DIGITALNA ARHIVA ŠUMARSKOG LISTA
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ŠUMARSKI LIST 11-12/1997 str. 12     <-- 12 -->        PDF

B. Prpić, Z. Seletković i I. Tikvić: O UTJECAJU KANALA DUNAV - SAVA NA ŠUMSKE EKOSUSTAVE Šumarski list br. 11-12. CXXI (1997), 579-592
Table 1. Decline of pedunculate oak, conditions, causes and consequences, improvement measures


B. Prpić, 1996.
Site, range and ways
of tree decline


Dieback causes of groups and
stands in ali pedunculate oak sites,
survival of marsh species - white vvillow,
black alder, narrovv-leaved ash.


Dieback of pedunculate oak in
different sites along water reservoirs
(hydro-power stations, artifical lakes,
potable and technical vvater storages,
etc.


First, dieback of individual trees,
followed by group and entire štand
dieback after 3 to 5 years, ali middle-
aged and old stands. Trees under the
age of 30 survive. A decline inthe increment.
Ali pedunculate oak sites.


Seedlings and young group die.
Hydrophyte plants occur in ground
storev. Ali pedunculate oak sites except
drained micro-elevations. Death
after final, but also regeneraton cut.


Extensive death of forests in ali
sites of pedunculate oak ecosystems.
Observed acidic emisions pH
values less than 4 in the accumulative
soil horizont. Pests and discases occur.
Ali tree species decline. Extent
of dieback assumes the caracter of an
ecological catastropfe.


Dieback causes


Precipitation and flood vvater
during vegetation period remain on
soil surface. Lack of oxygen and
build-up of C02 in the rhizosphere.
Death of roots due to C02 build-up
and general roots necrosis. Insect
and fungi attack on weakened trees.


Permanent rise in groudwater
levels, absence of oscillations in water-
table. Slovved movement of groundvvater,
bild-up of C02 in the rhizosphere
accompained with lack of
ozvgen, root necrosis.


Permanent fali in groundvvater
levels during vvegvvtation period by
more than 0,5 m compared to previous
mean values.


After regeneration felling, štand
rejuvenates poorlv. Soil is waterlogged
due to vvater surplus in the
site, which had previously been
transpired and intercepted by old pedunculate
trees.


Synergetic action of swamping,
lovvered vvater-table, climatic excesses,
pest and disease attacks emission
of harmful substances into the
air and vvater, regulated monocultures.
Svvamping is most dangerous
(floods and excessive precipitation
in vegetation period), together vvith
a drop in vvater-table by more than


0.5 mmin 1-2 years.
Measures aimed at improving
the condition


Surface dreinage, building drains
in roads. Prevention of change in vvater-
table. After drainage, regenerate
štand vvith adequate tree species. But
pedunculate oak monocultures shouldbeestablished.


Present tehnical possibilities cannot
improve the situation.


Štand regeneration vvith tree species
which correspond to a particular
site.


Surface drainage and introduction
of pedunculate oak ond other
tree species responding to the site.


Stop emissions by installing devices
for cleansing industrial gases
and polluted industrial and urban
vvater. Drainage of marshy sites.
Treatment of polluted forest soils
with zeoli substances. Introduction
of species responding to nevv site
conditions.