124 



FOREST TREES OF THE PACIFIC SLOPE. 



on west slopes, in deep ravines opening toward the sea ; smaller or stunted higher 

 up in more exposed places. Porous, rocky, gravelly, and sandy soils ; where best growth 

 occurs, soil is moist, even in summer, from contiguous stream bed. 



Probably capable of forming, under favorable conditions, pure or nearly pure stands. 

 As now known — doubtless greatly thinned and checked by fires — only small groups and 

 straggling lines occur, associated more or less with canyon live oak. broadleaf maple, 

 white alder, California laurel, madrofia, and somewhat less often or remotely with 

 tanbark oak, Douglas fir, and Coulter pine. 



Fig. 47. — Abies venusta: a, cone: 6, cone scale; c, seed. 



Climatic conditions. — Temperature in its habitat seldom goes to zero or above 

 100° F. On exposed contiguous slopes, crests of ridges, where possibly this tree once 

 grew, seasonal range of temperature is somewhat greater. Moisture laden west winds 

 maintain fairly high degree of atmospheric humidity during most of the year. Annual 

 precipitation, almost entirely rain, varies between 20 and 50 inches. Snowfall of the 

 region, light even at high altitudes. 



Tolerance. — Very little is known of its shade endurance. Appears to endure consid- 

 erable shade throughout life, particularly in early growth. Bears dense side shade, as 

 shown by retention by old trees of vigorous lower branches in deep shade ; full overhead 

 light is doubtless required for best growth. 



