Current Literature. 63 



The pine and the larch are of the same age, or belong to two or 

 three generations of the same age. But in the age of the spruce 

 there is much variety. This is due to the origin of the stand. 

 Most of the present stands started on fire-swept areas. Thus in 

 this region one frequently finds stands now (1908) 165 to 170 

 years old — i. e. originating between 1738 and 1743. These dates 

 agree with those of the great drought-period of the seventeenth 

 century ; the Russian historical documents show that in this 

 period extensive forest fires devastated much of middle and 

 northern Russia. 



The rivers, brooks, swamps, etc., caused brakes in the spread 

 of these fires ; nevertheless many stands can be traced in their 

 origin to this fire-period. On one Oberforsterei (National 

 forest) 33 per cent, of the area, in another 50 per cent., is covered 

 with stands of practically the same age. 



Since, after the forest fires, pine, larch, and birch were left 

 alive singly or in groups, whereas the spruce was usually killed, 

 the natural reproduction is generally made up of pine, larch, and 

 birch of the same age, according to the condition of the remain- 

 ing seed trees and the length of time elapsing before the next 

 seed year. But the spruce can only be seeded in from such parts 

 of the original stand as were untouched by the fire. Therefore 

 spruce enters into the mixture of pine and larch some ten to fifty 

 years after the establishment of these species, depending on the 

 distance from the original unburned stand. 



Later seedlings of pine and larch are rare, but the spruce con- 

 tinues to spread gradually, sometimes achieving 97 per cent, of 

 the stand with pine, larch, birch and aspen constituting the re- 

 maining 3 per cent. In the selection cutting of the pine and larch 

 these species are still further reduced in numbers, sometimes none 

 remain, whereas the spruce being younger and hence of smaller 

 diameter, secures entire control of the stand. 



It is characteristic in stands from 150 to 200 years of age to 

 find spruce seedlings on decayed tree trunks ; about 95 per cent, 

 of the spruce seedlings grow there and only 5 per cent, on the 

 forest floor proper. Pine and larch are not able to do this, hence 

 only 3 per cent, of all the seedlings are of these species. Com- 

 plete decay of a log requires well into the second century after 

 the tree's death. On the remains of an old spruce log an 81 



