BOTANICAL AND ECOLOGICAL CHARACTERISTICS
SPECIES: Viburnum edule | Highbush Cranberry 



GENERAL BOTANICAL CHARACTERISTICS : 
Highbush cranberry is a straggling to erect deciduous shrub that reaches
heights ranging from 2 to 12 feet (0.6-3.5 m) [22,32,58].  It has
several to many stems that may grow to 1.5 inches (4 cm) in diameter
[58].  The plant has smooth gray bark and sharply toothed leaves that
are shallowly lobed.  Milky-white flowers are borne in few-flowered
terminal cymes.  The fruit is an orange to red drupe that contains one
seed [1,32,58].  The berries often overwinter on twigs.  Highbush
cranberry roots in the organic layer [51] and is rhizomatous [22].


RAUNKIAER LIFE FORM : 
   Phanerophyte (Microphanerophyte)
   Phanerophyte (Nanophanerophyte)
   Cryptophyte (Geophyte)


REGENERATION PROCESSES : 
Sexual reproduction:  Highbush cranberry begins to produce fruits at
approximately 5 years of age, and then produces large quantities nearly
every year thereafter.  The one-seeded fruits are dispersed by the birds
and mammals that consume them [6,22].  Germination is normally delayed
until the second growing season after ripening.  The seeds exhibit seed
coat and embryo dormancy that requires a two-stage stratification to be
broken.  Most successful germination takes place when a warm period is
followed by cold stratification [21,22,59].  The radicle emerges and
begins growth during the warm period, and the cold period breaks the
dormancy of the plumule, which then grows when temperatures become
warmer.  The time period of these stages is critical but has not been
worked out in detail.  Clean, air-dried seeds can be stored up to 10
years without losing viability.  Highbush cranberry is a seed-banking
species [21,22].

Vegetative reproduction:  Highbush cranberry can reproduce vegetatively
by natural layering and sprouting from damaged root stocks, stembases,
and stumps.  The plant is rhizomatous, but there is no evidence of
lateral spread from the parent by rhizome or root suckers [22].


SITE CHARACTERISTICS : 
Highbush cranberry is found in moist woods or forests, along stream or
lake margins on gravel or rocky banks, and on swamp or bog margins
[22,49,58].  In British Columbia, the plant is found from sea level to
about 4,900 feet (1,500 m) [22], but in Colorado elevational range is
7,000 to 9,000 feet (2,100-2,700 m) [26]. The southern extent of
highbush cranberry's distribution is determined by high temperatures and
low humidity.  Its presence at northern latitiudes indicates a high
tolerance to frost and the ability to grow in low soil and air
temperatures.  In moist climates, highbush cranberry grows on submesic
to subhydric soils, but in drier climates it is restricted to subhygric
and wetter moisture regimes.  Highbush cranberry commonly grows under a
deciduous or coniferous canopy but probably develops best under full
sunlight [22].

Highbush cranberry grows best on well-drained, alluvial soils
[6,9,12,62].  Soil textures include clay, silty clay, sandy clay loam,
and fine loam [9,33,62].  Soil types include Luvisols, Brunisols,
Humo-Ferric Podzols, Regosols, and Gleysols [22].


SUCCESSIONAL STATUS : 
Highbush cranberry is moderately shade tolerant [6] and is important
throughout all stages of forest succession [46,61].  In floodplain
succession, highbush cranberry is present from the pioneer willow
through seral balsam poplar stages.  It remains important in mature and
climax white spruce and black spruce-white spruce types [56].

Highbush cranberry sprouts following fire and is an important component
of early, midseral, and climax postfire communities [13,61].  The
following frequencies and densities were found in white spruce stands in
interior Alaska:

  Stage        Years after fire    Frequency(%)    Density(stems/acre)
_______________________________________________________________________
Newly burned         0-1               78         15,201 (37,562 st/ha)
Moss-herb            1-5               21           2,795 (6,906 st/ha)
Tall shrub-sapling   3-30              30         13,445 (33,222 st/ha)
Dense tree          26-45              36           3,713 (9,175 st/ha)
Hardwood            46-150             55         15,378 (38,000 st/ha)
Spruce             150-300+            39           2,049 (5,062 st/ha)

Low successive peaks between the newly burned, tall shrub-sapling, and
hardwood stages may have been caused by stand differences or successful
establishment followed by opportunism [19].


SEASONAL DEVELOPMENT : 
Highbush cranberry flowers from May to August, depending on location.
Fruits ripen from August to October and persist throughout the winter
[18,22,58].  Leaf flush begins in April or May, and senescence and
abscission take place earlier than on associated shrubs [22].

Related categories for Species: Viburnum edule | Highbush Cranberry