LXVIII GUNNAR SCHOTTE. 
riation. The Swedish larch-quality I corresponds very closely to HAMm's ground- 
class I; and the Swedish larch qualities II and III resemble HAMM's classes 
II and III. The Swedish quality IV, on the other hand, seems to correspond 
to HAMM'S class VI, which, however, is only indicated by some few figures; 
the Swedish quality V lies somewhat under HamMmmM's class VII. 
The most interesting thing, therefore, is that the best larch-stands (see fig. 
48) in Sweden attain the same quality as the best larch-stands in South Ger- 
many. In mean diameter, on the other hand, the Swedish stands fall short, 
which is not surprising, as they had been thinned so slightly or not at all at 
an earlier stage. 
In order to make some sort of estimate of the productivity of pure larch 
woods in Sweden, however, comparison might also probably be made with 
Maass' yleld-table for the pine (see Table 9). 
Table 10 gives a comparative view of the productive time that is needed 
for certain types of larch- and of pine-timber. 
On pp. 652—0664 is treated the development of the larch in mixed woods. 
The objects foresters wish to attain by means of mixed woods are expressed 
in the following terms: 
Higher production. 
More valuable dimensions. 
Better condition of the ground. 
Greater powers of resistance to injuries and diseases. 
The different mixtures of trees with larch which occur in Sweden are then 
examined from these stand-points. 
The most common type of mixture is larch and pine. This has come into 
existence, as a rule, through the fact that in forest sowings mixed pine and 
larch seed have been used, or sometimes by the sowing of larch seed by it- 
self in certaim compartments, and pine or a mixture of pine and spruce in 
others. Less frequently both kinds of tree have been planted simultaneously, 
for instance, by the alternate planting of a row of larch and a row of pine. 
Many sylvicultural writers, for example HEss (536 a), maintain that itis fu- 
tile to raise mixed woods of two light-loving kinds of tree; and they conse- 
quently condemn the very common mixture of pine and larch. Others, such 
as WAHLGREN (255), assert that the inconveniences of this mixture are to be 
sought in the quick-growing properties of the larch. The present writer does 
not seek to deny that there are very clear examples of this in forest-cultures 
in Sweden of from 20 to 40 years old; but he refers this phenomenon 
exclusively to the origin of the seed. "The more branchy and spriggy Tyro- 
lean larch is usually troublesome in mixed woods. It is quite different with a 
race that grows straighter and throws off fewer branches. Accordingly the 
Scottish race, and probably, to judge by the investigations of CIESLAR, 
(465), the Silesian race too, intrudes far less on its neighbours. 
On pp. 653 and 656 a number of examples are given from the sample- 
plots illustrating the productivity of the plants in mixed woods (see too the 
plans in Plates 3—7). These examples show that a mixture of larch greatly 
increases the productivity of the stand and not least its value. Moreover the 
larch certainly increases the fertility of the ground owing to the abundant needle 
refuse, so that it is probable that the pine too grows more rapidly than it 
would have done if the larch did not occur there — a matter which cannot 
