SYLVICULTURE 



" series of strips," all triplets, consisting of a preparatory, a seeding 

 and a final strip. 



r lhe first strips are usually made, as in the cleared strip type, 

 in well-sheltered ravines or gullies; or at the windward edge of 

 lakes, fields, young growth; or at the windward edge of storm-firm 

 trees (Oaksj, where there is a mixture of storm-firm species with 

 species endangered by storm. 



The form of the strips need not be exactly rectangular. In the 

 mountains, the strips usually run up and down the slopes not hori- 

 zontal so as to facilitate the transportation of timber and wood 

 removed from the strip. 



B. Actual application : This type is frequently seen in the coni- 

 ferous woods of the Eureopean moderately cold zone; also in Beecii 

 woods and Oas woods. 



Like the uniform type, the strip type is not exactly natural. 

 For that reason, the primeval woods do not exhibit any illustra- 

 tions of the strip type. 



C. Advantages: The advantages of the shelterwood strip type 

 are identical with those of the shelterwood compartment type ex- 

 cepting advantage III. It is especially adapted to small pieces ot 

 property, which could not yield steady returns under the uniform 

 type. Greater security from storm is characteristic for the strip 

 type. 



D. Disadvantages: 



I. Difficulty of obtaining a desired mixture of species in the 

 young growth. 



II. Trees at the extreme windward edge of a cutting series 

 obtain an extravagantly high age, whilst regeneration proceeds 

 slowly and gradually against them. 



III. Tardiness of a complete regeneration of a whole compart- 

 ment, slope or cove, where there are only a few points of first attack. 



IV. Operations are more scattering than in the shelterwood 

 compartment type. 



Paragraph L. The shelterwood group type of natural seed regenera- 

 tion. 



A. Characteristic features. 



I. Species: All species can be dealt with in a group system; 

 those endangered by windfall, however, require a modification of 

 the system, or small rotation, or a regular progress of the groups 

 toward the storm danger. 



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