PRACTICAL FORESTRY EXPLAINED 



53* 



PBACTICAL FORESTRY EXPLAINED 



Bv Gen. C. C. ANDREWS 



FORMERLY FORESTRY COMMISSIONER OF MINNESOTA 



Tr 1 OBESTRY is the science of deriving a sure and fairly good rev- 

 -*- enue from the production of valuable timber trees on such hilly, 

 rocky or sandy laud as is unfit for field crops. The pine takes from the 

 soil only a twelfth part of the mineral matter that is required for field 

 crops. Air and light are its principal food. 



The average net income from the German state forests is about 

 three per cent, per annum. The average value of the land containing 

 the forest is about $150 per acre. Much of the land is mountainous. 



A normal forest is one from which enough trees can be cut annually 

 for revenue, without impairing the capital. The forest crop has this 

 advantage over field crops that it is not absolutely necessary to cut it 

 at any particular time, but that the cutting can be at a time that will 

 best suit the market. If we had a natural or virgin forest of consider- 

 able extent, we should find in it trees of various sizes and ages. (In 

 the Minnesota National Forest, December, 1906, a white pine was cut 

 that was 425 years old, six feet in diameter breast high, and which 

 yielded 6,200 board feet.) If our natural forests were handy to a per- 

 manent railroad or the logs could be floated from it by water to a saw- 



What Forestry Science does. A German forest of spruce planted and managed 

 according to forestry science ; trees about eighty and one hundred years old. 



