Natural Resources
Conservation Service
Ecological site F044AF006MT
Lower Subalpine Moderately Cool and Moist Coniferous Pend Oreille-Kootenai Valleys western redcedar-western hemlock/bride's bonnet
Last updated: 5/01/2024
Accessed: 11/13/2024
General information
Provisional. A provisional ecological site description has undergone quality control and quality assurance review. It contains a working state and transition model and enough information to identify the ecological site.
MLRA notes
Major Land Resource Area (MLRA): 044A–Northern Rocky Mountain Valleys
This MLRA includes the northern portion of the Northern Rocky Mountain Valleys Province of the Rocky Mountain System. The mountain valleys are deeply dissected and are typically bordered by mountains trending north to south. The nearly level broad flood plains are bordered by gently to strongly sloping terraces and alluvial fans. The surrounding mountains and in some areas the valleys experienced glaciation. The average precipitation is 12 to 16 inches generally, though can vary widely. The dominant soil orders are Inceptisols, Mollisols and Andisols. The valleys support coniferous forests, shrublands and grasslands.
LRU notes
The landscape is valleys with landforms including floodplains, stream and outwash and lacustrine terraces, foothills and glacial moraines. Glaciation of this area was in the form of alpine, icecap and valley outlet glaciers. It also includes associated alluvium and outwash features. This area includes valleys with elevation ranging 545 to1680m, with an average elevation of 855m. The climate is cold and wet with mean annual air temperature of 8 degrees C, mean frost free days of 106 days and mean annual precipitation of 863mm. The relative effective annual precipitation is 88cm. The soil temperature regime is frigid, and the soil moisture regime is udic and xeric. Soils are generally very deep, moderately to well developed and formed in alluvium, glacial outwash and till from metasedimentary parent materials. Soils tend to be well drained, slightly acidic to slightly alkaline soils with skeletal silt loam, loam and sandy loam textures. Poorly drained soils are present, but are generally confined to areas along riparian corridors. Volcanic ash influenced soils occur here as well, but tend to be limited to stable footslope positions above the valley floor. The geology of this area is predominantly alluvium and Belt series (Missoula group) and minor Glacial lake deposits. There are numerous large lakes and reservoirs including Pend Oreille Lake, Priest Lake, Noxon Reservoir, Cabinet Gorge Reservoir, Bull Lake and numerous short rivers and creeks.This area is predominantly Western Hemlock and Western Red Cedar, with moderate Douglas Fir, Grand Fir, agricultural lands and minor Cottonwood-willow, Idaho fescue grasslands and Ponderosa Pine.
Classification relationships
This ecological site resides within the NRCS land classification of MLRA 431 and LRU F Pend Oreille – Kootenai Valleys. MLRA 431 is referred to as the North Central Mountains and Foothills. Specifically, LRU K is the Pend Oreille – Kootenai Valleys.
This is related to the EPA land classification framework of: Level 3- 15 Northern Rockies. Specifically, it includes Level 4-15q Purcell-Cabinet-North Bitterroot Mountains. This area is related predominantly to the USFS Provinces M333Ba Purcell-North Cabinet Mountains and M333Dc Clark Fork Valley and Mountains.
Ecological site concept
The lower subalpine frigid coniferous site group is found west of the Continental Divide in moist areas within a maritime climate. It is found primarily in lake terrace and mountain slope landforms, on back, foot and toe slope positions, and on all aspects, spanning elevations from 650 to 850 meters.
The Reference Community is dominated by western cedar and western hemlock, with seral tree species constrained to less than 25 percent of the total overstory canopy. The ground cover consists predominantly of litter and duff with fairly high cover of moss and trace cover of embedded litter and stones. The vegetation structure is that of multistoried overstory trees ranging from 40 feet to over 120 feet tall of western redcedar, western hemlock, western larch and Douglas fir. The understory is multistoried though fairly sparse. The tallest understory layer is 20 to 40 inches tall and can include common snowberry (Symphoricarpos albus) and white spirea (Spiraea betulifolia). The lowest layer is less than 10 inches tall and can include fireweed (Chamerion angustifolium), pipsissewa (Chimaphila umbellata), queencup beadlily (Clintonia uniflora), western rattlesnake plantain (Goodyera oblongifolia), twinflower (Linnaea borealis), threeleaf foamflower (Tiarella trifoliata), and Oregon boxleaf (Paxistima myrsinites). The understory has less species diversity and canopy cover is very low in comparison to other forested ecological sites. Species are shade-loving and include princes plume, queencup beadlily, western rattlesnake plantain, twinflower, and a thick cover of moss.
Soils associated with this ecological site are very deep, loamy, usually ash-capped soils over rocky subsoils. Ash thickness on these soils varies and is mixed (not pure) and provides a boost in water-holding capacity to these sites. These soils generally belong in the Andic Eutrudepts soil subgroup, but also in the Andic Hapludafls and Typic Dystrudepts. There is a thin organic layer present in these soils, generally less than 5 cm thick.
Associated sites
F044AF001MT |
Lower Subalpine Moderately Warm and Moist Coniferous Pend Oreille-Kootenai Valleys grand fir/bride's bonnet This associated ecological site resides in areas that are slightly less warm and moist than this ecological site due to aspect or elevation or other factors. |
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Similar sites
F044AP904MT |
Upland Cool Moist Woodland Group This similiar ecological site is broader in scope but has similiar site conditions and the overstory is dominated by western redcedar and western hemlock. |
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Table 1. Dominant plant species
Tree |
(1) Thuja plicata |
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Shrub |
(1) Symphoricarpos albus |
Herbaceous |
(1) Clintonia uniflora |
Physiographic features
The lower subalpine frigid coniferous site group is found west of the Continental Divide in moist areas within a maritime climate. It is primarily located on lake terrace and mountain slope landforms on back, foot and toe slope positions, with linear slope shape down and across, and on all aspects, spanning elevations from 650 to 850 meters. In Montana, the site group is generally found at elevations ranging from 2,000 to 5,000 feet. The annual precipitation average is above 32 inches (USFS H.T. Guide, 1977).
Table 2. Representative physiographic features
Landforms |
(1)
Terrace--stream or lake
(2) Outwash terrace (3) Ground moraine (4) Alluvial fan |
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Elevation | 610 – 1,524 m |
Slope | 5 – 35% |
Water table depth | 152 cm |
Aspect | W, NW, N, NE, E, SE, S, SW |
Climatic features
This ecological site is found in the frigid soil temperature regime and the udic soil moisture regime. The soils that support this native plant community occur in the frigid soil temperature regime (average annual temperature less than 8 degrees C, with more than 5 degrees C summer-winter fluctuation). A udic soil moisture regime denotes that the rooting zone is usually moist throughout the winter and most of the summer. This site is found on the west side of the Continental Divide and has more maritime weather influences.
Table 3. Representative climatic features
Frost-free period (characteristic range) | 68-79 days |
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Freeze-free period (characteristic range) | 124-129 days |
Precipitation total (characteristic range) | 559-762 mm |
Frost-free period (actual range) | 65-80 days |
Freeze-free period (actual range) | 122-130 days |
Precipitation total (actual range) | 483-838 mm |
Frost-free period (average) | 73 days |
Freeze-free period (average) | 127 days |
Precipitation total (average) | 660 mm |
Figure 1. Monthly precipitation range
Figure 2. Monthly minimum temperature range
Figure 3. Monthly maximum temperature range
Figure 4. Monthly average minimum and maximum temperature
Figure 5. Annual precipitation pattern
Figure 6. Annual average temperature pattern
Climate stations used
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(1) TROY [USC00248390], Troy, MT
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(2) TROUT CREEK RS [USC00248380], Trout Creek, MT
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(3) HERON 2 NW [USC00244084], Heron, MT
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(4) LIBBY 1 NE RS [USC00245015], Libby, MT
Influencing water features
This ecological site is not influenced by wetland or riparian water features but may be found on stream terraces or adjacent to wetland and riparian areas.
Soil features
Soils associated with this ecological site are very deep, loamy, commonly ash-capped soils sometimes over rocky subsoils. Ash thickness on these soils varies and is mixed (not pure) and provides a boost in water-holding capacity to these sites. These soils generally belong in the Andic Eutrudepts soil subgroup, but also in the Alfic Udivitrands and Udivitrands. There is a thin organic layer present in these soils, generally less than 5 cm thick.
Diagnostic horizons and features recognized in this pedon in the (Sunroad) - Andic Eutrudepts subgroup are:
Ochric epipedon -- from 0 to 16 cm (Oi, Oe, E horizons)
Andic soil properties -- 12 to 38 cm (E, Bw1, Bw2 horizons)
Cambic horizon -- from 16 to 38 cm (Bw1, Bw2 horizons)
Particle-size control section -- from 37 to 112 cm (part of the Bw2, 2C1, part of the 2C2 horizons)
Courvash soils -
Diagnostic horizons and features recognized in this pedon are: a volcanic ash mantle from the mineral soil surface to 18 inches (A, Bw1 and Bw2 horizons); an ochric epipedon from the mineral soil surface to 7 inches (A, Bw1 horizons); an albic horizon from 18 to 31 inches (2E horizon); an argillic horizon from 31 to 60 inches (2Bt/E, 2Bt horizons); a particle size control section from 0 to 40 inches below the mineral soil surface (A, Bw1, Bw2, 2E, and 2Bt/E horizons). Courvash soils have a udic moisture regime and a frigid temperature regime.
