202 FORESTRY IN THE LANDES 



Bert is authority for the following data: 



"Two cubic meters (about 550 board feet) of maritime pine will furnish 1 ton of 

 boards. For rough calculations the average volume of mine props is ... 20 mine 

 props to the ton. A cubic meter of fuel wood weighs 0.7 ton, expanding to 1J steres. 

 The weight of a stere (0.227 cord) is 0.467 of a ton. A barrel of resin (Gironde) of 

 235 quarts weighs 0.2415 of a ton with a density of 1.05. A barrel of resin (Landes) 

 of 340 quarts weighs 0.357 of a ton." 



A 235-quart barrel produces 110 pounds of turpentine and 352 pounds of dry 

 material, chiefly resin. 



Yield of Maritime Pine. In 1892 there were 105,763 acres of conifer 

 State high forests in the Landes, and in addition, 22,625 acres, or between 

 one-fourth and one-fifth as much as the productive area, had to be given 

 up to protection. The production amounted to 30,072 cubic meters of 

 timber (about 8,360,000 feet board measure or 80 feet per acre) and 4,161,- 

 960 pounds of resin. 



The yield of maritime pine stands 31 in the Mont-de-Marsan Inspection 

 for the year 1905 showed a total of 47.6 cubic meters per acre (on an area 

 of 22.2 acres) for pine 40 to 50 years old. According to Lapasse: 



"The resinous products represent approximately one-fifteenth the total weight 

 or 7 per cent of the yield in weight of a maritime pine felling; the proportion of the 

 product realized then, in weight, is wood product fourteen-fifteenths or 93 per cent, 

 resinous products one-fifteenth or 7 per cent. The production of resin is variable; 

 it depends on the density of the stand, on the underwood, on the state of growth, the 

 size of the trees, the age of the face, the distance from the ocean, and on the skill of 

 the workman. The yield attains its maximum in open stands completely cleared of 

 undergrowth, situated near the sea and during the second or third year of tapping. 

 A humid and hot atmosphere favors the secretion of gum. The yield in resin is, on an 

 average for 1,000 trees tapped alive, 640 quarts . . . per year, and in 5 years, the dura- 

 tion of the tapping alive, 10,200 quarts. One might say that . . . 166 pines can yield 

 annually a barrel of resin, but in order to collect 100 quarts it is necessary to have 50 

 pines tapped alive, each tree producing an average of two quarts. In the thinnings 

 1,000 trees tapped to death may yield (according to the size of the trees) from four to 

 six barrels of 340 quarts each or an average of five barrels or 1,700 quarts per year 

 and in the 4 years' duration of the tapping to death, 6,800 quarts. In this case, 200 

 pines . . . produce annually a barrel or 59 pines tapped to death are necessary to 

 obtain 100 quarts of resin. In the regeneration fellings with pine 65 to 70 years old 

 with four faces each, each face can produce lj quarts or 6 quarts per tree per year. 

 One thousand pines tapped to death should produce 6,000 quarts or about 18 barrels 

 per year, and 24,000 quarts in 4 years. An acre stocked on an average with 80 trees 

 will yield about 480 quarts of resin per year and 1,920 in 4 years. To collect 100 quarts 

 of resin it is necessary to have seventeen pines tapped to death per year." 



These figures are below rather than above the average. In the thin- 

 nings marked during 1900 to 1905 on a total area of 57,847 acres in the 



31 Rendement des Forets Domaniales de pin maritime dans les dunes landaises, Revue 

 des Eaux et Forets, June 1906. To simplify the calculations the author has taken a 

 liter as equal to 1 liquid quart, whereas a liter is really 1.05671 quarts (liquid). 



