APPENDIX. 



11 



Other tree to thoso in its immediate vicinity. It is fonnrl to he of the 

 same age a? well. Now uote in the tigure next given liow plainly the 

 difterence in tlirift is sliown. Curve 1 is the same one that was given 

 before. 2 is tli<> iieiglit curve of tlic tree on poorer soil. The shrinkage 

 is striking in amount, and persists througli the life of tlie tree. The 

 effect of soil conditions on the lieight growth of tlie tree is thus illus- 

 trated and proved. Diagrams like this might be used as a measure of 

 such effects. 



yea.rs o^ f\S^ 



Heiglit cui-ves, showing comparative growth of spruce and pincMind of spruce 

 under different conditions. 



1. Curve of spruce on good soil — land cleared by fire. 



2. Curve of spruce on verj^ poor soil— land cleared by fire. 



."5 and 4. Curve of spruces grown \\\i in mixed hind under shade. 

 a. Pine on same site as Xo. 1. 



Those trees, it was stated, grew up on cleared land where they had the 

 advantage of unobstructed sunlight throughout life. Tlie}- might be 

 called normal trees, showing for the climate and site what the species 

 will do. But a small proportion, however, of the trees that make up our 

 spruce lumber have grown up in any such way. Most have grown up 

 under a shade, often a dense and overpowering one, and the effect of this 

 limitation, no less plainly than of the other, is shown by the height curves. 



