SYLVICULTURE. 



Abies lasiocarpa (Balsam). At edge of tree growth only a 

 shrub. In Colorado at lower, warmer situations a valuable tree. 

 Occurs in all states of the west. 



Larix lyallii (Larch of British Columbia). Occurs here and there 

 in Washington, Idaho and Montana, at very high altitudes. 



Tsuga mertensiana (Hemlock). A storm-battered Hemlock, at 

 high altitudes in Sierras, Cascades, Montana. A branchy tree up to 

 100 feet high, inaccessible and hence of no value. 



Paragraph V. General definitions and explanations. 



A. In Europe, under the term " Wood " is understood an aggre- 

 gate of trees of such uniform character that it can be subjected to 

 the same manner of treatment. In the American virgin forests, 

 "woods"' are rare. As a matter of fact the term "woods" as well 

 as the term " forests " has no definite meaning in America. A fores- 

 ter should keep in mind, however, that a plantation or a natural 

 regeneration, whatever its age and its condition, must be classed 

 under the heading " forests." 



A " group ; ' of trees consists of even-aged specimens of the same 

 species and is larger than a bunch, clump, or cluster. No recog- 

 nized definitions of the term " group " and " clump " are at hand, un- 

 fortunately, based on the space or the acreage covered by them as 

 units. Groups, as understood in the following pages, are distinct 

 aggregates of trees covering -^ to 4 acres. 



B. Pure forests, pure woods, pure groups or bunches are such 

 as contain one timber species only, 5 per cent, admixture being 

 permissible. Species able to form pure forests are termed gregari- 

 ous or ruling species, sub-divided into distinctly ruling species, which 

 are usually found in pure stands, and conditionally ruling species, 

 which are occasionally found in pure stands. 



I. After Drude, the participation of a species as a mess-mate at 

 the forest table is expressed by the following terminology: 



a. Social species, denoting the main character, the striking 

 feature (in numbers and volume) of the forest; the rank and file 

 of the forest; 



b. Gregarious species, occurring in clumps and groups, island 

 like; 



c. Copious species, interspersed with others, the degree of fre- 

 quency being interpreted by exponents, f. i., copious 3 , copious 2 , 

 copious 1 ; 



d. Sparse species, occurring isolated and in single specimens; 



e. Solitary species, very isolated and very rare. 



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