190 FORESTRY IN THE LANDES 



"The thinnings made every 5 years will aim to open up the forest. This favors 

 both the production of wood and resin in maritime pine. The thinnings will aim to 

 maintain the timber in a good state of growth by placing it under the best conditions 

 for increment; owing to the fact that the maritime pine is a light demanding species 

 one should not forget that in the case of this species the underwood as well as the sup- 

 pressed trees are valueless and that the upper story alone is of interest. This cul- 

 tural rule seems much surer than that given in the working-plan report. 



"In the regenerated stands the thinnings with tapping will commence at about 

 25 years of age, or as soon as the timber shall have attained a sufficient size to enable 

 it to stand a face. Except when the removal of a pine is more or less urgent tapping 

 to death or 'tapping to exhaustion' will be followed. The 'tapping to exhaustion' 

 will precede the application of tapping to death by at least the length of a period 

 (5 years) ; it can then be accomplished by one or by two faces according to the size of 

 the trees. This method of tapping will be applied to the entire stand of each periodic 

 block during the period which precedes regeneration. The tapping without killing 

 (gemmage a vie) will continue to be applied to the pine 14 inches and over at breast 

 height. Very vigorous trees measuring at least 16 inches in diameter can be intensively 

 tapped without killing and receive two faces. This method of extracting the resin 

 can be made general and will be justified chiefly during the three or four periods pre- 

 ceding regeneration. 



"The application of 'exhaustive tapping' and of intensive tapping without killing 

 (without injury to the stands) has been rendered possible by the decision of the Direc- 

 tor General, dated March 23, 1908, who has authorized the Mont-de-Marsan inspection 

 to reduce the sizes of the faces in height and in diameter." 



It should be particularly noted that so-called exhaustive tappings 

 which precede the usual thinnings by tapping to death is a new feature 

 of French practice aimed at the increase of resin production in State 

 forests. This means that there is a good deal of marking expense. 

 In 1905, in the inspection of Mont-de-Marsan, 15,180 acres had to be 

 marked; the work lasted practically continuously from February, 1915, 

 to July 8, and the marking removed on an average of almost exactly 40 

 trees per acre, or 612,455 trees. This illustrates the heavy thinnings 

 followed in State forests so necessary for maritime pine to develop 

 good crowns. The first cleaning in private forests takes place at 4 

 years, and the first tapping to death for thinning at 15 years. By 30 

 years the stand is pretty well reduced to its final number and tapping 

 of all trees alive begins. The "Landes" rule is that no permanent tree 

 should be tapped until it is at least 13 inches in diameter. All private 

 tapping is now being done 4 years to a face. 



Rotations. The State forest rotations adopted in the past have been 

 70 years with fourteen periods of 5 years each, 72 years with twelve 

 periods of 6 years each, 75 years with fifteen periods of 5 years each, 

 and 80 years with sixteen periods of 5 years each. When the length of 

 the period is six years the consecutive tapping is separated by one year 

 of rest. In a large number of forests, however, the final rotation is 

 preceded by a transitory rotation which usually differs for each working 



