Natural Resources
Conservation Service

Ecological site XA232X02Y210

Boreal Forest Loamy Frozen Plains Warm

Last updated: 5/18/2020
Accessed: 11/13/2024

Home / Esd catalog / MLRA 232X / Ecological site XA232X02Y210

USC

Metric

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): 232X–Yukon Flats Lowlands

The Yukon Flats Lowlands MLRA is an expansive basin characterized by numerous levels of flood plains and terraces that are separated by minimal breaks in elevation. This MLRA is in Interior Alaska and is adjacent to the middle reaches of the Yukon River. Numerous tributaries of the Yukon River are within the Yukon Flats Lowlands MLRA. The largest are Beaver Creek, Birch Creek, Black River, Chandalar River, Christian River, Dall River, Hadweenzic River, Hodzana River, Porcupine River, and Sheenjek River. The MLRA has two distinct regions—lowlands and marginal uplands. The lowlands have minimal local relief and are approximately 9,000 square miles in size (Williams 1962). Landforms associated with the lowlands are flood plains and stream terraces. The marginal uplands consist of rolling and dissected plains that are a transitional area between the lowlands and adjacent mountain systems. The marginal uplands are approximately 4,700 square miles in size (Williams 1962).

This MLRA is bounded by the Yukon-Tanana Plateau to the south, Hodzana Highlands to the west, Porcupine Plateau to the east, and southern foothills of the Brooks Range to the north (Williams 1962). These surrounding hills and mountains partially isolate the Yukon Flats Lowlands MLRA from weather systems affecting other MLRAs of Interior Alaska. As a result, temperatures are generally warmer in summer and colder in winter than is characteristic in other areas at comparable latitude. There is a moisture and temperature gradient in which the lowlands region tends to be drier and colder and the surrounding marginal uplands region tends to be moister and warmer (PRISM Climate Group 2006).

The Yukon Flats Lowlands MLRA is mostly undeveloped lands that are sparsely populated and not accessible by a road system. A number of villages, including Beaver, Birch Creek, Chalkyitsik, Circle, Fort Yukon, Stevens Village, and Venetie, are adjacent to the Yukon River or one of its major tributaries. The largest village is Fort Yukon, which according to the 2010 U.S. Census has 583 residents that are dominantly Gwich’in Alaska Natives.

LRU notes

Alaska has no officially recognized LRU. However, there appear to be two distinct LRU in the Yukon Flats Lowlands MLRA. These LRU are thought to have differing climatic regimes, landforms, and soil types (STATSGO and Jorgensen and Meidinger 2015). The two LRU were previously discussed in the MLRA notes section above and are termed the lowlands LRU, and the marginal uplands LRU.

This ecological site is associated with the uplands LRU.

Classification relationships

Yukon Flats Lowlands MLRA.

Ecological site concept

This ecological site occurs on warmer slope positions (i.e. South facing slopes) in the marginal uplands region of the Yukon Flats Lowlands MLRA. Associated soils have very deep loess deposition and are well drained. The reference state supports multiple community phases related to a fire regime.

The reference plant community is characterized as an open needleleaf forest (25 to 60 percent cover; Viereck et al. 1992) primarily composed of mature white spruce (Picea glauca). Commonly observed understory species include prickly rose (Rosa acicularis), twinflower (Linnaea borealis), russet buffaloberry (Shepherdia canadensis), lingonberry (Vaccinium vitis-idaea), Siberian alder (Alnus viridis ssp. fruticosa), sidebells wintergreen (Orthilia secunda), false toadflax (Geocaulon lividum), and splendid feathermoss (Hylocomium splendens).

