• GENERAL BOTANICAL CHARACTERISTICS
• RAUNKIAER LIFE FORM
• REGENERATION PROCESSES
• SITE CHARACTERISTICS
• SUCCESSIONAL STATUS
• SEASONAL DEVELOPMENT

GENERAL BOTANICAL CHARACTERISTICS:

Big huckleberry is a native, rhizomatous, frost-tolerant [17] shrub. Stems range from 12 to 47 inches (30-120 cm) in height [61,71,104,160]. Leaves are alternate, elliptic to oblong [76], and small, ranging from 0.7 to 2.75 inches (1.8-7 cm) long [71,160]. Roots may penetrate up to 39.4 inches (100 cm) of soil. Rhizomes are usually found within the 3.15 to 11.8 inch (8-30 cm) range of a soil profile [107]. Largent and others [88] observed a minor occurrence of mycorrhizal symbiosis.

RAUNKIAER [123] LIFE FORM:

Phanerophyte
Geophyte

REGENERATION PROCESSES:

Big huckleberry reproduces from seed and by vegetative production from adventitious buds on rhizomes [77,137] and root crowns [1]. Reproduction through seed is rare under natural conditions. Populations are usually maintained through lateral expansion of vegetative clones [77,137].

Seed:  Flowers are pollinated by bees [76,96] with each stem node having the capacity to produce 1 berry [29]. New seedlings usually require 3 growing seasons to flower [111]. A typical berry carries 42 seeds. Mean germination is around 42% [137].

Fruit production is not halted during dry summers. Fructification may occur after 4 to 6 months void of rain [30]. In the Cascades of southern Washington, individual stems are capable of producing fruit for 14 years [29]. Although berries are moderately tolerant of moisture deficits, successful germination and subsequent establishment is extremely reduced or eliminated by water stress. Cool spring temperatures also negatively affect seed germination [137].

Postdisturbance seedling establishment is not heavily relied upon. The number of seedlings emerging from soil blocks collected from a western hemlock/Pacific rhododendron (Rhododendron macrophyllum)/dwarf Oregon-grape community was monitored after experimental disturbance. Big huckleberry showed no regeneration from seed after burning and mechanical mixing of soil layers [77].

Big huckleberry offers a relatively minor contribution to soil seed banks. Viable seed most often occurs within the 1st 1.97 inches (5cm) of soil. Kramer and Johnson [86] evaluated the soil seed banks of Douglas-fir/ninebark, grand-fir/Rocky Mountain maple, and grand-fir/big huckleberry habitat types in central Idaho. The constancy (%) of viable, buried, big huckleberry seed is summarized below:

Douglas-fir/ninebark	Grand fir/Rocky Mountain maple	Grand fir/big huckleberry
6	31	25

Vegetative:  Big huckleberry possesses an extensive system of rhizomes [61,104], with adventitious buds distributed evenly across the length of the rhizome [104]. Vegetative production is highly relied upon for regeneration after disturbance [77]. Fruit productivity is more sensitive to solar radiation than vegetative production [29].

SITE CHARACTERISTICS:

Big huckleberry has wide ecological amplitude [106], occupying moist, moderately deep, well-drained soils [61,117]. It is found on moderate slopes or benches, rocky hillsides, and avalanche chutes [62,95,119,145]. Big huckleberry is rarely found in valley bottoms [79]. As an understory species, big huckleberry can grow beneath a partially closed forest canopy (in partial shade), or in sunny openings [51,61]. Big huckleberry has greatest potential on cool mesic sites with minimal overstory [29].

Soils: Big huckleberry prefers acid soils with a pH around 5.5 [109]. Clay and silt content are usually low (under 40%) with fine, loamy texture [135]. Relatively low concentrations of essential elements are required to sustain growth. Mesic and drier sites are preferred, although big huckleberry may inhabit soils with a wide range of available moisture [61].

In Montana, Goldin And Nimlos [55] evaluated big huckleberry presence in the Garnet Mountains in relation to soil physical properties. Big huckleberry preferred quartzite and granitic soils to limestone-derived soils with similar pH and gravel content. Quartzite soils resulted in the greatest coverage of big huckleberry compared to granite and limestone derived soils:

	Relative Cover (%)
Quartzite	16
Limestone	1
Granite	9

	Quartzite	Limestone	Granite
Average organic horizon thickness (cm)	4.0	2.3	4.0
Soil texture	loam	silty loam	sandy loam
Gravel content	very gravelly	gravelly to very gravelly	slightly gravelly
pH	5.7-6.9	6.5-8.0	5.5-6.5
Calcareousness	none at surface, slight to strong at depth	slight to strong on surface, strong at depth	none

Within sites, big huckleberry grew under Douglas-fir on limestone, limber pine on quartzite, and subalpine fir on granite.

