BOTANICAL AND ECOLOGICAL CHARACTERISTICS
SPECIES: Juniperus virginiana | Eastern Redcedar 



GENERAL BOTANICAL CHARACTERISTICS : 
Eastern redcedar is a variable, small to medium-sized tree or shrub
which ranges from 20 to 100 feet (6.1-30 m) in height at maturity
[6,39,46,101].  Plants tend to be much smaller on drier sites and seldom
attain heights of more than 20 or 30 feet (6.1-9 m) on shallow soils
[6,61].  Eastern redcedar has a dense crown [76] and assumes a narrowly
pyramidal or columnar shape [44].  Old individuals are often
characterized by an open, irregular crown [44].  Maximum longevity has
been estimated at 300 years [57].  The reddish-brown branches are
slender and ascending [40,44].  The thin, fibrous, reddish-brown to
grayish bark exfoliates in narrow strips [25,40].  Roots are fibrous
[54] and may reach depths of 5 to 10 feet (1.5-3 m) [5].

Leaves on young growth are sharp and awl shaped, and generally occur in
whorls of three [30,90].  Mature foliage is scalelike and opposite or
overlapping [30,90].  The yellowish-green to bluish-green leaves are
extremely variable [40,71].

Eastern redcedar is dioecious or, more rarely, monocecious [88].
Yellowish-brown staminate cones occur in abundance at the tips of small
twigs [40,71].  The berrylike pistillate cones are borne on axillary
branches of new scale leaves [39,40,54].  Pistillate cones are glaucous,
dark blue or bluish-purple, and 0.2 to 0.3 inch (4-7 mm) in diameter
[40].  Each cone contains one to four rounded or angled, smooth, brown
to yellowish-brown seeds [40,54].

Important distinctions between recognized varieties are summarized below
[13,32]:

     var. virginiana - seeds deeply pitted, broad pyramidal form
     var. crebra - seeds shallowly pitted, columnar form
     var. ambigens - matted shrub with creeping or somewhat ascending stems


RAUNKIAER LIFE FORM : 
   Phanerophyte


REGENERATION PROCESSES : 
Eastern redcedar regenerates through seed [11].  Mature plants produce
some seed annually, and large seed crops are produced every 2 to 3 years
[46,54].  Average age of first reproduction has been estimated at 25
years, although some individuals produce seed as early as 10 years of
age [57].

Seed dispersal:  Seed is dispersed by gravity and by a wide variety of
birds and mammals [46].  Many junipers rely on avian winter frugivores
for seed dispersal [81].  Birds may be effective in promoting some
long-distance dispersal, but most bird-dispersed seed is dropped less
than 66 feet (20 m) from the parent tree [60].  Herds of cattle can
disperse seed into adjacent grasslands [91] and can aid in "planting"
juniper seeds, as trampling disturbs the top layers of soil.

Germination:  Juniper seeds have a thick impermeable seed coat, and
exhibit both seed coat and chemical dormancy [77].  Germination is
generally enhanced by warm moist stratification (75 degrees Fahrenheit
[23 deg C] for 6 weeks) followed by cold moist stratification (41
degrees Fahrenheit [5 deg C] for 10 weeks) [77].

Properly stored seed can remain viable for long periods of time [46,67].
Stratified seed generally begins germinating 6 to 10 days after
planting, and germination continues for 4 to 5 weeks.  Under natural
conditions, seeds may germinate during the first or second spring.
However, most seed germinates during the early spring of the 2nd year
after dispersal [54].

Seedling establishment:  Seedlings often establish along fence rows as a
result of bird dispersal.  On dry sites, seedlings establish in rock
crevices or in other moist protected microsites [54].  Eastern redcedar
seedlings are tolerant of drought [11] but exhibit slow initial growth.
Severe competition greatly increases early seedling mortality [54].