Associated sites

XA232X02Y217	Boreal Woodland Loamy Frozen Plain Wet This ecological site occurs where water accumulates on the slopes (i.e. lower third of slopes and swales) of the marginal uplands region of the Yukon Flats Lowlands MLRA. The marginal uplands are characterized by broad and extensive plains. Associated soils have very deep loess deposition, are prone to ponding, and are poorly drained. The reference plant community is characterized as needleleaf woodland (10 to 25 percent cover; Viereck et al. 1992) primarily composed of black spruce (Picea mariana).
XA232X02Y203	Boreal Scrub Loamy Frozen Drainages This ecological site occurs in drainageways of the marginal uplands region of the Yukon Flats Lowlands MLRA. The marginal uplands are characterized by broad and extensive plains. Associated soils flood occasionally (5 to 50 times in 100 years) for long durations of time (between 7 and 30 days). Soils range from poorly to very poorly drained. The reference plant community is characterized as closed tall scrub (Viereck et al. 1992). Black spruce commonly occurs but cover is generally low.
XA232X01Y201	Boreal Woodland Peat Frozen Terraces This ecological site occurs in organic rich bogs in the lowlands and marginal uplands regions of the Yukon Flats Lowlands MLRA. The cumulative thickness of organic material often exceeds 50 inches in the soil profile. Reference state soils are poorly drained and organic material is considered ultra to extremely acidic. The soils associated with the reference plant community generally has permafrost at moderate depth (20 to 40 inches). This ecological site has an alternative state related to thermokarst.
XA232X02Y227	Boreal Forest Loamy Frozen Plains Cold This ecological site occurs on colder slope positions (i.e. North facing slopes) in the marginal uplands region of the Yukon Flats Lowlands MLRA. Associated soils have very deep loess deposition and range from poorly to somewhat poorly drained. The reference plant community is characterized as an open needleleaf forest (25 to 60 percent cover; Viereck et al. 1992) primarily composed of black spruce.
XA232X02Y211	Boreal Loamy Escarpments This ecological site is associated with steep and erosive slopes in the marginal uplands region of the Yukon Flats Lowlands MLRA. During field work, these escarpments were not sampled and this ecological site is currently a provisional concept.

Similar sites

XA232X01Y204	Boreal Forest Loamy Flood Plain High XA232X01Y204 is associated with the lowlands LRU, is on flood plains, and has plant community phases related to a flood regime. Unique species occur on floodplain that do not typically occur on loess covered plains.
XA232X01Y221	Boreal Forest Loamy Terraces XA232X01Y221 occurs on stream terraces and gravelly fan remnants. Reference state communities are similar but XA232X01Y221 appears to have less productive stands of trees.

XA232X01Y204

Boreal Forest Loamy Flood Plain High

XA232X01Y204 is associated with the lowlands LRU, is on flood plains, and has plant community phases related to a flood regime. Unique species occur on floodplain that do not typically occur on loess covered plains.

XA232X01Y221

Boreal Forest Loamy Terraces

XA232X01Y221 occurs on stream terraces and gravelly fan remnants. Reference state communities are similar but XA232X01Y221 appears to have less productive stands of trees.

Table 1. Dominant plant species

Tree	(1) Picea glauca
Shrub	(1) Rosa acicularis (2) Linnaea borealis
Herbaceous	(1) Hylocomium splendens

Legacy ID

F232XY210AK

Download full description

Physiographic features

This ecological site and its associated communities occur on rises of plains in the marginal uplands LRU of the Yukon Flats Lowlands MLRA. The marginal uplands are characterized by broad and extensive plains. Due to weathering, these plains are often highly dissected and often resemble hill complexes. In areas where plains are highly dissected, slopes can be steep. This ecological site is associated with areas within the marginal uplands that have very deep accumulations of loess (greater than 60 inches).

Four ecological sites were observed on slopes of these loess covered plains. This ecological site is associated with rises on warmer slopes (e.g. south facing or steeper slopes). Ecological site XA232X01Y227 occurs on rises of colder slopes (e.g. north facing or less steep slopes). Ecological site XA232X01Y217 occurs in positions where water accumulates on the slopes (e.g. lower third of slopes, swales, or dips). Ecological site XA232X01Y211 is associated with steep and erosive escarpments on slopes. These differences in site characteristics lead to dramatically different assemblages of vegetation and resulted in unique ecological site concepts.

Figure 1. Lowlands (white) and marginal uplands (light gray) LRU in the Yukon Flats Lowlands MLRA.

