Periodical Literature 105 



In Germany, humidity is the important factor found in mini- 

 mum, hence silvicultural methods have to look carefully to avoid 

 drying of the site, in Switzerland such care is entirely unnecessary, 

 even to the extent of favoring exposure to the sun. 



The differences of climate are indicated by the occurrence of 

 fig, olive and chestnut forest forming in the southern cantons up 

 to the cessation of tree growth at timberlimit, through the broad- 

 leaf forest of oak and beech, the mixed broadleaf and conifer, 

 then the spruce and finally the White pine and larch. 



Frost danger is small in the mountains, due to fogs and late 

 opening of vegetation. Wind danger is also less than one would 

 expect, due to the break of the wind by the mountain configura- 

 tion. Significant, however, is the Fohn, corresponding to our 

 Chinook winds, which sometimes necessitate to locate felling 

 series from North to South. Otherwise localized direction of wind 

 must be studied. 



The soils vary, alluvial and diluvial deposits continue to form. 

 Tertiary formation is found in the parts between Jura and Alps 

 and chalk formation especially around the foot of the Jura. Silurian 

 and Devonian formations are rare, but the crystalline gneisses and 

 slates aboimd, as well as the various granites, while porphyry and 

 basalt are rare. Here a close connection between soil quality and 

 rock is observed. 



Spruce is most widely distributed and forms about 40 per cent 

 of the forest. Stands are characterized by even growth, com- 

 pleteness, large stem number, large cross section area and volume, 

 and low bark per cent, excellent quality, even grain, freedom from 

 damage. Its management is very easy, since it keeps a close 

 cover, preventing undergrowth, has the capacity to recuperate 

 from suppression and responds to thinning practice of any kind 

 readily. Pure stands are financially best, admixtures bring 

 economic detriment, except with beech, merely in small propor- 

 tion; even below 5 per cent. Going up from the optimum be- 

 tween 800 to 1,000 w, growth conditions rapidly change, decreas- 

 ing in development in all directions until close stands cease to 

 exist and in 200 years is accomplished what can be produced in 

 100 years on its proper site. A 189-year old stand at 1830 m 

 elevation exhibited still 440 stems with a basal area of only 258 

 square feet, a height of 60 feet and an average diameter of 11 

 inches, not less than 17 years to the inch. 



