SYLVICULTURE 25 



American and Asiatic species, several of which may in the 

 course of time become generally recognised as valuable 

 additions to the forest flora of Western Europe. From 

 a sylvicultural point of view, those especially deserving men- 

 tion are : American White Ash (Fraxinus alba Americana), 

 Red Oak (Quercus rubra\ Black Walnut (Juglans nigra), 

 Douglas Fir (Pseudotsuga Douglasii), Sitka Spruce (Plcea 

 sitchensls or Abies Menziesii), Western Hemlock ( Tsuga 

 Mertensiana or Abies Albertiana), Lawson's Cypress (Cha- 

 mcecyparis or Cupressus Lawsoniana\ Pacific Arborvitae 

 (Thuya gigantea, T. Lobbi, or T. Menxiesii), Bank's Pine 

 (P'mus Bankslana\ Japanese Larch (Larix leptolep'is\ Great 

 Silver Fir (Abies grandis\ Concolor White Fir (Abies 

 c one o lor). 



Tree Growth in Relation to Soil and Situation 



A term much used in technical forestry is "locality." 

 It comprehends both soil and climate the latter being in- 

 fluenced by situation as they affect tree growth. The 

 locality largely determines the species to grow and the 

 sylvicultural treatment to adopt for any given area. The 

 estimation of the capabilities of the locality forms, perhaps, 

 the chief concern of the practical forester. 



Apart from the general management of the forest, the 

 prosperity of the trees depends upon the physical and 

 chemical composition of the soil, the geographical position, 

 the altitude, slope, and aspect of the ground. 



Owing to the great number of factors collectively con- 

 stituting the locality, there is difficulty in determining the 

 importance of each individually. In selecting trees, the 

 general conditions that are found to prevail must overrule 

 opposing but non-vital considerations. 



As regards the demands which trees make upon the 

 physical properties of the soil, the most important qualities 

 are depth, moisture, consistency, and permeability. A soil 

 of at least moderate depth, fairly fresh, and of a porous and 