Table 2. Representative physiographic features

Geomorphic position, flats	(1) Rise
Hillslope profile	(1) Summit (2) Backslope (3) Shoulder
Landforms	(1) Plains > Plain (2) Plains > Hillslope
Flooding frequency	None
Ponding frequency	None
Elevation	450 – 1,475 ft
Slope	3 – 35%
Aspect	W, NW, N, NE, E, SE, S, SW

Climatic features

Short, warm summers and long, very cold winters characterize the subarctic continental climate of the area. The surrounding hills and mountains of this MLRA partially isolate it from weather systems affecting other interior lowlands. As a result, temperatures are generally warmer in summer and colder in winter than is characteristic in other areas of comparable latitude. The average annual temperature ranges from about 20 to 25 degrees F (-7 to -4 degrees C). The freeze-free period averages 70 to 120 days. The temperature usually remains above freezing from early June through late August. The average annual precipitation ranges from about 6 inches (150 millimeters) in the central basin to 15 inches (380 millimeters) along the boundary with the surrounding highlands. The maximum precipitation occurs in late summer, mainly as a result of thunderstorms. The average annual snowfall is about 45 to 55 inches (115 to 140 centimeters) (USDA, NRCS 2006).

The tabular data in this report is specific to the marginal uplands LRU in the Yukon Flats Lowlands MLRA. All tabular data was calculated from the PRISM dataset (1971-2000).

Table 3. Representative climatic features

Frost-free period (characteristic range)	45-97 days
Freeze-free period (characteristic range)	70-120 days
Precipitation total (characteristic range)	9-22 in
Frost-free period (average)	75 days
Freeze-free period (average)
Precipitation total (average)	11 in

Bar

Line

Figure 2. Monthly precipitation range

Bar

Line

Figure 3. Monthly minimum temperature range

Bar

Line

Figure 4. Monthly maximum temperature range

Bar

Line

Figure 5. Monthly average minimum and maximum temperature

Soil features

Correlated soil components for the Soil Survey of Yukon-Charley Rivers National Preserve Area Alaska (AK684): Boreal forest gravelly escarpments, frozen.

Correlated soil components for the Yukon Flats Areas, Alaska soil survey (AK685): Typic Haplocryepts; Folistic Haplorthels.

After fire, permafrost can thaw in the soil profile. For this ecological site, this transition marks a change in soil components from Folistic Haplorthels to Typic Haplocryepts.

Figure 6. Typical soil profile associated with Folistic Haplorthels soil component. After fire, these soils often thaw resulting in Oxyaquic Haplocryept.

Table 4. Representative soil features

Parent material	(1) Organic material (2) Loess
Family particle size	(1) Coarse-silty
Drainage class	Well drained

Ecological dynamics

Fire

In the Yukon Flats Lowlands MLRA, fire is a common and natural event that has a significant control on the vegetation dynamics across the landscape. A typical fire event in areas associated with this ecological site will reset the plant succession and alter dynamic soil properties (e.g., presence or thickness of permafrost). For this ecological site to progress from the pioneering fire stage to the reference plant community 1.1, data suggest that 100 years or more must elapse without another fire event.

When comparing all major land resource areas of Interior Alaska, land in the Yukon Flats Lowlands MLRA burns most frequently (Begét et al. 2006). Within this MLRA, fire is considered a natural and common event that typically is unmanaged. Fire suppression generally occurs adjacent to villages or on allotments with known structures, both of which have a relatively limited acre footprint. From 2000 to 2015, 132 known fire events occurred on land in the Yukon Flats Lowlands MLRA and the burn perimeter of the fires totaled about 4.1 million acres (AICC 2016). Fire-related disturbances are highly patchy and can leave undisturbed areas within the burn perimeter. Ten of the fire events were attributed to human activities (affecting a total of 2,864 acres), but the majority were caused by lightning strikes (AICC 2016).

