16 TEEMS rSED TX FORESTRY AXD LOGGTXG. 



National forest. A forest which is the property of the United States. 

 Syn. : federal forest. 



Forest belonging to the National Government is in G., Staatswald; F., foret 

 domaniale, and in the British dependencies, Crown forest. 



National forest reserye. A tract of land set apart from the public domain by proc- 

 lamation of the President under section 24 of the act of March 3, 1891, or created 

 by special act of Congress, and administered under laws of the United States passed 

 for that purpose, in order "to improve and protect the forest within the reserva- 

 tion, or for the purpose of securing favorable conditions of waterflows and to furnish 

 a continuous supply of timber for the use and necessities of citizens of the 

 United States." 



Syn. : Federal forest reserve. 



National park. A tract of Government land withdrawn by special act of Congress 

 from settlement, occupancy, or sale, under the laws of the United States, for the 

 benefit and enjoyment of the people. 



Natural pruning". See Pruning. 



Natural reproduction. See Reproduction. 



Normal, a. See Index. 



Normal forest. See Index forest. 



Normal form factor. See Form factor. 



Nurse, n. A tree which fosters the growth of another in youth. 

 G., Schutzholz. F., essence d'abri. 



Nursery ^roivn. Grown in a forest nursery. 



Old-field g'roTrtli. See Volunteer growth. 



Old growth. See First growth. 



Open, a. See Crown density. 



Overmature forest. Forest in which, as the result of age, growth has almost 

 entirely ceased, and decay and deterioration have l)egun. 



Overtopped, a. Having the crown shaded from above, although a side or sides 

 may be free to light. See Crown class. 



Oyerwood, n. See Two-storied forest. 



Park forest. See Crown density. 



Partial section analysis. See Tree analysis. 



Partial stump analysis. See Tree analysis. 



Patch method. The clean cutting of small patches to invite reproduction by self- 

 sown seed from the surrounding forest. See Forest management. 

 G., Kesselhieb, Ldcherhieb. F., coupes par trouees. 



Patch sowing. Sowing forest seed in spots. See Seed spot. 

 G., Pliitzesaat, Plattensaat. F., semis par places. 



Periodic annual increment. The total increment for the period, divided by the 

 number of years in the period. See Periodic increment. 



Periodic increment. The volume of wood produced by the growth of a tree or 

 stand in a specified number of years. 



Periodic working. See Working. 



Permanent sample area. See Experiment area. 



Permanent sample plot. See Experiment area. 



Physical rotation. See Rotation. 



Pit planting. See Trench planting. 



