76 PLANTING 



transpiration being often retarded, a lesser degree of moisture 

 will usually be admissible. Or perhaps a southern aspect 

 will be advisable where otherwise a northern aspect would 

 be indicated. 



2. The Demands of Trees as to Shelter and Protection 

 from Gales and Frosts. 



The necessity for considering the liability of trees being 

 damaged or thrown by storms is far greater when planting 

 maiden land than when planting well-managed forest land. 

 In the former case, there is probably no shelter from other 

 crops of trees ; whereas in the latter case, if fellings have been 

 made in a direction opposite to that of the prevailing winds, 

 the older compartments will protect the younger crops. 

 Though on exposed steep hills this protection will be reduced 

 to a minimum. 



The trees which are most likely to be thrown by the wind 

 are Norway Spruce and English Elm. Sitka Spruce, how- 

 ever, is a storm-proof tree, and has a much deeper root 

 system than Norway Spruce. 



Douglas Firs are rather liable to have their tops blown 

 off, but if planted over large areas this danger greatly dis- 

 appears. 



Scots Pine is very liable to be broken by any weight of 

 snow on its branches, as they are brittle. But it must none 

 the less be considered as a very storm-proof tree. 



Although most trees, except Norway Spruce and English 

 Elm, are firmly anchored to the soil by their roots, yet many 

 of these must, for other reasons, be avoided in exposed 

 places. 



The trees best suited to withstand ordinary gales are : 

 Austrian Pine, Corsican Pine, Scots Pine, Sycamore, and 

 Norway Maple. 



Now, when planting up maiden land, it will often be 

 necessary to plant shelter belts of these storm-proof trees. 

 For such a purpose the Austrian Pine and Sycamore are 

 perhaps the most suitable. These belts should be about 30 