The fire regime within Interior Alaska follows two basic scenarios—low-severity burns and high-severity burns. It should be noted, however, that the fire regime in Interior Alaska is generally thought to be much more complex (Johnstone et al. 2008). Burn severity refers to the proportion of the vegetative canopy and organic material consumed in a fire event (Chapin et al. 2006). Fires in areas of cooler and moister habitat tend to result in low-severity burns, and those in areas of warmer and drier habitat tend to result in high-severity burns. As a result of field observations and because the associated soils are warm and well drained, the typical fire scenario for this ecological site is considered to result in a high-severity burn.

Large portions of the organic mat are consumed during a high-severity fire event, commonly exposing pockets of mineral soil. The loss of this organic mat, which insulates the mineral soil, and the decrease in site albedo tends to cause overall soil temperatures to increase (Hinzman et al. 2006). In areas that have permafrost before a fire event, the increase in soil temperatures leads to a decrease in the depth to the permafrost or loss of permafrost in the soil profile (Hinzman et al. 2006). For this ecological site, permafrost was typically not observed in the soil profiles after recent fire events and a soil component was developed for this change in dynamic soil properties (Oxyaquic Haplocryepts soils). Data from fieldwork indicate that permafrost aggradation in the soil profile typically does not occur until community 1.2 and that permafrost is commonly associated with community 1.1. Fire events also destroy a majority of the vascular and nonvascular biomass above ground.

Field data suggest that each of the forested community phases will burn and that fire events will cause a transition to the pioneering stage of fire succession. This stage (community 1.4) is a mix of species that either regenerate in place (e.g., subterranean root crowns for willow and rhizomes for graminoids) and/or from wind-dispersed seed or spores that colonize exposed mineral soil (e.g., resin birch [Betula neoalaskana] and Ceratodon moss [Ceratodon purpureus]). The pioneering stage of fire succession is primarily composed of tree seedlings, forbs, grasses, and weedy bryophytes. Willow (Salix spp.) and deciduous tree seedlings continue to colonize and grow on recently burned sites until they become dominant in the overstory, which marks the transition to the early stage of fire succession (observed but not documented in the field). In the absence of fire, tree species continue to become more dominant in the stand. The later stages of succession have an overstory that is dominantly deciduous trees (community 1.3), a mix of broadleaf and needleleaf trees (community 1.2), or needleleaf trees (community 1.1).

The time elapsed since the most recent fire event plays a large role in determining the community phase observed in the field. Using data from the burn perimeter (AICC 2016) and tree age, the pioneering and early fire stages are thought to persist for about 10 to 30 years postfire. After approximately 30 years, an open forest with some combination of birch and white spruce will persist until the next fire event. Field data suggest that broadleaf trees (primarily resin birch) are dominant in the canopy first. During this phase of broadleaf tree dominance, white spruce colonize and mature in the understory. Eventually, white spruce gains dominance in the overstory and begins to replace the shade-intolerant broadleaf tree species. Late-fire community 1.2 has a mixture of immature and mature white spruce, while the reference community 1.1 has a stand composed primarily of mature white spruce. The average age of white spruce in the reference state is 106 years; therefore, it takes more than a century to progress from the pioneering stage to the reference community phase.

Other Observations

Animal use (browsing and grazing) of this ecological site primarily consists of moose browse on willow and tree regeneration in 1.3 and 1.4. The severity of moose browse is considered slight for all communities. A browse severity rating of slight on willow and tree regeneration is defined as a majority of individuals having no signs of browsing.

No alternative states for this ecological site were documented.

State and transition model

More interactive model formats are also available. View Interactive Models
Click on state and transition labels to scroll to the respective text

Ecosystem states

1. Reference State

State 1 submodel, plant communities

1.1. White spruce / prickly rose-twinflower / splendid feathermoss

1.2. White spruce-resin birch / prickly rose-twinflower / splendid feathermoss

1.3. Resin birch-white spruce / Bebb willow-prickly rose

1.4. Bebb willow / bluejoint / Polytrichum moss-Marchantia liverwort

State 1
Reference State

Figure 7. An aerial image of the marginal uplands in the Yukon Flats Lowlands MLRA. This ecological site occurs on warm and dry slopes in the marginal uplands.

