DIGITALNA ARHIVA ŠUMARSKOG LISTA
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ŠUMARSKI LIST 7-10/1975 str. 50     <-- 50 -->        PDF

average was d = 40.5 cm and h = 28.2 m. For the productive part of the stand this
indicatesthat the dried-up trees — according to their constitution (d and h) — are
below the average of trees in the productive part of the stand.


In the forest community of Pedunculate Oak with Genista elata and Carex
brizoides (Genisto elatae — Quercetum roboris caricetosum brizoidis Horv.) there
died 46 trees of Pedunculate Oak or 27.6 m3/ha out of a total growing stock of 363
m3/ha. In the productive part of the stand the average was d = 29.0 cm and h =


27.7 m, while the average of the dried-up trees was d = 23.2 cm and h = 23.2 cm.
In the forest community of Pedunculate Oak and Hornbeam there died in the
productive part of the stand 26 trees of Pedunculate Oak or 33.8 m3/ha out of the
total growing stock ofPedunculate Oak in this part of the stand amounting to


331.6 m-Vha.
In these stands, as wisible from the composition, there were only a few Field
Elm trees, and that mainly in the auxiliary part (layer) of the stand.


From the aforementioned data it follows that the least drying up of standing
trees occurred in the optimal Pedunculate Oak coenosis, while in the initial and
terminal ones it was 3—4 times heavier. However, also these intensities of drying
up did not disturb the normal stand structure, whereas the growing-stock volume
after the recorded dieback in the optimal community of Pedunculate Oak was about
498 m3/ha (at 108 years). In the initial community the growing stock was 387 m3/ha
(at 71 years), and in the terminal 448 m:!/ha (at 95 years). From these data it is
visible that the stands are of normal stocking density, and that the dying seemed
to us to have the apperance of a thinning (during our investigations, naturally).


In the management unit »Žutica« in the community of Peduculate Oak with
Genista elata and Carex remota — a coenosis representing the plant-sociological
optimum — it is visible that the water regime is unfavourable (duration of floods
and fluctuation of groundwater level in the probe). The consequence of such a
regime is a very high proportion of Black Alder (over 40B/o) in the stand. In the
productive part of the stand there died 10 trees of Peduncualate Oak or 12.2 m3/ha,
and 56 trees of Black Alder or 50 m3/ha. This data, too, is indicative, among other
things, of a disturbance in the zone of the rhizosphere (swamp formation due to
absence of draining possibilities, the whole compartment looking like a chamber,
whose embankments are formed by a road). The growing stock amonts to 308 m3/ha
at the age of 88 years. The stand structure is disturbed, and it can be said that the
anthropogenic factor had played a prominent role in the creation of conditions
having led to the dying of Pedunculate Oak.


In the forest community of Pedunculate Oak with Genista elata and Carex
brizoides as the initial association the water regime with periodic floods (mainly
during the rest period) is very favourable and there been no dying of Pedunculate
Oak in the productive part of the stand. The growing stock amounts to 392.2 m3/ha
at the age of 88 years. The stand exhibits a normal stocking density.


In the forest community of Pedunculate Oak and Hornbeam, as the terminal
association, there died 4 trees of Pedunculate Oak with a volume of 7.2 mVha. The
growing-stock volume amounts to 423.8 m3/ha at the age of 77 years. The stocking
density is normal, and the stand structure is undisturbed.


From the present results (although obtained on a small number of experimental
plots and during a relatively short interval of investigations) it is visible that
by the disturbance of only one of the edaphic factors there occurs a disorder, while
in addition to the activity of certain biological factors are created preconditions
for the perishing of one of this country´s most valuable tree species of lowland
regions — Pedunculate Oak.