82 NATURAL REGENERATION 



seed fellings conservatively but, after the seedlings are once established, 

 to cut the mature stand very rapidly [193]. As with the fir, the shelter- 

 wood system has not been wholly successful. 



Shelterwood for Fir and Spruce in Mixture. Fir and spruce are very 

 often found in mixture. From the economic viewpoint they have about 

 the same value. It is silviculturally advisable to have them in mixture 

 since, when mixed, insect and fungous damage is not so dangerous and the 

 soil is better conserved. When in mixture advance growth of fir is quite 

 common under the old stand. It is therefore necessary to fell old trees 

 here and there in order to enable the spruce to profit by the light and 

 establish itself in the center of the openings. While the advance growth 

 of the fir has the advantage of age the spruce seedlings develop more 

 rapidly and make an excellent mixture. The more you want to favor the 

 spruce the larger the openings should be made. It is also advisable to 

 favor it by wounding the soil. The mixture can be regulated in the clean- 

 ings and thinnings that follow [202]. 



The Selection System in Broadleaf Stands (Beech). In practice 

 the [137] treatment by selection fellings is not systematically applied 

 in France to broadleaves. The beech is an exception. Because of the 

 irregularity of beech regeneration, even if treated by the method of pro- 

 gressive fellings, it may often assume the character of a selection forest. 

 The beech may be treated under the selection system except in those 

 forests where it is mixed with fir. In theory, at least, the selection system 

 is very simple. .In the working plan the exploitable or maximum size of 

 trees is given and the amount, either in number of trees or in cubic 

 meters, that should be cut each year. The entire forest is cut over, and 

 trees above the stated diameter limit are removed to the amount of the 

 estimated yield. In practice the forest is often divided into a number of 

 compartments and, for the sake of economy in lumbering, the selection 

 fellings are concentrated on a portion of the forest. Selection fellings 

 avoid the crisis of regeneration which other more regular methods pre- 

 cipitate at the time of the seed fellings. Moreover, the classic selection 

 felling is only suitable to shade-enduring species. Selection fellings 

 mean irregularity as opposed to the regularity of clear cutting, shelter- 

 wood (progressive fellings), etc., [213]. Practically speaking the classic 

 selection fellings of a few trees from the entire area under treatment is 

 never applied in France except possibly in the sub-alpine forests where, 

 in order to assist the forest in its struggle for existence against unfavor- 

 able climate and soil conditions, a light selection (or improvement) fell- 

 ing is usually employed. Clear cutting, even by strips or by the shelter- 

 wood method, is extremely dangerous in the mountains, but in the sub- 

 alpine forests, where the larch is one of the most important species, the 

 simple selection felling becomes a group selection, since the larch (see 



