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CHAPTER VIII. 



SYLVICULTURE. 



Sylviculture literally means the culture of forests. Although business man- 

 agement and the utilisation of timber occupy a great deal of the forester's time, 

 his real work is growing trees. Sylviculture is the science of growing trees in such 

 a manner that they shall most economically realise the desires of the owner of the 

 forest land. 



The owner may be a private individual or a Government, and it remains with 

 the owner to indicate to the forester the purposes which he desires the forest to 

 serve. The forester adopts these proposals as his "objects of management." 



The following list serves to show that the treatment of a forest must depend 

 largely on the "objects of management" which govern it. A forest may be man- 

 aged with the object of providing — 



(1) the largest possible annual income; or 



(2) the largest possible yield of timber each year; or 



(3) a special class of forest-produce such as turpentine; or 



(4) shelter for man and beast and beautifying the landscape; or 



(5) protection against excessive floods, droughts, and extremes of tem- 



perature. 

 As soon as the objects of management are fixed the forester must decide upon 

 the species of tree and the method of growing it which will give the best results. 

 To decide upon the species of tree to be grown a close study of the "factors of 

 the locality" is necessary. The next consideration is the "method of regeneration" 

 to be adopted, and linked with it the "sylvicultural system" under which the forest 

 is to be managed. 



The factors of the Locality which influence tress are numerous, and interact 

 to such an extent that it is impossible in many cases to discover why one species 

 of tree should flourish in a certain position, and other specimens of the same species 

 show poor development on apparently similar soil in the same neighbourhood. 



The factors in the locality may be divided into factors dependent on climate 

 and factors dependent on soil and subsoil. 



The climate of a given locality depends on its geographical position, and it 

 is no use trying to introduce trees from Canada, England, or Scandinavia into 

 Western Australia on a large scale. In order that trees may grow here with any 

 degree of success they must be either indigenous or brought from some country, 

 such as certain land bordering the Mediterranean Sea, which has a similar climate 

 to Western Australia. Within Western Australia itself the main climatic factor 

 is rainfall. It is not sufficient to refer to the average rainfall; the minimum rain- 

 fall and its distribution throughout the year are of vital importance. Certain 

 parts of England have less rainfall than many parts of this country, but it is 

 evenly distributed over the twelve months of the year, whereas in Western Aus- 

 tralia trees have to withstand nearly six months' drought each year. 



Soil and Subsoil. — In countries where rainfall is distributed more or less evenly 

 throughout the year the soil is of greater importance than the subsoil, for the roots 

 of a tree flourish and continue to flourish in the top soil layers. 



In southern Australia, however, most trees are forced to go to the subsoil for 

 the necessary moisture, especially during the summer months, and consequently 

 the subsoil is there of major importance. 



