is contagious, which is more typical for young natural forests.
Additionally were calculated tree differentiation indexes (T i ) and species
diversity indexes (M i ). The values of differentiation index (from 0,5 to 0,7) and
species diversity index (0,43-0,84) means, that oak’s coppices have high level of
trees differentiation and species diversity.
Conclusions. It’s important to study three different components for forest
structure describing: spatial position of variety, species and varieties
differentiation. Our research proving, that oak woods (coppices) in this region are
natural origin and ecologically stable. The stands are forming multilevel, different
ages with diffuse horizontal structure. The species and variety differentiation are
quite high. Availability of undergrowth and low stand level (about 15 years old)
are indicating, that in these stands were stopped harvesting of minor forest
products.
So the horizontal structure is showing the process of stand forming,
interconnection between individuals of population (competition and cooperation,
dying and survival), estimating the level of anthropogenic influence for forest
biocenosises.
This work was spent within scientific research project «Zadrzewienia
dębowe w krajobrazie wiejskim regionu Karpat: pochodzenie, dynamika i
wartości przyrodnicze» with finance supporting of National Science center of
Poland (https://www.ncn.gov.pl/) , number DEC-2013/11/B/NZ9/00793.