Natural Resources
Conservation Service
Ecological site R035XB249AZ
Mudstone/Sandstone Upland
6-10" p.z.
Limy, Channery
Accessed: 04/30/2026
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Draft. A draft ecological site description is either incomplete or has not undergone quality control and quality assurance review.
MLRA notes
Major Land Resource Area (MLRA): 035X–Colorado Plateau
AZ CRA 35.2 - Colorado Plateau Shrub – Grasslands
Elevations range from 3500-5500 feet and precipitation averages 6 to 10 inches per year. Vegetation includes shadscale, fourwing saltbush, Mormon tea, blackbrush, Indian ricegrass, galleta, blue grama, and black grama. The soil temperature regime is mesic and the soil moisture regime is typic aridic. This unit occurs within the Colorado Plateau Physiographic Province and is characterized by a sequence of flat to gently dipping sedimentary rocks eroded into plateaus, valleys and deep canyons. Sedimentary rock classes dominate the plateau with volcanic fields occurring for the most part near its margin.Associated sites
R035XB217AZ Sandy Upland 6-10" p.z.
At site locations near Chinle, this site intermingled with the referenced site. It is found in areas of greater eolian sand deposits.
R035XB251AZ Mudstone/Sandstone Hills 6-10" p.z. Warm
This site is found in association with the referenced site, but on steeper slopes.
R035XB255AZ Sandstone Rockland 6-10" p.z.
Often adjacent to the referenced site on sandstone rock outcrops.
Similar sites
R035XB251AZ Mudstone/Sandstone Hills 6-10" p.z. Warm
This site has greater slopes than the referenced site.
R035XY130UT Desert Shallow Sandy Loam (Shadscale)
This is a corresponding site from Utah.
R035XB201AZ Mudstone/Sandstone Hills 6-10" p.z.
This site has greater slopes, sometimes deeper soils, and less surface and subsurface channers than the referenced site.
R035XY122UT Desert Shallow Loam (Shadscale)
This is a corresponding site from Utah.
Table 1. Dominant plant species
Tree Not specified
Shrub (1) Atriplex confertifolia
(2) Gutierrezia sarothraeHerbaceous (1) Pleuraphis jamesii
Physiographic features
This site consists of shallow to very shallow, well-drained soils that formed in eolian and alluvial deposits on plateaus and hills and residuum derived from weathered sandstone, mudstone and shale. It can be located on the tops of plateaus and mesas, but also on the summits and sideslopes of eroding dissected ridges of the sandstone/mudstone/shale parent material. This site sheds most of the runoff that is generated above it and generates high amounts of runoff to sites below it.
Table 2. Representative physiographic features
Landforms (1) Plateau
(2) Hill
Flooding frequency None Ponding frequency None Elevation 4900 – 5600 ft Slope 2 – 35 % Aspect Aspect is not a significant factor Climatic features
Area has a very dry and windy climate that is hot in the summer and cold in the winter. Average annual precipitation is from 6 to 10 inches. Soil moisture regime is typic aridic and the soil temperature regime is mesic. A slight majority of the precipitation arrives during the late fall, winter, and early spring. This winter season moisture originates in the Pacific Ocean and arrives as rain, or sometimes snow, during widespread frontal storms of generally low intensity. The majority of the snow falls from December through February, but rarely lasts more than a few days. The driest period is from late May to early July. Summer rains occur from July through September during brief intense local thaunderstorms. The rain is sporadic in intensity and location. Windy conditions are common year-round with the strongest most frequently in the spring.
Table 3 Representative climatic features
Frost-free period (average) 180 days Freeze-free period (average) 210 days Precipitation total (average) 10 in BarLineFigure 1. Monthly precipitation range
BarLineFigure 2. Monthly average minimum and maximum temperature
">Influencing water features
Soil features
The soils are very shallow to shallow. Surface textures may be clay loam, sandy clay loam, fine sandy loam, or sandy loam. Parent materials are alluvium, colluvium, and eolian deposits from the San Rafael Group, Chinle and Moencopie geologic formations. Channers comprise greater than 35% of the soil surface horizon (0-2 inches). Depth to restrictive features, either paralithic or bedrock, is 4 to 18 inches. Saturated Hydraulic Conductivity (Ksat) for the soil horizons (solum) is 0.06 to 0.60 inches per hour (0.42 to 4.23 micrometers per second). Ksat for the restrictive layer is 0.20 to 2.00 inches per hour (1.41 to 14.11 micrometers per second). Shrink-swell potential is 4.5 LEP (moderate). Hydrologic soil group D. Rills and other water flow patterns may be common on the steeper slopes, due to the slow permeability and high runoff characteristics of the site. A few very short pedestalls or terracettes may form on the steeper slopes. Due to the clayey surface textures, this soil may be easily compacted when wet. Biological crusts, including lichens and mosses, are important for the stability and function of the soil surface on this site, especially on the steeper slopes and with the inherent low productivity of this site. Cyanobacteria is the most common crust component, followed by lichens and mosses. Biological crusts may comprise 20% of soil suface cover. They are most susceptable to trampling when the soil is dry.
