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ŠUMARSKI LIST 11-12/1968 str. 38     <-- 38 -->        PDF

A STUDY OF THE COMPOSITION OF
LEAF(NEEDLE)FALL OF TREES IN CERTAIN FOREST
ASSOCIATIONS IN THE KARST AREA OF WESTERN CROATIA


Summary


The work represents a first contribution from the territory of Croatia to the
knowledge of the role and position of certain forest tree species in the process of
the biological circulation of matter in forest associations. The investigation includes
the determination of the percent content of N, P, K, Ca and Mg in the leaffall
of Beech, Fir, Maple and Elm. For the investigations in question were avaible 18
experimental areas in the region of western Croatia (the Mountains Velebit—
Kapela—Viševica) situated in Beech and Beech Fir forest associations. The soils
there belong to the group of brown soils lying on pure limestones and to a smaller
extent on pure dolomites. Within the zone of 400—1200m attitude a warm moderate
climate, while in the regions over 1200m a snowy forest climate is prevailing.
According to the established index of rainfall efficiency the whole region has a
perhumid climate (P/E > 128). Results of investigations are presented in Tab. 5
and their mean values in Fig. 1. On the ground of the investigations carried out
so far the following can be concluded:


1. In approximately equal ecological and other conditions in the association
Fagetum croaticum abietetosum Horv. the tree species studied differ considerably
from one_another in respect of the percent content of N, P, K, Ca, and Mg in leaf
(needle)fall. According to the mean value of percent content of the elements determined
in the leaffall the tree species have the following order of sequence:
N — Fir (1:50), Elm (1:37), Maple (1:21), Beech (0:90)
P — Fir (0:12), Elm (0:09), Maple (0:07), Beech (0:05)
K — Elm (0:77), Fir (0:37), Maple (0:22), Beech (0:21)
Ca — Elm (4:05), Maple (2.55), Beech (1:82), Fir (1:43)
Mg — Maple (0:27), Elm (0:24), Fir (0:14), Beech (0:14)


2. The Beech leaffall in Beech stands of equal soil conditions (the group of
brown soils on limestones and dolomites) and in various climatogenic associations
is differing as to its content of N, P, K, Ca and Mg. As to individual associations
these differences are considerably greater with respect to K, Ca and Mg, and very
small with respect to P and N. According to the present value of the percent content
of analysed elements in the Beech leaffall the investigated forest associations
have the following order of sequence:
N — Fagetum croat. subalpinum Horv. (0:85), Fagetum croat. montanum
Horv. (0:83), Fagetum croat. seslerietosum Horv. (0:81), and Fagetum
croat. abietetosum Horv. (0:80);


P — Fagetum croat. abietetosum Horv. (0:05), Fagetum croat. subalpinum
Horv. (0:04), Fagetum croat. montanum Horv. (0:04), Fagetum croat.
seslerietosum Horv. (0:04);


K — Fagetum croat. seslerietosum Horv. (0:22), Fagetum croat. abietetosum
Horv. (0:21), Fagetum croat. subalpinum Horv. (0:16), and Fagetum
croat. montanum Horv. (0:13);


Ca — Fagetum croat. subalpinum Horv. (2:20), Fagetum croat. seslerietosum
Horv. 1:91), Fagetum croat. montanum Horv. (1:85), Fagetum croat.
abietetosum Horv. (1:82);


Mg
— Fagetum croat. montanum Horv. (0:26), Fagetum croat. seslerietosum
Horv. (0:18), Fagetum croat. abietetosum Horv. (0:14), and Fagetum
croat. subalpinum Horv. (0:12).


3. According to data concerning the percent content of elements determined in
the leaffall in the association Fagetum croat. abietetosum Horv., and under soil
conditions characterized by a group of brown soils on limestones, the studied tree
species exhibit varying ameliorative capacities considering the nutrient status of
the soil. In relation to Fir and Beech, Elm and Maple possess an even many times
higher percent content of K, Ca, and Mg in the leaffall.
Taking into consideration that the leaching of bases in the soil represents an
essential pedodynamic process under the investigated conditions, it is necessary
to combat this harmful process — from the standpoint of soil fertility — by maintaining
and introducing into the forests and forest cultures Maple and Elm as ameliorative
species with high degree of biological accumulation of K, Ca, and Mg.