The reference state has four associated community phases. The phases are grouped by the structure and dominance of the vegetation (e.g., coniferous trees, deciduous trees, shrubs, and forbs) and their ecological function and stability. Plant communities in the reference state appear to be largely controlled by the influences of fire. This report provides baseline vegetation inventory data for the ecological site. More data collection is needed to provide further information about existing plant communities and the disturbance regimes that would result in transitions from one community to another. The common and scientific plant names are from the USDA PLANTS database. All plant communities in this report are characterized using the Alaska Vegetation Classification (Viereck et al. 1992).

Community 1.1
White spruce / prickly rose-twinflower / splendid feathermoss

Figure 8. Typical plant community associated with community 1.1.

Figure 9. Canopy cover table for community 1.1.

The reference plant community is characterized as an open needleleaf forest (25 to 60 percent cover) composed primarily of mature white spruce. The majority of the white spruce trees are similar in size and age, and the tree cover is primarily in the tall tree stratum (greater than 40 feet in height). Gaps occur in the tree canopy, but they are limited in size and extent and are likely the result of occasional windthrow. Live deciduous trees, primarily resin birch, occasionally occur in the tree canopy, but most have been replaced by white spruce. The soil surface is primarily covered with bryophytes, and to a lesser extent, woody debris and herbaceous litter. Commonly observed understory species include prickly rose, twinflower, russet buffaloberry, lingonberry, Siberian alder, sidebells wintergreen, false toadflax, and splendid feathermoss. The understory vegetative strata that characterize this community are bryophytes, medium forbs (4 to 24 inches in height), and dwarf shrubs (less than 8 inches in height). White spruce trees were sampled for diameter at breast height (dbh), height, and age at dbh (10 trees). The basal area of the stand was determined for each sample plot; site index was determined on trees from each sampled plot. The mean dbh is 10.2 inches (ranging from 4.8 to 14.5), the mean height is 67 feet (ranging from 48 to 92 feet), and the mean age is 106 years (ranging from 76 to 144 years). The mean basal area of the stands is 147 (ranging from 105 to 192). Mean site index is 62 (ranging from 51 to 84) (Farr 1967).

Dominant plant species

white spruce (Picea glauca), tree
resin birch (Betula neoalaskana), tree
prickly rose (Rosa acicularis), shrub
twinflower (Linnaea borealis), shrub
russet buffaloberry (Shepherdia canadensis), shrub
lingonberry (Vaccinium vitis-idaea), shrub
Siberian alder (Alnus viridis ssp. fruticosa), shrub
willow (Salix), shrub
sidebells wintergreen (Orthilia secunda), other herbaceous
false toadflax (Geocaulon lividum), other herbaceous
fireweed (Chamerion angustifolium), other herbaceous
splendid feather moss (Hylocomium splendens), other herbaceous
Schreber's big red stem moss (Pleurozium schreberi), other herbaceous

Community 1.2
White spruce-resin birch / prickly rose-twinflower / splendid feathermoss

Figure 10. Typical plant community associated with community 1.2.

Figure 11. Canopy cover table for community 1.2.

Community 1.2 is in the late stage of fire-induced secondary succession for this ecological site. It is characterized as an open mixed forest (25 to 60 percent cover). Deciduous trees are starting to be replaced by white spruce in the tree canopy. White spruce cover is generally split between immature medium-sized trees (15 to 40 feet in height) and mature tall trees (greater than 40 feet in height). The soil surface is primarily covered with herbaceous litter and bryophytes. Commonly observed understory species include prickly rose, twinflower, lingonberry, false toadflax, tall bluebells, and splendid feathermoss. The understory vegetative strata that characterize this community are bryophytes and dwarf shrubs (less than 8 inches in height). White spruce trees were sampled for diameter at breast height (dbh), height, and age at dbh (18 trees, 1 without age data). The basal area of the stand was determined for each sample plot. The mean dbh is 8.0 (ranging from 2.8 to 18.3), the mean height is 63 feet (ranging from 19 to 127 feet), and the mean age is 70 years (ranging from 41 to 89 years). The mean basal area of the stands is 133 (ranging from 98 to 165).

