SYLVICULTURE 



Paragraph LXV. Key to the Forms of High Forest. 



That general condition of a forest is termed its " sylvicultural 

 form " which is brought about by its type or types of past regenera- 

 tion, hence by its display of age classes and by the arrangement of 

 the species exhibited. 



The treatment alloted to the "form" by the forester, provided 

 that it is a systematic treatment, is termed its "sylvicultural 

 system.'' 



The multitude of forms found inprimeval nature is innumerable, 

 since the "molds" from which the forms are cast, vary indefinitely 

 with every wrinkle of the topography and every variation of the 

 climate. 



Man's interference has tended — at least temporarily — to further 

 increase the multitude of forms. 



It is a hard task to differentiate amongst this huge collection of 

 forms and to arrange the collection into ''orders," "families," 

 "genera" and "species" composing it. 



A priori, two great groups of forms might be singled out, 

 namely "primeval forms" the product of unbiased nature and 

 "scoond growth forms," the product of nature influenced by man's 

 interference. This human interference might have been of a char- 

 acter utterly disregarding sylvicultural ends ("culled forms") ; or 

 human art might have tried, successfully or unsuccessfully, to lend 

 a helping hand ( "cultured forms" ) . 



The manner in which the various age classes of the forest are 

 mixed within the "orders of forms" is of paramount interest. From 

 this manner of mixing depend : 



I. The manner and the possibility of remunerative lumbering. 



II. The type method and the expense of regeneflation and 

 pedagogy. 



III. The dangers from insects, fungi, fire, storm, etc., threatening 

 the forest. 



The functions of the mixture are so all-important in forestry, 

 that the synthesis of the age-classes must serve as a main criterion 

 in the construction of a key to the sylvicultural forms. 



It must not be forgotten, however, that age differences of, say, 

 20 years are very conspicuous during the seedling, sapling and pole 

 stage of the forest; whilst the keenest eye cannot detect these same 

 differences in an old tree forest. 



In mixed forests exhibiting a large variety of species the analysis 

 of the form presents particular difficulties. Such is the case by far 



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