SYLVICULTURE 



difficult to differentiate them. Definitions might be based either 

 on the age of the wood crop tended, or on the purpose aimed at, 

 or on the financial side of the tending. 



' Cleaning and weeding are applied for the benefit of very yoimg 

 growth and usually require an investment. 



Pruning, thinning and improvement cutting are applied for the 

 uenefit of polewoods or thickets. 



Improvement cuttings and thinnings usually furnish a surplus 

 revenue whilst pruning succeeds only in rare cases to be directly 

 remunerative. 



Paragraph LIX. Cleaning in high forest. 



Cleaning may occur during the seedling stage and the small 

 sapling stage. It implies the removal of saplings forming a 

 shrubby advance growth (wolves) ; or the removal of undesirable 

 stoolshoots; or the removal of seedlings and saplings belonging to 

 a less-desirable species competing for space in a young forest. In 

 natural seed regenerations, cleaning is particularly desirable. In- 

 stances: Removing poor coppice shoots which oppress by faster 

 growth the valuable seedlings of Yellow Poplar. Removing Birch, 

 Fire Cherry, Thorns and Briars in young plantations of 'White Pine, 

 'Velio w Pine and Spruce. Where a regeneration area of strong soil 

 has been burned previous to planting, the competition of volunteer 

 growth is frequently such as to make cleaning necessary. The for- 

 ester should take care, however, not to extirpate species now of 

 little value, but possibly of a fair future value. 



In mixed regeneration, cleaning offers a good means to regulate 

 the proportion of species admixed. The expense incurred for cleaning 

 must be commensurate to the financial effect of the operation. In- 

 struments used are axe and brush hook; also long-handled clean- 

 ing shears. 



Paragraph LX. Weeding in high forest. 



A plant, either herbaceous or ligneous, which has a negative 

 value is a " weed." ' It might be a cripple of an otherwise very 

 valuable species (fire crippled Chestnut in Pisgah Forest), or it might 

 belong to a species having no commercial value (Rhododendron, 

 Witch-hazel, Black Gum, Halesia, Chinqtfiipin). 



Weeding implies the removal of large saplings, poles and trees 

 having the character of weeds. Weeding may take place before 

 regeneration, or after regeneration has been started. It may act 

 incidentally as a preparatory cutting, a seeding cutting or a final 



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