SYLVICULTURE 



II. Beginning: In the shelterwood system, the nuclei for groups 

 are formed at a time, at which the soil begins to be, here and there, 

 a ready recipient for seed. In the nucleus, two or three trees are 

 cut, to begin with, and a few seedlings soon enter an appearance. 



III. Continuation : The young growth gradually spreads out, 

 more or less peripherically, from the nucleus, appearing at the feet 

 of the nearest trees. These trees, in turn, are gradually removed, 

 whilst the groups of seedlings continue to enlarge. Finally one 

 group will How into the other, and the regeneration will present 

 a waving leaf canopy. The irregularity of the canopy depends on 

 the rapidity with which the groups could be enlarged. 



IV. Means of transportation: The type obviously requires a 

 finely meshed, permanent network of transportation. The axe re- 

 turns to the group under formation periodically, say every three to 

 ten years, during a period of regeneration comprising from fifteen to 

 fifty years. 



V. Soil protection : The soil is continuously protected from in- 

 tensive insolation, and is hence kept in continuous productiveness 

 and water-storing capacity. 



VI. Dangers: Protection from fire is very difficult; protection 

 from storm difficult, although easier than in the shelterwood com- 

 partment type. Insects, fungi, and snowbreak are not to be dreaded 

 much more than under the selection system. 



VII. Lumbering: Mother trees are always felled in a manner 

 forcing them away from the group. Hypermature trees close to 

 the group are extracted at the same time. Lumbering operations 

 are necessarily scattered. Hence the logging expenses and the cost 

 of supervision range very high. The removal (snaking) of the trees 

 cut takes place through the benches of trees left between the groups 

 so that the soil is stirred up continuously within the benches. 



The groups should be started, if possible, at the upper end of a 

 slope so that the logs need not be snaked through young growth. 



VIII. Artificial help: To start regeneration of a nucleus, and 

 to accelerate the enlargement of a group, mosses, weeds and litter 

 on the ground may be removed previous to a seed year (bastardiz- 

 ing with advance growth group type). 



The so-called " hair-dressing " of groups, by which misshapen 

 and branchy growth is cut back, and the wave-form of groups is 

 maintained, may be seen in the Black Forest. 



B. Actual application: The shelterwood group type appears to 

 be a type of regeneration sometimes adopted by primeval nature 

 in Beech, Maple, Fir and Pine woods. 



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