De I. VNER VEW D Forest Trees of the Pacific Slope

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 Inurel, madrofia, and somewhat less often or remotely with
tanbark oak, Douglas fir, and Coulter pine.
FiG. 47.-A bics vcnusta: a, cone; b, cone scale; c, seed.
CLIMATIC CONDITIONs.-Temperature in its habitat seldom goes to zero or above
100' v'. On exposed contiguous slopes, crests of ridges, Nbhere 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.
TOLuRANcE -Very little is known of its shade endurance. Appears to endure considerable
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.