152 FOREST TREES OF THE PACIFIC SLOPE. 



3,000 feet, and on cool slopes to 2,500 feet. Madera County: East of Fresno Flat on road 

 to China Creek, beyond Fresno Flat, headwaters of Fresno Creek near California Saw- 

 mill at 5,500 feet. Fresno County: Pine Ridge and eastward into mountains; south- 

 ward on Pine Ridge occurs on upper waters of Sycamore and Big creeks ; eastward in 

 bottom of Kings River Canyon into Bubbs Creek canyon ; south of Kings River between 

 Mill Creek and Eshom valleys, and east of latter on Redwood Mountain at about 7,000 

 feet. Tulare County: Sequoia National Park and east of park on warm slopes into 

 Buck Canyon and canyon of Middle Fork Kaweah River to 7,500 feet ; Kern River 

 Canyon, in vicinity of Kern Lakes ; East Fork of Kaweah River to about 7,200 feet. 

 Southern Sierras, generally at 3,000 to 7,000 feet southward to Greenhorn and Piute 

 mountains ; not in Breckenridge nor Tehachapi ranges, except near mouth of Tejon 

 Canyon. Not known in coast ranges of central California. Monterey County: Santa 

 Lucia Mountains on north slopes ; on north side of Santa Lucia Peak near summit ; west 

 of this, in Arroyo Seco Canyon about a mile above its mouth ; north slopes of Cone Peak 

 at 3,500 to 4,000 feet ; also farther north on Big Pine Ridge on north slope of Bear 

 Basin. San Benito County: Mount San Carlos (4,980 feet near New Idria) and neigh- 

 boring peaks ; Santa Barbara National Forest, San Rafael Mountains, Mount Medulce, 

 and from near summit of Pine Mountain to Piru Creek, at 5,000 to 7,200 feet, or lower. 

 San Gabriel National Forest, on north slopes of Mount Wilson, at 5,200 to 5,800 feet, 

 and in Santa Anita Canyon, at 3,300 feet ; Mount Islip, at 5.500 feet ; Waterman Moun- 

 tain, at 6,500 feet, and at point 6 miles east of Pasadena, at 4.000 feet. Highest val- 

 leys and summits of San Bernardino Mountains, as Bear Valley and Santa Ana River, 

 at 5,000 to 7,000 feet, or sometimes to 9,500 feet. High summits of San Jacinto Moun- 

 tains and at 3,000 to 8,000 feet in larger valleys and along streams. Santa Ana 

 Mountains in Orange County. Ranges between San Jacinto Mountains and Mexican 

 line, such as Palomar, Balkan, and Cuyamaca mountains, where noted on Cuyamaca Peak 

 at 6,550 feet, and on Mexican boundary at Campbell's Ranch at 5,000 feet. 



Lower California. — Southward on Hanson Laguna Range and Mount San Pedro 

 Martir, at 7,500 feet and over. 



OCCURRENCE. 



In general, commoner on west than on east mountain slopes ; but somewhat higher on 

 east slopes, chiefly because of more moisture. Most abundant and largest on west slope 

 of Sierras, especially where sugar pine, bigtrees, and yellow pine thrive best. As latitude 

 increases it appears to seek lower elevations. In drier parts of range (southern Cali- 

 fornia) confined chiefly to borders of streams, canyons, gulches, and cool north slopes, 

 while at north limit it occurs mainly on warm south slopes. Adapted to a variety of 

 soils, but usually prefers cool, moist soils (humid situations), occurring in rather dry 

 soils (warm, open exposures) probably only because it is capable of enduring them. With 

 deficient soil moisture, fairly deep, porous soils are essential, while with sufficient mois- 

 ture the quantity and quality of soil is less important. Abundant moisture and good 

 porous soil produce largest growth. 



Seldom or never occurs pure, except in very small stands. Usually in mixture and more 

 or less subordinate, scattered singly, in groups, or patches, and, under best conditions 

 for growth, forming 50 per cent of stand, with yellow and sugar pine ; also with white fir in 

 lower part of latter's vertical range. In southern California, chiefly with western yellow 

 and Jeffrey pines, and sparingly with white fir and big cone spruce, and along streams at 

 lower elevations (at south) with red and white alder, broadleaf maple, and black cotton- 

 wood. In Oregon Cascades, with yellow pine, Douglas fir, white fir, western white pine, and 

 sugar pine. In Sierras, with sugar pine, western yellow pine, Jeffrey pine, white fir, 

 and bigtrees ; at lower levels with Kellogg oak, red alder, broadleaf maple, and canyon 

 live oak. 



Climatic Conditions. — Climate variable. Insufficient precipitation and excessive heat 

 (southern California) most unfavorable; conditions more favorable in Cascades and 

 Sierras. Precipitation, snow in winter at high elevations, and at lower elevations rain. 

 Average annual precipitation from less than 15 to over 50 inches. Relative humidity, 

 variable. Fogs (chiefly from ocean) common, especially on west slope of Sierras; their 

 influence on general climate and tree growth is considerable. Height of the dry season 

 includes July, August, and September, with October in south, when destructive forest 

 fires are likely to occur. 



Tolerance. — Moderately tolerant, enduring more shade than sugar pine, yellow pine. 

 Jeffrey pine, Douglas fir, or western white pine, and in mature stands usually intermediate 

 or subordinate on account of slower growth and greater tolerance ; often dominant in 

 open stands and openings, or as an advance growth, at lower timber line, pushing into 

 oak and brush. Adapted to both shade and full light. Tolerance varies with age, mois- 

 ture, soil, and climate ; tolerates shade well in youth, but requires more light in later life. 