Dewberry soils -
Diagnostic horizons and features recognized in this pedon are: a volcanic ash mantle from 1 to 24 inches (A, Bw1 and Bw2 horizons); an ochric epipedon from the mineral soil surface to 7 inches (A, Bw1 horizons); a particle size control section from 0 to 40 inches below the mineral soil surface (A, Bw1, Bw2 and 2C horizons).
Soils have a frigid temperature regime and an udic moisture regime.
“Mount Mazama (Crater Lake, Oregon) violently erupted around 6,700 years ago. The massive plume of volcanic ash from the eruption drifted in a northwest direction through northwest Montana. Deposition was widespread throughout western Montana, but is greatest in the northwest corner of the state. The ash likely fell uniformly across the landscape and was then re-distributed by wind and water erosion. The resulting distribution, given the dominate winds from the south and southwest, favors thicker deposits of ash on slopes with north-facing aspects. Little ash is usually found on south-facing slopes except at the higher elevations in cirque basins. Volcanic ash has a large impact on overstory and understory plant productivity due to the increase in water-holding capacity that it adds to the soil. The ash is typically found as a surface mantle overlying whatever existing soil or parent material it was deposited on top of. The ash mantles exhibit varying amounts of mixing with the underlying material, but tend to lack the rock fragments commonly found in the sub-soils of the park. Ashy soil layers generally tend to have brighter colors than the underlying sub-soils and have a soft and very friable consistency.” (J. Skovlin, personal communication, 2015; Soil Survey Staff, 2015).
For more information on soil taxonomy, please follow this link:
http://http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/survey/class/?cid=nrcs142p2_053580
Table 4. Representative soil features
Parent material |
(1)
Volcanic ash
(2) Till (3) Lacustrine deposits (4) Alluvium – metasedimentary rock |
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Surface texture |
(1) Very gravelly sandy clay loam (2) Silt loam (3) Fine sandy loam |
Drainage class | Well drained |
Soil depth | 99 – 150 cm |
Soil reaction (1:1 water) (0-101.6cm) |
5.6 – 6.4 |
Subsurface fragment volume <=3" (0-101.6cm) |
0 – 15% |
Subsurface fragment volume >3" (0-101.6cm) |
0 – 35% |
Ecological dynamics
►OVERVIEW:
This group is found throughout this MLRA/LRU unit and in the Kootenai NF.
This ecological site relates to the USFS Habitat Types of western redcedar/brides bonnet and western hemlock/brides bonnet which are in Fire Group 11 and are in the updated USFS Region 1 Montana Potential Vegetation Type THPL2 (moderately cool and moist) and in the old Habitat Type Group 5. McDonald had these Habitat Types in the western redcedar-western hemlock grouping which had historical western white pine and potential for root rot Armillaria complex. In the Vegetation Response Unit these were in group 5.
►MANAGEMENT:
Various management strategies can be employed for this ecological site group depending on the ownership of the particular land and which value is prioritized. The management of the forest determines the composition of the stand and the amount of fuel loading. A stand will be managed differently and look differently if it is managed for timber or ecological services like water quality, old growth, or endangered species. If a stand is managed for timber, then it may be missing certain attributes necessary for lynx habitat. If a stand is managed for lynx habitat, it may have increased fuels and therefore an increased risk of wildfires.
The USFS Habitat Type Guide (1973) states that the basal area on the western side of the Continental Divide for TSHE/CLUN2 is 267+/-55 ft2 per acre. The fifty-year site index for western white pine is 62, western larch is 80, PICEA is 77, and grand fir is 50. Basal area for THPL/CLUN2 is 305+/-96 ft2 per acre and the site index for Douglas-fir is 66, western larch is 63, PICEA is 72+/-14, grand fir is 61, and ABLA is 74.
Timber production on these sites is very high, particularly in the seral phases of this ecological site.
Each national forest has a specific management plan. The management plan for the Kootenai National Forest. also has an Appendix B that gives specific management guidelines for habitat types (which relate to our forested ecological sites) found on the forest in relation to current and historic data on forest conditions (Kootenai N.F. Plan, 2001 and Appendix B). Another guiding USFS document is the Green et al. document (2005) which defines “Old Growth” forest for the northern Rocky Mountains. This document provides an ecologically-based classification of old growth based on forest stand attributes including numbers of large trees, snags, downed logs, structural canopy layers, canopy cover, age, and basal area. While this document finds that the bulk of the pre-settlement upland old growth in the northern Rockies was in the lower elevation, ground-fire maintained ponderosa pine/western larch/Douglas-fir types (Losensky, 1992), it does not mean that other types were not common or not important. This may apply to some of the areas of this ecological site.
State and transition model
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Click on state and transition labels to scroll to the respective text
Ecosystem states
T1A | - | Substantial loss of western white pine as a major seral tree species. |
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R2A | - | Western white pine restored as a major seral tree species. |
T2A | - | Significant loss of susceptible tee species at a site due to Armillaria root rot and conversion of the forest to a shrubland. |
R3A | - | Conversion of the Armillaria root rot induced shrubland to forest, generally of less susceptible seral tree species and eventually to climax tree species. |
State 1 submodel, plant communities
Communities 1 and 5 (additional pathways)
1.1A | - | Fire and post fire recovery |
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1.2A | - | Aging and density increase in stand due to the process of forest in the absence of fire. |
1.3A | - | Maturing of the forest stand in the absence of fire or disturbance. |
1.3B | - | The mature stand dynamics with the absence of fire and aging stand opening processes. |
1.4A | - | Fire, controlled or wild, or other stand renewing practices that spark a renewal of early seral trees. |
1.5A | - | Fire, controlled or wild, or other stand renewing practices that spark a renewal of early seral trees. |
State 2 submodel, plant communities
Communities 1, 5 and 2 (additional pathways)
2.1A | - | This pathway represents a major, stand-replacement disturbance such as a high-intensity fire, large-scale wind event, or a large insect infestation. |
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2.2A | - | This pathway represents growth over time with no further significant disturbance. The areas of regeneration pass through the typical stand phases, namely: competitive exclusion, maturation, understory reinitiating. |
2.3B | - | This pathway represents a major, stand-replacement disturbance such as a high-intensity fire, large-scale wind event or a large insect infestation. |
2.3A | - | This pathway represents continued growth over time with no further major disturbance. |
2.4B | - | This pathway represents a major, stand-replacement disturbance, such as a large insect outbreak, or major fire event which leads to the stand initiation phase of forest development. |
2.4A | - | This pathway represents continued growth over time with no further major disturbance. |
2.5A | - | This pathway represents no further major disturbance. Continued growth over time, as well as ongoing mortality, leads to continued vertical diversification. |
2.5B | - | This pathway represents a major stand-replacement fire disturbance leading to the stand initiation phase of forest development. |
State 3 submodel, plant communities
State 1
Historic State
Western white pine (Pinus monticola)-western redcedar-western hemlock/common snowberry-white spirea/twinflower-creeping barberry/wild sarsaparilla-bride's bonnet
Historically western white pine would have been throughout this MLRA/LRU unit and Kootenai NF. Western white pine covered five million acres in the Inland Northwest. Western white pine is incredibly productive for timber due to a fast growth rate, tall stature, deep roots, and the ability to compete best on highly variable, high resource sites. Additionally, it is tolerant to the native root rot diseases and other native forest pests. Western white pine is susceptible to Armillaria root disease only when young, and to mountain pine beetle largely at advanced ages (over 140 years). It also has the capability to thrive in a wide variety of sites and environments, which means it has high ecological flexibility. It is a long-living seral species that tolerated intense timber harvesting practices and severe fire disturbance with its ability to regenerate on mineral soil and full sunlight. Fire greatly influences the composition, structure, and function of vegetation across the landscape. Historically, it was mixed severity fire between severe stand replacement fires. Western larch and western white pine are long-lived, fire-adapted, shade-intolerant tree species that historically thrived. Also present in significant amounts, particularly in young stands, were the shorter-lived, shade-intolerant and fire-adapted tree species such as Douglas-fir and lodgepole pine. Shade-tolerant, fire-intolerant tree species such as western cedar, western hemlock, grand fir, Engelmann spruce, and subalpine fir were present, but rarely survived long enough to dominate stands except in areas where the interval between fires was unusually long and where root disease was not severe. Prior to the 20th century, western white pine was a major component in forested ecosystems of the inland northwest United States. However, it has now been greatly reduced in distribution and abundance by white pine blister rust, mountain pine beetles, and anthropogenic fire exclusion (Tomback and Achuff, 2010). Western white pine has been replaced by Douglas-fir, grand fir, and western hemlock. Out of these tree species, Douglas-fir and grand fir are susceptible to a greater variety of insect and disease problems, whereas hemlock is more sensitive to drought and decay. More stands have also progressed to the climax species-dominated phase, which previously were rarely achieved due to the fire rotations and susceptibility of these species to disease and forest pests. A study of pathogen and insect effects on forests within the Inland Empire found that there were more than 90% of sample stands changed to a different cover type, structure stage, or both during a 40-year period that was coincident with the blister rust epidemic and fire suppression policy. This accelerated the succession of western white pine, ponderosa pine, and lodgepole pine to later successional, more shade-tolerant species. Furthermore, structure was reduced in stand density and prevented canopy closure. Grand fir, Douglas-fir, and subalpine fir were the predominant cover types at the end of the period, and were highly susceptible to root diseases, bark beetles, fire, and drought. It is estimated that there will be continuation of this trend occurring in low-density mature stands and younger pole-sized stands that result from root disease and bark beetle-caused mortality (Byler and Hagel, 2000). These stands also are less productive in terms of timber. They are dominated by species with high nutrient demands, and therefore nutrient storage and cycling rates are increasingly depressed. This will likely lead to ever-increasing stress and destabilization by pests and diseases, which can be further exacerbated by drought. The Inland Empire Tree Improvement Cooperative and the USFS have a breeding program for blister-resistant western white pine. Approximately 5 percent of the original acre range was re-planted with rust-resistant stock. Currently, the modified stock shows about 60 percent resistance to blister rust. A study modeling the effects of climate change found that warming temperatures would favor increased abundance of western white pine over existing climax and shade-tolerant species in Glacier NP, mainly because warmer conditions may increase wildfire frequency and extent, which helps western white pine regeneration (Loehman, et al 2011).