Aspect/Slope: Big huckleberry prefers northern aspects [89] although populations may exist on all aspects [96]. Martin [96] observed that big huckleberry preferred moderate to steep slopes (25-40%). Gentle slopes allowed greater competition from other plant species.

Elevation:  Ranges by geographic area are as follows:

California	3,609 to 7,217 feet (1,100-2,200 m)  [71]
Montana	3,000 to 9,650 feet (914-2,930 m)
Oregon and Washington	3,000 feet (914 m) to high mountains [135]
Utah	8,202 to 10,318 feet (2,500-3,145 m) [160]

SUCCESSIONAL STATUS:

Big huckleberry may occur in early- to late-seral stages [29,66,96]. It generally shows greatest productivity within sites that experienced disturbance about 50 years previously [96]. Hamilton and Yearsley [66] describe big huckleberry as a "fairly shade-tolerant" species.

Fields dominated by big huckleberry are seral. Decline of big huckleberry as forests move toward climax status is inevitable, especially in areas of crown closure [29]. Without disturbance, big huckleberry gradually decreases in dominance, crowded out by trees [106].

Early seral:  In spruce-fir forests big huckleberry may have a significant presence within 1 to 5 postdisturbance years [19]. Response varies greatly with intensity of disturbance. In a spruce-fir forest in Idaho, big huckleberry was not a dominant shrub until 40 to 79 years after clearcutting. It shared understory dominance with wild ginger (Asarum caudatum) in sites undisturbed for 80 years or longer [130].

Habeck [59] observed big huckleberry as a common understory component of pioneer and seral communities within western redcedar-western hemlock habitats of Glacier National Park, Montana. Big huckleberry is also an early seral species in western redcedar-western hemlock forests of northern Idaho [147].

In grand fir habitats of north-central Idaho, big huckleberry may occupy an important role in early seral stages at high elevations on north slopes [165]. As stands move toward maturity, big huckleberry decreases as a major understory species of developing grand fir/Douglas-fir stands above 3,937 feet (1,200 m) in the Selway-Bitteroot Wilderness of Montana and Idaho [60]. Big huckleberry is well represented throughout all seral stages in grand fir/big huckleberry habitat types. Steele [139] presents a detailed model of succession in the grand-fir/big huckleberry habitat type.

In subalpine prairies of the Mount Hood area, Oregon, big huckleberry is an early seral species [115]. Big huckleberry is greater in frequency and coverage in open stands of mountain hemlock and Pacific silver fir associations and decreases as stands close [39]

Late seral:  Big huckleberry is a widespread understory dominant in late seral and climax communities in subalpine forests [57]. Within Montana, northern Idaho, and eastern Washington habitat types, big huckleberry generally shows slow postdisturbance recovery, increasing toward a peak at 20 to 30 postdisturbance years [89].

SEASONAL DEVELOPMENT:

Leaf primordia are initiated prior to spring bud break [56]. Throughout big huckleberry's range in Montana, flowering begins the 1st week of June. Total floret development requires 4 months (mid-July to October) [56]. With an 80-day field growing season, Gough [56] observed vegetative and reproductive development at 6,562 feet (2,000 m) in the Lee Metcalf Wilderness of Montana. Shoot growth from vegetative buds on stems began in mid-May. Buds on plants where the soil was still frozen showed no bud break. Vegetative buds on shoots greater than 0.08-inch (2 mm) diameter swell before buds on thinner, less vigorous shoots. Shoot elongation occurred until mid- to late June. Seasonal shoot growth was generally completed within a 4-week period.

Drew [41] mapped the phenology of big huckleberry within the western redcedar/western hemlock zone of Idaho. Onset of leaf fall was directly related to limitations in soil moisture availability. Bud burst occurred from early to mid-April, followed by leafing out (beginning of May) and stem elongation (May-beginning of July). Leaf fall was initiated in mid-August [41].

Related categories for SPECIES: Vaccinium membranaceum | Big Huckleberry