şi prof.dr. W. Zwölfer - Revista Pădurilor

thinning of young european beech stands:
the outputs of a demonstration field exercise
(Mikes estate, Zăbala-Covasna)
1. Introduction
As shown in both Romania (Nicolescu, 2005)
and abroad (Belgium – Baar and Snoeck, 2004;
Baar et al., 2005), demonstration plots can be a
valuable tool for the “training” of field foresters
on different issues related to forest
management.
Taking into account this conclusion a demonstration
plot of 2,000 sq.m (50 x 40 m) was established
on September 13, 2010 in a forest stand
(formerly sub-compartment 15B, Forest
Management Unit V Bixad) part of the Mikes
Estate (Zăbala-Covasna) and managed by the
Forest District of Covasna. The demonstration
plot was established by Prof. Valeriu-Norocel
Nicolescu (University “Transilvania” of Braşov)
together with a group of French students in forestry
from AgroParisTech-ENGREF, Centre de
Nancy as well as some local foresters. This plot
is part of a large (24.6 ha) 40-year old stand
(European beech mixed with hornbeam, goat
willow, silver birch, and mountain elm), highly
productive (second yield class). According to the
Density and basal area of initial, marked and remaining trees
Species
N*
last forest management plan released in 2005,
the standing volume per hectare is 128 cu.m and
the current annual increment is 7.9 cu.m/ha.
The only silvicultural intervention performed
in this stand since its regeneration is a cleaning-respacing
in 1996. In addition the stand
was marked for thinning by the field foresters of
Covasna Forest District earlier this year.
Silvicultural racks to provide easiest access within
the stand and limit logging damages have
not been opened yet.
2. Main characteristics of european beech
stand before, during and after thinning
After establishing the demonstration plot all
existing trees (270 individuals) within it have
had their dbh measured. In addition 85 individual
trees (both initial and marked for thinning)
had their total heights measured as well. The main
data of initial trees, trees marked for thinning
and trees remained after the thinning to be performed
later on are shown in table 1.
Initial trees/ha Marked trees/ha Remaining trees/ha
N,
%
G**,
sq.m
G,
%
18 REVISTA PĂDURILOR • Anul 126 • 2011 • Nr. 2
N
N,
%
Ludovic LEJOUR
Elise PARES
Bernhard Freiherr von PUTTKAMER
G,
sq.m
G,
%
N
N,
%
G,
sq.m
Table 1
European beech EB 1080 80 23.98 75.0 220 57 2.7 38.5 860 89.0 21.3 85.3
Hornbeam HB 210 15.6 3.09 9.7 135 35 2.0 28.1 75 7.8 1.1 4.5
Other broadleaves
OB***
60 4.4 4.91 15.3 30 8 2.3 33.4 30 3.2 2.5 10.2
Total 1350 100 31.98 100 385 100 7.0 100 965 100 24.9 100
N* = number of trees; G** = basal area; OB*** = silver birch, goat willow, mountain elm
G,
%