SITE CHARACTERISTICS : 
Eastern redcedar grows on exposed rock outcrops, bluffs, cliffs, stable
dunes, in thin-soiled glades or barrens, and in dry woodlands
[54,62,90,93,100].  It commonly invades abandoned fields, pastures,
prairie hillsides, and disturbed forests [35,40].  Eastern redcedar also
grows on relatively moist sites such as along lakeshores and
streambanks, in swamps, river bottoms, and alluvial woods, on natural
levees, shell mounds, and on moist to wet hammocks [39,54,82,90].  It
grows on ridgetops, slopes, and flatlands [54] but is most common on
west- or north-facing slopes or in protected cooler stream bottoms at
the drier western edge of its range [88].

Plant communities:  Eastern redcedar commonly forms pure stands on
abandoned agricultural lands, drier uplands, and in thin-soiled "glades"
[54,88].  It is a constituent of various pine-hardwood, mixed hardwood,
post oak (Quercus stellata) savanna, prairie, and plains grassland
communities [96,97].

Plant associates:  Trees - In the South, eastern redcedar commonly grows
with shortleaf pine (Pinus echinata), Virginia pine (P. virginiana), and
numerous hardwoods [54].  In Southern cedar glades, winged elm (Ulmus
alata), blackjack oak (Quercus marilandica), Carolina buckthorn (Rhamnus
caroliniana), and rusty blackhaw (Viburnum rufidulum) commonly occur
with eastern redcedar [41,54].  Eastern redcedar is associated with
northern red oak (Quercus rubra), white oak (Q. alba), hickories (Carya
spp.), black walnut (Juglans nigrum), and many other hardwoods in the
central and eastern portions of its range [54].  Gray birch (Betula
populifolia), red maple (Acer rubrum), and aspen (Populus tremuloides)
are common associates in the Northeast, while cottonwoods (Populus
spp.), willows (Salix spp.), blackjack oak, post oak, and chokecherry
(Prunus virginiana) frequently grow with eastern redcedar in the Great
Plains [23,49].  Understory - Numerous herb and shrubby species grow
with this widespread species in the East and Northeast [88].  Fragrant
sumac (Rhus aromatica), Alabama supplejack (Berchemia scandens), little
bluestem (Shcizachryium scoparium), big bluestem (Andropogon gerardii
var. gerardii), dropseed (Sporobolus spp.), and switchgrass (Panicum
spp.) are common understory associates in cedar glades of the South
[41,53].  Black-seed ricegrass (Oryzopsis micrantha), poison-ivy
(Toxocodendron rydbergii), and American pasqueflower (Anemone patens)
often occur with eastern redcedar in parts of the Great Plains [23,40].

Soils:  Eastern redcedar grows on a wide range of soils but generally
exhibits best development on deep, well-drained alluvial soils derived
from limestone [6,44,61].  It is also capable of growing on poor, rocky
sites with shallow soils [44].  Competition often limits its growth on
better sites [54].  Eastern redcedar occurs on sandy, silty, or clayey
loam, loamy sand, or heavy clay [40,76,83,88].  Soils are often high in
calcium, with limited soil moisture and nutrients [14].  Soils may be
saturated in the spring but droughty by fall [90].  Parent materials
include limestone, dolomite, quartzite, shale, granite, sandstone, and
gypsum [34,66,83,88,91].  Soil pH ranges from 4.7 to 7.8 [54], but
eastern redcedar most commonly occurs on neutral or slightly alkaline
soils.  It is fairly intolerant of strongly alkaline soils [54]; growth
may be slow on acidic soils [17].

Climate:  Eastern redcedar is adapted to a wide climatic range [88] but
commonly grows under a dry continental climatic regime [49].  Average
annual precipitation ranges from 15 inches (38 cm) in the Great Plains
to more than 60 inches (152.4 cm) in the Southeast [54,88].  Summer
precipitation may be more limiting than average annual precipitation
[54].  Summer temperatures are often high, and winter temperatures quite
low [99].  Temperatures may drop to -40 degrees Fahrenheit (-40 deg C)
in Minnesota and the central Great Plains and climb to 115 degrees
Fahrenheit (46 deg C) in the central and southern Great Plains [88].
The growing season ranges from 120 days in the Dakotas to 250 days in
the southern Coastal Plain [88].

