74 BiTAILED DK3CRIPTI0N OF COMPARTMENTS. 



The density of a crop, viewed as a canopied collection of trees, 

 is described by stating whether the leaf canopy is complete or not, 

 close or open, discontinuous or only with an opening here and there, 

 and this to what extent and in what manner. It may, for instance, 

 be of greatly varying density and even interspersed with complete 

 blanks. 



With respect to the species of trees, only the principal and aux- 

 iliary 1 ones need be mentioned, and, if necessary, their relative pro- 

 portions should be given, but this always in the most brief and sim- 

 ple manner possible. Nay it is often sufficient simply to state that 

 an associated species is abundant or rare. Numerical ratios usually 

 afford but inadequate information ; this is always the case for in- 

 stance wlien any species is represented by lanky, unhealthy or irregu- 

 larly distributed individuals, or when the presence of the species is 

 useful only in varying proportions according to the soil and aspect. 

 As regards secondary or accessory species, only those should be men- 

 tioned which are characteristic of any special fact observed ; the 

 birch and aspen, for instance, if confined to certain compartments 

 alone ; or again the species comprised under the collective name of 

 brushwood or the soft woods, it they are abundant only exceptional- 

 ly here and there. If there is more than one stage of growth, as in 

 a copse with standards, each should be described separately. 



(1.) The various species of trees in a forest naturally group themselves 

 into 3 well defined classes acooiding to their relative importance in the organi- 

 sation of that forest ; we will denote them severally by the specific terms 

 PrinoipaI), Auxiliakt and Complbmbntart. 



Among the species present there is one (or it may be more), which from 

 the superior value of the produce it yields and the general suitability of pre- 

 vailing conditions for its favorable growth, necessarily stands out as the central 

 pivot round which the whole Organisation Project turns. The BSgime and the 

 flotation adopted are determined entirely by the requirements of that ou« 

 species, which thus constitutes the Principal species of the forest in question. 

 As parenthetically observed higher up, there may be in the same forest several 

 principal species, the K€gime and chiefly the Rotation being judiciously mani- 

 pulated to suit them all more or less equally. 



Of the remaining species, well distributed throughout the forest or capable 

 of being generally introduced there, one or more form the natural associates of 

 the principal species, the growth of which they promote and improve, while, 

 thanks to different requirements, they usefully occupy apace both in the soil 

 and in the leaf canopy, which the former could not but leave unutilised. These 

 we have designated the Auxiliary species. 



All the other species, which are neither principal nor auxiliary, we have 

 included in one comprehensive class under the name of Complkmknt.vky species. 

 These are either too slightly distributed, or do not attain a sufiBcieiitly large size 

 in the forest in question, or yield produce of too little value, to influence in any 

 way the choice of the Regime or the Rotation to adopt. (.Translator.) 



