• FIRE ECOLOGY OR ADAPTATIONS
• POSTFIRE REGENERATION STRATEGY

FIRE ECOLOGY OR ADAPTATIONS:

The foliage extractive heating value for snowbrush ceanothus has been reported at 11,942 Btu per pound [64]. Richards [222] found that the potential rate of spread through snowbrush ceanothus can be expected to increase as the growing season progresses from June 20 to September 10. This expectation is based on an increase in caloric content (from 1,400-2,400 calories/gram) and a decrease in the water content (from 68% to 53%) of green vegetation.

The following table presents information on snowbrush ceanothus fuel loading; the data is based on single-species plots and presented by fuel category [64]:

Fire Adaptations: | Snowbrush Ceanothus Snowbrush ceanothus has dormant, ground-stored seed that requires heat treatment to germinate [109,148,168,236]. Snowbrush ceanothus is promoted by fire, regenerating from seed stimulated by fire [63,143,163,201,228]. Where its seeds are present in the soil, snowbrush ceanothus may dominate early seral growth following a "medium or hot" fire [12]. Snowbrush ceanothus also sprouts vigorously from the root crown after fire [201,228,236]. Resprouting may be an adaptation to recurring fires, allowing for rapid growth and recovery [201]. Fire creates conditions more favorable for snowbrush ceanothus growth by removing the overstory [109]. Snowbrush ceanothus shows a marked increase in burned forest areas due to heat scarification of seed, sprouting, and increased light [109,119]. When conifers overtop the shrubfields, snowbrush ceanothus may die out because of reduced light intensities in the forest understory [119,120].

As a nitrogen fixer, snowbrush ceanothus plays an important role in nitrogen reaccumulation following fire [143].

Early seral shrub layers dominated by snowbrush ceanothus form in grand fir/big huckleberry [242], grand fir/Rocky Mountain maple [245,247], Douglas-fir/ninebark [244], Douglas-fir/pinegrass [246,248], Douglas-fir/white spirea [249], and Douglas-fir/Rocky Mountain maple [244] habitat types in response to fire. Dry weather patterns following canopy removal and repeated severe fires are likely to produce persistent seral shrubfields [239,304]. In the northern Rocky Mountains, pure stands of snowbrush ceanothus may form on the south-facing slopes of these shrubfields [239].

Fire Regimes: | Snowbrush Ceanothus  Fire regimes for plant communities and ecosystems in which snowbrush ceanothus occurs are listed below. For further information regarding fire regimes and fire ecology of communities and ecosystems where snowbrush ceanothus is found, see the 'Fire Ecology and Adaptations' section of the FEIS species summary for the plant community or ecosystem dominants listed below.

POSTFIRE REGENERATION STRATEGY [258]:

Related categories for SPECIES: Ceanothus velutinus | Snowbrush Ceanothus