• IMMEDIATE FIRE EFFECT ON PLANT
• DISCUSSION AND QUALIFICATION OF FIRE EFFECT
• PLANT RESPONSE TO FIRE
• DISCUSSION AND QUALIFICATION OF PLANT RESPONSE
• FIRE MANAGEMENT CONSIDERATIONS

IMMEDIATE FIRE EFFECT ON PLANT:

Big huckleberry foliage is of low flammability. Individuals may survive low-severity fires [104] with top-kill occurring on more intense fires [27,104,136].

DISCUSSION AND QUALIFICATION OF FIRE EFFECT:

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PLANT RESPONSE TO FIRE:

Big huckleberry is adapted to sprout after fire and is efficient in storing nutrients released from burning [136]. Big huckleberry resprouts after fire from shallow and deep rhizomes [27,104] or root crown [1]. Heat penetration into soil layers where rhizomes occur will affect big huckleberry's ability to produce vegetative sprouts after fire [104].

In preferred habitats, big huckleberry generally survives low to moderately severe fires. Big huckleberry attains preburn coverage within 3 to 7 years [16,22]. High-severity fires may result in moderate to high big huckleberry mortality [36] or greatly reduced sprouting [68]. Moderate to severe fires on coarse-textured soil or areas with a thin organic layer may kill underground rhizomes, resulting in heavy mortality [22,127]. Strong decreases occur after severe broadcast burning or wildfire, with recovery generally occurring within 15 to 20 years [6]. Overall, low-severity burns result in heavy sprouting from rhizomes [36].

DISCUSSION AND QUALIFICATION OF PLANT RESPONSE:

Low- to moderate-severity fire: Big huckleberry showed good vegetative response in lightly burned areas of western larch/Douglas-fir forests in western Montana. The same result was seen in moderate fires top-killing the majority of  shrubs and consuming up to half of the litter [138].

A comparison of postfire big huckleberry sprouting was made after spring (May-June) and fall (September-October) fires at the Lubrecht Experimental Forest of western Montana. The number of stems present before burns was closely related to the number of stems present after fire. Spring burns produced lower mortality of adventitious buds on rhizomes than did fall burns. Moist duff and soil present during spring burns served as a heat shield. Spring burns causing rhizome mortality occurred only in areas with duff and soil of low moisture content. Results summarizing the average stem number/meter² on 9 sites are presented below [104].

Spring Fires:

Before Fire (1973)	1974 (yr 1)	1975 (yr 2)	1973-1974 change in stem # (%)	1973-1975 change in stem # (%)
49.54	61.62	66.23	24.38	33.69
28.15	39.65	50.58	40.85	79.68
23.08	28.77	39.08	24.65	69.32
45.77	62.85	83.27	37.3	81.93
43.08	46.65	53.85	8.29	25.00
3.35	35.50	23.08	959.7	589.96
18.54	32.15	40.69	73.41	119.47
27.38	39.00	47.58	42.44	73.78
30.19	35.46	39.88	17.46	32.10

Fall Fires:

Before Fire (1973)	1974	1975	1973-1974 change in stem # (%)	1973-1975 change in stem # (%)
16.85	5.69	14.35	-66.23	-14.84
33.19	29.85	33.81	-10.06	1.87
18.73	37.54	46.62	100.43	148.91
34.65	38.08	47.35	9.90	36.65
97.96	92.96	117.54	-5.10	19.99
26.08	26.31	49.73	0.88	90.68
16.42	23.88	31.58	45.43	92.33
12.42	4.54	11.46	-63.45	-7.73
15.73	38.00	42.31	141.58	168.98

Moderate to high-severity fire: Doyle and others [40] evaluated plant species richness 17 years after the July 17, 1974, Waterfalls Canyon Fire in Grand Teton National Park, Wyoming. Big huckleberry dominated (30-36% coverage) the understory of an unburned area adjacent to the burn. Big huckleberry showed greatly reduced coverage (approximately 7%) in moderately burned areas and almost no coverage in severely burned areas. In another study, populations were greatly reduced the 1st growing season following a severe fire in the Payette River drainage near Lowman, Idaho [142].