Mapped in the following Soil Survey areas:
SSA 712 Canyon de Chelly NM MU 7 Claysprings and
SSA UT689 Glen Canyon Area MU's 11 Juanalo family, 13 Moenkopie, 39 Somorent family, 43 Tsaya family & Moenkopie.Table 4. Representative soil features
Surface texture (1) Very channery clay loam
(2) Flaggy fine sandy loam
(3) Silty clay loam
Family particle size (1) Loamy
Drainage class Moderately well drained Permeability class Very slow to slow Soil depth 4 – 18 in Surface fragment cover <=3" 10 – 75 % Surface fragment cover >3" 2 – 15 % Available water capacity
(0-40in)2.7 in Soil reaction (1:1 water)
(0-40in)7.7 – 8.4 Subsurface fragment volume <=3"
(Depth not specified)0 – 10 % Subsurface fragment volume >3"
(Depth not specified)0 – 10 % Ecological dynamics
The historic climax plant community (HCPC) for a site in North America is the plant community that existed at the time of European immigration and settlement. It is the plant community that was best adapted to the unique combination of environmental factors associated with the site. The historic climax plant community was in dynamic equilibrium with its environment. It is the plant community that was able to avoid displacement by the suite of disturbances and disturbance patterns (magnitude and frequency) that naturally occurred within the area occupied by the site. Natural disturbances, such as drought, fire, grazing of native fauna, and insects, were inherent in the development and maintenance of these plant communities. The effects of these disturbances are part of the range of characteristics of the site that contribute to that dynamic equilibrium. Fluctuations in plant community structure and function caused by the effects of these natural disturbances establish the boundaries of dynamic equilibrium. They are accounted for as part of the range of characteristics for an ecological site. Some sites may have a small range of variation, while others have a large range.
The historic climax plant community of an ecological site is not a precise assemblage of species for which the proportions are the same from place to place or from year to year. In all plant communities, variability is apparent in productivity and occurrence of individual species. Spatial boundaries of the communities; however, can be recognized by characteristic patterns of species composition, association, and community structure. The HCPC for this ecological site has been estimated by sampling relict or relatively undisturbed sites and/or reviewing historic records.
Plant communities that are subjected to abnormal disturbances and physical site deterioration or that are protected from natural influences, such as fire and grazing, for long periods seldom typify the historic climax plant community. The physical site deterioration caused by the abnormal disturbance results in the crossing of a threshold or irreversible boundary to another state, or equilibrium, for the ecological site. There may be multiple thresholds and states possible for an ecological site, determined by the type and or severity of abnormal disturbance. The known states and transition pathways for this ecological site are described below and in the accompanying state and transition model.
1 Historic Climax Plant Community (HCPC)
1.1 HCPC – The plant community is composed primarily of relatively equal amounts of perennial sodgrasses and shrubs. Annual forbs, perennial bunchgrasses and annual grasses are present in lesser amounts. The dominant grasses is galleta. The dominant shrub is shadscale saltbush.
1.1A – Extreme spring/summer herbivory.
1.1B – Extreme continuous herbivory.
1.2 Shadscale Overstory and Annual Grass/Forb Understory – Shadscale increases over grasses. Perennial grasses decrease and annual grasses and forbs increase. Galleta may increase initially but will decrease as extreme herbivory continues. Native annual grasses, such as six-weeks grama and forbs, such as woolly plantain increase.
1.2A – Proper grazing practices and/or rest allow native perennial grasses to increase.
1.2B – Extreme continuous herbivory.
