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Conservation Service

Ecological site R035XA118AZ

Sandy Upland 10-14" p.z.

Accessed: 04/25/2024

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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.

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Figure 1. Mapped extent

Areas shown in blue indicate the maximum mapped extent of this ecological site. Other ecological sites likely occur within the highlighted areas. It is also possible for this ecological site to occur outside of highlighted areas if detailed soil survey has not been completed or recently updated.

MLRA notes

Major Land Resource Area (MLRA): 035X–Colorado Plateau

This ecological site occurs in Common Resource Area 35.1 - the Colorado Plateau Mixed Grass Plains

Elevations range from 4800 to 6700 feet and precipitation averages 10 to 14 inches per year. Vegetation includes Stipa species, Indian ricegrass, galleta, and blue grama, fourwing saltbush, winterfat, and cliffrose. The soil temperature regime is mesic and the soil moisture regime is ustic 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.

Table 1. Dominant plant species

Tree	Not specified
Shrub	(1) Artemisia filifolia (2) Atriplex canescens
Herbaceous	(1) Achnatherum hymenoides (2) Hesperostipa comata ssp. comata

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Physiographic features

This site occurs in an upland position as gently rolling plains and mesas. It neither receives a significant amount of run-in moisture nor experiences an excess of runoff moisture.

Table 2. Representative physiographic features

Landforms	(1) Plain (2) Mesa
Flooding frequency	None
Elevation	4,800 – 6,300 ft
Slope	15%
Aspect	Aspect is not a significant factor

Climatic features

50-60% of moisture falls as rain Jul-Sept and is the most effective moisture for plant growth. The remaining moisture comes as snow during the winter.

Mean temperatures for the hottest month (Jul) is 72 degrees F; for the coldest month (Jan) is 32 degrees F. Extreme temperatures of 105 degrees F and -26 degrees F have been recorded. Long periods with little or no effective moisture are relatively common.

Cool season plants begin growth in early spring and mature in the early summer. Warm season plants take advantage of summer rains and grow from July through September.

Table 3. Representative climatic features

Frost-free period (average)	160 days
Freeze-free period (average)	180 days
Precipitation total (average)	13 in

Bar

Line

Figure 2. Monthly precipitation range

Bar

Line

Figure 3. Monthly average minimum and maximum temperature

Soil features

Soils on this site are deep and well-drained with no plant root restricting layers. The surface texture ranges from sand to course sandy loam. The substratum is loamy fine sand, loamy sand or sand. The soil ranges from neutral to moderately alkaline (pH 6.6 to 8.4). Permeability is rapid and the soil can absorb all the moisture the climate supplies but has a very low available water capacity.

Typical taxonomic units include:

Coconino County Central (AZ631) Soil Map Units - 25-Mespun;
Navajo County Central (AZ633) Soil Map Unit - 45-Pensom;
Apache County Central (AZ635) Soil Map Units - ER2-Eroded Land, PSB-Sheppard, SMB-Sheppard;
Little Colorado River(AZ707)Soil Map Unit- 30-Mespun; 30-Mespun limy substratum; 31-Mido;49-Santrick;
Navajo Mountain(AZ711)Soil Map Units- 5-Pensom moderately deep; 22-Mespun, 21-Mespun 23-Mespun, 24-Mespun;24-Mespun limy substratum;21-Bispen;27-Mido, 65-Mido;23-Santrick, 48-Santrick; 55-Shoegame family;
Chinle(AZ713) Soil Map Units- 39-Pinavetes;
Fort Defiance Area (AZ715)Soil Map Units - 15-Pinavetes family,

Table 4. Representative soil features

Surface texture	(1) Coarse sand (2) Sand (3) Coarse sandy loam
Family particle size	(1) Sandy
Drainage class	Well drained to somewhat excessively drained
Permeability class	Moderately rapid to rapid
Soil depth	40 – 60 in
Surface fragment cover <=3"	5%
Available water capacity (0-40in)	2.5 in
Calcium carbonate equivalent (0-40in)	2%
Soil reaction (1:1 water) (0-40in)	6.6 – 8.4
Subsurface fragment volume <=3" (Depth not specified)	15%

Ecological dynamics

The plant communities found on an ecological site are naturally variable. Composition and production will vary with yearly conditions, location, aspect, and the natural variability of the soils. The historical climax plant community represents the natural potential plant communities found on relict or relatively undisturbed sites. Other plant communities described here represent plant communities that are known to occur when the site is disturbed by factors such as grazing, fire, or drought.

Production data provided in this site description is standardized to air-dry weight at the end of the summer growing season. The plant communities described in this site description are based on near normal rainfall years.

