82 FOEEST CULTURE AND 



an age of fifty years, and yet is not prevented by this 

 crowded growth to be then one hundred feet high ; 

 the stems are then very straight, eighteen inches in 

 diameter at the base. If Pines and Oaks are promis- 

 cuously planted, then the former, which act as nurse- 

 trees, are moved in ten or twenty years, and the 

 ground is left to the Oak, or any other deciduous 

 tree, at distances at first ten or twelve feet apart, and 

 subsequently wider still. No decayed wood is left 

 in planted forests, as it would harbor boring insects. 

 Pines are considered not to increase much in value 

 after eighty years, when most of them have attain- 

 ed full maturity, and grow only afterward slowly. 

 Sometimes as many as one thousand two hundred 

 Pine-trees are set out on an acre, with a view of early 

 utilization of a portion of the young trees. The rate 

 of growth may be much accelerated in most trees 

 by irrigation ; hence mountain streamlets should be 

 diverted into horizontal ditches where forests are 

 occupying hill-sides. The best-cultivated forests of 

 Germany are worth from three to five times as much 

 as native woods. 



For shelter plantations, intended to yield ultimate- 

 ly also timber and fuel to farming populations, it is 

 recommendable to adopt the American method, ac- 

 cording to which belts of trees are regularly planted 

 at about quarter-mile distance ; the belts, according 

 to circumstances, to be from four to ten rods wide, 

 and to be formed in such direction as to front the pre- 

 vailing winds. These timber-belts are usually fenc- 

 ed. Such shelter - trees are likely to rise to thirty 

 feet in ten years, and have proved so advantageous 

 8S to double the farm crop, while judicious manage. 



