Giant Sequioa - Sequoiadendron
Giganteum
Description and Size
Giant
Sequoia discovered in the mid-nineteenth century hold title to
being the most magnificent tree in the world with an imposing
stature making them the world's biggest tree by volume, growing
to an average height of 68m / 215ft and 6m / 19.5ft in
diameter. Largest recorded trees have grown to 93.6m / 307ft
tall and 8.85m / 29ft diameter. The longest-lived Giant Sequoia
had a ring count indicating it was 3,200 years old. The species
is evergreen and belongs to the family Cupressaceae and is also
know as Sierra Redwood, Wellingtonia, Giant Redwood or Big
Tree. The bark is fibrous, furrowed and up to 60cm / 2ft thick
at the base of the columnar trunk and provides excellent fire
protection. The green leaves are awl-shaped, 3-6mm
/0.12-0.24-inches and long grow spirally along shoots.
Distribution in
U.S.
Giant Sequoia groves have a natural distribution wholly within
Sierra Nevada mixed conifer type forests in central California,
extending along the west slope. Groves distinguish themselves
from similar habitats only by the presence of the giant sequoia
itself with no other species restricted to the groves.
California White Fir (Abies Concolor var. Lowiana) typically
dominates the groves based on canopy coverage or density. The
giant sequoia does not grow anywhere in a pure stand, although
a few small areas approach this condition.
 Groves
Approximately 75
groves exist throughout the natural range, forming a belt
420Km / 260 miles long and no wider than 24Km / 15 miles.
The groves occupy a total area of 35,607 acres. Stand
structure and species abundance vary largely with
elevation, latitude, exposure, soil moisture, and time
since fire or other disturbance. Generally, protection of
groves from fire has resulted in ascendancy of California
White Fir, reduced regeneration of giant sequoia and
pines, and reduced concentration of shrubs. The age-class
distribution of giant sequoia also varies widely among
groves. Most groves today, however, appear to have
inadequate young giant sequoias to maintain the present
density of mature trees in the future. Giant sequoia
groves regeneration evidently has been declining over a
period of 100 to 500 years or more. As the species has
enormous public appeal and a restricted natural range,
most groves have protected status.
Habitat
Giant Sequoia are found in their preferred habitat of a humid
climate with dry summers and cold winters. Snow between October
and April contributes most of the annual precipitation of 900
to 1400mm / 35 to 55-inches. Maximum temperatures of the groves
are 24° to 29° C / 75° to 84° F. Minimum temperatures vary from
1° to -6° C / 34° to 21° F. Temperature extremes range from 24°
and 40° C / -12° and 104° F.
Growing
Conditions
Soils that provide the best growing conditions derive from a
variety of rock types with most groves on granitic-based
residual and alluvial loams. Deep well-drained sandy loam with
adequate moisture throughout the dry growing season is critical
for establishing the giant sequoia. Soil moisture content
provides a major role in the successful distribution of the
species, with the type of soil a minor role as the giant
sequoia grows vigorously in extremes of soils around the world.
Soil pH ranges mostly from 5.5 to 7.5, with an average of about
6.5. Grove elevations range from 1400 to 2000m / 4,590 to
6,560ft in the north and 1700 to 2150m / 5,580 to 7,050ft
in the south. The lowest natural occurrence of the species is
830m / 2,720ft and the highest is 2,700m / 8,860ft.
 To Giant Sequoia
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Giant Sequioa - Sequoiadendron
Giganteum
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