California black oak attains the largest size of any of the mountain-inhabit- 

 ing oaks of Oregon and California. As the common name indicates it is mostly 

 confined to California and belongs to the group of oaks commonly known as 

 the black oaks, which are, as a rule, characterized by dark or black bark, reddish 

 or dark wood, bristle-tipped leaf lobes, and biennial acorns. Its range is from 

 the McKenzie River in western Oregon, south through the Sierras and inner 

 coast ranges, to the high mountains of southern California. 



This species is characteristically associated with and reaches its highest 

 development in the mixed conifer belt. Here it commonly becomes a tree 30 

 to 80 feet in height, but is markedly smaller outside this, zone, especially at 

 the upper altitudinal limits. The species is widely distributed within its 

 range, occurring from elevations of several hundred feet in the foothills up 

 to 8,000 feet in the mountains, but it does not occur near the sea or on the 

 plains. It is very adaptable, growing in the shade of coniferous forests, on cold 

 northern slopes, and on exposed and warm southern exposures. It sometimes 

 forms pure stands over extensive areas, especially on canyon slopes and benches. 

 Soils do not seem to be an important limiting factor, as this tree occurs on nearly 

 all types of soils, from fertile valley loams to extremely stony sites or even talus 

 slopes, although its preference is well-drained situations. 



Ordinarily California black oak in tree size is wholly beyond the reach of 

 grazing animals. However, the species is abundant, and the reproduction and 

 the dwarf, high-altitude forms provide an important source of browse. Older 

 trees frequently sprout from the trunk base, and fire-killed individuals send 

 forth a profuse new growth. Mackie found that the foliage was high in 

 nutrient value as compared with that of other oaks but believed that the 

 high resin and wax content impaired its palatability. 1 Field observations, how- 

 ever, on California national forests clearly indicate that California black oak 

 is extensively browsed by livestock. It is a very important feed wherever 

 available and abundant, being rated fair forage for cattle and fairly good for 

 sheep. Deer relish its foliage, and are especially fond of the acorns as a fall 

 and winter feed. 3 California black oak is subject to overgrazing as the sprouts, 

 reproduction, or low dwarf forms all have an open growth, thus making the 

 entire foliage within grazing height available. Close use of the large leaves 

 for several seasons causes the stems and branches to die, or where the plant 

 has sufficient height, it results in the production of new growth at a level 

 beyond the reach of browsing livestock. 



California black oak is not valuable for lumber as the wood is porous and 

 brittle, and most of the older trees are defective. It is highly prized locally 

 for fuel and is used limitedly in the manufacture of tool handles and wooden 

 mauls. Chemical studies 3 indicate that the yield of acetic acid and alcohol 

 from destructive distillation of this oak equals that obtained from birch and 

 is greater than that obtained from beech and maple; however, little com- 

 mercial use of the wood for distillation purposes has been made. 



California black oak often develops into a handsome broad-crowned tree when 

 growing in the open, but the individuals in dense stands are slender and have 

 few branches. The forms growing at high altitudes are dwarfed, mostly less 

 than 20 feet in height, very irregular in shape, and usually develop their 

 longest branches near the ground. The bark of the young trees and of the 

 limbs is smooth and gray, becoming darker and checked with age until, on the 

 trunks of old trees, it is dark and divided into broad ridges below and oblong 

 plates above. The deciduous leaves vary in color ; they emerge from the 

 chestnut-colored, scaly winter buds a dark red or purple and gradually change 

 to a lustrous dark yellow green at maturity. In the fall they turn to various 

 shades of yellow, red, and brown, adding much to the autumnal beauty of 

 their native hills and valleys. 



1 Mackie, W. W. THE VALUE OF OAK LEAVES FOR FORAGE. Calif. Agr. Expt. Sta. Bull. 

 150, 21 pp., illus. 1903. 



2 Dixon, J. S. A STUDY OF THE LIFE HISTORY AND FOOD HABITS OF MULE DEER IN CALI- 

 FORNIA. PART 2 FOOD HABITS. Calif. Fish and Game 20 (4) : f315]-354, illus. 1934. 



8 Palmer, R. C. YIELDS FROM THE DESTRUCTIVE DISTILLATION OF CERTAIN HARDWOODS. 

 SECOND PROGRESS REPORT. U. S. Dept. Agr. Bull. 508, 8 pp., illus. 1917. 



