30 



A PRIMKR OF FORKSTRY. 



Fn;. 17. Mimic pure sdrrtion forest, showing 

 the mixture of a,u< -. 



The silvicultural system called Pure Selection is ap- 

 plied to forests of this kind. It is used chiefly for 

 protection forests in places where it is desirable to 

 keep the coyer always unbroken: elsewhere it is out 



of place. Under this 

 system the annual in- 

 crease of the forest 

 must be found before 



the yield can be deter- 

 mined. (See ]). l.V) 

 Then the fully mature 

 trees are cut in every 

 part of the t'orol 

 every year. The cost 

 of 1 oo-u- ing is high, f o r 

 where .single trees are taken here and there, roads or 

 other means of transport must be yery numerous and 

 costly in proportion to the amount of the cut. 



l.nCAI.I/KD SKI.KCTIOX. 



Logging under the system just mentioned is so ex- 

 pensive a- to prevent its application in the Tinted 

 States, except for WOOds like cherry and black walnut, 

 which have a special and unusual value. But if. instead 

 of taking the yield from every part of a selection for- 

 est, a comparatively small area is cut over each year. 

 the cost of logging may be very greatly reduced. Such 

 a method is admirably adapted to certain forest regions 

 in the Tinted States, as. for example, to the Adiron- 

 dack Mountains of New York, where the forest is com- 

 about equally of coniferous and broadleaf tree-. 