1.3 Composite Shrub Overstory and Annual Grass/Forb Understory – Perennial composite shrubs such as broom snakeweed and succulents such as prickly pear increase over shadscale saltbush. Perennial grasses decrease and annual grasses and forbs increase. Galleta may increase initially but will decrease as extreme herbivory continues. Native annual grasses, such as six-weeks grama and forbs, such as woolly plantain increase.
1.3A – Proper grazing practices and/or rest allow shadscale and perennial grasses to increase.
T1A – Exotic grass species, such as cheatgrass and exotic forbs, such as Russian thistle are introduced into the site.
2 Native Overstory with Mixed Native – Exotic Understory
2.1 Shadscale Overstory and Mixed Understory – Exotic annual grasses and forbs are present in the understory but the amount of native perennial grasses remains relatively unchanged.
2.1A – Extreme continuous herbivory.
2.2 Shadscale/Composite Shrub Overstory and Mixed Understory – Composite shrubs and succulents increase in the overstory and exotic annual grasses and forbs are present in the understory but the amount of native perennial grasses remains relatively unchanged.
2.2A – Proper grazing practices and/or rest allow shadscale and perennial grasses to increase.
T2A – Extreme herbivory favors exotic annual grasses and forbs over native grasses and forbs. Fire is unlikely on this site but if it occurs, it could drive this pathway as well.
3 Native Overstory with Exotic Understory
3.1 Shadscale Overstory and Exotic Understory – Exotic annual grasses and forbs dominate the understory.
3.1A – Extreme continuous herbivory.
3.2 Shadscale/Composite Shrub Overstory and Exotic Understory – Composite shrubs and succulents increase in the overstory and exotic annual grasses and forbs dominate the understory.
3.2A – Proper grazing practices and/or rest allow shadscale and perennial grasses to increase.
R3A – Proper grazing practices and/or rest will allow shadscale and native perennial grasses to outcompete the composite shrubs and exotic grasses over the long term on this site as these species are better adapted to the soil and climate conditions on this site. Due to the arid nature of the site, these changes would be expected to happen over a long timeframe. Reseeding efforts may fail due to the low annual rainfall and sporadic nature of rainfall on this site.
The Plant Community Plant Species Composition table provides a list of species and each specie’s or group of species’ annual production in pounds per acre (air-dry weight) expected in a normal rainfall year. Low and high production yields represent the modal range of variability for that species or group of species across the extent of the ecological site.
The Annual Production by Plant Type table provides the median air-dry production and the fluctuations to be expected during favorable, normal, and unfavorable years.
The present plant community on an ecological site can be compared to the various common vegetation states that can exist on the site. The degree of similarity is expressed through a similarity index. To determine the similarity index, compare the production of each species to that shown in the plant community description. For each species, count no more than the maximum amount shown for the species, and for each group, count no more than the maximum shown for the group. Divide the resulting total by the total representative value shown in the Annual Production by Plant Type table for the reference plant community. Variations in production due to above or below normal rainfall, incomplete growing season or utilization must be corrected before comparing it to the site description. The Worksheet for Determining Similarity Index is useful in making these corrections. The accompanying growth curve can be used as a guide for estimating percent of growth completed.State and transition model
Custom diagramStandard diagram
More interactive model formats are also available. View Interactive Models
More interactive model formats are also available. View Interactive Models
Click on state and transition labels to scroll to the respective textEcosystem states
State 1 submodel, plant communities
State 2 submodel, plant communities
State 3 submodel, plant communities
State 4 submodel, plant communities
State 5 submodel, plant communities
State 6 submodel, plant communities
State 7 submodel, plant communities
State 1
Historic Climax Plant CommunityCommunity 1.1
Historic Climax Plant CommunityThe Historic Climax Plant Community (HCPC) is dominated by galleta (PLJA) and shadscale saltbush (ATCO). This vegetative community is fairly stable under proper grazing management practices. Both galleta and shadscale are well-developed to light or moderate grazing levels. Fire is not a major management issue on this site due to the naturally sparse distribution of vegetation.
