244 EXPERIMENT STATION RECORD. 



study of the commercial hickories conducted with the view of deriving infor- 

 mation relative to the best means of producing and maintaining the necessary 

 supply. 



The study is reported under the following general headings: Economic im- 

 portance of the hickories, the hickory supply, lumbering, the tree and its forms, 

 range and distribution, soil and moisture requirements, tolerance, reproduc- 

 tion, growth, length of life, susceptibility to injuries, volume and yield, the 

 wood and its mechanical properties, and the outlook for future supply. Growth, 

 volume, and yield tables, based on measurements of different stands, are given. 

 In the mechanical tests which were conducted at the Forest Service laboratory 

 at Purdue University, moisture, weight, rate of growth, heartwood and sap- 

 wood, position in the tree, age, soil and situation, geographic location, species, 

 and defects were considered as factors affecting strength, and the following 

 points were determined : Specific gravity as tested and oven dry, weight per 

 cubic foot as tested and oven dry, fiber sti-ess at elastic limit, modulus of 

 rupture, modulus of elasticity, horizontal shear at maximum load, work or 

 resilience to elastic limit, work to maximum load, and total work. The data 

 are tabulated and discussed. 



The investigation as a whole showed that hickory has a number of important 

 sijecial uses for which no satisfactory substitute is known. The commercial 

 supply is derived almost entirelj- from the true hickories, including the shag- 

 bark, big shagbark, big shellbark, pignut, and mockernut. Hickory-producing 

 woodland is owned mainly in small holdings. Although the present stumpage 

 prices are comparatively low, the expectations are that hickory will soon bring 

 more adequate returns and it should rank among the more important timber 

 trees of the managed wood lot. 



The technical value of the wood differs greatly within the same species under 

 similar silvicultural conditions and even within an individual tree. In general 

 the wood put on by a thrifty tree during the period of its gi-eatest vigor is the 

 best and the wood from the butt cuts is superior to that from the upper cuts. 

 For thrifty trees of the same age, there are no differences in value according 

 to geogi'aphic regions or local soil conditions. The best criterion of the value 

 of the wood is its weight. The heartwood, or red hickory, is equally as strong 

 and tough as the sapwood, or white hickory, and should be placed on the same 

 footing to prevent waste. Economy in the usage through closer cooperation 

 and the adoption of a just log measure to improve the economic position of 

 the tree are also recommended. 



On the saving of damag'ed beeches, Eckstein {Naturw. Ztschr. Forst u. 

 Landw., 8 {1910), No. 11, pp. 525, 526, fig. 2). — The author briefly describes the 

 method of saving young beech trees which have been injured by mice by 

 mounding up the dirt around the trees, and also notes a case in which young 

 beeches have reestablished themselves after injury by the production of sec- 

 ondary roots. The secondary root formation appears to have been aided by 

 the presence of a good covering of leaf-mold which retained sufficient moisture 

 for the roots to become established. 



On the relation between yield performance and soil properties with the 

 pine, W. ScnoENBERG (Ztffchr. Forf^t u. Jogdw., -',2 (1910), No. 11, pp. 6},9~656, 

 fig. 2). — Physical and chemical analyses of a number of forest soils in the 

 vicinity of Eberswald were made with a view of determining whether there is 

 any definite relation between the yield of pine and the soil properties. The data 

 are presented in tabular form and discussed. 



The soils which consisted of valley sands and alluvial deposits showed con- 

 siderable variation in their content of mineral foods. As a rule the soils con- 

 taining the highest content of mineral foods showed the best yield performance, 



