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ŠUMARSKI LIST 7-8/1969 str. 31     <-- 31 -->        PDF



Investigated were changes of some soil fertility factors brought about by the
influence of coniferous forest monocultures within a zone of Beech forests in the
region of Western Croatia. The cultures are about 80 years old and occur in two
localities, viz. Drvarija and Zagolik belonging to the area of perhumid climate
according to the factor P/E = 128. The cultures of the first locality (Drvarija)
grow on a brown soil with dolomitized limestone as parent rock within the zone
of Fagetum croaticum seslerietosum Horv., and those of the second locality (Zagogik)
on a brown acid soil with fine-grained Palaeozoic sandstones as parent
material within the zone of Blechno-Fagetum Horv. forest plant community.

Undex.equal ecological conditions was compared the state with each of the
cultures of Norway Spruce, European Larch and Eastern White Pine with conditions
of the soil in the natural Beech forest (locality of Drvarija). In the locality
of Zagolik were performed comparisons with each of the cultures of Norway
Spruce, Douglas Fir and Silver Fir Under natural Beech forest. Results of investigations
are presented in Tabs. 1—8, and Figs. 1—4. The most imoprtant conclusions
are as follows:

1. The greatest Ai-horizon depth and the greatest forest liter amount is
exhibited by a brown acid soil under Douglas Fir and Norway Spruce. Brown soil
on limestones has the mentioned values highest under Norway Spruce, and lowest
under European Larch.
2. A Norway Spruce culture acidifies the soil, more on the limestone than on
the sandstone. The decrease of the soil reaction amounts to 0.3—0.8 pH units.
3. In the brown soil on limestone were established larger amounts of total
nitrogen and humus under natural forest vegetation than under cultures (plantings).
In brown acid soil the condition is converse.
4. The process of accumulation of exchangeable bases within the adsorption
complex of brown acid soil is most strongly pronounced unter the trees of Douglas
Fir and Silver Fir.
5. The per cent content of N, P2O0, K2O, CaO and MgO in the forest litter and
the amount of the latter are strongly affected by the tree species. Of the mentioned
elements per ha. the forest litter of Douglas Fir contains 1735, Norway Spruce 868,
Beech 428 and of Silver Fir 409 kg. (brown acid soil); while the forest litter of
Norway Spruce contains 1860, Beech 1191, Eastern White Pine 587 and of European
Larch 236 kg. of the mentioned elements (brown soil on the limestone).
6. According to the per cent content of the biogenic elements in the needle
(leaf) litter there were evaluated as organisms-concentrators (within the zone of
Fagetum croaticum seslerietosum Horv.) European Larch with regard to phosphorus
and Beech with regard to calcium. The same properties with regard to
nitrogen and phosphorus are displayed by Silver Fir within the zone of Blechno-
Fagetum Horv. forest association.
7. No morphological signs were noticed to the effect that the soil erosion due
to water would assume a more unfavourable patern in a terrain under forest
culture (planting) than under natural forest vegetation (regeneration).
8. In a general way the analysed factors of soil fertility have experienced no
untoward change.