Community 1.1
Reference Plant Community
Reference Plant Community of multi-storied forest canopy dominated by western redcedar and western hemlock. Subalpine fir-Engelmann spruce overstory. Minor western white pine-western larch-grand fir. Rare phase due to disturbance rotations. Structure: Multistory with small gap dynamics.
Community 1.2
Post Fire
Post fire disturbance community of herb and shrub species. Western white pine-western larch-(lodgepole pine) seedlings. ►STRUCTURE: Patchy clumps, single story. ►TIME: 1 to 50 years
Community 1.3
Intermediate Aged Forest
Intermediate aged forest, dense thick pole sized trees. Western white pine-western larch-(subalpine fir-grand fir-Engelmann spruce). ►STRUCTURE: Dense single story with diminished understory. ►TIME: 50 to 140 years.
Community 1.4
Maturing Forest
Maturing forest phase of seral tree species and western redcedar and western hemlock. Western white pine-(western hemlock-western redcedar-grand fir). ►STRUCTURE: Some vertical differentiation in stand. ►TIME: 140 years to centuries.
Community 1.5
Mature Forest
Mature forest with some small gap dynamics, remnant seral trees species and western redcedar and western hemlock dominant. Western white pine-(western hemock-western redcedar-grand fir). ►STRUCTURE: Mature stand with patches of open canopy cover. ►TIME: 140 years to centuries.
Pathway 1.1A
Community 1.1 to 1.2
Fire and post fire recovery
Pathway 1.2A
Community 1.2 to 1.3
Aging and density increase in stand due to the process of forest in the absence of fire.
Pathway 1.3A
Community 1.3 to 1.4
Maturing of the forest stand in the absence of fire or disturbance.
Pathway 1.3B
Community 1.3 to 1.5
The mature stand dynamics with the absence of fire and aging stand opening processes.
Pathway 1.4A
Community 1.4 to 1.1
Fire, controlled or wild, or other stand renewing practices that spark a renewal of early seral trees.
Pathway 1.5A
Community 1.5 to 1.1
Fire, controlled or wild, or other stand renewing practices that spark a renewal of early seral trees.
State 2
Reference State
Western redcedar-western hemlock/common snowberry-white spirea/twinflower-creeping barberry/wild sarsaparilla-bride's bonnet
State 2 is different than State 1 in that western white pine no longer plays a significant role in the seral communities. It has been dramatically reduced in numbers and area by the epidemics of white pine blister rust, western spruce budworm, and by dramatic fire suppression. As a result, climax species have been able to fill the seral role that western white pine once held. Additionally, more forests are progressing toward this state than historically, when most forests were in the fire-maintained western white pine-dominated seral phase. State 2 forests are now dominated by the shade-tolerant climax species western redcedar and western hemlock. While there is a large effort to bolster the numbers of western white pine, it currently covers only 5 percent of its historic range. State 2 is dominated by western redcedar and western hemlock, both of which are shade-tolerant climax conifers that grow in similar environments. Western redcedar has a larger geographic extent in Montana, but western hemlock usually is capable of dominating over western redcedar and other species at climax because it is better able to reproduce under a dense forest canopy. Western redcedar is able to maintain itself indefinitely as a minor climax species because of its shade tolerance and longevity (average lifespan of 600-1,000 years). Within Glacier NP, these species are co-dominant in nearly all of the sites visited. The seral successional stages have very diverse overstory tree composition and can be very productive in terms of basal area. Douglas fir, western larch and, to a lesser extent, spruce are often dominants in seral stands with lodgepole, western white pine, and paper birch as minor components. Grand fir and subalpine fir can be either minor seral or climax components. Western redcedar and western hemlock will regenerate after disturbance along with seral species, and it will take centuries for these species to gain dominance in the overstory over the seral species. The early successional phase can be dominated by fireweed (Chamerion angustifolium). The understory in seral successional phases have moisture-loving forbs or shrubs including Scouler’s willow, thimbleberry, serviceberry, Rocky Mountain maple, thinleaf huckleberry, and snowbush ceanothus. The historic fire regime of these forests is one of low fire frequency, but fire severity can be highly variable. It can be low due to the most common moist conditions and can be severe during times of drought. Fire return intervals range from 50 to greater than 200 years, but include mixed severity fires on 50-85 year intervals, as well as stand replacement fires on 150 to 250 year intervals. Western redcedar can thrive for centuries on this ecological site without disturbance. The Northern Rocky Mountain mesic-montane-mixed-conifer-forest-cedar groves are in fire regime group 5 and have a fire interval of 334 years, with 87 percent of fires classified as of replacement severity and 13 percent of fires classed as mixed severity and none as low severity (USDA, USFS, FEIS, Fire Regime). Fuel loadings for this ecological site can be very high due to deadfall and natural thinning of small and medium-sized branches. In early and intermediate successional phases, the understory can have high cover, which adds to fuel loadings. In general, the variability in fire regime and the high diversity of tree species present in most stands, except the reference phase, allow this ecological site group to form a diverse mosaic landscape with varying dominance or mixes of seral species. The general fire succession process is that after stand replacement fires, the community reverts to an herbaceous one, then to shrubland. If fire is reoccurring in this phase, then the phase is maintained for a long time. The herbaceous community can be dominated by the disturbance-loving fireweed, beargrass, or numerous other species, depending upon the seedbank at the site and beyond. Duration of the herbaceous or shrubland phase is also dependent upon the availability of tree seed. If serotinous lodgepole pine seeds are available, then the site will become dominated by it and a lodgepole pine stand will develop for about 10-25 years (Habeck, 1968). After that time, other species become established including western larch and other conifers. If serotinous lodgepole pine seeds are not present, then the seedlings are a very diverse mixture of conifers. These seedlings form a thick carpet on the site shared with shrub species such as Scouler’s willow, white spirea, thinleaf huckleberry, thimbleberry, and Oregon boxwood. Forbs present include ferns, beargrass and fireweed. Moss cover can be variable. If fire does not occur, the seedlings will grow to pole-sized trees of diverse seral species. Low to moderate fires in this stage would favor fire-tolerant seral species over western redcedar, grand fir, or western hemlock, which are less fire-resistant. Severe fires will return these to the herbaceous or shrubland phase. In the pole-sized phase, seral species are abundant and western redcedar and western hemlock are just becoming established and usually have low cover (3-15 percent of the stand).Without further disturbance, this phase will continue to the maturing forest in which western redcedar and western hemlock become more evident in the stand and eventually have higher cover than the seral tree species. Western larch may survive severe fires in the maturing or mature phases. These trees would then provide seed for the stand initiation phase after a fire. Additionally, after frequent low to moderate fires in the mature phase, a relict western larch stand could occur. Reference stands in which only western redcedar and western hemlock occur can be rare, as seral species are long-lived and fire occurs frequently enough that stands seldom develop beyond the mature phase. However, there were abundant reference phase stands along the shores of Lake McDonald in Glacier NP. The Robert fire in 2003 heavily impacted some areas on the west side of Lake McDonald, but other areas close to the shore were not affected. Reference stands may withstand low fires that thin the stand, but severe fires would return the site to the herbaceous or shrubland phase. Significant fires that have occurred on the west side of the Continental Divide that have affected this ecological site are the Robert Fire in 2003 that burned 54,191 acres, the Moose Fire in 2001 that burned 66,688 acres, and the Middle Fork Complex Fire in 2003 that burned 11,996 acres. There were historic fires within the area of this ecological site that burned significant portions in 1735 and another portion in 1926 (NPS Stand Age spatial layer). Both western hemlock and western redcedar are subjected to a variety of diseases and insect pests including Armillaria root disease, Annosus root disease, pouch fungus, red belt fungus, pini rot, metallic wood borers, and roundheaded borers. Western redcedar is also susceptible to cedar laminated butt rot, cedar brown pocket rot, and cedar bark beetles. Western hemlock is also susceptible to Indian paint fungus.
