IMPORTANT FOREST SPECIES 389 



hand, has a very high calorific power; as compared with beech wood, the ratio is 108 

 to 100 and it bums slowly, with a short flame to be sure, but producing live embers 

 that last till entirely burnt out. 



Oak charcoal is valued as compared with beech as 91 is to 100. 



By-Products. — The bark yields tannin of good quality, inferior, however, to that 

 of the other species of the same genus. Yoxmg pole stands (coppice) between 20 to 30 

 years of age yield the best tannin. 



Silvicultural Characteristics. — (See sessile oak.) 



SESSILE OAK 

 (Quercus sessUiflora) 



Climate and Soil. — The sessile oak, as well as the pedunculate oak, is dependent 

 upon the texture, depth, and fertility of the soil rather than on its mineral composition. 

 It prefers loose clay. For some time foresters considered that the sessile oak could be 

 substituted for the pedunculate oak, or vice versa. Now, they realize that the pedun- 

 culate oak requires a moister, or, at least, fresher soil; sandy loam, even inundated at 

 certain seasons of the year, is considered very favorable since it is a species of the plains 

 or valleys. On the other hand, low wet clays are less favorable to the sessile oak. 



It is distributed almo.st all over France, except in the high mountains and in the hotter 

 regions bordering the Mediterranean. The pedunculate oak is very abundant in the 

 southwest where it forms almost pure stands in the Landes and the Adour Basin. The 

 sessile oak is the dominant species in the center of France and in the hilly coimtiy, where 

 it extends to 3,281 feet of altitude and slightly above. Both the species attain their 

 maximum development in the temperate zone where they are of characteristic abundance 

 in the region which corresponds to that cultivated for grapes. Above the oak comes the 

 fir. 



Tolerance. — Both species are hardy when young. They have a light foliage, often 

 incomplete, as in the case of the pedunculate oak. They resist heat as well as the cold 

 of winter, but their leaves are very liable to spring frost. The pedunculate oak, which 

 begins growing later than the sessile oak, is less liable to frost damage. They are both 

 good sprouters. 



Root System and Seeding. — Both species have long tap roots. The fruit is a heavy 

 acorn and the seed j-ears are usually frequent in the southwest where it is possible to 

 collect seed almost every year; as one advances toward the north, seed are less frequent. 

 In northern France they come every 10 to 15 years. 



Growth Longevity. — The growth of these oaks, slow at the start, soon becomes 

 quite rapid on good soil and continues to an advanced age, for their longevity is very 

 considerable and exceeds 200 years. The growth in height in a dense stand, as well as 

 isolated individuals, slows up towards 100 years. 



Utilization. — Oak wood must take the first rank for its general quality but its 

 strength depends more or less on whether the growth is rapid or slow. Generally speak- 

 ing, the wood of the pedunculate oak is denser than that of sessile oak and is better for 

 construction purposes. Sessile oak is more highly valued for wood working and for 

 cabinet work; but the pedunculate oak of Hungary is highly esteemed for that purpose. 



By-Products. — The bark is used for tanning purposes. The bark of sessile oak is 

 generally richer in tannin than is pedunculate oak when it grows in warm situations and 

 in the open. 



Silvicultural Characteristics. — " The chief value of oak for the private owner," 

 says Broilliard, " is because it is abundant, because it grows on almost every kind of soil, 

 because it flourishes whether growing alone or in dense stands, whether in high forest 