Dominant plant species

white spruce (Picea glauca), tree
resin birch (Betula neoalaskana), tree
prickly rose (Rosa acicularis), shrub
twinflower (Linnaea borealis), shrub
lingonberry (Vaccinium vitis-idaea), shrub
bog Labrador tea (Ledum groenlandicum), shrub
Siberian alder (Alnus viridis ssp. fruticosa), shrub
grayleaf willow (Salix glauca), shrub
false toadflax (Geocaulon lividum), other herbaceous
tall bluebells (Mertensia paniculata), other herbaceous
horsetail (Equisetum), other herbaceous
sidebells wintergreen (Orthilia secunda), other herbaceous
splendid feather moss (Hylocomium splendens), other herbaceous
felt lichen (Peltigera), other herbaceous

Community 1.3
Resin birch-white spruce / Bebb willow-prickly rose

Figure 12. Typical plant community associated with community 1.3.

Figure 13. Canopy cover table for community 1.3.

Community 1.3 is in the middle stage of fire-induced secondary succession for this ecological site. It is characterized as a closed broadleaf forest (greater than 60 percent cover). Deciduous trees, primarily resin birch, are dominant in the tree canopy, and the majority of the tree cover is in the tall tree stratum (greater than 40 feet in height). Immature white spruce commonly occur but are generally under the deciduous tree canopy. The forest floor is primarily covered with herbaceous litter and woody debris. Commonly observed understory species include Bebb willow, prickly rose, lingonberry, Siberian alder, false toadflax, sidebells wintergreen, fireweed, and splendid feathermoss. The understory vegetative strata that characterize this community are tall shrubs (greater than 10 feet in height), medium shrubs (between 3 and 10 feet), and dwarf shrubs (less than 8 inches). White spruce trees were sampled for diameter at breast height (dbh), height, and age at dbh (2 trees). The basal area of the stand was determined for each sample plot. The mean dbh is 4.1 (ranging from 3.9 to 4.2), the mean height is 45 feet (ranging from 40 to 50 feet), and the mean age is 49 years (ranging from 40 to 58 years). The mean basal area of the stands was 84 (ranging from 73 to 95).

Dominant plant species

resin birch (Betula neoalaskana), tree
white spruce (Picea glauca), tree
prickly rose (Rosa acicularis), shrub
Bebb willow (Salix bebbiana), shrub
lingonberry (Vaccinium vitis-idaea), shrub
Siberian alder (Alnus viridis ssp. fruticosa), shrub
false toadflax (Geocaulon lividum), other herbaceous
sidebells wintergreen (Orthilia secunda), other herbaceous
fireweed (Chamerion angustifolium), other herbaceous
horsetail (Equisetum), other herbaceous
splendid feather moss (Hylocomium splendens), other herbaceous

Community 1.4
Bebb willow / bluejoint / Polytrichum moss-Marchantia liverwort

Figure 14. Typical plant community associated with community 1.4.

Figure 15. Canopy cover table for community 1.4.

Community 1.4 is in the pioneering stage of fire-induced secondary succession for this ecological site. It is characterized as mesic graminoid herbaceous. Tree cover primarily is in the regenerative tree stratum (less than 15 feet in height). Deciduous tree seedlings, primarily resin birch, are common throughout the community. Although small areas of exposed bare soil are common, the soil surface is primarily covered with a mixture of weedy bryophyte species, woody debris, and herbaceous litter. Commonly observed species include Bebb willow, prickly rose, bluejoint, fireweed, field horsetail, Polytrichum moss, Marchantia liverwort, and Ceratodon moss. The stratum that characterize this community are bryophytes, tall graminoids (greater than 2 feet in height), medium forbs (between 4 and 24 inches in height), and medium shrubs (between 3 and 10 feet in height).