Resilience management. Various management strategies can be employed for this ecological site, depending upon the ownership of the land and which value is prioritized. The management of the forest determines the composition of the stand and the amount of fuel loading. A stand will be managed differently and look differently if it is managed for timber or ecological services like water quality and quantity, old growth, or endangered species. If a stand is managed for timber, then it may be missing certain attributes necessary for lynx habitat. If a stand is managed for lynx habitat, it may have increased fuels and therefore an increased risk of wildfires. The USFS Habitat Type Guide (1973) states that the basal area on the western side of the Continental Divide for TSHE/CLUN2 is 267+/-55 ft2 per acre. The fifty-year site index for western white pine is 62, western larch is 80, PICEA is 77, and grand fir is 50. Basal area for THPL/CLUN2 is 305+/-96 ft2 per acre and the site index for Douglas-fir is 66, western larch is 63, PICEA is 72+/-14, grand fir is 61, and ABLA is 74. Timber production on these sites is very high, particularly in the seral phases of this ecological site. Each national forest has a specific management plan. The management plan for the Kootenai N.F. also has an Appendix B that gives specific management guidelines for habitat types (which relate to our forested ecological sites) found on the forest in relation to current and historic data on forest conditions (Kootenai N.F. Plan, 2001 and Appendix B). Another guiding USFS document is the Green et al. document (2005) which defines “Old Growth” forest for the northern Rocky Mountains. This document provides an ecologically based classification of old growth based on forest stand attributes including numbers of large trees, snags, downed logs, structural canopy layers, canopy cover, age, and basal area. While this document finds that the bulk of the pre-settlement upland old growth in the northern Rockies was in the lower elevation, ground-fire maintained ponderosa pine/western larch/Douglas-fir types (Losensky, 1992), it does not mean that other types were not common or not important. This could apply to some of the areas of this ecological site.
Community 2.1
Reference Plant Community
Western redcedar-western hemlock/common snowberry/western brackenfern/twinflower/brides bonnet/moss
Western redcedar-western hemlock/ western oakfern-wild sarsaparilla / queencup beadlily-threeleaf foamflower-twinflower Structure: Multistory with small gap dynamics of tall trees (100+ feet), that are larger (DBH 20+ inches) and older and dominated by western redcedar and western hemlock, though seral tree species can be present in very low cover. ►TIME: 200+ years This ecological site is substantiated by datasets taken at five various time periods and in different locations to give both temporal and geographic variability to the distribution and breadth of the ecological site. The five datasets used were historic (1980s generally) NRCS soil survey data in which both soils and vegetation were sampled throughout the area of the LRU. Current NRCS soil survey data include work on an update project around the Troy MT and Bull Lake MT area in 2018 in which both soils and vegetation were sampled. In another update soil survey project around Plains MT area, soil and vegetation data was collected in 2020 and 2021. In 2021, NRCS was able to collect soils and vegetation data in the USFS Lower Ross Creek Research Natural Area, which is located within the vicinity of the Troy -Bull Lake update project, and the Seeley-Swan RNA located in the Seeley-Swan valley MT. COMMUNITY PHASE 2.1: REFERENCE A summarization of each dataset will follow. The reference phase can occur in moister site conditions in which there has been minimal management action of any kind as seen in the Lower Ross Creek Cedars RNA area. These have additional moist plant species such as common ladyfern and British Columbia wild ginger. Other areas further east within this LRU, or areas that have been recently logged or managed, have some drier site species such as common snowberry, Rocky mountain maple and twinflower. The following is a summarization of all field sampled sites. The overstory of reference sites are dominated by western redcedar and western hemlock that are older, tall, large and robust. Western redcedar and western hemlock are regenerating successfully on the site. Seral tree species that can occur in very low cover include Grand fir, subalpine fir, western larch, lodgepole pine, Engelmann spruce, western white pine and Douglas fir. On streamside terrace positions, deciduous tree species may occur in low cover including black cottonwood and quaking aspen. Lower canopy layers are also dominated by western redcedar and western hemlock and seral species can occur in low cover. The understory consistently has western oakfern and wild sarsaparilla in the tallest layer and queencup beadlily, threeleaf foamflower and twinflower in the lowest layer. The understory is diverse but occurs in low cover that is patchy rather than uniform distribution and the ground cover is namely litter and duff. Shrub species that can occur in patchy low cover: Saskatoon serviceberry, thimbleberry, white spirea, thinleaf huckleberry, dwarf bilberry, Rocky Mountain maple, Utah honeysuckle, rusty menziesia, Devil’s club, Oregon boxleaf, thimbleberry, common snowberry, bunchberry dogwood, creeping barberry, currant and rose species. Herbaceous species that can occur in low cover include American trailplant, yarrow, heartleaf arnica, mountain brome, pinegrass, pipsisewa, enchanter’s nightshade, blue wildrye, woodland strawberry, sweetcicely, feathery false lily of the valley and viola species. Moist site species can occur including common ladyfern, Pacific oakfern, western brackenfern, horsetail, Pacific yew, Idaho goldthread, northwestern sedge and shortbeak sedge. 2021 Ross Creek Cedars RNA dataset (2 sites). These sites represent the oldest stand of western redcedar and western hemlock and the least managed sites and therefore, closest to reference condition, which includes natural disturbances such as insects, disease and fire but not logging or grazing. Western redcedar-western hemlock/common ladyfern/ western oakfern-wild sarsaparilla/drops-of-gold/ queencup beadlily-threeleaf foamflower Structure: Multistory with small gap dynamics of tall trees (100+ feet), that are larger (DBH 25-50+ inches range) and older and dominated by western redcedar and western hemlock, though rarely seral tree species are present. The Ross Creek Cedars Natural Research Natural Area and adjacent Scenic Area has western redcedar trees that are reported to be over 1,000 years old. We were able to sample two sites considered to be in reference condition for the western redcedar and western hemlock ecological site. The overstory is dominated by large, mature western redcedar and to a lesser degree, western hemlock. Western redcedar was very large with average diameter at breast height of fifty-four inches with a range of twenty-one to sixty-one inches, that are over one hundred and fifty feet tall and very high basal area averaging 480 (ranging from 440 to 520). The understory is diverse and includes common ladyfern, western oakfern, drops-of-gold, threeleaf foamflower, British Columbia wildginger and starry false lily of the valley. Understory foliar cover is moderately high (61%), predominantly common ladyfern (23%) and drops-of-gold (14%). The canopy cover was like the foliar canopy cover with common ladyfern having the highest average cover (26%), British Columbia wildginger (10%), threeleaf foamflower (9%) and drops-of-gold (7%) and wild sarsaparilla (6%). The tallest understory species is Rocky Mountain maple ranging from 4.5-13 feet tall, Devil’ Club which is 2 to 4.5 feet tall. The bulk of species are 1-2 feet tall and include: wild sarsaparilla, common ladyfern, drops-of-gold, currant species, thimbleberry. Species that are 0.5-1 foot tall include: American trailplant, western oakfern, starry false lily of the valley, Pacific trillium, while those below 0.5 foot tall include: British Columbia wildginger, bride’s bonnet, smallflower miterwort. The ground had high cover of litter, predominantly litter under plants. The type of litter is predominantly duff (90%), low embedded litter (7%), very little moss (1%) and bare soil (2%). Sampling sites located on private logging and USFS lands near Libby Montana. Western redcedar-western hemlock/common snowberry (white spirea-oceanspray-thimbleberry)/western brackenfern (wild sarparilla)/twinflower (kinninick)/ queencup beadlily (Idaho goldenthread-mountain brome-pinegrass) Structure: Multistory with small gap dynamics of tall trees (40-120+ feet), that are larger (DBH average 17-21, but range up to 27 inches) and older and dominated by western redcedar and western hemlock though seral tree species are present The Reference Community is dominated by western cedar and western hemlock (proportionately 75% total overstory canopy cover), with seral tree species constrained to 25%. The total overstory absolute cover averages 66% and ranges from 55 to 82% in height classes from 40 to 120+ feet tall. Proportionately, there are more trees in the taller height classes (7 and 8 which are taller than 40 feet, than in the shorter class 6). The vegetation structure is that of tall multi-storied overstory trees from 40-120+ feet tall, predominantly western redcedar and western hemlock. The most common seral tree species is western larch. Seral tree species that may be present include western larch and Douglas fir (average canopy cover is 8% absolute cover each) and less cover (5% or less each species) of Grand fir, lodgepole, Englemann spruce and western white pine. The understory is moderately diverse in species and cover is low to moderate. Species are shade-loving and include prince’s plume, queencup beadlily, western rattlesnake plantain, and twinflower. The understory is multistoried though fairly to very sparse. Species with the highest frequency of occurrence include common snowberry, white spirea, twinflower, creeping barberry, wild sarspirilla, and queencup beadlily (7 sites of canopy cover data). The ground cover consists predominantly of litter and duff with fairly high cover of moss and trace cover of gravel, cobbles and stones. Foliar cover at three sites indicate that the foliar cover can range widely (averaging 41%; range 9-95%) and the ground cover is primarily litter (98%) and moss (2%). Two of the three sites with foliar cover had total foliar cover of 9% and 18% which seems typical compared to reference sites of this ecological site in Glacier NP, whereas the one site with foliar cover of 95% seems an anomaly. The tallest understory layer (4.5-13 feet) is very sparse (averages 5%) and includes Rocky Mountain maple and serviceberry. The next lower layer (2-4.5 feet) is sparse (averages 10% cover) and includes thinleaf huckleberry. The next layer (1-2 feet) has moderate cover (10-35%) and includes wild sarspirilla, rose, thimbleberry, white spirea and common snowberry. The low layer (0.5-1 foot) has moderate cover and includes dwarf bilberry, creeping barberry, sweet cicely and threeleaf foamflower. The lowest layer (
Forest overstory. The forest overstory is substantiated by various datasets that reveal that typically this ecological site community phase has tall, mature western redcedar and western hemlock in a multi-storied stand.
