FOREST TREES OF THE PACIFIC SLOPE. 105 



large seeds (figs. 37, a) are dark chocolate brown and shiny on the upper side, 

 which contrasts strongly with the dull, very slightly reddish-brown under sur- 

 face. Seed-leaves, usually 6, but often 7, pointed, and about an inch long. 

 Wood, reddish-brown, fine-grained, rather tough and hard; suitable for coarse 

 lumber, but not used commercially. An exceedingly important tree for increas- 

 ing the protective cover on dry mountain slopes of its range where few other 

 conifers are at home. 



Longevity. — Little is now known of the longevity of this tree. Probably 

 long-lived. A tree 213 inches in diameter showed an age of 109 years. Doubt- 

 less larger trees occasionally found would prove to be from 200 to 300 years old. 



RANGE. 



Southern California, from eastern Santa Barbara County and southwestern corner of 

 Kern County to northern Lower California ; range includes Santa Inez, Zaca, San Rafael, 

 Pine, San Emigdio, Sierra. Liebre, Sierra Madre, San Bernardino, San Jacinto, Santa 

 Ana, Palomar, Cuyamaea, and San Pedro Martir mountains. Chiefly on north and east 

 slopes and in canyons nearly throughout these ranges, at elevations of .3,000 to 5,000 feet, 

 but often to 6,000 or 7,000 feet, and down to 1,500 feet in canyon bottoms. Western 

 limits are Mission Canyon (above Santa Barbara) in Santa Ynez Mountains, where one 

 tree occurs at 1,500 feet, and Zaca Peak, in San Rafael Mountains. Northern limits are 

 San Emigdio Mountains and south side of Tejon Canyon (west of Tehachipi Mountains). 

 Most common in San Gabriel and San Bernardino Mountains. Not frequent in Santa 

 Barbara National Forest, but most abundant in Matili.ia, Cuyama, Sespe, and Piru creek 

 basins. Locally noted as follows : Mount Medulce, Big Pino Mountain, Pine Mountain, 

 Piedro Blanco Peak, near Pine Mountain Lodge, south side of Sierra Liebre Range, and 

 on mountain back of Fort Tejon. General in San Gabriel National Forest and between 

 about 3,000 and 5,000 feet; locally noted on Mount Wilson, on Bubio Mountain, 

 down to 2,200 feet, near Alpine Tavern, between 5,100 and G.000 feet, and Mount Lowe, 

 at from 2,000 feet to summits. Common in San Bernardino National Forest, on both 

 sides of range ; on north side down to 1,500 feet, and sparingly in pine belt and on 

 plateau up to 6,000 or T.noo feet, but up only to 3,000 feet on south side. Not detected 

 in Santa Monica Mountains west of Los Angeles. Trabuco National Forest, at L',000 

 to 3,000 feet, in bottoms at heads t,( canyons in Santa Ana Mountains. San Jacinto 

 Mountains, northern and western slopes and canyon bottoms, at 3,000 to 5,500 feet; 

 less frequent up to (i.ooo or T.ooo feet. Forms 5 per cent of forest in Palomar Mountains 

 (southwest of San Jacinto Mountains), and 10 per cent of forest in Balkan Mountains — 

 few miles southeast, near Julian — while farther south it is very rare in Cuyumaca Moun- 

 tains. 



Lower California. — Sparingly represented at 5,000 to 7.000 feet on Mount San 

 Pedro Martir. 



OCCURRENCE. 



Scattered in cool ravines, gulches, canyons, over north slopes ; approximately inter- 

 mediate in position between chaparral belt and western yellow and Jeffrey pine forest. 

 This occurrence is often very irregular, owing to unfavorable local conditions of soil and 

 moisture, and destructive forest tiros. Generally on dry to fresh sandy or gravelly loam 

 soils, or on rocky, shallow ones, any of which are too dry for Jeffrey pine, western yel- 

 low pine, sugar pine, white fir, and incense cedar, all common to the region. It avoids 

 stream beds and other wot places preferred by incense cedar. 



Pure small groups and patches, or single trees interspersed through pine belt, chapar- 

 ral, and oak growth. Probably once occurred In much larger, pure stands, which were 

 doubtless reduced by frequent fires. In pine belt, associated with Coulter pine, western 

 yellow pine, Jeffrey pine, sugar pine, incense cedar, and white fir ; below this, common 

 with canyon and California live oak. and scattered through chaparral ; extends into latter 

 to limit of moisture conditions, and into pine belt as far as severe climate there permits. 



Climatic Conditions. Precipitation insufficient now to support good forest cover. 

 Average annual precipitation (chiefly rain in winter at low levels, and snow at high 

 elevations) from less than 10 inches to 30 inches; snow melts while falling, or soon 

 after, in range of this spruce: remains only above it. Relative humidity, likewise vari- 

 able and correspondingly low. Precipitation greater at high levels than at low ones, and 

 greater on west than on east side of coast ranges facing dry interior. Snow may come 

 at upper limit as late as May and as early as October. Fog common during rainy season 

 (winter), depositing considerable moisture, comparatively speaking, on cool, forested 



