Ecological dynamics
Ecological Dynamics of the Site
This ecological site is highly diverse in tree species, shrub and forb composition. Forest composition is dependent of fire severity, occurrence, and tree species seed source after fire. Western white pine used to dominate stands after stand replacing fires before the white pine blister rust. Now, western larch, Douglas-fir, lodgepole, and ponderosa pine (dry exposures) have replaced it. Grand fir and western red cedar also get established but sit in understory underneath the other species until release from canopy openings. In early stands after fire Quaking aspen, paper birch, and black cottonwood will be present only to be overtopped in later years. Shrub competition can be severe after fire with many shrub species dominating the site. Red stem ceanothus or snowbrush ceanothus (drier areas) could dominate sites with severe burns. Mixed severity fires create a patchy mosaic of all tree species being present. Reference condition will have fire exclusion or fire intervals of over 150 years which produce an all-aged western red cedar – grand fir forest. Relic western larch, Douglas-fir, and ponderosa pine may be present.
State 1
Reference
This state with extended fire intervals turns into an all aged western redcedar stand with some grand fir present. Most understory regeneration is western redcedar again with some grand fir. Stand replacing fires start off in the herb/shrub stage with many species of shrubs potentially occupying the site. Shrubs include Douglas maple, serviceberry, snowbrush ceanothus, redstem ceanothus, snowberry, and ninebark. Tree regeneration is variable depending on available seed source. A host of seral species can establish including western larch, Douglas-fir, ponderosa pine, lodgepole pine, and western white pine (limited due to blister rust). Cedar and grand fir can also establish, but will sit underneath the seral species until released. Severe fires can cause soil degradation causing sites to remain in shrubs for long periods preventing tree establishment. With successful tree regeneration a mix of seral tree species can occupy the stand or in some cases, a single species like western larch will dominate the stand. These stands go into the stem exclusion phase with tree to tree competition. Understory vegetation will be sparse. As these stands mature mixed severity fires create a mosaic of stand structure and species composition with a combination of seral species and shade tolerant cedar and grand fir.
Sites on midslopes are more likely to burn more intensely than lower slopes due to a “thermal belt” condition with lower slopes being cooler and midslopes warmer and drier in summer conditions.
Community 1.1
Reference
Mature stands of 150+ old western redcedar with some grand fir. An all aged stand structure is present with most regeneration being cedar with some grand fir. Relic western larch, Douglas-fir, ponderosa pine, and western white pine (if not killed by blister rust) may be present. Paper birch can be present in the understory. Major herb species include queencup beadily (brides bonnet), starry Solomonplume, w. rattlesnake plantain, and round-leaved violet. Major shrubs include pachistima, twinflower, w. prince’s pine, baldhip rose, Oregon grape, Douglas maple, and Utah honeysuckle.
Dominant plant species
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western redcedar (Thuja plicata), tree
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grand fir (Abies grandis), tree
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Rocky Mountain Douglas-fir (Pseudotsuga menziesii var. glauca), tree
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western larch (Larix occidentalis), tree
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Oregon boxleaf (Paxistima myrsinites), shrub
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longtube twinflower (Linnaea borealis ssp. longiflora), shrub
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pipsissewa (Chimaphila umbellata), shrub
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Rocky Mountain maple (Acer glabrum), shrub
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Utah honeysuckle (Lonicera utahensis), shrub
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dwarf rose (Rosa gymnocarpa), shrub
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hollyleaved barberry (Mahonia aquifolium), shrub
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darkwoods violet (Viola orbiculata), other herbaceous
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bride's bonnet (Clintonia uniflora), other herbaceous
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western rattlesnake plantain (Goodyera oblongifolia), other herbaceous
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starry false lily of the valley (Maianthemum stellatum), other herbaceous
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Piper's anemone (Anemone piperi), other herbaceous
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Pacific trillium (Trillium ovatum ssp. ovatum), other herbaceous
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fairy slipper (Calypso bulbosa), other herbaceous
Community 1.2
Mixed Species Stand
Mixed severity fires create a mosaic of mixed tree species. Western larch, Douglas-fir, western white pine, ponderosa pine (drier sites), and lodgepole pine can compose the stand. Cedar and grand fir will be mixed into the stand structure. Quaking aspen, black cottonwood and paper birch can be part on these mosaic stands.
Community 1.3
Stem Exclusion
Dense pole size stand competition. Stands composed of mixed seral species or in some cases only cedar
Community 1.4
Stand Initiation
Shrub and herb phase with tree regeneration depending on seed source. Single species regeneration such as western larch or mixed with larch, Douglas-fir, white pine, grand fir and cedar. Ponderosa pine establishment mostly on drier warmer sites. Lodgepole pine establishment possible on hotter burn sites. Shrubs can dominate for long periods preventing tree establishment
Pathway 1.1A
Community 1.1 to 1.4
Stand replacing fire
Pathway 1.2A
Community 1.2 to 1.1
Fire interval extended to allow shade tolerant cedar and grand fir to grow up from understory to dominate stand.
Pathway 1.3C
Community 1.3 to 1.1
Time, fire interval extended to allow cedar and grand fir to dominate stand. No disturbance to allow seral species to dominate.
Pathway 1.3A
Community 1.3 to 1.2
Time, allowing stands to reach maturity before a stand replacing fire. Mixed severity fires then occur.
Pathway 1.3B
Community 1.3 to 1.4
Stand replacing fire in dense pole stands.
Pathway 1.4A
Community 1.4 to 1.3
Time, allowing tree regeneration to grow into pole stands
State 2
Shrubfields
Severe fires change reference state to a shrubfield site. No tree regeneration due to shrub competition and soil conditions. Major shrubs include snowbrush and redstem ceanothus, serviceberry, ninebark, Scouler willow, elderberry species, snowberry, spirea, and Douglas maple
Community 2.1
Reference
Severe fires change reference state to a shrubfield site. No tree regeneration due to shrub competition and soil conditions. Major shrubs include snowbrush and redstem ceanothus, serviceberry, ninebark, Scouler willow, elderberry species, snowberry, spirea, and Douglas maple
Transition T1A
State 1 to 2
Severe fires creating shrubfields preventing tree establishment for long time periods.
Restoration pathway R2A
State 2 to 1
Site by site analysis to determine tree planting survival. Tree planting species mostly seral species like, larch, Douglas-fir, ponderosa pine, and white pine (blister rust resistant).