At the Ross Creek RNA site, western hemlock trees had diameter at breast height ranging 50 to 70 inches with lower canopy trees with diameters at 20 to 30 inches. The heights ranged 150 to 160 feet tall, the crown ratio was 35 to 65 percent of the tree. The basal area ranged 400 to 600.
On private logging lands and USFS lands around Libby Montana, the overstory was Multistory with small gap dynamics of tall trees (40-120+ feet), that are larger (DBH average 17-21, but range up to 27 inches) and older and dominated by western redcedar and western hemlock though seral tree species are present.
The 2021 dataset near Plains Montana the overstory was Multistory canopy (40-120+ feet) with small gap dynamics, of tall trees (most trees over 100 feet tall), that are larger (DBH average 23 inches for western redcedar and western hemlock but range up to 40 inches) and older (over 100 years old) and dominated by western redcedar and western hemlock though seral tree species are present.
The 2021 dataset in Swan River RNA had forest of Multistory canopy (40-120+ feet) with small gap dynamics, of tall trees (most trees over 100 feet tall), that are larger (DBH average 27 inches for western redcedar and western hemlock average 24 inches but ranges 19 inches up to 33 inches) and older (over 100 years old) and dominated by western redcedar and western hemlock though seral tree species are present. Basal area ranges 180 to 280. There is high foliar cover (73%) and high ground cover mostly under plant cover of litter. The litter is predominantly duff (93%), moss (4%) and soil (1%), water (2%).
Forest understory. The forest understory is very diverse, each species has low canopy cover generally.
Dominant plant species
-
western redcedar (Thuja plicata), tree
-
western hemlock (Tsuga heterophylla), tree
-
twinflower (Linnaea borealis), shrub
-
bride's bonnet (Clintonia uniflora), other herbaceous
-
threeleaf foamflower (Tiarella trifoliata), other herbaceous
-
wild sarsaparilla (Aralia nudicaulis), other herbaceous
-
Pacific oakfern (Gymnocarpium disjunctum), other herbaceous
Figure 7. Annual production by plant type (representative values) or group (midpoint values)
Table 5. Soil surface cover
Tree basal cover | 5-15% |
---|---|
Shrub/vine/liana basal cover | 0-10% |
Grass/grasslike basal cover | 0-5% |
Forb basal cover | 0-10% |
Non-vascular plants | 0-5% |
Biological crusts | 0-2% |
Litter | 40-60% |
Surface fragments >0.25" and <=3" | 0-5% |
Surface fragments >3" | 0-5% |
Bedrock | 0% |
Water | 0% |
Bare ground | 0-10% |
Table 6. Canopy structure (% cover)
Height Above Ground (m) | Tree | Shrub/Vine | Grass/ Grasslike |
Forb |
---|---|---|---|---|
<0.15 | 0-5% | 0-10% | 0-5% | 0-10% |
>0.15 <= 0.3 | 0-5% | 5-15% | 0-5% | 0-10% |
>0.3 <= 0.6 | 5-10% | 5-20% | – | – |
>0.6 <= 1.4 | 5-10% | – | – | – |
>1.4 <= 4 | 5-10% | – | – | – |
>4 <= 12 | 5-10% | – | – | – |
>12 <= 24 | 10-30% | – | – | – |
>24 <= 37 | 10-40% | – | – | – |
>37 | 10-40% | – | – | – |
Community 2.2
Post Fire Stand Initiation
Post Fire Stand Initiation Regen: Lodgepole pine-western larch-Douglas fir Post- fire 1-5 years Structure: Initially this post fire stand initiation community is dominated by herbaceous and shrub species most commonly fireweed, species with a resident seedbank or disturbance loving species. Structure: Continuous cover of regeneration-single story mixed tree species. Post-fire 5-50 years Structure: This is a forest in the stand initiation phase, possibly with scattered remnant mature trees; the composition of the seedlings depends on the natural seed sources available. Habeck found that in the vicinity of Lake Mcdonald in Glacier N.P., the dominant seral tree species is Lodgepole pine for 10-25 years post-fire. Afterwards, Western Larch will co-dominant from 25-50 years post-fire with other seral tree species at lower cover. Throughout the entire area of this ecological site, the regeneration will probably be a mixture. Overstory canopy cover is generally less than 10%, but the regeneration tree cover is very high forming a thick carpet. It is a mixture of species including: Lodgepole pine, Western larch, subalpine fir, Paper birch, Engelmann spruce, Western white pine, Black cottonwood, Quaking aspen, Douglas fir, Western redcedar and Western hemlock. The understory is a diverse mixture of herbaceous and shrub species including tall willow species, particularly Scouler’s willow, medium statured shrubs white spirea and thinleaf huckleberry, the low statured shrubs thimbleberry and Oregon boxwood. Herbaceous species include: fireweed, beargrass. Moss cover is variable. LATER EARLY SERAL STAGE: Single story overstory canopy that has high canopy cover of shorter (less than 40 feet), smaller (DBH less than 10 inches) and younger seral species with western redcedar and western hemlock less than 10% canopy cover Lodgepole-Douglas fir/kinnikinic-bunchberry dogwood-creeping barberry-twinflower/wild sarsaparilla-western brackenfern/pinegrass Overstory of trees predominantly of shorter, smaller and younger trees with a few large remnant trees from previous fires. Total overstory canopy cover in the height classes 6 to 8 is 50%. The majority of tree cover falls within height classes 6 and 7, as opposed to the taller height classes which dominate the mature and reference phase communities. These trees are young and have DBHs less than 10 inches, except for remnant fire seral trees that are larger. Foliar cover of the understory is moderate to high (average total foliar cover is 68%, ranging from 52% to 79%). The dataset is completely comprised of post logging operation sites that mimic the post-disturbance early seral phase of this ecological site.
Forest understory. PRODUCTION
Historic Wood 5 dataset (two sites) of total annual production (not to species) of 575.2 and 1196 pounds per acre.
2018 NRCS dataset (three sites) of annual production by species with total production of site at 550, 1157 and 1977 pounds per acre.
These have complete soil pedon descriptions and vegetation field sampling data of ocular estimation of canopy cover and tree production including site index and basal area and canopy cover, but are not GPS located, rather are historic and use township, section, range information.
Dominant plant species
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lodgepole pine (Pinus contorta), tree
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western larch (Larix occidentalis), tree
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Douglas-fir (Pseudotsuga menziesii), tree
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kinnikinnick (Arctostaphylos uva-ursi), shrub
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redosier dogwood (Cornus sericea ssp. sericea), shrub
-
twinflower (Linnaea borealis), shrub
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pinegrass (Calamagrostis rubescens), grass
-
wild sarsaparilla (Aralia nudicaulis), other herbaceous
-
western brackenfern (Pteridium aquilinum), other herbaceous
Figure 8. Annual production by plant type (representative values) or group (midpoint values)
Community 2.3
Intermediate aged Forest
Lodgepole pine-Douglas fir-western larch-grand fir-ponderosa pine/white spirea-snowberry-oceanspray/creeping barberry-kinnikinick/western brackenfern-Idaho goldenthread/pinegrass
COMMUNITY PHASE 2.3: Intermediate aged Forest. Lodgepole pine-Douglas fir-western larch-Grand fir-ponderosa pine (western redcedar-western hemlock)/white spirea-snowberry-oceanspray/creeping barberry-kinnickinik/western brackenfern-Idaho goldenthread/pinegrass Structure: Single story, moderately sized (pole size), seral tree species dominant forests with much less western redcedar and western hemlock than in the mature or reference community phase (only 5-15% of total canopy cover). These trees are larger and taller than the later early community phase, but smaller than the reference phase. This community phase is dominated by seral tree species that have matured to pole size and are in the competitive exclusion phase of forest succession. Overstory tree canopy is dense and competition for resources is very high. Canopy cover averages 50%. This community is incredibly diverse in tree species including: Lodgepole pine, Douglas fir, Engelmann spruce, Western larch, Paper birch, subalpine fir, Western white pine, Western redcedar and Western hemlock. The overstory canopy of Western redcedar and Western hemlock averages 5% as they are just beginning to become established. The understory can have high cover of the medium sized shrubs white spirea, snowberry, Oregon boxleaf, common snowberry and thinleaf huckleberry. The short statured thimbleberry can have high cover. The herbaceous layer is diverse, with medium statured beargrass occurring frequently and sometime in high cover. Other herbaceous species include the short statured prince’s plume, queencup beadlily, trailplant and twinflower. HISTORIC WOOD 5 DATASET: ALL SERAL DOMINANT STANDS SUMMARIZED: These have complete soil pedon descriptions and vegetation field sampling data of ocular estimation of canopy cover and tree production including site index and basal area and canopy cover, but are not GPS located, rather are historic and use township, section, range information. There are variations within seral dominant forests within the cedar-hemlock ecological site. One species may be dominant in terms of canopy cover over the other seral tree species. The seral dominant forests include western larch dominant, lodgepole dominant and mixed seral species, in which no tree