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ŠUMARSKI LIST 13/2005 str. 238     <-- 238 -->        PDF

P. Jaloviar: FINE ROOT DISTRIBUTION IN A PURE NORWAY SPRUCE POLE-STAGE STAND Šumarski list - SUPLHMENT (2005), 229-237
on loam and sandy soils, states for sandy soils the biomass
of 5,650 kg/ha. For the loam soils he states the
value 359 g/m2, what presents 3,590 kg/ha in the top 20
cm of soil. Kodri k (1998) found out 430 respectively
230 g of fine root biomass on 1 m on two plots with different
immission impact in the region of Moravskosliezskc
Beskydy, what constitutes 4,300 respectively
2,300 kg/ha, he investigated the layer with depth of
30 cm. The necromass weight was 175 g/m2 on the plot
under immission impact. The average fine root density
varies about 3,000 kg/ha in mature coniferous stands in
central European conditions. Kodri k (1997) also states
the value of constant biomass (dry mass) of roots
with diameter under 5 mm only 1,300 kg/ha for the primeval
forest in Biosphere Reserve Pol´ana. Surov y
(2000) gives 4,525 kg of fine roots on 1 ha for a spruce
shelterwood forest (mature stand together with second
layer of next generation).


The relation between the soil depth and vital fine
root biomass was tested using the method of linear correlation.


The comparison of particular spa


The fine root density is given in mg of fine roots in
100 ml of fine soil. The advantage of this parameter is
its independence from the thickness of investigated
layer. At first the fine root density from 7 plots was


Vital f


The overview about the coefficients of regression
lines for all spacings is given in Table 4.


From Table 4 results that all absolute and regression
coefficients, which are determinant for the shape of
particular relation, are statistically high significant different
from zero. By testing of diffcrencies between the
regression coefficients (t-test) a high significant difference
of the b-coefficient from the plot B was found.


The differencics in the incline of the lines reflect the
various distribution of the fine root biomass. The explanation
for this can be that by wider and more asymmetric
spacings with low initial plant number (2,500 ha"´)


e.g. by the spacing 5.0 x 0.8 m, the available stand space
for the crown development is not used as good as by
the other more symmetric spacings. This spacing is the
only one at present, where the crowns of trees don´t
touch in the inter-row space. Therefore the biomass
distribution corresponds more or less to the way how
the roots take the soil profile in the stands with low
stand density, where the competition of neighbour trees
is less than in the stands with full density. In symmetric
spacings the available stand space is fully used and the
competition in the crown layer is much stronger than in
the previous case. The proof of it is the visible more intensive
drying in the lower parts of the crowns in these
spacings and therefore the gradual reduction of the
crown capacity compared to the spacing 5.0 x 0.8 m.
igs according to fine root density


analysed as a whole i.e. the relation between the avera


ge concentration and the soil depth was quantified. The


comparison was conducted using the method of linear


correlation.


i roots


Despite the significant diffcrencies from zero the regression
coefficients of the lines from other plots differ
not significant from each other.


The correlations between the soil depth and fine
root concentration is quite weak, the strongest is on the
plot A (5.0 H 0.8) and F (2.5 H 0.8 m), while the computed
line explains 69 % respectively 62 % of the variability.


Dead fine roots


Also in this case the method of linear correlation
was used for the comparison of relation between the fine
root concentration and the soil depth. The results are
shown in the Table 5.


The strength of the correlations is more variable at
dead roots than vital roots. From previous experiences
the state is known, when the dead fine roots shows substantially
higher variability and often nearly no relation
to the soil depth.


On the plots with higher initial plant number on 1 ha
the decrease of biomass concentration as well as total fine
rhizomass with the soil depth is less strong than on
the plots with less dense spacings. The more expected


result will be that at higher density and symmetric spacing
the fine root concentration will be more homogenous
what will be confirmed by less marked depth gradients.
We can assume that compared with the summertime
the soil moisture was already higher at the beginning
of autumn growth of fine roots optionally in the time
of their harvesting. On the plots with more dense
spacings surely the interception is higher and soil layers
under 20 cm were obvious more dry in the time of the
harvesting than on the plots with less dense spacings
with lower canopy degree. Therefore we can presume
on the plots with dense spacing also the root growth was
limited only on the soil horizon A in the time of harvesting
i.e. on the layers in the depth 0-20 cm.