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FENNIA 66, N;o 4
47
also in North Finland, in the latter case apparently owing to the large
regeneration of poor growing over-mature forests. In East Finland,,
on the contrary, the growth has decreased.
The proportions of the different species of trees to the total
growth are as follows: pine 18.98 million m3 or 41.5 per cent, spruce
14.89 million m3 or 32.6 per cent, birch 9.57 million m3 or 21.o per
cent, aspen 0.92 million m3 or 2.o per cent and alder 1.34 million m3
or 2.9 per cent. If the results of the first survey concerning the growth
are made comparable to the results of the new survey, it is noticeable
that the growth of pine has fallen off by about 1.9 million m3 since
1922—23. The reduction refers to the southern half of Finland, while
in North Finland, where pine is generally the most productive species,
there has been an increase. The growth of spruce has increased during
these 15 years by about 2.o million m3. The increase refers to the
southern half of Finland and chiefly to West Finland. No change
worth mentioning has occurred in regard to the growth of birch, the
growth of aspen has increased slightly and the growth of alder has.
decreased. Great efforts have been made of late in Finland to increase
the yield of spruce and in the course of 15 years this has been achieved
to a considerable extent (15 per cent), the yield having increased as
much as 25 per cent in West Finland.
In drawing definite conclusions regarding the changes in the
growth the periodicity of growth should be borne in
mind; investigations in regard to this are still incomplete, but indicate
that at any rate the decrease in the growth of pine in the southern
half of Finland is partly explained by it.
The data contained in the present paper are insufficient for
estimating the condition and the trend of the development of the forest
resources and for drawing conclusions as to the future utilisation
of the forests. Sufficient bases for this will only be forthcoming,
when the results of the National Survey of the forests have been
worked out in detail and especially the results concerning the
silvi-cultural condition of the forests, the silvicultural measures to be
adopted, the proportions of age-classes and the cutting quantities.
And finally the completion of investigations into the utilisation of
the forests must be awaited before a proper basis is provided for
establishing the yield and utilisation of the Finnish forests, the
forest balance.
All this need not, however, prevent the following sufficiently well
founded conclusion being drawn at the present juncture.
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