Figure 3. Annual production by plant type (representative values) or group (midpoint values)
Table 5. Annual production by plant type
Plant type Low
(lb/acre)Representative value
(lb/acre)High
(lb/acre)Grass/Grasslike 20 60 100 Shrub/Vine 20 40 80 Forb 10 30 80 Tree 0 0 0 Total 50 130 260 Table 6. Ground cover
Tree foliar cover 0% Shrub/vine/liana foliar cover 0-10% Grass/grasslike foliar cover 0-10% Forb foliar cover 0-10% Non-vascular plants 0% Biological crusts 10-20% Litter 10-20% Surface fragments >0.25" and <=3" 10-50% Surface fragments >3" 0-20% Bedrock 0% Water 0% Bare ground 10-80% Table 7. Soil surface cover
Tree basal cover 0% Shrub/vine/liana basal cover 0-10% Grass/grasslike basal cover 0-0% Forb basal cover 0-0% Non-vascular plants 0% Biological crusts 10-20% Litter 10-20% Surface fragments >0.25" and <=3" 10-50% Surface fragments >3" 0-20% Bedrock 0% Water 0% Bare ground 20-90% Figure 4. Plant community growth curve (percent production by month). AZ3071 , 30.2, 6-10 p.z. - Rayless Goldenhead. Cool season shrub most growth in March - May..
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec J F M A M J J A S O N D 0 0 15 60 20 5 0 0 0 0 0 0 Figure 5. Plant community growth curve (percent production by month). AZ3521 , 35.2 6-10" p.z. all sites. Growth begins in the spring and continues through the summer. Most growth in this CRA occurs in the spring using stored winter moisture..
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec J F M A M J J A S O N D 0 1 9 20 27 14 10 11 5 3 0 0 Figure 6. Plant community growth curve (percent production by month). AZ5201 , 35.2 6-10" p.z. galleta. Growth begins in spring, most growth occurs during summer rains..
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec J F M A M J J A S O N D 0 0 5 10 20 10 15 35 5 0 0 0 Figure 7. Plant community growth curve (percent production by month). AZ5202 , Indian ricegrass, 35.2 6-10" p.z.. Growth begins in spring, most growth occurs in May, goes dormant during summer heat..
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec J F M A M J J A S O N D 0 0 10 15 40 20 0 0 10 5 0 0 Figure 8. Plant community growth curve (percent production by month). AZ5206 , 35.2 6-10" p.z. blackbrush. Most growth occurs in the srping, goes dormant during the summer..
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec J F M A M J J A S O N D 0 0 10 20 50 20 0 0 0 0 0 0 Figure 9. Plant community growth curve (percent production by month). AZ5209 , 35.2 6-10" p.z. Torrey Mormon tea. Growth occurs mostly in spring and early summer..
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec J F M A M J J A S O N D 0 0 5 25 25 20 15 10 0 0 0 0 Figure 10. Plant community growth curve (percent production by month). AZ5212 , 35.2 6-10" p.z. bud sagebrush. Growth begins in early spring, goes dormant from July through January. Flowers and sets seed in the spring..
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec J F M A M J J A S O N D 0 10 15 30 30 15 0 0 0 0 0 0 Figure 11. Plant community growth curve (percent production by month). AZ5216 , 35.2 6-10" p.z. shadscale saltbush. Growth occurs mostly in the spring and early summer using stored winter moisture..
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec J F M A M J J A S O N D 0 0 5 20 50 20 5 0 0 0 0 0 State 2
Shadscale Overstory and Annual Grass/Forb UnderstoryCommunity 2.1
Shadscale Overstory and Annual Grass/Forb UnderstoryShadscale saltbush (ATCO) dominates the overstory on this site. Native annual grasses and forbs dominate the understory. Perennial grasses and forbs are present in small amounts.
State 3
Shadscale/Composite Shrub Overstory and Annual Grass/Forb UnderstoryCommunity 3.1
Shadscale/Composite Shrub Overstory and Annual Grass/Forb UnderstoryShadscale saltbush (ATCO) and various other shrub species such as snakeweed (GUSA2) and rayless goldenhead (ACSP) and pricklypear (OPUNT) dominate the overstory on this site. Native annual grasses and forbs dominate the understory. Perennial grasses and forbs are present in small amounts.
State 4
Shadscale Overstory and Mixed UnderstoryCommunity 4.1
Shadscale Overstory and Mixed UnderstoryShadscale saltbush (ATCO) dominates the overstory on this site. Perennial native grasses and forbs dominate the understory but Exotic annual grasses such as cheatgrass (BRTE) and red brome (BRRU2) and exotic annual forbs such as Russian thistle (SALSO) and burning bush (BASC5) are present in the understory.
