THE LARCH AND ITS IMPORTANCE IN SWEDISH FOREST ECONOMY. LXXVII 
true that, as in the natural forests of Siberia, it will get some few metres 
start of the pine. But there is still less risk in the case of the Siberian larch 
than in that of the European larch that neighbouring trees of a similar kind 
will be smothered, for the Siberian larch, as a rule, has a narrower crown, 
specially in Norrland. — On strong soil, however, it is possible, if desired, 
to raise pure stands. 
In order to illustrate the increment and productivity of the Siberian 
larch we can also use Table 17 on page 644, the material of which is taken 
from sample plots in both European and Siberian larch. The reason for this is 
that no great difference was visible in the material from the samples of the 
different species. Moreover the figures given by TOVvsTtTOoLJES from the great 
larch wood at Nykyrka in Finland agree pretty well with the figures from 
the older forests of European larch in Sweden. Besides, the material from 
the Swedish sample plots that bears on the Siberian larch cannot properly 
be placed in a special stand-survey because it is limited to age-groups of 
10— 25 years. 
Amongst the seventeen sample plots in Siberian larch measured, how- 
ever, all five grades of ground-quality for larch are represented. ”The 
stand-survey of the present writer shows considerably greater numbers than 
the unreasonably low figures HEMBERG (8:) has given from the Urals. He 
set up three grades of quality, which are characterized by the following 
mean heights: 
Mean height. 
ES Hemberg Hemberg Hemberg 
hå Quality I Quality II Quality III 
20 5-9 4 2.9 
BÖR 23.0 20.0 16.0 
LÖD: oo 28.2 20.4 24.5 
At the age of twenty, on the other hand, the five qualities of the State 
Institute attain the following heights in metres — 11.5, 9.5, I1.6, 6.o, 4.7. 
And at the age of 160, according to TOovsTtOoLJEs, as has been shown in the 
tables in Chap. IV B, the five quality-classes attain the mean height of 37.7 m, 
35.8 M, 34<5, IM; 33-40; HIS MmETESPeCtVelys 
That the Swedish woods will attain the same good development as that at 
Nykyrka is probable, though there is not much use in letting them grow longer 
than 8o years for the qualities I—III. For lower qualities, that is to say 
the weaker Norrland woods, a longer period may be properly fixed. If the 
intention is only to produce sleepers, on the other hand, the period can be 
restricted to about 52 years for quality I, 58 for II, 64 for III, 70 for IV 
and 70=1or: Vi. 
Sleepers can thus be obtained on the best ground, as at Omberg, for instance, 
in about 352 years, on moderately good ground in the central parts of the 
country in 64 years, and on better pine grounds in upper Norrland in 76 
years. By intensive care of the woods and heavy thinnings these times can 
be further shortened: how much, cannot be decided until after comparative 
experiments in thinning have been carried out for a considerable time. 
As the Siberian larch is a tree that is distinctly fond of light, it ought to 
be thinned early and heavily. On ground of larch-quality I thinning is pos- 
