1 1 8 F< ) R K ST R KG \ 1 1.. . \ T I O X 



2. A good practice of thinning can reduce Rotation by many 

 years. 



3. Planting of strong plants, 4-5 years old and proper spacing 

 can in many places save ten years on Rotation. 



In our wild woods and where a beginning is made by the selec- 

 tion method, the natural Rotation is apt to be misleading. In certain 

 Lodge Pole forests a technical Rotation is indicated by the time it 

 takes to grow a railway tie; say 150 years. If this forest is to be 

 regulated, as to yearly cut, by Hundeshagen (or Von Mantel's modi- 

 fication of this) it becomes necessary to set a definite Rotation. In 

 deciding this Rotation, the temptation is to use the age of "mature 

 stuff" and employ natural Rotation as criterion, largely on assump- 

 tion that a shorter Rotation would furnish a much smaller volume. 

 If the cut is 12 M. ft. per acre and mature stuff largely 200-250 

 years old, the assumption usually is that it takes about 200 years 

 to produce this volume of 12 M. ft. This is an error, and it will be 

 found, in most cases, that volume (not only in tie. timber) is fully as 

 great, -say, at 150 years, as at any time later, and that, therefore, this 

 Rotation of 150 years not only furnishes the proper size, but fully 

 as large a volume.* 



* That a stand of timber does not add volume indefinitely, or even to 

 great age is self evident and is well shown by European Tables. And no 

 amount of care in thinning, etc., is able to change materially this fundamental 

 fact. In wild woods pure even age stands reach the point of maximum 

 volume, apparently much earlier than in forests receiving proper care. 



In Oak, site I (as per Schwappach) yield of stuff 3" and better of the 

 "main stand" is, at 140 years about 7000 cubic feet, and at the age of 2CO 

 years only 8500, making only 1500 in 60 years in spite of all care! In Scotch 

 Pine yield per acre does not materially increase after 120 years, even on 

 good sites and with best of care. Schwappach's tables give for the "main 

 stand" at 100 years a'bout 6000 cubic feet and for 120, 6300, and only 6400 

 at 140. These figures are for fully stocked stands and must, in this respect, 

 be regarded the exception, for it is here where Silviculture finds its hardest 

 problem, to keep the stand intact. A century of storm, hail, ice, insect and 

 disease affects the forester's efforts, and German forestry today has not yet 

 succeeded to hold its stands better than about 85-9x3% stocked, even up to 

 IOQ years, and longer Rotation's would certainly reduce these percents rapidly. 

 In wild woods dense stands of the sapling and pole age introduce great and 

 lasting struggles, ordinary and normal competition helps to injure the forest, 

 and there is no agency to correct this mischief. Results are evident, the fully 

 stocked "forty" in wild woods is rare, particularly in pure stands of in- 

 tolerants. 



