ll: 



THE FORESTER. 



May, 



knowledge of the growth and production 

 of forests under different conditions. The 

 growth is of great importance in the silvi- 

 cultural treatment of trees. With some 

 trees the rapidity of growth is the factor 

 which enables them to maintain their posi- 

 tion in the forest. The relative rate of 

 growth must always be considered in creat- 

 ing mixed forests and is one of the impor- 

 tant characteristics which the tree planter 

 has to know. 



A knowledge of the production of for- 

 ests is used chiefly in problems of manage- 

 ment. In making a working plan such in- 

 formation is absolutely necessary. Where 

 planting is done the owner must know how 

 soon he may expect some returns and 

 whether they will be enough to cover 

 the initial outlay. Empirical and normal 

 tables of yield for even aged forests are, 

 therefore, of the greatest value. Most of 

 our forests will be managed according to 

 some system of selection. It is just as im- 

 portant in this case for the owner to have 

 a knowledge of future production as 

 when a forest is planted. The owner 

 must know how much timber can be cut 

 at present, and how much can be cut in 

 the future. This information should be 

 gathered and presented in tables of yield. 

 Our forests are very irregular, and proph- 

 ecies of future vield can at the best be 

 only approximations. Where possible 



they should always be founded on the 

 growth of trees which are grown under 

 conditions like those which will prevail 

 under the new system of management. It 

 is nearly always possible to find such con- 

 ditions, but if they cannot be found, the 

 growth of virgin trees must be used. The 

 figures will certainly be conservative, for 

 the growth is slower than under new con- 

 ditions of light after lumbering. Such 

 tables of growth should be made for dif- 

 ferent localities wherever possible and, of 

 course, for all forests under different sys- 

 tems of management. 



The forester must take the conditions 

 which he finds at hand. The fact that he 

 cannot determine the future growth with 

 mathematical accuracy is no reason why 

 he should not determine the facts as accu- 

 rately as possible. Some working basis 

 he must have and it is perfectly legitimate 

 and scientific to take the best figures which 

 can be obtained, and to use them until 

 empirical tables can be made. Let no 

 person make the mistake that a scienti- 

 fic study of the forest is unnecessary in 

 this country. Every system of manage- 

 ment which is not based on such study 

 will fail. And the successful forester 

 will be the man who appreciates that 

 the study of the science of silviculture 

 and the practice of silviculture go hand 

 in hand. 



AN EXAMPLE OF SLOW GROWTH OF LODGEPOLE PINE. 



By C. S. Crandall. 

 Division of Forestry. 



THE southern extension of the Lodge- 

 pole Pine in the Rocky Mountains 

 covers the full width of Colorado 

 and occupies large areas between altitudes 

 of 7,000 and 10,000 feet. Owing to its 

 aggressiveness in taking possession of lands 

 on which other species have been killed 

 by fire, the Lodgepole Pine is gradually 

 increasing its holdings. This ability to 

 reclothe burned areas is a valuable charac- 



teristic of the species and it may be de- 

 pended upon to perpetuate forest cover on 

 many acres that might otherwise remain 

 treeless. 



All species of the mountain region are 

 of slow growth because the conditions are 

 semi-arid, but no species shows such ex- 

 tremes in rate of growth, and such per- 

 sistence under adverse conditions as does 

 the Lodgepole Pine. Trees in moist situa- 



