DIGITALNA ARHIVA ŠUMARSKOG LISTA
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ŠUMARSKI LIST 1-2/1966 str. 95     <-- 95 -->        PDF

This will give rectangular plots 4,20 X 8,40 m = 35,28 m2 for pine and
square plots 6 X 6 m = 36 m2 for spruce. With the 8 replicates planned each
provenance will cover 282,24 m2 and 288,0 m2 for a pine and spruce plantation
respectively. Thus on a site of 5 ha it will be possible to include about 170
provenances. Smaller number of provenances will require a relatively smaller
area.


In Table 1 the number of trees per plot at different ages is given for pine
and spruce. The number of trees per ha. at different ages shown in Table 1
were taken from Schwappach´s yield tables (1943) for the best site class. On
poorer sites there will be more trees per ha.


Table 1


Number of trees per hectare and per plot at different ages for pine and spruce


Age,
years
Pin e
per ha.
1.20 X 0.60 m.
per plot 35.22 sq. m.
Spruc e
per ha.
1 X 1 m.
per plot 36:
1 14,000 49 10,000 36
25 4,380 15.5 5,110 18.4
30 2,880 10.0 3,702 13.3
35 2,080 7.3 2,800 10.0
40 1,570 5.5 2,210 7.9
5(1 998 3.5 1,468 r>.´i
60 739 2.6 1.037 3.7
70 583 2.1 771 2.8
80 480 1.7 598 2.2
90 403 1.4 479 1.7
100 342 1.2 396 1.4
120 265 0.9 284 1.0


The values per plot have been calculated from Schwappach´s figures
corrected for the actual plot size.
If the site quality is lower than class I, then there will be more trees per
plot at a given age.


As can be seen from Table 1, the proposed arrangement will give about
8 trees per plot at 1/3 of the rotation age assuming a rotation of 100 years for
pine and 120 years for spruce. Thus, as has been discussed above, there will
be enough trees to evaluate the productivity per unit area.


At the end of the rotation there will still be one tree per plot and, with
the 8 replicates, 8 trees of the same provenance in the whole experimental
area. This will be sufficient to compare the provenances in respect of tree
quality and of numerous other features.


Productivity per ha will of course no longer be estimable. However, it
will be possible to corroborate all other characters with those tested earlier,
and to establish juvenile-mature correlations.


For the reconstruction of the population by means of a seed orchard, 40
trees are deemed necessary. These will be available at the age of 40 years in
pine (from all the 8 replicates), and at the age of 50 years for spruce. At these
ages both the productivity per hectare and most of the other qualities of
interest will have been reliably compared for the provenances in the experiment
and the best ones would have been selected.