species is dominant. The trees in general are pole sized, with few remnant large seral trees that survived previous fires. Cedar and hemlock have very low canopy cover (<5%). The median age of this stand is 55 years old with average height ranging 60-90 feet tall for the western larch dominated stands. The Lodgepole pine dominated stands had a median age of 50 years old and average height range 65-100 feet tall. The mixed seral stands had a median age of 65 years old and heights ranging 55-100 feet tall. All these sites have been previously logged. Western Larch Dominant: western larch (Grand fir-lodgepole pine-Douglas fir-ponderosa pine) / common snowberry-white spirea/western bracken fern/twinflower /pinegrass/ Idaho goldthread FOREST OVERSTORY METRICS Total Canopy Cover Average = 72% Range = 50-90% Relative Canopy Cover by species = LAOC = 50-95% PSME, PICO, PIPO = 10-35% PIMO3, TSHE, THPL = 5% DBH Range LAOC = 6-18” PSME = 10-19” PIPO = 11-22” Basal Area Average (all species included): 165 Range = 102-260 SITE INDEX, CUBIC FEET, BOARD FEET BY SPECIES LAOC (8 sites): Site Index=77 113 Cubic Feet 412 Board Feet PSME (5 sites): Site Index=68 108 Cubic Feet 405 Board Feet PIPO (4 sites): Site Index=78 118 Cubic Feet 476 Board Feet PICO (1 site): Site Index=104 126 Cubic Feet 440 Board Feet Forest Understory: The most frequent species are pinegrass (4 percent), western brackfern (3 percent), and common snowberry (4 percent). Lodgepole Pine Dominant: Lodgepole pine (western larch-Grand fir-Douglas fir)/common snowberry-white spirea / creeping barberry-twinflower / pinegrass/ Idaho goldthread. Total Canopy Cover Average = 82% Range = 60-96% Relative Canopy Cover by species = PICO = 50-95% PSME, LAOC, PIPO, PIMO3 = 1-35% PIEN, TSHE, THPL = 5% DBH Range PICO = 7-19“ LAOC = 8-15” PSME = 9-14” Basal Area Average (all species included): 188 Range = 140 - 280 SITE INDEX, CUBIC FEET, BOARD FEET BY SPECIES PICO (9 site): Site Index=95 109 Cubic Feet 395 Board Feet LAOC (6 sites): Site Index=65 128 Cubic Feet 480 Board Feet PSME (1sites): Site Index=66 Cubic Feet Board Feet The understory is diverse with tall and medium statured shrubs and herbaceous forbs below. The most frequent species include twinflower, Idaho goldthread, Oregon boxwood, creeping barberry, white spirea and common snowberry. MIXED SERAL: western larch-Grand fir-Douglas fir-Ponderosa pine/common snowberry-white spirea/western brackenfern/creeping barberry-twinflower/pinegrass/Idaho goldthread. FOREST OVERSTORY METRICS Total Canopy Cover Average = 75% Range = 40-100% Relative Canopy Cover by species = PICO = 19% PSME =25% LAOC = 33% PIPO = 26% PIMO3= 3% TSHE= 2% THPL = 2% DBH Range LAOC =9-24” PSME = 9-24” PIPO =8-29” Basal Area Average (all species included): 167 Range = 110-220 SITE INDEX, CUBIC FEET, BOARD FEET BY SPECIES LAOC (11sites): Site Index= 68 118 Cubic Feet 439 Board Feet PSME (9sites): Site Index= 66 109 Cubic Feet 419 Board Feet PIPO (10sites): Site Index= 115 131 Cubic Feet 590 Board Feet PICO (8site): Site Index= 95 114 Cubic Feet 411 Board Feet The understory is diverse with many species of shrubs and herbaceous forbs. The most frequently occurring species are twinflower, creeping barberry, Idaho goldthread, bride's bonnet, Saskatoon serviceberry, western brackenfern, white spirea, common snowberry and wild sarsaparilla.
Community 2.4
Maturing Forest
Western larch-Douglas fir-grand fir-western redcedar/snowberry-oceanspray/twinflower/western brackenfern-Idaho goldenthread
COMMUNITY PHASE 2.4: Maturing Forest. Western larch-Douglas fir- Grand fir-western redcedar/ snowberry-oceanspray/ twinflower /western brackenfern-Idaho goldenthread LATER INTERMEDIATE AGED FOREST WITH >15% TSHE-THPL PRESENT Structure: Single story overstory canopy cover of predominantly pole sized trees of seral species with western redcedar and western hemlock in more abundance than in previous intermediate phase datasets (7-18% total canopy cover) but much less than in the mature or reference community phases. Structure: This community is a maturing forest with vertical differentiation in the overstory tree canopy. Canopy cover averages 57%. The median age for these stands is 75 years old and average heights range 75-100 feet tall. This community has diverse tree species with Western redcedar and Western hemlock ranging 7-18% total canopy cover and other seral tree species about equally distributed. These species include: Subalpine fir, Lodgepole pine, Engelmann spruce, Western white pine. The understory has patchy medium sized shrubs including: thinleaf huckleberry, snowberry, white spirea. There is a diverse understory of herbaceous species including: wild sarsaparilla, heartleaf arnica, queencup beadlily, twinflower and beargrass. There can be high cover of moss. HISTORIC WOOD 5 DATASET: These have complete soil pedon descriptions and vegetation field sampling data of ocular estimation of canopy cover and tree production including site index and basal area and canopy cover, but are not GPS located, rather are historic and use township, section, range information. Table 1. Forest overstory summarization table. FOREST OVERSTORY FROM HISTORIC WOOD 5 FORMS (8 sites): Average Relative (total equals 100%) Forest canopy by species: LAOC=23%; PSME=22%; ABGR=20%; THPL=18%; TSHE=7%; PIMO3=5%; PICO=3%; POTR5=T; BEPA=T Absolute Forest Total Canopy Cover Average: 57% Range=30%-90% DBH Range per species: PIPO=17-26 PSME=11-26 LAOC=10-19 ABGR=14-19 Average basal area: 120 Site Index at 100 yrs.: LAOC 65-85; PSME 58; PIPO 118 Cubic Feet: LAOC 104-158; PSME 88 CU FT; PIPO 142 CU FT. Board Feet: LAOC 365-635 BF; PSME 300 BF; PIPO 587 BF The forest understory is diverse and the most frequently occuring species include pinegrass, bride's bonnet, Idaho goldthread, oceanspray, twinflower, western brackenfern and common snowberry..
Community 2.5
Mature Forest
Western redcedar-western hemlock (western larch-grand fir)/Sitka alder/western brackenfern-wild sarsaparilla/pinegrass
COMMUNITY PHASE 2.5: Mature Forest. Western redcedar-western hemlock (western larch-Grand fir)/Sitka alder/western brackenfern-wild sarspirilla/pinegrass Structure: Mature Forest with vertical differentiation in the stand. The overstory canopy cover is comprised of taller (over 40 feet tall), moderately large (DBH over 13 inches) and older trees of predominantly western redcedar and western hemlock and seral tree species. These trees are smaller and younger than those in the reference phase, but significantly larger than the later early phase. These forests are dominated by western redcedar and western hemlock, far more than in the intermediate community phase. Overstory is dominated by Western redcedar and Western hemlock (72% of total canopy cover) although seral tree species are present (28% total canopy cover). Overstory canopy cover averages 75% and ranges 74-85%. The trees are predominantly in the taller height classes 7 and 8, over 40 feet tall. These trees are smaller girth or diameter at breast height than trees in the reference state. Western larch is the most common seral species but others include: Grand fir, subalpine fir, Paper birch, Lodgepole pine, Western white pine, and Douglas fir. The understory is diverse but generally has low overall cover. Thinleaf huckleberry occurs in clumps and queencup beadlily and western rattlesnake plantain are common. Western brackenfern has the highest foliar cover (8 percent), wild sarsaparilla (6 percent) and pinegrass and white spirea have 5 percent each. All of the sites used to represent this community phase have been previously logged. OVERSTORY Basal Area Average = 143 Range = 120-200 There was 1 site with very low BA (40-60) DBH Average/Range: PIMO3 = 12/11-13; PSME (1 site)= 14; PICO = 13/11-15; TSHE = 13/8-17; LAOC = 18/18-18; THPL = 13/7-17; ABGR = 20/15-23 Predominantly tall trees in height class 8, as opposed to the later early seral stage and the intermediate seral stage with trees predominantly shorter in height classes 6 and 7.
Pathway 2.1A
Community 2.1 to 2.2
This pathway represents a major, stand-replacement disturbance such as a high-intensity fire, large-scale wind event, or a large insect infestation.
Pathway 2.2A
Community 2.2 to 2.3
This pathway represents growth over time with no further significant disturbance. The areas of regeneration pass through the typical stand phases, namely: competitive exclusion, maturation, understory reinitiating.
Pathway 2.3B
Community 2.3 to 2.2
This pathway represents a major, stand-replacement disturbance such as a high-intensity fire, large-scale wind event or a large insect infestation.
Pathway 2.3A
Community 2.3 to 2.4
This pathway represents continued growth over time with no further major disturbance.
Pathway 2.4B
Community 2.4 to 2.3
This pathway represents a major, stand-replacement disturbance, such as a large insect outbreak, or major fire event which leads to the stand initiation phase of forest development.
Pathway 2.4A
Community 2.4 to 2.5
This pathway represents continued growth over time with no further major disturbance.
Pathway 2.5A
Community 2.5 to 2.1
This pathway represents no further major disturbance. Continued growth over time, as well as ongoing mortality, leads to continued vertical diversification. The community begins to resemble the structure of the reference community, with small pockets of regeneration and a more diversified understory.
Pathway 2.5B
Community 2.5 to 2.2
This pathway represents a major stand-replacement fire disturbance leading to the stand initiation phase of forest development.