Dominant plant species

resin birch (Betula neoalaskana), tree
white spruce (Picea glauca), tree
willow (Salix), shrub
Bebb willow (Salix bebbiana), shrub
prickly rose (Rosa acicularis), shrub
bluejoint (Calamagrostis canadensis), grass
fireweed (Chamerion angustifolium), other herbaceous
tall bluebells (Mertensia paniculata), other herbaceous
field horsetail (Equisetum arvense), other herbaceous
polytrichum moss (Polytrichum), other herbaceous
(Marchantia polymorpha), other herbaceous
ceratodon moss (Ceratodon purpureus), other herbaceous

Pathway 1.1A
Community 1.1 to 1.4

White spruce / prickly rose-twinflower / splendid feathermoss

Bebb willow / bluejoint / Polytrichum moss-Marchantia liverwort

Fire.

Pathway 1.2B
Community 1.2 to 1.1

White spruce-resin birch / prickly rose-twinflower / splendid feathermoss

White spruce / prickly rose-twinflower / splendid feathermoss

Time without fire.

Pathway 1.2A
Community 1.2 to 1.4

White spruce-resin birch / prickly rose-twinflower / splendid feathermoss

Bebb willow / bluejoint / Polytrichum moss-Marchantia liverwort

Fire.

Pathway 1.3B
Community 1.3 to 1.2

Resin birch-white spruce / Bebb willow-prickly rose

White spruce-resin birch / prickly rose-twinflower / splendid feathermoss

Time without fire.

Pathway 1.3A
Community 1.3 to 1.4

Resin birch-white spruce / Bebb willow-prickly rose

Bebb willow / bluejoint / Polytrichum moss-Marchantia liverwort

Fire.

Pathway 1.4A
Community 1.4 to 1.3

Bebb willow / bluejoint / Polytrichum moss-Marchantia liverwort

Resin birch-white spruce / Bebb willow-prickly rose

Time without fire.

Additional community tables

Table 5. Community 1.1 forest overstory composition

Common name	Symbol	Scientific name	Nativity	Height (ft)	Canopy cover (%)	Diameter (in)	Basal area (square ft/acre)
Tree
white spruce	PIGL	Picea glauca	Native	48–92	40–69	4.8–14.5	–

Table 6. Community 1.2 forest overstory composition

Common name	Symbol	Scientific name	Nativity	Height (ft)	Canopy cover (%)	Diameter (in)	Basal area (square ft/acre)
Tree
white spruce	PIGL	Picea glauca	Native	19–127	30–63	2.8–18.3	–

Table 7. Community 1.3 forest overstory composition

Common name	Symbol	Scientific name	Nativity	Height (ft)	Canopy cover (%)	Diameter (in)	Basal area (square ft/acre)
Tree
resin birch	bene4	Betula neoalaskana	Native	–	45–95	–	–
white spruce	pigl	Picea glauca	Native	40–50	15–20	3.9–4.2	–

Interpretations

Table 8. Representative site productivity

Common name	Symbol	Site index low	Site index high	CMAI low	CMAI high	Age of CMAI	Site index curve code	Site index curve basis	Citation
white spruce	PIGL	49	91	–	–	–	–	–

Supporting information

Inventory data references

NASIS User Site ID / Modal Datasets
12SN00703 F232XY290AK community 1.1
2015AK290801 F232XY290AK community 1.1
2015AK290802 F232XY290AK community 1.1
2015AK290803 F232XY290AK community 1.2
2015AK290850 F232XY290AK community 1.2
2015AK290860 F232XY290AK community 1.2
2017AK290541 F232XY290AK community 1.2
2017AK290909 F232XY290AK community 1.2
08TC01901 F232XY290AK community 1.3
12SN00701 F232XY290AK community 1.3
2015AK290868 F232XY290AK community 1.4
2017AK290545 F232XY290AK community 1.4
2017AK290912 F232XY290AK community 1.4

Other references

Alaska Interagency Coordination Center (AICC). 2016. http://fire.ak.blm.gov/

Begét, J.E., D. Stone, and D.L. Verbyla. 2006. Regional overview of Interior Alaska. In Alaska’s Changing Boreal Forest. F.S. Chapin III, M.W. Oswood, K. Van Cleve, L.A. Viereck, and D.L. Verbyla, editors. New York, Oxford University Press. Pages 12-20.

