BIRCH, ALDER, OAK 119 



plays so important a part. Cattle parks are often 

 chiefly covered with birch. It is also present in the 

 mixed forests and in the areas which have been long 

 worked irregularly to furnish the domestic require- 

 ments of villagers and private proprietors. The two 

 species are found generally together, B. verrucosa pre- 

 ferring the drier and B. odorata the moister localities. 



The white alder (Alnus incana), originally only exist- 

 ing as a fringe to the water-courses (with the exception 

 of the coast in the south-west of Finland), has become, 

 as a direct outcotne of the system of shifting cultiva- 

 tion, the chief species over great tracts in Car61ie, the 

 Savolaks, Tavastland and the regions beyond Kajana. 

 The glutinous alder (A. ghitinosa) forms narrow pure 

 woods along the shores of the lakes, especially in the 

 south-west of Finland. In the south it spreads over 

 the marshy lands, where it occasionally forms pure 

 woods, as, for instance, in the coastal regions. 



The oak (Quercus pedunculata), which forinerly, in 

 the ** oak period," held a place of considerable import- 

 ance amongst the forest species in the south, is now 

 only found in small isolated woods in the extreme 

 south. The aspen (Populus tremula) is widespread, 

 and is found on the fertile soils as well as on the 

 driest of the sterile moors, but only reaches consider- 

 able dimensions on the former soils, where it occa- 

 sionally forms small pure woods. Larch (Larix sibirica 

 and L. europcea) has been introduced and some of the 

 plantations formed have done well. The oldest, of 

 L. sibirica, was planted between 1738 and 1820 and 

 shows excellent results. Willow, maple, ash, lime, and 

 elm occur sparingly in the south. 

 10 



