BOTANICAL AND ECOLOGICAL CHARACTERISTICS
SPECIES: Calocedrus decurrens | Incense-Cedar 



GENERAL BOTANICAL CHARACTERISTICS : 
Incense-cedar forms a dense, narrow, pyramidal crown.  It has flattened
branchlets with green overlapping scales.  Cones are oblong, small (0.8
to 1.5 inches [2.00-3.75 cm]), and hang from the tip of the branch.
Bark on mature trees is dark brown, fibrous, and deeply and irregularly
furrowed [1,6].

In the Coast Ranges and southern California, the largest trees
generally are from 60 to 80 feet (18-24 m) tall and 36 to 48 inches
(90-120 cm) d.b.h.  In the Sierra Nevada, they frequently grow to heights
of 150 feet (46 m) with d.b.h's of about 84 inches (210 cm).  Trees
have been measured at 225 feet (69 m) tall and 148 inches (375 cm) d.b.h.
Incense-cedar is a long-lived species.  Large trees are often over 500
years old.  The oldest recorded incense-cedar is 542 years old [19].



RAUNKIAER LIFE FORM : 
   Phanerophyte


REGENERATION PROCESSES : 
Incense-cedar does not reproduce vegetatively in nature but can under
greenhouse conditions [19].

Flowering and fruiting:  Terminal strobili are borne as early as
September and shed pollen in late winter to early spring.  Incense-cedar
is monoecious.  Cones mature in late summer.  Each seed has two
unequal-sized wings.  Embryos have two cotyledons [19].

Seed production and dissemination:  Seed crops may fluctuate from
prolific crops every 3 to 6 years, to years without any seed production.
As many as 389,100 seeds per acre (961,500/ha) may fall during heavy
production years.  Seed production varies greatly with geographic
distribution.  Seed dispersal begins in late August in the lower
elevations, and in October at higher elevations.  Incense-cedar averages
15,000 seeds per pound (33,100/kg) and varies from 6,400 to 29,000 seeds
per pound (14,100-63,900/kg).  Seeds fall slowly (5.9 feet per second
[1.8 m/s]) and are carried great distances by wind [19].

Seedling development:  Cold stratification may double the germination
rate for incense-cedar.  Germination under controlled conditions may be
as high as 98 percent but usually averages 20 to 40 percent.  In natural
conditions, germination is best under partial shade.  Initial growth is
typically slow to moderate compared to other conifers.  Root growth is
slow the first year but develops rapidly by the second growing season.
Established incense-cedar seedlings are very drought tolerant due to
their fine-root mass [19].

Growth and yield:  Incense-cedar growth varies greatly by location.  It
grows more slowly than associated conifers.  On poor sites,
incense-cedar has been known to do well, often outcompeting all of its
associates.  On good sites, however, it generally falls behind due to an
increase in shade.  Incense-cedar shows good response to release.  Much
of the extremely slow growth of seedlings results from suppression or
browsing.  When released, seedlings grow rapidly, but because height
growth is usually slower than that of associated species of comparable
age, incense-cedar is usually a secondary species in mature conifer
stands [19].



SITE CHARACTERISTICS : 
Incense-cedar is a good competitor on hot, dry sites and is commonly
found on southwestern slopes.

Climate:  Incense-cedar occurs where the summers are typically dry, with
less than 1 inch (2.5 cm) of precipitation per month.  Annual
precipitation varies from 20 to 80 inches (50-200 cm) and may be as low
as 15 inches (38 cm) a year on the east side of the Cascades and in the
Warner Mountains of Oregon and California.  Temperatures range from -30
to 118 degrees Fahrenheit (-34 - 48 deg C) [19].

Soils:  Incense-cedar may grow on a wide variety of soils derived from
many kinds of parent materials.  It has been found to extract soil
phosphorus and calcium, and exclude surplus magnesium.  Soil pH ranges
from nearly neutral to strongly acidic.  Textures vary from coarse sands
to very fine clays.  Incense-cedar grows best on deep, well-drained,
sandy loam soils developed on granitic rocks and sandstones; deep clay
loams developed on basalt and rhyolite; and occasionally on deep,
coarse-textured, well-drained soils developed from pumice [19].

Elevation:  Incense-cedar grows between 165 and 6,600 feet (50-2,010 m)
at its northern distribution, and between 3,000 and 9,700 feet
(910-2,960 m) in its southern limits.  In the Sierra Nevada,
incense-cedar grows best at elevations between 2,000 and 6,900 feet
(610-2,100 m) [19].


SUCCESSIONAL STATUS : 
Facultative Seral Species

Along the western slope of the Sierra Nevada, incense-cedar and white
fir form an understory in forests of ponderosa and sugar pine.  In early
seral development, small groups of these trees grow beneath the canopy
in shady conditions until an opening in the crown is created.
Incense-cedar will then establish as a codominant species in the stand
[15].



SEASONAL DEVELOPMENT : 
Seasonal growth durations of incense-cedar at various elevations in the
Sierra Nevada are as follows [8]:

                Height      Radial
                Growth*     Growth
                ------      ------
Start (days)**   144         105
Start (date)    May 24     April 15
Length (days)     91         136
Rapidity (day)    37          39

* An 8-year average.
** Number of days from January 1st.

Related categories for Species: Calocedrus decurrens | Incense-Cedar