Big huckleberry showed no postfire reestablishment through seed after the Sundance fire of 1967, a severe burn in northern Idaho [148].

In general, big huckleberry is slow to recover from moderate- to high-severity fire. After stand-replacing fire in upland Douglas-fir/big huckleberry sites in Pattee Canyon, west-central Montana, big huckleberry showed "slow" recovery. In severely burned ravines, big huckleberry sprouted from rhizomes at depths of 3.5 to 6 inches (9 to 15 cm). Before effective fire exclusion began in the early 1900s, fire return intervals in the area averaged 15.8 years [27]. Vegetation recovery for big huckleberry after an August wildfire in Sleeping Child Creek, Bitterroot Valley, Montana was slow; density and crown volume showed little recovery after 4 postburn years [94]:

	Before burn	1	2	3	4
Plants/1,000 feet2	113	--	2.2	18.4	28.3
	Before burn	1	2	3	4
Crown volume feet3/1,000 feet2	96.9	--	1.2	2.5	5.4

FIRE MANAGEMENT CONSIDERATIONS:

In most areas, fire exclusion reduces big huckleberry populations over time. In Washington, a big huckleberry field of 8,000 acres (3,238 ha) within an old burn has diminished to 2,500 acres (1,012 ha), replaced by trees and brush after 40 years of fire exclusion [105]. Repeated low-severity burns may control competing vegetation, enhancing big huckleberry vigor [107]. Franklin and Dyrness [48] attribute the occurrence of widespread big huckleberry fields within the southern Washington Cascades to large and repeated wildfires.

The Gitxsan and Wet'suwet'en people of northwestern British Columbia used fire to manage big huckleberry fields. Fires were usually set in early fall, late August, and September. Late fall burns were specifically chosen to reduce fire severity and spread because fall frontal storm systems were likely to bring precipitation. Eldar women decided burning time and scheduled fires during times they felt were prior to rainfall. Intervals between burns varied [79]. In the Cascades, where big huckleberry is a seral postfire dominant, Sahaptin and Chinook Native Americans started fires in the fall (at the end of huckleberry season) after winter rains began [51].

In habitat types were big huckleberry is dominant, fires conducted when the duff is relatively moist and not completely consumed result in heavy sprouting from rhizomes [36,115,124]. Low-severity burning may stimulate lateral bud growth and assist in the eradication of parasites [115]. Burning that consumes large amounts of duff is most harmful to big huckleberry regeneration [104]. Quantity of heat released by fire and relative amounts of duff and soil moisture are controlling factors in big huckleberry postfire recovery [103].

In western Montana, spring burning is recommended to increase big huckleberry density within the Douglas-fir/western larch habitat type, except when lower duff and soil are dry [104]. In moist Douglas-fir habitat types of Montana, where ponderosa pine and lodgepole pine are seral components, low-severity burning in the early spring stimulates big huckleberry, increasing shoot density [150]. In the Lolo National Forest, low- and moderate-severity surface fires increase density and nutrient content of big huckleberry in moist Douglas-fir and cool, dry Douglas-fir habitat types [32]. In the Douglas-fir/big huckleberry habitat type, spring fires and moderate amounts of shade may enhance production of big huckleberry [15].

In the grand fir series of the eastern Cascade Range, 2 consecutive fires in short intervals favored big huckleberry over grand fir, and big huckleberry shared dominance with lodgepole pine after intense fires on moist sites [1]. Due to low flammability of big huckleberry foliage, dense stands of big huckleberry may not burn if fuels are limited [104]. Density of big huckleberry may be increased by low severity surface fires in subalpine fir/big huckleberry habitat type in northern Utah [98].

In sub-boreal spruce zones of British Columbia, postfire sprouting of big huckleberry occurs almost exclusively through rhizomes. Postfire recovery is slow in the first 10 years postfire [66]. Likewise, in mesic and drier sites of the sub-boreal spruce zone in Canada, big huckleberry recovers slowly after fire [65].

Related categories for SPECIES: Vaccinium membranaceum | Big Huckleberry