State 3
Root Rot
Another disease affecting this ecological site is root rot. While Douglas-fir, grand fir, and subalpine fir are most susceptible, western redcedar and western hemlock can be affected as well. Armillaria root disease is the most common root disease fungus in this region, and is especially prevalent west of the Continental Divide. It may be difficult to detect until it has killed enough trees to create large root disease pockets or centers, ranging in size from a fraction of an acre to hundreds of acres. The root disease spreads from an affected tree to its surrounding neighbors through root contact. The root disease effects the tree species most susceptible first, leaving less susceptible tree species that may mask its presence from land managers. When root rot is severe, the pocket has abundant regeneration or dense brush growth in the center. Western redcedar is moderately resistant to Armillaria root rot in Idaho and Montana. The common disease expression is some mortality in saplings, and residuals of partial harvests often develop severe infections but are very slow to die (Hagle, 2010). There has been a link determined between parent material and susceptibility to root disease (Kimsey et al., 2012). Metasedimentary parent material is thought to increase the risk of root disease. Glacier National Park is dominated by metasedimentary parent material and may be more at risk than other areas to root disease (Kimsey et al., 2012). If a stand sustains very high levels of root disease mortality, then a conifer stand could cross a threshold and become a shrubland once all conifers are gone (Kimsey et al., 2012). Management tactics include to identify the type of Armillaria root disease, and manage for pines and larch. Pre-commercial thinning may improve growth and survival of pines and larch. Harvests that leave susceptible species, such as Douglas-fir or true firs, as crop trees should be avoided (Hagel, 2010).
Community 3.1
Shrubland
►STRUCTURE: Shrub-dominated area ►TIME: 50+ years
Transition T1A
State 1 to 2
Substantial loss of western white pine as a major seral tree species.
Restoration pathway R2A
State 2 to 1
Western white pine restored as a major seral tree species.
Transition T2A
State 2 to 3
Significant loss of susceptible tee species at a site due to Armillaria root rot and conversion of the forest to a shrubland.
Restoration pathway R3A
State 3 to 2
Conversion of the Armillaria root rot induced shrubland to forest, generally of less susceptible seral tree species and eventually to climax tree species.
Additional community tables
Table 7. Community 2.1 plant community composition
Group | Common name | Symbol | Scientific name | Annual production (kg/hectare) | Foliar cover (%) | |
---|---|---|---|---|---|---|
Forb
|
||||||
1 | Perennial and annual forbs | – | ||||
wild sarsaparilla | ARNU2 | Aralia nudicaulis | – | 0–24 | ||
drops-of-gold | PRHO2 | Prosartes hookeri | – | 0–14 | ||
bride's bonnet | CLUN2 | Clintonia uniflora | – | 0–11 | ||
threeleaf foamflower | TITR | Tiarella trifoliata | – | 0–9 | ||
American trailplant | ADBI | Adenocaulon bicolor | – | 0–8 | ||
British Columbia wildginger | ASCA2 | Asarum caudatum | – | 0–5 | ||
starry false lily of the valley | MAST4 | Maianthemum stellatum | – | 0–5 | ||
Idaho goldthread | COOC | Coptis occidentalis | – | 0–4 | ||
woodland strawberry | FRVE | Fragaria vesca | – | 0–3 | ||
fragrant bedstraw | GATR3 | Galium triflorum | – | 0–2 | ||
roughfruit fairybells | PRTR4 | Prosartes trachycarpa | – | 0–2 | ||
heartleaf arnica | ARCO9 | Arnica cordifolia | – | 0–1 | ||
feathery false lily of the valley | MARA7 | Maianthemum racemosum | – | 0–1 | ||
smallflower miterwort | MIST3 | Mitella stauropetala | – | 0–1 | ||
western meadow-rue | THOC | Thalictrum occidentale | – | 0–1 | ||
Sitka valerian | VASI | Valeriana sitchensis | – | 0–1 | ||
violet | VIOLA | Viola | – | 0–1 | ||
woodland strawberry | FRVE | Fragaria vesca | – | 0–1 | ||
arrowleaf rattlesnakeroot | PRSA | Prenanthes sagittata | – | 0–1 | ||
common yarrow | ACMI2 | Achillea millefolium | – | 0–1 | ||
white hawkweed | HIAL2 | Hieracium albiflorum | – | 0–1 | ||
sidebells wintergreen | ORSE | Orthilia secunda | – | 0–1 | ||
4 | Fern | – | ||||
western oakfern | GYDR | Gymnocarpium dryopteris | – | 0–30 | ||
common ladyfern | ATFI | Athyrium filix-femina | – | 0–23 | ||
Pacific oakfern | GYDI2 | Gymnocarpium disjunctum | – | 0–1 | ||
western brackenfern | PTAQ | Pteridium aquilinum | – | 0–1 | ||
Grass/Grasslike
|
||||||
2 | Grasses, sedges, rushes | – | ||||
pinegrass | CARU | Calamagrostis rubescens | – | 0–3 | ||
mountain brome | BRMA4 | Bromus marginatus | – | 0–2 | ||
mountain brome | BRMA4 | Bromus marginatus | – | 0–1 | ||
roughleaf ricegrass | ORAS | Oryzopsis asperifolia | – | 0–1 | ||
sedge | CAREX | Carex | – | 0–1 | ||
Shrub/Vine
|
||||||
3 | Shrubs and subshrubs | – | ||||
white spirea | SPBE2 | Spiraea betulifolia | – | 0–10 | ||
Pacific yew | TABR2 | Taxus brevifolia | – | 0–5 | ||
dwarf bilberry | VACE | Vaccinium cespitosum | – | 0–4 | ||
twinflower | LIBO3 | Linnaea borealis | – | 0–4 | ||
creeping barberry | MARE11 | Mahonia repens | – | 0–3 | ||
Saskatoon serviceberry | AMAL2 | Amelanchier alnifolia | – | 0–2 | ||
bunchberry dogwood | COCA13 | Cornus canadensis | – | 0–2 | ||
common snowberry | SYAL | Symphoricarpos albus | – | 0–2 | ||
rose | ROSA5 | Rosa | – | 0–1 | ||
currant | RIBES | Ribes | – | 0–1 | ||
thimbleberry | RUPA | Rubus parviflorus | – | 0–1 | ||
dwarf red blackberry | RUPU | Rubus pubescens | – | 0–1 | ||
Rocky Mountain maple | ACGL | Acer glabrum | – | 0–1 | ||
Utah honeysuckle | LOUT2 | Lonicera utahensis | – | 0–1 | ||
kinnikinnick | ARUV | Arctostaphylos uva-ursi | – | 0–1 | ||
western mountain ash | SOSI2 | Sorbus sitchensis | – | 0–1 | ||
thinleaf huckleberry | VAME | Vaccinium membranaceum | – | 0–1 | ||
Sitka alder | ALVIS | Alnus viridis ssp. sinuata | – | 0–1 |
Table 8. Community 2.1 forest overstory composition
Common name | Symbol | Scientific name | Nativity | Height (m) | Canopy cover (%) | Diameter (cm) | Basal area (square m/hectare) |
---|---|---|---|---|---|---|---|
Tree
|
|||||||
western redcedar | THPL | Thuja plicata | Native | 36.6–48.8 | 20–40 | 50.8–190.5 | – |
western hemlock | TSHE | Tsuga heterophylla | Native | 36.6–48.8 | 20–40 | 50.8–190.5 | – |
Table 9. Community 2.1 forest understory composition
Common name | Symbol | Scientific name | Nativity | Height (m) | Canopy cover (%) | |
---|---|---|---|---|---|---|
Grass/grass-like (Graminoids)
|
||||||
mountain brome | BRMA4 | Bromus marginatus | Native | – | 0–3 | |
Forb/Herb
|
||||||
Canadian wildginger | ASCA | Asarum canadense | Native | – | 0–30 | |
wild sarsaparilla | ARNU2 | Aralia nudicaulis | Native | – | 0–15 | |
roughfruit fairybells | PRTR4 | Prosartes trachycarpa | Native | – | 0–10 | |
threeleaf foamflower | TITR | Tiarella trifoliata | Native | – | 0–10 | |
American trailplant | ADBI | Adenocaulon bicolor | Native | – | 0–5 | |
bride's bonnet | CLUN2 | Clintonia uniflora | Native | – | 0–5 | |
fragrant bedstraw | GATR3 | Galium triflorum | Native | – | 0–5 | |
sweetcicely | OSBE | Osmorhiza berteroi | Native | – | 0–3 | |
San Joaquin bluecurls | TROV | Trichostema ovatum | Native | – | 0–2 | |
violet | VIOLA | Viola | Native | – | 0–2 | |
Virginia strawberry | FRVI | Fragaria virginiana | Native | – | 0–2 | |
Fern/fern ally
|
||||||
common ladyfern | ATFI | Athyrium filix-femina | Native | – | 0–30 | |
western oakfern | GYDR | Gymnocarpium dryopteris | Native | – | 0–20 | |
western brackenfern | PTAQ | Pteridium aquilinum | Native | – | 0–5 | |
Shrub/Subshrub
|
||||||
twinflower | LIBO3 | Linnaea borealis | Native | – | 0–5 | |
rose | ROSA5 | Rosa | Native | – | 0–4 | |
white spirea | SPBE2 | Spiraea betulifolia | Native | – | 0–4 | |
common snowberry | SYAL | Symphoricarpos albus | Native | – | 0–4 |
Table 10. Community 2.2 plant community composition
Group | Common name | Symbol | Scientific name | Annual production (kg/hectare) | Foliar cover (%) | |
---|---|---|---|---|---|---|
Forb
|
||||||
1 | Perennial and annual forbs | 112–560 | ||||
white hawkweed | HIAL2 | Hieracium albiflorum | 0–39 | 5 | ||
Idaho goldthread | COOC | Coptis occidentalis | 0–39 | – | ||
feathery false lily of the valley | MARA7 | Maianthemum racemosum | 0–34 | 1 | ||
sweetcicely | OSBE | Osmorhiza berteroi | 0–28 | 2 | ||
wild sarsaparilla | ARNU2 | Aralia nudicaulis | 0–28 | – | ||
