Ill 



WHITE PINE IN MIXTURE 



White Pine is seldom found perfectly pure in 

 Pennsylvania, except on very limited areas. It 

 is a general law that in the original forest a 

 much greater variety of species occurs on the 

 best than on the poorer soils. Thus, in the Sap 

 Pine groups of the valleys there is a much 

 larger number of species in mixture with Pine 

 than in the original groups on the poorer soUs 

 of the mountains. 



The species which occurs most commonly 

 mixed with the White Pine in Pennsylvania is 

 the Hemlock {Tsuga canadensis, Carr.). It forms 

 a lower story under the Pine, the shorter height 

 classes of which it equals in length. Seen from 

 above or from a distance, such a mixed group 

 appears densely stocked with Pine, whereas, 

 upon entering the wood. Hemlock seems to pre- 

 dominate. The Pine stretches above the Hem- 

 lock, and although it hides the latter at a dis- 

 tance, it is not noticed at first from below. 

 Once the difference has been perceived, the dark 

 reddish-brown bark of the Hemlock contrasts 



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