DIGITALNA ARHIVA ŠUMARSKOG LISTA
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ŠUMARSKI LIST 11-12/1973 str. 44     <-- 44 -->        PDF

The author obtained nonsignificant results in investigating the influence of
the horizontal projections of tree crowns of the 2nd story on the elemente of regeneration,
but he obtained highly significant results in trees of the 3rd story of the
stand. Under a maximal shading of the soil through tree crowns of the 3rd story
the number of the newly established reproduction decreased 4 times in a 5-year
period. The number of Fir stems diminished 3 times, and the number of Spruce
stems 21 times.


The more the coefficient of crown cover approaches the value of 1.00, the more
favourable are the conditions far regeneration. Fir is more indiffirent to this change
than Spruce. Similarly to the coefficients of crown cover, the multiple shaded crowns
exercise an influence on the natural regeneration. Through the increase of multiple
shaded crowns per unit of area the conditions for regeneration diminish.


When the unshaded area in the stand increases, Spruce reacts with its presence
most, then Fir and Beech. In the maximally unshaded area — in the studied forest


— the sum of height increments of Spruce stems increased 13times, that of Fir stens
5times with respect to the minimally unshaded area.
Through the increase of the volume of tree crowns per umt of area the conditions
for natural regeneration are conspicuously diminished. When comparing the
influence of the horizontal crown projections on the elements of regeneration with
the influence of the crown volumes on these same elements, it can be concluded
that the horizontal projection of crowns exercises a greater influence on the regeneration
than volume of crowns does.


Ninsignificant results were obtained when investigating the influence between
the basal area and the elements of regeneration, and it can be concluded that this
element of stand structure is not the best index of the conditions for natural regeneration.


Of the total light intensity in the open — in the studied stands — a minimum
of 0.675% and a maximum of 19.57°/o reach down to 20 cm. above ground.


Despite the fact that Fir adapts itself very well to a relatively small amount of
light, one part of seedlings die, apart from other causes, also from lack of light.
During the developmental stage of young reproduction also one part of plants die
because of insufficient amount of light, and that with the highest percentage at the
age of 1—5 years. A small number of plants which succeed to survive this age
vegetate and put up with the minimum amount of light, waiting that the space
above them should somehow be opened and the light brought to them in order to
supply conditions for their normal life.


Spruce is much more sensitive to the lack of light than Fir, so that in areas with
minimum amount of light it does not appear, or if it does, it dies the developmental
stage of seedling already.


Because of a small number of Beech seedlings and saplings, and because of
lack of Beech stems in the upper storeys of the investigated stands, the author was
not able to draw conclusions to the behaviour of Beech under the conditions ruling
in these stands.


On the basis of the results of his investigations the author can maintain that in
the investigated stands of Fir with Hardfern there exist all conditions for a good
and successful natural regeneration. These conditions relate to the biological-ecological
characters of individual tree species composing this stand, as well as to the
ecological factors ruling in the region investigated. If there appears a problem of
renewal of these stands, it is caused by the absence of tending or by ill-conducted
tending and felling of stands.


Considering that with his results of investigations the author has established
that there exists a very strong correlation between the elements of stand structure
and those of the regeneration, and that by changing the elements of structure also
the conditions for regeneration are changing — the silviculturist can affect with his
interventions the structural elements by changing them, all with the aim to convey
these stands to optimum regeneration and maximum production.