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

FOREST TREES OF THE PACIFIC SLOPE. 147
Redwood Peak in Oakland Hlills; but south of San Francisco, on seaward coast range,
covers crest and west slope, mixed with Douglas fir and other trees, extending southward
through Santa Cruz Mountains. Ceases for a few miles around Monterey Bay, but in
Santa Lucia Mountains (Monterey County) occurs in canyons chiefly on seaward side of
range at altitudes from sea-leval to 3,000 feet (the largest trees growing in Little Sur
River Basin, near Pico Blanco), extending south to Salmon Creek Canyon (12 miles
south of Punta Gorda, lat. 350 50'), the southern limit.
OCC [RRENCE.
Best stands and all pure stands on protected flats and benches along larger streams,
sheltered, moist coastal plains, river deltas, moderate west slopes and valleys opening
toward sea. At higher, more exposed levels, where It is drier, and on steeper slopes
growth is smaller and gradually gives way in mixture to less exacting species. In north,
often on east slopes, but in south restricted to west side of coast range. Very exacting
in requirements as to soil moisture ; prefers deep to shallow soils, and grows better In
fresh, well-drained soils than in wet ones. Sandstone prevails in range, and soil Is
clayey to sandy (greasy when wet), yellowish, and capable of holding much water.
Sandy to clayey loam soil, even on steep slopes, usually of fair depth and of good composition.
Boggy soils near mouths of streams are not suitable, such localities being mainly
given over to an irregular forest of Sitka spruce, grand fir, Port Orford cedar, and
hardwoods.
Relatively small part (less than 50 square miles) of redwood forest is pure growth.
This is dense, and with little undergrowth except moss and small herbaceous plants.
Greater part (about 1,800 square miles) a mixture of redwood (50 to 75 per cent),
Douglas fir (most abundant associate everywhere except on damp places), tanbark oak,
grand fir, western red cedar, western hemlock, and madrofla; Douglas fir and tanbark oak
characteristic on upper slopes and hemlock on lower. Steep slope and uneven height
of different species make this an open forest, and except where fires are frequent there is
a dense undergrowth of huckleberry, salaI, Oregon grape, thimbleberry, and ferns.0 On
rich river flats scattered Sitka spruce, Port Orford cedar, western hemlock, and grand
fir are occasionally mingled. Pacific yew, California torreya, California laurel, cascara
buckthorn, red alder, knobeone pine, and Gowen cypress are also more or less associated,
but hold only occasional sites against the climatically more favored redwood.
CLIMATIC CONDITIONS.-Closely confined to humid region subject to frequent and heavy
sea fogs; trees outside this influence are scattered and small. Fogs conserve moisture
In soil and in trees by checking evaporation and transpiration from trees. In the redwood
forest, therefore, soil and air are typically moist. Temperature, rarely below 15°
or above 1000 ; annual average from 500 to 600 F. Annual precipitation, between 20
and 60 inches, mainly as winter rains. Snow lies on tops only of highest ridges.
TOLERANCE.-Moderately tolerant of shade except in early youth; even then shade
is not required, most rapid growth being in full light. Ilas marked characteristics of
intolerant trees; a thin open crown, rapid loss of side branches, and the eager bending
of crowns toward openings In crown cover; seedlings not able to come up in shaded
places. Yet, despite this, forms the densest of forests. Stump sprouts often exist under
the densest shade for one hundred years, growing very slowly in diameter during this
time, but recovering completely and growing rapidly when released from suppression.
This tolerance of sprouts is, however, peculiar to trees on moist bottoms, which endure
so much shade that other species are usually driven out. On drier hills, with more light,
redwood generally gives way to the less tolerant Douglas fir and other drought-enduring
trees.
REPRODUCTION.-Fairly prolific seeder. Very small percentage (15 to 25 per cent) of
seed perfect; hence exceedingly low rate of germination; vitality moderately persistent.
Sparsely reproduced by seed, but very abundantly by sprouts from old or young stumps,
root collar, and (suckers) roots.' Sprouts grow very rapidly, are long-lived, and produce
large trees of good form. Seedlings grow more slowly than sprouts and require
more light.
a Redwood forests yield 10,000 to 75,000 board feet per acre, or very exceptionally
400,000 feet, while over a million feet have been cut per acre.
bRedwood is about the only conifer whose reproduction by sprouts is of commercial
Importance. The Sierra bigtree sprouts vigorously from tall broken stubs (not from
stumps or roots) and thus repairs its broken crown. A number of pines produce ephemeral
stump sprouts, while some of the junipers produce persistent collar sprouts after
cutting and fire.