108 NATURAL REGENERATION 



In coppice cleanings protect the seedlings. They must be started 

 4 or 5 years after cutting the coppice and continue for 15 or 20 years. 

 They act as a thinning in increasing growth and in removing the briars 

 and weeds, weed trees, and poor stems of more valuable species. The 

 increased growth due to a cleaning may be 40 to 50 per cent or more. 

 Where the coppice is grown under standards the cleaning is all the 

 more essential, because the best standards are of seedhng origin, a class 

 of tree especially protected by the cleaning. To give the best results 

 cleanings, according to Schaeffer, must be made every 3 or 4 years. 

 The growth of the standards is increased. Jolyet is satisfied with clean- 

 ings at 5, 10, or 15 years. 



Thinnings. — Thinnings have three main objects: (1) To eliminate 

 the least desirable specimens; (2) to increase the rate of height and 

 diameter growth of the final stand by artificially removing a portion of 

 it in order that the competition for existence need not weaken the best 

 trees; (3) to improve the quaHty of the trees of the final stand. (See 

 Fig. 9, a and b). It is erroneous to beUeve that a very dense stand 

 means rapidity of height growth. To secure proper development trees 

 must have sufficient growing space so that their crowns can increase in 

 vigor. 



While thinnings do not always result in a greater final yield the 

 quantity of large, good-quahty timber is certainly increased and the 

 intermediate plus the final yield of a thinned stand is always more 

 than the final yield of an unthinned stand. Thinnings decrease insect 

 and fungus loss as well as windfall and snow breakage. There is a 

 general f eehng among foresters that the French beUeve in making heavier 

 thinnings than do the Germans. The old axiom of thinning early and 

 often is actually practiced in the forest in France and is advocated in 

 the text-books. The French believe in thinning the top story in order to 

 decrease the struggle for existence among the dominant species.^^ On the other 

 hand, as in other divisions of French silviculture, the French methods are 

 simple and direct. They have not classified the thinnings, as have the 

 Germans, into a large number of grades. 



In coppice with long rotations the French believe in moderate thin- 

 nings [111].25 Most thinnings start in France when the stand is 20 

 years old and continue every 6 to 20 years. They are marked by the 

 guards and rangers under the personal direction of the inspector, assist- 

 ant inspector, or forest assistant [134]. With a species hke maritime 



" The bracketed page references are to Jolyet. 



" This naturally is not an ironclad rule. In the forests of Mouthe and Puvelle (Jura 

 fir) up to 50 to 60 years the thinnings were largely in the understory; only after the stand 

 had closed were the thinnings in the top story. This is logical. After 60 to 70 years the 

 t hi nn in gs in fir may remove up to one-fifth the stand. 