Elevation:  Eastern redcedar generally occurs between 100 feet (30 m)
and 3,500 feet (1,070 m) in elevation [54].  In the southern and eastern
portions of its range, eastern redcedar is restricted to elevations
above 100 feet (30 m).  In western Nebraska and Kansas, it grows from
sea level to more than 5,000 feet (1-1,524 m) in elevation [88].


SUCCESSIONAL STATUS : 
Eastern redcedar is a pioneer on many types of disturbed, unburned sites
[91,103] and persists in certain dry, harsh climax stands [14].  On
well-drained bottomland sites, eastern redcedar is an initial colonizer
but is soon replaced by species such as common persimmon (Diospyros
virginiana) and sassafras (Sassafras albidum) [88].  In the upper
Mississippi Valley, more shade-tolerant species such as northern red oak
may enter the canopy as eastern redcedar is eliminated [11].  Eastern
redcedar is typically a successional species on rolling upland sites
[14].  However, succession to hardwoods may proceed very slowly on drier
sites [88].  In many areas, stands begin to deteriorate at age 60 as
competing hardwoods begin to shade out eastern redcedar [54].  Scattered
individuals or small groups of eastern redcedar may survive in a
suppressed state beneath hardwoods for a fairly long period [88].
Suppressed redcedars may resume growth as decadent hardwoods fall, and
the canopy opens [91].

Eastern redcedar forms long-lived, stable communities in the Interior
Low Plateau, Limestone Valley, and Upland Soils Provinces at the central
portion of its range.  These communities have alternately been described
as climax or subclimax [14].  It also forms stable communities on
thin-soiled, rocky glades in the Ozarks [54,61] and along the
Mississippi River from Missouri to Minnesota [14].

Old-field communities:  Eastern redcedar is a woody invader on abandoned
agricultural lands and in certain rolling hill prairies in which fire
suppression has brought about vegetative changes [11,88].  It is
characteristic of successional stages in many old-field communities [65]
and is often one of the first trees to invade these communities [6].
Eastern redcedar is particularly common on abandoned fields that are not
burned or grazed [99].  In central New Jersey, seedlings were observed
by the 3rd year after abandonment, and establishment continued through
the 12th year [60].  Elsewhere it may be associated with later or
"advanced stages" in old-field succession [80].  No seedlings were
observed during the first 8 years after abandonment in New Jersey
old-field communities, and seedlings were first noted in year 14 [73].
In old-field communities of Massachusetts and Connecticut, eastern
redcedar and gray birch initially dominate early successional stages but
are eventually replaced by white oak, black oak, northern red oak, red
maple, black birch, and hickory [75].  White ash (Fraxinus americana)
may replace eastern redcedar in old-field communities in parts of New
York [75].


SEASONAL DEVELOPMENT : 
Cambial growth occurs from May to July [41].  Pollen forms in staminate
conelets by late September; staminate cones mature during winter [54].
Ovulate cones develop by late summer or early fall but grow little over
the winter and do not become conspicuous until late February or early
spring.  Pollination occurs from mid-February to March, depending on
location, and is completed within just a few days [54].  Maturation of
cones takes an average of 162.3 days [81]; cones generally mature from
late July to November [54].  In the central part of its range, cones
generally mature by September [88].  Fruit ripening is generally 1 month
later in New England than in Texas [88].  Seasonal variation of up to 2
weeks has been observed in Massassachusetts [88].

Phenological development by geographic location is as follows:

(1)  Northeast:  plants flower from mid-March to mid-May; fruit ripens
        from September to November; and seed dispersal occurs from
        February to March [46].
(2)  New England:  fruit ripens in late July [78].
(3)  southeastern U.S.:  plants flower from January to April [25].
(4)  Blue Ridge:  plants flower from January to March [93].
(5)  North and South Carolina:  plants flower January to March; fruit
        ripens from October to November [71].
(6)  Kansas:  seed dispersal occurs from September 6 to March 27 [81].
(7)  northern Great Plains: plants flower in April; fruit ripens in
        September [82].
(8)  Great Plains:  plants flower from April to May [40.

Related categories for Species: Juniperus virginiana | Eastern Redcedar