Chapin, F.S., III; L.A. Viereck; P.C. Adams; K. Van Cleve; C.L. Fastie; R.A. Ott; D. Mann; and J.F. Johnstone. 2006. Successional processes in the Alaskan boreal forest. In Alaska’s Changing Boreal Forest. F.S. Chapin III, M.W. Oswood, K. Van Cleve, L.A. Viereck, and D.L. Verbyla, editors. New York, Oxford University Press. Pages 100-120.

Farr, W.A. 1967. Growth and yield of well-stocked white spruce stands in Alaska. U.S. Department of Agriculture, Forest Service, Pacific Northwest Forest and Range Experiment Station General Technical Report PNW-GTR-53.

Hinzman, L.D., L.A. Viereck, P.C. Adams, V.E. Romanovsky, and K. Yoshikawa. 2006. Climate and permafrost dynamics of the Alaskan boreal forest. In Alaska’s Changing Boreal Forest. F.S. Chapin III, M.W. Oswood, K. Van Cleve, L.A. Viereck, and D.L. Verbyla, editors. New York, Oxford University Press. Pages 39-61.

Johnstone, J.F., T.N. Hollingsworth, and F.S. Chapin III. 2008. A key for predicting postfire successional trajectories in black spruce stands of Interior Alaska. U.S. Department of Agriculture, Forest Service, Pacific Northwest Forest and Range Experiment Station General Technical Report PNW-GTR-767.

Jorgensen, T. and D. Meidinger. 2015. The Alaska Yukon Region of the Circumboreal Vegetation map (CBVM). CAFF Strategies Series Report. Conservation of Arctic Flora and Fauna, Akureyri, Iceland. ISBN: 978-9935-431-48-6

PRISM Climate Group. 2006. Climate data of United States, 1971-2000. Oregon State University, Corvallis.
Schoeneberger, P.J., and D.A. Wysocki. 2012. Geomorphic description system. Version 4.2. U.S. Department of Agriculture, Natural Resources Conservation Service, National Soil Survey Center, Lincoln, Nebraska.

Schoeneberger, P.J., D.A. Wysocki, E.C. Benham, and W.D. Broderson, editors. 2012. Field book for describing and sampling soils. Version 3.0. U.S. Department of Agriculture, Natural Resources Conservation Service.

Soil Survey Division Staff. 1993. Soil survey manual. Soil Conservation Service. U.S. Department of Agriculture Handbook 18.
United States Department of Agriculture, Natural Resources Conservation Service. 2006. Land resource regions and major land resource areas of the United States, the Caribbean, and the Pacific Basin. U.S. Department of Agriculture Handbook 296.

Viereck, L.A., C.T. Dyrness, A.R. Batten, and K.J. Wezlick. 1992. The Alaska vegetation classification. U.S. Department of Agriculture, Forest Service, Pacific Northwest Forest and Range Experiment Station General Technical Report PNW-GTR-286.
Williams, J.R. 1962. Geologic reconnaissance of the Yukon Flats District, Alaska. U.S. Department of the Interior, Geologic Survey Bulletin 1111-H.

Contributors

Blaine Spellman

Approval

Michael Margo, 5/18/2020

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	05/11/2020
Approved by	Michael Margo
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:

Download reference sheet

Search

Natural ResourcesConservation Service

Ecological site XA232X02Y210

Boreal Forest Loamy Frozen Plains Warm

Last updated: 5/18/2020 Accessed: 11/13/2024

General information

MLRA notes

LRU notes

Classification relationships

Ecological site concept

Associated sites

Similar sites

Table 1. Dominant plant species

Legacy ID

Ecosystem states

State 1 submodel, plant communities

Natural Resources
Conservation Service

Last updated: 5/18/2020
Accessed: 11/13/2024