TERMS IN FORESTRY. 19 



Root collar. That place at the base of a tree where the swelUng which is the 

 direct result of the ramifications of the roots begins. 

 G., Wurzelhals. F., collet. 

 Root sucker. See Sprout. 



Rotation, n. The period represented by the age of a forest, or a part of a forest, at 

 the time when it is cut, or intended to be cut. 

 G., Umtrieb, Umtriebszeit. F., revolution. 

 The following classes of rotation are distinguished: 



Financial rotation, under which a forest yields the highest net interest on its 

 capital value, calculating at compound interest. 



Income rotation, under which a forest yields the highest net return, calculating 

 without interest. 

 Syn. : rotation of the highest income. 



Silvical rotation, the rotation most favorable to the natural reproduction of the 

 forest under a given method. 



Syn. : physical rotation, silvicultural rotation. 



Technical rotation, under which a forest yields the material most suitable for a 

 certain purpose. 



Volume rotation, under which a forest yields the greatest quantity of material. 

 Syn. : rotation of the greatest volume. 

 Rotation of the greatest volume. See Rotation. 

 Rotation 'Of the hig-hest income. See Rotation. 



Row planting. A method of planting in which the young trees are placed in rows, 

 the distance between the rows being greater than the distance between the young 

 trees in the rows. In planting seeds or seedlings in the forest nursery this method 

 is known as drill planting. 



G., Reihenpfianzung. F., plantation en lignes. 

 Sample area. See Valuation area; Experiment area. 

 Sample plot. See Valuation area; Experiment area. 



Sample tree. A tree which in diameter, height, and volume is representative of a 

 tree class. 



G., Probestamm. F., tige d'experience. 



A class sample tree is a tree which in diameter, height, and volume represents 

 the average of several tree classes. 

 Syn. : arithmetical mean sample tree. 

 Sapling, n. A tree 3 feet or over in height, and less than 4 inches in diameter 

 breasthigh. See Tree class. 



A small sapling is a sapling from 3 to 10 feet in height. 

 A large sapling is a sapling 10 feet or over in height. 

 Scald, n. See Sun scald. 



Scale rule. See Log rule. • ' 



Scattered seed method. That method of conservative lumbering in which repro- 

 duction is provided for by leaving, after a single cutting, scattered seed trees of the 

 kind desired. See Forest management. 

 Scratcher, n. An instrument used for marking trees. It usually consists of a hook- 

 like gouge fastened to a flat, elliptical iron hoop, with wooden handle plates on 

 the opposite side from the gouge. 



Syn.: bark blazer, bark gouge, cruiser's bark blazer, tree scribe. G., Risser. 

 F., griffe. 

 Screen, n. See Shade frame. 



