SPRUCE 115 



This latter species, owing to its very light seed, 

 easily wind-borne, and to the fact that it seeds abun- 

 dantly every year, while the pine in Central Finland 

 only produces a seed-crop every seventh year, quickly 

 invades burnt-out areas. The year following a fire 

 will see the birch beginning to appear. The great 

 stretches of birch forest existing in Lapland and 

 Northern Finland arose in this fashion. Other great 

 tracts of poor soil existing in Finland, now absolutely 

 devoid of tree-growth, are also chiefly the result of 

 incendiarism, and, to a less extent, of the wasteful 

 devastation by man of the previously existing forests. 

 With the protection of the forests and the rarer occur- 

 rence of fires the distribution of the species again began 

 to change. Starting from the swampy lands and damp 

 hollows where it had held its own, the spruce invaded 

 the pine and birch forests, forming at first an under- 

 wood. With the development in height and crown 

 extension of this spruce underwood, it in time came to 

 form a high forest, from which the old pine or bir9h 

 gradually disappeared. Owing to the thick shade 

 which the spruce throws on the forest floor below, no 

 young pines or birches— both species requiring light to 

 enable them to develop — could grow. Young spruce, 

 on the other hand, are able to develop in the shade of 

 their parent trees; and, owing to this peculiarity, 

 the species gradually took possession not only of all the 

 soils on which it was able to grow to perfection, but 

 also of others less well suited to it, which, from a com- 

 mercial point of view, were better occupied by the 

 pine. In the coastal regions of Nyland and the 

 Governments of Abo and Vasa the spruce is already 



