848 JJOURNAL OF FORESTRY 



Stand close enough. The total increment per acre was not as large 

 in either case as would have been secured through more judicious 

 spacing. Trees 20 inches or less in circumference show a mean annual 

 increment of 1.5 per cent as compared to 2.44 pe rcent for those over 

 20 inches in circumference. The smaller trees owe their slow growth 

 partly to being suppressed and partly to being old stock and conse- 

 quently slow growers. These figures favor the compartment system 

 in beech woods, for under that system all the suppressed and slow- 

 growing trees are removed and the best-growing trees are encouraged ; 

 the removal of the small trees automatically raises the percentage of 

 growth of the larger trees. C. R. T. 



Wood, Leslie S. The Mapledurham Statistics. Quart. Jour. For., 14 :49-59. 

 1920. 



By making use of the fact that the form factor 

 Form Factor varies according to the form-point, which is a 

 and Form Class relation between form of crown and form of 

 stem, certain characteristic relations of crown, 

 form, diameter and height are expressed and the variations of these 

 according to the site and density of the stands. The form classes are 

 expressed as 0.55, 0.60, 0.65, 0.70 and 0.75, the last being the best 

 form. A tree of 40 cm. diameter breast high in the 0.55 class has a 

 crown diameter of 5.5 m., and a tree of the same diameter of stem 

 but in the 0.70 form class has a crown diameter of only 4.3 m. Trees 

 of the first kind need an area of 30.25 sq. m., while those of the latter 

 require only 18.49 sq. m. In the first class there would be 33 trees per 

 dekar (0.1 hectar) and those of the 0.70 class would stand 54 per 

 dekar. From this study it is concluded, among other things, that 

 it is very poor policy to cut in such a manner as to open the stand 

 sufficiently to lower the form class. J. A. Larsen. 



Haslund, Ole. Granens Stammeform. Tidsskr. Skogbruk, 28 :44-53. Fig. 4. 

 1920. 



Due to heavy cutting in the State forests, and 

 Management especially in young stands, during the war, cer- 

 Changes in tain changes in management are necessary. Most 



Prussian Forests important is to shorten the rotation period. An 

 average rotation of 100 years is set for pine and, 

 in general, also for spruce. Since it will be necessary to produce high- 

 grade large timber, common timber, and mine timber and pulpwood, 



