42 



of bheold tiv.-s, \\hcn they have become fit for economic purposes. By 

 ^ m.Mli lira tii ms have been introduced which lead to a number of distinct 

 methods : 



( 1 ' Tin xi'li'i'f'ioit si/strni. 



(2) 7'ln- ,'//"/' system. 



(:>) 77/. compartment system. 



(4) Y7/< *////> xi/ntem. 



In eacli of these there are certain general conditions of success which hold 

 good for all. 



Tinier the selection system, regeneration goes on in all parts of the forest by 

 the removal of the oldest, largest, diseased or defective trees, wherever they are 

 found. No part of the forest is ever at rest ; advantage is taken of all seed years 

 for the restocking of small holes cut into the cover here and there by the removal 

 of one or a fe\\ r trees. Of the large quantities of seed which fall annually or 

 periodically to the ground, only a small portion finds conditions favorable for 

 the development of young trees ; the latter are found chiefly in those parts 

 where old trees are standing, or where the cover has been interrupted. Here 

 little groups of seedlings spring up, which must be assisted by cuttings either 

 final or intermediate, to afford them the necessary light. 



CHOICE BETWEEN DIRECT SOWING AND PLANTING. 



Formerly the artificial formation of woods was chiefly effected by direct 

 sowing, planting being restricted to special cases where the other method was 

 not likely to succeed. The reasons for this were that sowing was considered to 

 be more certain, cheaper, and that it was generally the custom to use too large 

 transplants. In the course of time the raising of plants was elaborated, smaller 

 plants were used, and the expense considerably reduced, so that now far more 

 planting than direct sowing is done. 



Yet it is not always a foregone conclusion that planting is better or more 

 suitable than direct sowing, since many different conditions and factors affect the 

 ultimate results. The effect of some of these factors is as yet somewhat obscure, 

 but in many respects experience has taught the forester which of the two- 

 methods is preferable under a given set of conditions. 



Sowing and planting are costly. The outlay on the latter can, however, be 

 considerably reduced by planting small plants according to a simple and cheap 

 method. 



Where artificial regeneration follows clear cutting, the young plants are 

 exposed to damage by frosts, drought, insects and weeds in a far higher degree than 

 if the regeneration is conducted under a shelter- wood. In fact, tender species 

 must be raised in the latter way, so that for them clear-cutting is excluded. 

 Insects frequently become formidable to coniferous woods raised in clear-cuttings, 

 while experience has shown them to be less dangerous to natural seedlings, es- 

 pecially when these are raised under a shelter-wood. 



In the case of clear-cuttings, the laying bare of the ground for a series of 

 years may seriously affect the fertility of the soil, so much so that the method is 

 hardly admissible on inferior soils. 



Natural regeneration involves less expenditure than sowing or planting. 

 In some cases the outlay may be absolutely nil, but in most cases some artificial 

 help has to be given either by working (wounding) the soil, or by sowing and 