State 5
Shadscale/Composite Shrub Overstory and Mixed UnderstoryCommunity 5.1
Shadscale/Composite Shrub Overstory and Mixed UnderstoryShadscale saltbush (ATCO) and various other shrub species such as snakeweed (GUSA2) and rayless goldenhead (ACSP) and pricklypear (OPUNT) dominate the overstory on this site. Perennial native grasses and forbs dominate the understory but Exotic annual grasses such as cheatgrass (BRTE) and red brome (BRRU2) and exotic annual forbs such as Russian thistle (SALSO) and burning bush (BASC5) are present in the understory.
State 6
Shadscale Overstory and Exotic UnderstoryCommunity 6.1
Shadscale Overstory and Exotic UnderstoryShadscale saltbush (ATCO) dominates the overstory on this site. Exotic annual grasses such as cheatgrass (BRTE) and red brome (BRRU2) and exotic annual forbs such as Russian thistle (SALSO) and burning bush (BASC5) dominate the understory. Perennial grasses and forbs are present in small amounts.
State 7
Shadscale/Composite Shrub Overstory and Exotic UnderstoryCommunity 7.1
Shadscale/Composite Shrub Overstory and Exotic UnderstoryShadscale saltbush (ATCO) and various other shrub species such as snakeweed (GUSA2) and rayless goldenhead (ACSP) and pricklypear (OPUNT) dominate the overstory on this site. Exotic annual grasses such as cheatgrass (BRTE) and red brome (BRRU2) and exotic annual forbs such as Russian thistle (SALSO) and burning bush (BASC5) dominate the understory. Perennial grasses and forbs are present in small amounts.
Additional community tables
Table 8. Community 1.1 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Grass/Grasslike1 Perennial Sodgrass 20–70 James' galleta PLJA Pleuraphis jamesii 20–70 – blue grama BOGR2 Bouteloua gracilis 0–10 – 2 Perennial Bunchgrass 10–30 Indian ricegrass ACHY Achnatherum hymenoides 10–20 – mesa dropseed SPFL2 Sporobolus flexuosus 0–10 – 3 Native Annual Grass 0–5 sixweeks fescue VUOC Vulpia octoflora 0–5 – Forb4 Perennial Forb 5–15 globemallow SPHAE Sphaeralcea 0–15 – onion ALLIU Allium 0–5 – woolly locoweed ASMO7 Astragalus mollissimus 0–5 – rose heath CHER2 Chaetopappa ericoides 0–5 – bulbous springparsley CYBU Cymopterus bulbosus 0–5 – fleabane ERIGE2 Erigeron 0–5 – phacelia PHACE Phacelia 0–5 – pygmy fameflower PHBR16 Phemeranthus brevifolius 0–5 – 5 Annual Forb 0–10 thymeleaf sandmat CHSES Chamaesyce serpyllifolia ssp. serpyllifolia 0–5 – western tansymustard DEPI Descurainia pinnata 0–5 – wedgeleaf draba DRCUC Draba cuneifolia var. cuneifolia 0–5 – Shrub/Vine6 Shrub 20–80 shadscale saltbush ATCO Atriplex confertifolia 20–70 – Torrey's jointfir EPTO Ephedra torreyana 0–20 – broom snakeweed GUSA2 Gutierrezia sarothrae 0–10 – water jacket LYAN Lycium andersonii 0–10 – bud sagebrush PIDE4 Picrothamnus desertorum 0–10 – Cutler's jointfir EPCU Ephedra cutleri 0–10 – rayless goldenhead ACSP Acamptopappus sphaerocephalus 0–10 – blackbrush CORA Coleogyne ramosissima 0–5 – 7 Succulent 0–5 pricklypear OPUNT Opuntia 0–5 – Table 9. Community 2.1 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Table 10. Community 3.1 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Table 11. Community 4.1 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Table 12. Community 5.1 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Table 13. Community 6.1 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Table 14. Community 7.1 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Interpretations
Animal community
Suitability for grazing by livestock and big game animals is only fair due to the low productivity of the site. It is important for small birds for feed, cover, and nesting.
Recreational uses
The site provides opportunities for hiking, hunting, rock hounding and photography.
Wood products
This site may have only widely scattered juniper; not appropriate for fuelwood production.