NRCS uses a Similarity Index to compare existing plant communities to the plant communities described here. Similarity Index is determined by comparing the production and composition of a plant community to the production and composition of a plant community described in this site description. To determine Similarity Index, compare the production (air-dry weight) 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 normal year production shown in the plant community description. If rainfall has been significantly above or below normal, use the total production shown for above or below normal years. If field data is not collected at the end of the summer growing season, then the field data must be corrected to the end of the year production before comparing it to the site description. The growth curve can be used as a guide for estimating production at the end of the summer growing season.

The State and Transition model shows the most common occurring plant communities likely to be encountered on this ecological site. This model may not show every possible plant community, but only those that are most prevalent and observed through field inventory. As more data is collected and research is available, these plant communities may be revised, removed, and even added to reflect the ecological dynamics of this site.

State and transition model

Custom diagram

Standard diagram

Figure 4. 35.1 Sandy upland S&T model

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 text

State 1
Reference State

The refence state includes the Historic Climax Plant Community. This plant community (1.1) is composed primarily of cool season and warm season grasses with a small percentage of forbs and scattered large and half shrubs. Minor amounts (<5%) of introduced annuals may be present in this state.

Community 1.1
Native Perennial Grassland with Scattered Shrubs (HCPC)

Figure 5. Native Grassland with Shrubs (HCPC)

This plant community is composed primarily of cool and warm season grasses with a small percentage of forbs and scattered large and half shrubs. Dominant grasses include Indian ricegrass, needle and thread, blue grama, black grama, sand dropseed and galleta. Dominant shrubs include sand sagebrush, winterfat and fourwing saltbush. Trees may be present, but are widely scattered across the landscape. Natural disturbances, such as fire, maintain the native grassland with a light overstory of woody vegetation.

Figure 6. 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	245	370	490
Shrub/Vine	50	80	105
Tree	25	40	50
Forb	10	15	25
Total	330	505	670

Table 6. Soil surface cover

Tree basal cover	0-2%
Shrub/vine/liana basal cover	1-7%
Grass/grasslike basal cover	1-12%
Forb basal cover	1-4%
Non-vascular plants	0%
Biological crusts	0-25%
Litter	20-35%
Surface fragments >0.25" and <=3"	0-5%
Surface fragments >3"	0%
Bedrock	0%
Water	0%
Bare ground	25-55%

Figure 7. Plant community growth curve (percent production by month). AZ3511, 35.1 10-14" p.z. all sites. Growth begins in the spring and continues through the summer, most growth occurs during the summer rainy season. .

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	1	5	11	18	25	24	13	3	0	0

Figure 8. Plant community growth curve (percent production by month). AZ5102, 35.1 10-14" p.z. blue grama. Growth occurs mostly in summer and early fall during the rainy season..

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	0	5	5	15	30	30	15	0	0	0

Figure 9. Plant community growth curve (percent production by month). AZ5213, 35.1 10-14" p.z. winterfat. Growth begins in the spring and continues through the summer. Seed stalk extension and seed set occurs in 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	15	25	20	10	15	10	0	0	0

Community 1.2
Shrubland with Native Grasses

This plant community is characterized by a mix of shrubs and a well developed understory of perennial grasses and forbs. Common shrubs include fourwing saltbush, sand sagebrush, mormon tea, winterfat, rabbitbrush along with other native shrubs. The understory is a mix of cool season and warm season grasses and smaller amounts of forbs. Common grasses include Indain ricegrass, bluegrama, needle and thread, dropseeds, galleta and other native grasses. Junipers may be present, but occur scattered across the landscape. Shrub canopy is usually less than 25%.

Community 1.3
Sand sagebrush with Native Grasses

This plant community is characterized by an increase of sand sagebrush with a well developed understory of perennial grasses. This plant community phase is maintained by some soil disturbance and sand sage's ability to thrive after surface disturbance. This also includes other shrubs such as rabbitbrush, Culter's mormon tea, sand buckwheat, snakeweed, fourwing saltbush and/or other native shrubs. The understory is mixture of cool and warm season grasses such as needle and thread, blue grama, Indian ricegrass, sand dropseed, sandhill muhly and other native grasses. Shrub canopy is usually less 25% with an occasional scattered juniper.

Community 1.4
Active Dunes with Native Shrubs

This plant community is characterized by areas of bare ground with scattered shrubs and grasses. Vegetation cover is highly variable and tends to be patchy on more active dunes. The canopy is dominated by shrubs, such as sand sagebrush, sand buckwheat, Cutler's mormon tea, dune broom, frosted mint, Bigelow rabbitbrush as well as other native shrubs. Dominate grasses include Indian ricegrass, sand dropseed, spike dropseed, giant dropseed, sandhill muhly as well as other native grasses. Bare ground ranges from 60 to 90% with large connected bare areas common.

