Periodical Literature 157 



Forstmeister Michaelis, who with Heck 

 Moder7i (see Quarterly, Vol. Ill, p. 40) is an advo- 



Thinning cate of reform in the application of thin- 



Pradice. nings, cogently formulates the following in- 



structions for carrying out a thinning in 

 the dominant. The general rule is : always take away a stem if 

 it evidently damages or narrows in the important part of the 

 crown of one or more well formed, clear, valuable neighbors. 

 With Metzger, he classifies the trees into useful, obnoxious and 

 dispensable. The useful are (a) the more valuable stems and 

 kinds and, within the same species, the more clear and better 

 formed ; (b) the bushy, densely foliaged, subdominant stand, which 

 does not reach into the upper crown cover, cannot do any damage 

 above and serves as soilcover, and as nurse, helping to clear 

 the dominant and preventing formation of watersprouts, especi- 

 ally when of shade enduring species. Obnoxious are those which 

 limit the upper crownspace of the more valuable, especially when 

 they are themselves poor, stoutly branched, knotty, crooked, 

 shortboled, broomlike, etc. All the rest is dispensable, especially 

 the hopelessly suppressed, doomed to die. The struggle for exis- 

 tence taking place in the upper crown level, here a helping hand 

 is needed. Hence those which here interfere with the more val- 

 uable must first fall, and of the subdominant, whatever threatens 

 interference, provided the desirable length of clear boles is at- 

 tained, for then every branch is needed for the best diameter 

 development. The most suitable length of clear bole is 50 to 60% 

 of the total height, e.g., 30 to 35 feet when 60 feet in height, 45 

 to 55 feet when 90 feet in height. 



Generally speaking the obnoxious and dispensable are the ones 

 to be cut. But where equally valuable stems interfere with each 

 other assistance is required, for finally each main stem needs in 

 all directions free space for its crown development which produces 

 diameter development. Hence not to hunt up and mark all less 

 valuable members is the method, but the reverse, hunt up the 

 valuable and then determine the question which are to be removed 

 to the advantage of the most valuable. In this the conical crowns 

 in the dominant, the broad crowns in the subdominant are to be 

 favored. Even of the poor stems only so many are to be removed 

 as is necessary for the improvement of the more valuable. 



If the choice is between two equally obnoxious and equally 

 formed specimens of different diameter, consideration of future 



