DIGITALNA ARHIVA ŠUMARSKOG LISTA
prilagođeno pretraživanje po punom tekstu



ŠUMARSKI LIST 13/2005 str. 29     <-- 29 -->        PDF

S. Matić, I. Anić. M. Oršanić: S1LVICULTURAL TREATMENTS AIMED AT IMPROVING THE ANTI-EROSION ... Šumarski list SUPLEMENT (2005), 17-30
points out that it was the first cleaning in Slavonian state
forests. In 1898, Partaš agrees with Kozarac´s theses
on oak forest tending and points out that a young oak
stand should be cleaned several times and that multiple
thinning operations should be applied when the stand
reaches adulthood. In 1915,Zezulka writes about the
thinning practices in the oak stands in the Posavina region.
According to this author, low thinning was an important
silvicultural treatment aimed not at obtaining
fuelwood but at enhancing the principal stand. He
describes thinning in young, middle-aged and old pedunculate
oak stands. Pctračić (1919) discusses cleaning
and thinning in young developmental stages of ash
and oak, as well as the natural selection of trees into diameter
and value classes. In his book "On Thinning" Baien
(1929) points out: "Maybe we cannot bequeath large
reserves of mature forests to our descendents, but we
must leave them carefully tended young stands". He believes
that thinning practices should be above theoretical
discussions.


The issue of regeneration has always had an important
role in the history of managing pedunculate oak
forests in Croatia. The problem of regenerating old oak
forests was discussed at the first assembly of the Croatian-
Slavonian Forestry Society held in 1846. As seen
from Kozarac´s writings (1887, 1886), regeneration of
oak was a very important issue. He stressed that management
of pedunculate oak forests should be based on
natural regeneration.


Two methods of natural regeneration of oak forests
were used at that period:


1.
the "selection cut" method with a 10-15-year grazing
ban,
2. the "final cut" method with a five-year grazing ban.
The first method involved a gradual, selective removal
of all the trees except pedunculate oaks during the
10-15-year grazing ban (a period in which cattle was
banned from grazing and feeding on acorns). That period
was intended for the oaks to seed the regeneration
area. In actual fact, these were incomplete shelterwood
cuts (Matić 1996) consisting of the preparatory and
the final cut and a regeneration period of 10 to 15 years.
According to the second method, a stand was "excluded
from use" for five years before being cut. At that
time oaks fructified abundantly and frequently, so the
regeneration area was well seeded with acorns. After
the seedlings and the young plants had emerged, the old
stand was cut down. This was a primitive method of regeneration
in one cutting treatment and a shortened re


generation period of five years. Still, regeneration was
natural because it occurred in the previously seeded regeneration
area under the crown shelter. The seedlings
and the young growth developed under the crown shelter
of old trees during the five-year regeneration (and
seeding) period. When the crop was poor or tending
was absent, narrow-leaved ash or elm would suppress
the pedunculate oak, so the old oak stand would be regenerated
as an ash, hornbeam or elm stand.


P e t r a č i ć (1926) later stated that the shelterwood
harvest in pedunculate oak forest should be accomplished
in two cuts with a longer regeneration period. The
researchers investigating the regeneration of pedunculate
oak forests in Croatia (Matić 1996, 1984, Dekanić
1961, Starčević 1990,Đuričić 1986,Petračić
1926, Lončar 1949) agree that the best method
to use is the shelterwood method consisting of the
seeding cutting operation in two to three cuts and a regeneration
period of 6 to 8 years. Any possible artificial
regeneration should be executed according to the
principles of natural regeneration, which means that
before the final cut acorns should be sown or planted
and seedlings planted under the crown shelter.


The value of silvicultural treatments applied in the
management of pedunculate oak forests has been confirmed
by practice of many years and scientific research.
However, the following problems may occur:


1.
the absence of tending the young growth and the
young forest in terms of tending intensity and stand
area,
2.
the absence of first thinning in the young stands after
the culmination of height increment several years
after the last cleaning,
3.
the absence of thinning in the second and the third
age class,
4.
the maintenance of stands in which dieback and decline
have reduced the canopy, especially those in
which pedunculate oak has suffered dieback,
5.
no recovery of gaps bigger than 0.1 ha, which were
caused by dieback of the main tree species,
6.
the compartments should be selected more intensively
in dieback-affectcd stands in order to give timely
presentation of the realistic condition by compartments
and to apply timely silvicultural measures
(S t a r č e v i ć 2004),
7.
the game population density does not accord with
stand and site capacity
8.
the shelterwood method is favoured over large areas.
SELECTION FORESTS


A selection forest is considered by many an ideal of non-commercial functions, including the anti-erocommercial
forest form capable of providing an array sion and water-protective function. Viewed from this