22 TREE GROWTH IN RELATION TO 



only when we wish to plant land above i.ooo feet that we 

 must take elevation into consideration. It is generally con- 

 sidered that forests will not pay above 1,000 feet, but if properly 

 treated, and grown densely, it is likely that several species 

 would produce paying timber at a greater elevation (provided 

 that they are near a possible market), especially in the ravines 

 and glens where they are sheltered by higher land. 



When planting above 1,000 feet it is best to use only Scotch 

 pine, Austrian pine, larch, spruce, sycamore, and birch, which 

 are more likely to succeed than other species. 



Turning now to aspect, south and west aspects are warm, 

 and they are exposed to strong winds and heavy rain, but as 

 the sun shines strongly on them the soil dries rapidly. North 

 and east aspects are cool and the winds are less strong but 

 are drier and colder than those from south or west ; the soil 

 remains moist for a good time after rain ; vegetation is later 

 in awakening in spring, and owing to this plants escape to 

 a great extent from severe damage by late frosts. Moreover, 

 thaws are more rapid on warm aspects than on north and 

 east ones, and rapid thaws do more harm to plants than 

 slow ones. 



It is obvious that these differences in the climate of the 

 various aspects must have their effect on the growth of trees, 

 and we find in practice that, other conditions being equal, 

 some species do better on certain aspects than on others. 



The aspect most suited to a species may vary in different 

 parts of the country, because much depends on the latitude 

 and elevation. Thus a tree which does best on a north 

 aspect in the south of England will possibly prefer a south 

 aspect in the north of Scotland, and one which does well on 

 a north aspect at a low elevation may do best on a south 

 aspect at a high elevation. 



As a general rule the following aspects are best for the 

 various species, more especially in the Midlands and south of 

 England : 



