THE EXTENSION OF THE P RES SIT LIMITSOF 



THE Y/ESTERN YELLOW PUTS OUT ON THE DESERT .- 



The question of the extension of 

 the natural forest out into the open plains has 

 been before the forester for many years, and to- 

 day nearly every man who has given the subject 

 some study is quite certain in his own mind that 

 he knows the fundamental reasons for the lack of 

 natural forest on the plains. 



Experimental woik in the planting on 

 treeless areas has already proven that the pres- 

 ent plant formation or vegetation on the ground 

 does not mark the true boundary between the dif- 

 ferent plant zones, and that a complete analysis 

 of the habitat, or in other words - all the for- 

 ces and factors that have any bearing on plant 

 life must be summed up for each area before its 

 true formation or type can be determined. It 

 will, therefore, be seen that a thorough, knov;- 

 ledge of the history and conditions of each re- 

 gion, the silvical characterization of the species 

 dealt with and the peculiarities of each area are 

 essential before one can state whether a certain 

 area has any commercial or potential forest value. 



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