Community 1.5
Grassland with Mormon tea

This plant community is characterized by a dominance of Cutler's mormon tea, Indian ricegrass, blue grama and dropseeds. This plant community can result from a combination of drought and/or unmanaged grazing.

Pathway 1.1a
Community 1.1 to 1.2

Increases insect/wildlife herbivory, drought, lack of natural fire

Pathway 1.1b
Community 1.1 to 1.3

Insect/wildlife herbivory, drought, lack of natural fire, increase soil surface disturbance (soil deposition from wind or water).

Pathway 1.1c
Community 1.1 to 1.5

Drought, insect herbivory, unmanaged grazing, lack of fire.

Pathway 1.2b
Community 1.2 to 1.1

Fire to remove shrubs, favorable moisture.

Pathway 1.2a
Community 1.2 to 1.3

Drought, insect herbivory, lack of fire. Increased bare ground, along with frequent soil surface disturbance favors the increase of sand sagebrush.

Pathway 1.2c
Community 1.2 to 1.4

Prolonged drought with frequent soil surface disturbance and reduced perennial herbaceous cover.

Pathway 1.2d
Community 1.2 to 1.5

Drought, herbivory, unmanaged grazing, lack of fire.

Pathway 1.3b
Community 1.3 to 1.2

Reduced disturbance, favorable moisture, available seed source for perennial grasses provides increased soil stability allowing grasses to establish.

Pathway 1.3a
Community 1.3 to 1.4

Prolonged drought with frequent soil surface disturbance and reduced perennial herbaceous cover.

Pathway 1.4a
Community 1.4 to 1.3

Reduced soil disturbance, favorable moisture allows for increased soil stabilty and an increase of large shrubs (sand sagebrush, fourwing saltbush, rabbitbrush) and perennial grasses.

Pathway 1.5c
Community 1.5 to 1.1

Managed grazing with Rest, reduced soil disturbance, favorable moisture allows for increased soil stabilty and an increase of large shrubs (fourwing saltbush, rabbitbrush, sand sagebrush) and perennial grasses.

Conservation practices

Prescribed Grazing

Pathway 1.5a
Community 1.5 to 1.2

Reduced disturbance, favorable moisture, seed source for shrubs and grasses, managed grazing.

Pathway 1.5b
Community 1.5 to 1.3

Reduced disturbance, favorable moisture, seed source for perennial grasses, managed grazing.

State 2
Sand Sagebrush State

This plant community is dominated by sand sagebrush with other shrubs present. Perennial grasses are sub-dominant with scattered forbs and occasionally scattered junipers.

Community 2.1
Sand Sagebrush Overstory

This plant community is dominated by sand sagebrush. Other shrubs present are sand buckwheat, Mormon tea and rabbitbrush. Perennial grasses are sub-dominant with scattered forbs and occasionally scattered junipers. Grasses are mainly dropseeds, sandhill muhly, blue grama threeawns and galleta. Non-native annuals, such as cheatgrass or Russian thistle are present as are other introduced annuals. Shrub canopy is usually greater than 25 percent, with sand sagebrush the dominant component and most productive. Reduced competition from perennial grasses, increased bare ground, unmanaged grazing and drought conditions favor sand sagebrush persistence. Bare ground ranges between 60-80 percent with large connected bare patches common.

State 3
Juniper State

This plant community has an increased overstory of juniper (>10% cover) with a mixed shrub understory and few perennial grasses.

Community 3.1
Juniper Overstory

This plant community has an increase in juniper canopy greater than 10% with a mixed shrub understory. Grass cover is generally low, but forb cover is highly variable depending on climatic events. Bare ground ranges between 50-80 percent with large connected bare patches common. Common herbaceous vegetation includes Indian ricegrass, sandhill muhly, blue grama, sand dropseed with other native grasses and forbs. Shrubs include Mormon tea, snakeweed, sand sage, rabbitbrush, sand buckwheat along with other native shrubs. Non-native annuals, such as cheatgrass and Russian thistle are present along with other introduced annuals.

State 4
Annuals State

This plant community is characterized by a dominance of non-native and native annual forbs with half shrubs and few annual grasses. Some perennial grasses and forbs may be present in smaller amounts.

Community 4.1
Invasive Annual Forbs

This plant community is characterized by dominance of non-native and native annuals forbs with half shrubs, annual grasses. Some perennial grasses and forbs may be present in smaller amounts. Russian thistle is the most prevelant annual forb and very productive on this site. Other common annuals include croton, stickseed, woolly plantain, buckwheats, wire lettuce, false buffalograss, cheatgrass and scorpionweed.