Supporting information
Contributors
Karlynn Huling, Kevin Williams
Larry D. EllicottRangeland 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) Kevin Williams Contact for lead author NRCS Page Soil Survey Date 07/30/2007 Approved by Approval date Composition (Indicators 10 and 12) based on Annual Production Indicators
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Number and extent of rills:
A few rills may form on the steeper slopes due to slow permeabilty and high runoff characteristics of the soils and lack of natural vegetation on the site. The frequency of rock fragments limits this potential. -
Presence of water flow patterns:
Water flow patterns may be common where rock fragments are infrequent on steeper slopes due to slow permeability and high runoff characteristics of the soil. -
Number and height of erosional pedestals or terracettes:
A few pedestals or terracettes may form on steeper slopes. -
Bare ground from Ecological Site Description or other studies (rock, litter, lichen, moss, plant canopy are not bare ground):
Bare ground ranges from 15-45%. This iste has good cover by rock fragments. There is a low potential to produce plant cover and litter due to the average available water capacity of 2.7 inches. Drought may cause an increase in bare ground. -
Number of gullies and erosion associated with gullies:
Small gullies are occasional on this site. They usually form in small natural drainageways on steeper slopes due to slow permeablity an high runoff characteristics of the soils and lack of natural vegetation. The requency of rock fragments limits this potential. -
Extent of wind scoured, blowouts and/or depositional areas:
None. Some potential deposition from adjacent sandy upland sites. -
Amount of litter movement (describe size and distance expected to travel):
Herbaceous and fine woody litter will be transorted primarily by wind and in water flow pathways. Coarse woody litter will remain under shrub canopies. -
Soil surface (top few mm) resistance to erosion (stability values are averages - most sites will show a range of values):
Soil surface textures are clay loam. Soils have medium shrink/swell properties, but surface cracks are rare. This physical property could lead to low aggregate stability. When covered with a significant amount of rock fragments, most of the soils have a high resistance to both water and wind erosion. -
Soil surface structure and SOM content (include type of structure and A-horizon color and thickness):
Sol suface structure is weak medium subangular blocky parting to weak thin platy. The hickness of the A-horizon is 2 inches. The color of the A-horizon does not significantly differ from the subsurface soil horizons below it. -
Effect of community phase composition (relative proportion of different functional groups) and spatial distribution on infiltration and runoff:
This site is charaterized by a reatively even distribution of grasses, forbs and shrubs. Due to the fine-textured soils and dry conditions, vegetation is not dense but scattered sparsely across the site. Vegetative canoy cover ranges from 5-15% (grasses > shrubs = forbs > trees). Basal cover ranges 0-2% (grasses > forbs > shrubs > trees) for vascular plants and 5-15% for biological cust (cyanobacteria > lichen > moss). There may be an occasional tree. Both canopy and basal cover values decrease during prolonged drought. This type of plant community is poorly effective at capturing and storing precipitation. -
Presence and thickness of compaction layer (usually none; describe soil profile features which may be mistaken for compaction on this site):
None. Due to the clayey surface textures, this soil may be easily compacted when wet. However, the site is generally protected by a significant amount of rock fragment armor on the surface and within the surface horizons. -
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:
noneSub-dominant:
warm season colonizing grasses > annual forbs = shrubs >Other:
perennial forbs > annual grass > perennial bunchgrass > biological crustAdditional:
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Amount of plant mortality and decadence (include which functional groups are expected to show mortality or decadence):
All plant functional groups are adapted to survival in all but the most severe droughts. Severe winter droughts affect trees and shrubs most; severe summer droughts affect grasses the most. -
Average percent litter cover (%) and depth ( in):
Of the total litter amount, it would be expected that approximately 80-90% would be herbaceous litter and approximately 10-20% would be woody litter. Litter amounds increase during the first few years of drought, then decrease in later years. -
Expected annual annual-production (this is TOTAL above-ground annual-production, not just forage annual-production):
50-100 lbs/ac in drought years; 100-200 lbs/ac in median years; 200-300 lbs/ac in wet years. -
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:
Shadscale, broom snakeweed, rubber rabbitbrush, prickly pear and jointfir are native to the site, but have the potential to increase and dominate after heavy grazing. Cheatgrass and red brome are exotic annuals that are becoming established on the site and could dominate given a period of faborable moisture following heavy grazing or disturbance. Russian thistle and wooly pantlain are forbs that have the potential to invade and dominate after heavy grazing and/or disturbance, especially if the site is near farm fields or disturbed lands. -
Perennial plant reproductive capability:
All plants native to the site are adapted to the climate and are capable of producing seeds, stolons and/or rhizomes except during the mot severe droughts.
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