20 BULLETIN" 604, tJ. S. DEPARTMENT OP AGRICULTURE. 



not uncommon, therefore, to find reproduction occurring in even- 

 aged stands separated by an interval of several years from trees older 

 and younger. 



RANGE. 



GEOGKAPHICAL. 



Incense cedar, next to western yellow pine, adapts itself to a wider 

 variety of conditions than any other tree native to California. It is 

 found growing under almost every condition, and apparently is lim- 

 ited in distribution only by extreme drought, excessive humidity, and 

 the conditions prevailing at high elevations. Its range is from north- 

 ern Oregon to northern Mexico and from the eastern border of the 

 fog belt in northern California nearly to the limits of commercial 

 tree growth in western Nevada. Its northern limits are irregular, 

 reaching as far north as Breitenbush Creek, on the west side of the 

 Cascades, and to the foothills surrounding Mount Hood on the east 

 side. It also is found on the Rogue-Umpqua divide in eastern Ore- 

 gon, whence it extends south throughout the Siskiyous into northern 

 California. In California it ranges between the foothills and the 

 subalpine zones on both sides of the Sierras to the Kern River 

 Valley and throughout the coast ranges at increasing elevations into 

 northern Mexico and Lower California, where it finally disappears. 



ALTITUDINAL. 



East of the Cascades in northern Oregon the tree is found between 

 altitudes of 2,000 and 3,000 feet, and in the southern part of the 

 State between about 4,000 and 5,000 feet; on the west side of the 

 Cascades it is abundant between 1,500 and 3,000 feet, and even higher 

 in the warmer situations. In the coast ranges of California it occa- 

 sionally goes as low as 1,100 feet, owing to heavier precipitation and 

 an abundance of atmospheric moisture; but the bulk of it is found 

 between 3,000 and 5,000 feet. In the mountains of northern Cali- 

 fornia it grows between 2,500 and 6,000 feet, occasionally reaching 

 as low as 1,000 feet where conditions are particularly favorable. It 

 attains its best growth, however, between 3,000 and 0,000 feet. In 

 the southern Sierras it is seldom found below 3,500 feet, and extends 

 up to 7,000 or 7,500 feet, doing best between 4,000 and 6,800 feet. 

 On the east slope, in extreme eastern California and western 

 Nevada, its range is limited to the Warner Mountains and the 

 northern and central Sierras, where it is confined between the 5,000 

 *md 7,000 foot elevations. In the coast ranges of southern California 

 and northern Mexico it grows still higher, the extreme aridity fixing 

 its lower limit at about 4,000 feet and forcing it up as high as 9,000 

 or 9,500 feet at its southern limits. 



