24 FIELD WORK [CH. 



afforded by the growth of the crops, especially in the matter of 

 height-growth, it will then be possible to determine a site quality 

 for each component part of the area. 



22. General description of crop. 



It will now be possible to proceed to a general description of 

 the forest crop. The distribution and area of the different types 

 of growth, and their suitability to the local conditions of soil 

 and climate. The composition of the crops, the principal species 

 and their relative proportions; their size and rate of growth, 

 reproduction, and general conditions of vegetation. Then the 

 Constitution of the forest crop, that is, the relative proportions 

 of the various size or age-classes. Any deficiency or irregularity 

 in the succession of these classes should be noted, and, if possible, 

 explained. The origin and past history of the forest crop should 

 be stated, as well as the general density of stocking. Blanks and 

 areas out of production should be noted, and lastly the effects 

 of climatic influences such as altitude, wind, drought, frost, and 

 the danger of injuries from insects and other pests, fire, etc. 

 should be described. 



At this stage it may be possible to note at once some obvious 

 improvements that might be made in the selection of species, 

 or in the choice of silvicultural method, in order to carry out 

 the declared objects of management under the local conditions 

 of soil and climate that have just been investigated. 



23. The block. 



The next subject to which attention has to be paid is the 

 division of the forest into subdivisions. These may be either 

 purely topographical, and therefore more or less natural and 

 permanent, or they may be artificial, and dependant on the 

 organisation of the area with a view to its working under a 

 definite plan. Some existing subdivisions of the area will have 

 been already made use of for the purpose of describing the soil, 

 climate and crops, as indicated in the foregoing paragraphs. The 

 topographical and permanent subdivisions of a forest are the 

 block and the compartment. The block is a large natural sub- 

 division of a forest, formed either of a detached and self-contained 