orange hawkweed | HIAU | Hieracium aurantiacum | 0–17 | 15 | ||
common selfheal | PRVU | Prunella vulgaris | – | 3 | ||
violet | VIOLA | Viola | – | 2 | ||
common yarrow | ACMI2 | Achillea millefolium | – | 2 | ||
oxeye daisy | LEVU | Leucanthemum vulgare | – | 2 | ||
Engelmann's aster | EUEN | Eucephalus engelmannii | – | 1 | ||
4 | Fern | 56–560 | ||||
western brackenfern | PTAQ | Pteridium aquilinum | 0–560 | 46 | ||
Grass/Grasslike
|
||||||
2 | Grasses, sedges, rushes | 224–1345 | ||||
pinegrass | CARU | Calamagrostis rubescens | 0–1457 | 20 | ||
roughleaf ricegrass | ORAS | Oryzopsis asperifolia | 0–112 | 10 | ||
green needlegrass | NAVI4 | Nassella viridula | 0–112 | – | ||
mountain brome | BRMA4 | Bromus marginatus | 0–17 | 5 | ||
blue wildrye | ELGL | Elymus glaucus | 0–17 | 5 | ||
northwestern sedge | CACO11 | Carex concinnoides | – | 10 | ||
Richardson's needlegrass | ACRI8 | Achnatherum richardsonii | – | 5 | ||
rush | JUNCU | Juncus | – | 2 | ||
Shrub/Vine
|
||||||
3 | Shrubs and subshrubs | 112–336 | ||||
creeping barberry | MARE11 | Mahonia repens | 0–112 | 25 | ||
bunchberry dogwood | COCA13 | Cornus canadensis | 0–67 | 2 | ||
white spirea | SPBE2 | Spiraea betulifolia | 0–56 | 5 | ||
twinflower | LIBO3 | Linnaea borealis | 0–28 | 20 | ||
rose | ROSA5 | Rosa | 0–28 | 2 | ||
common snowberry | SYAL | Symphoricarpos albus | 0–28 | 1 | ||
kinnikinnick | ARUV | Arctostaphylos uva-ursi | – | 10 | ||
dwarf bilberry | VACE | Vaccinium cespitosum | – | 2 | ||
raceme pussytoes | ANRA | Antennaria racemosa | – | 1 | ||
spreading dogbane | APAN2 | Apocynum androsaemifolium | – | 1 |
Table 11. Community 2.2 forest overstory composition
Common name | Symbol | Scientific name | Nativity | Height (m) | Canopy cover (%) | Diameter (cm) | Basal area (square m/hectare) |
---|---|---|---|---|---|---|---|
Tree
|
|||||||
lodgepole pine | PICO | Pinus contorta | Native | 12.2–36.6 | 0–30 | 45.7–50.8 | – |
Douglas-fir | PSME | Pseudotsuga menziesii | Native | 4.6–36.6 | 0–20 | 27.9–63.5 | – |
grand fir | ABGR | Abies grandis | Native | 12.2–36.6 | 0–10 | 12.7–27.9 | – |
western hemlock | TSHE | Tsuga heterophylla | Native | 4.6–24.4 | 0–10 | 12.7–27.9 | – |
Engelmann spruce | PIEN | Picea engelmannii | Native | 4.6–24.4 | 0–10 | 12.7–25.4 | – |
western white pine | PIMO3 | Pinus monticola | Native | 4.6–36.6 | 0–10 | 17.8–63.5 | – |
ponderosa pine | PIPO | Pinus ponderosa | Native | 4.6–24.4 | 0–10 | 38.1–53.3 | – |
western redcedar | THPL | Thuja plicata | Native | 4.6–12.2 | 0–5 | 12.7–27.9 | – |
Table 12. Community 2.2 forest understory composition
Common name | Symbol | Scientific name | Nativity | Height (m) | Canopy cover (%) | |
---|---|---|---|---|---|---|
Interpretations
Supporting information
Contributors
Pat O'Connell
Jay Skovlin
Stephanie Shoemaker
Approval
Kirt Walstad, 5/01/2024
Rangeland health reference sheet
Interpreting Indicators of Rangeland Health is a qualitative assessment protocol used to determine ecosystem condition based on benchmark characteristics described in the Reference Sheet. A suite of 17 (or more) indicators are typically considered in an assessment. The ecological site(s) representative of an assessment location must be known prior to applying the protocol and must be verified based on soils and climate. Current plant community cannot be used to identify the ecological site.
Author(s)/participant(s) | |
---|---|
Contact for lead author | |
Date | 10/26/2023 |
Approved by | Kirt Walstad |
Approval date | |
Composition (Indicators 10 and 12) based on | Annual Production |
Indicators
-
Number and extent of rills:
-
Presence of water flow patterns:
-
Number and height of erosional pedestals or terracettes:
-
Bare ground from Ecological Site Description or other studies (rock, litter, lichen, moss, plant canopy are not bare ground):
-
Number of gullies and erosion associated with gullies:
-
Extent of wind scoured, blowouts and/or depositional areas:
-
Amount of litter movement (describe size and distance expected to travel):
-
Soil surface (top few mm) resistance to erosion (stability values are averages - most sites will show a range of values):
-
Soil surface structure and SOM content (include type of structure and A-horizon color and thickness):
-
Effect of community phase composition (relative proportion of different functional groups) and spatial distribution on infiltration and runoff:
-
Presence and thickness of compaction layer (usually none; describe soil profile features which may be mistaken for compaction on this site):
-
Functional/Structural Groups (list in order of descending dominance by above-ground annual-production or live foliar cover using symbols: >>, >, = to indicate much greater than, greater than, and equal to):
Dominant:
Sub-dominant:
Other:
Additional:
-
Amount of plant mortality and decadence (include which functional groups are expected to show mortality or decadence):
-
Average percent litter cover (%) and depth ( in):
-
Expected annual annual-production (this is TOTAL above-ground annual-production, not just forage annual-production):
-
Potential invasive (including noxious) species (native and non-native). List species which BOTH characterize degraded states and have the potential to become a dominant or co-dominant species on the ecological site if their future establishment and growth is not actively controlled by management interventions. Species that become dominant for only one to several years (e.g., short-term response to drought or wildfire) are not invasive plants. Note that unlike other indicators, we are describing what is NOT expected in the reference state for the ecological site:
-
Perennial plant reproductive capability:
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The Ecosystem Dynamics Interpretive Tool is an information system framework developed by the USDA-ARS Jornada Experimental Range, USDA Natural Resources Conservation Service, and New Mexico State University.
Click on box and path labels to scroll to the respective text.
Ecosystem states
T1A | - | Substantial loss of western white pine as a major seral tree species. |
---|---|---|
R2A | - | Western white pine restored as a major seral tree species. |
T2A | - | Significant loss of susceptible tee species at a site due to Armillaria root rot and conversion of the forest to a shrubland. |
R3A | - | Conversion of the Armillaria root rot induced shrubland to forest, generally of less susceptible seral tree species and eventually to climax tree species. |
State 1 submodel, plant communities
Communities 1 and 5 (additional pathways)
1.1A | - | Fire and post fire recovery |
---|---|---|
1.2A | - | Aging and density increase in stand due to the process of forest in the absence of fire. |
1.3A | - | Maturing of the forest stand in the absence of fire or disturbance. |
1.3B | - | The mature stand dynamics with the absence of fire and aging stand opening processes. |
1.4A | - | Fire, controlled or wild, or other stand renewing practices that spark a renewal of early seral trees. |
1.5A | - | Fire, controlled or wild, or other stand renewing practices that spark a renewal of early seral trees. |
State 2 submodel, plant communities
Communities 1, 5 and 2 (additional pathways)
2.1A | - | This pathway represents a major, stand-replacement disturbance such as a high-intensity fire, large-scale wind event, or a large insect infestation. |
---|---|---|
2.2A | - | This pathway represents growth over time with no further significant disturbance. The areas of regeneration pass through the typical stand phases, namely: competitive exclusion, maturation, understory reinitiating. |
2.3B | - | This pathway represents a major, stand-replacement disturbance such as a high-intensity fire, large-scale wind event or a large insect infestation. |
2.3A | - | This pathway represents continued growth over time with no further major disturbance. |
2.4B | - | This pathway represents a major, stand-replacement disturbance, such as a large insect outbreak, or major fire event which leads to the stand initiation phase of forest development. |
2.4A | - | This pathway represents continued growth over time with no further major disturbance. |
2.5A | - | This pathway represents no further major disturbance. Continued growth over time, as well as ongoing mortality, leads to continued vertical diversification. |
2.5B | - | This pathway represents a major stand-replacement fire disturbance leading to the stand initiation phase of forest development. |