Transition T1A
State 1 to 2

Dominance of sand sagebrush and increased composition of non-native species from lack of fire, unmanaged grazing, and other frequent ground disturbance.

Transition T1B
State 1 to 3

Juniper establishment on site. Reduced competition from perennial grasses and shrubs, lack of fire, unmanaged grazing, juniper seed source available from adjacent sites coupled with increased bare ground allow for seedling establishment and encroachment. Favorable precipitation may increase seedling establishment even with moderate grass or shrub cover.

Transition T1C
State 1 to 4

Prolonged drought, unmanaged grazing, along with severe and frequent soil surface disturbance occurs. Soil stability is reduced and soils are subject to active soil erosion, blowouts and mounding. Low perennial herbaceous cover, along with large connected areas of bare ground are common. This allows for invasion of annuals and the increase of less desirable shrub species.

Restoration pathway R2A
State 2 to 1

Reduced soil surface disturbances that maintain sand sage persistence. This site may return to a shrubland/grassland (1.2 or 1.3) with prescribed grazing, favorable moisture and a pernnial grass seed source. This pathway is also possible with woody species control (chemical or mechanical) and re-seeding to accelerate grass establishment.

Conservation practices

Brush Management
Grazing Land Mechanical Treatment
Prescribed Grazing
Herbaceous Weed Control

Transition T2A
State 2 to 3

Juniper establishment on site. Reduce competition from perennial grasses and shrubs, lack of fire, unmanaged grazing, juniper seed source available from adjacent sites coupled with increased bare ground allow for seedling establishment and encroachment. Favorable precipitation may increase seedling establishment even with moderate grass or shrub cover.

Transition T2B
State 2 to 4

Restoration pathway R3B
State 3 to 1

Juniper control through fire or mechanical methods, managed grazing and a seed source for grass re-establishment.

Conservation practices

Brush Management
Prescribed Grazing
Herbaceous Weed Control

Restoration pathway R3A
State 3 to 2

Juniper control through fire or mechanical methods, managed grazing and a seed source for grass re-establishment.

Restoration pathway R4B
State 4 to 1

This restoration pathway would require extensive inputs. Improved soil stability with perennial grass re-seeding or available seed source,non-native invasive weed control, favorable moisture, and managed grazing with rest could allow for the increase of perennial grass and shrubs. This pathway could take several years to decades to occur without significant inputs.

Conservation practices

Grazing Land Mechanical Treatment
Range Planting
Prescribed Grazing
Herbaceous Weed Control

Restoration pathway R4A
State 4 to 2

This restoration pathway would require extensive inputs. Improved soil stability with perennial grass re-seeding or available seed source, non-native invasive weed control, favorable moisture, and managed grazing with rest could allow for the increase of perennial grass and shrubs. This pathway could take several years to decades to occur without significant inputs.

Conservation practices

Range Planting
Prescribed Grazing
Herbaceous Weed Control

Additional community tables

Table 7. Community 1.1 plant community composition

Group	Common name	Symbol	Scientific name	Annual production (lb/acre)	Foliar cover (%)
Grass/Grasslike
1	Cool season dominant grasses			105–260
	Indian ricegrass	ACHY	Achnatherum hymenoides	50–130	–
	needle and thread	HECOC8	Hesperostipa comata ssp. comata	25–55	–
	squirreltail	ELELE	Elymus elymoides ssp. elymoides	25–50	–
2	Warm season dominant grasses			50–105
	blue grama	BOGR2	Bouteloua gracilis	25–80	–
	black grama	BOER4	Bouteloua eriopoda	25–55	–
3	Other grasses			25–80
	alkali sacaton	SPAI	Sporobolus airoides	15–50	–
	James' galleta	PLJA	Pleuraphis jamesii	10–35	–
4	Misc. grasses			25–55
	spike dropseed	SPCO4	Sporobolus contractus	0–20	–
	sand dropseed	SPCR	Sporobolus cryptandrus	0–20	–
	mesa dropseed	SPFL2	Sporobolus flexuosus	0–20	–
	Grass, perennial	2GP	Grass, perennial	0–10	–
	threeawn	ARIST	Aristida	0–10	–
	sandhill muhly	MUPU2	Muhlenbergia pungens	0–10	–
	Grass, annual	2GA	Grass, annual	0–5	–
Forb
5	All forbs			10–25
	Forb, perennial	2FP	Forb, perennial	0–8	–
	globemallow	SPHAE	Sphaeralcea	4–7	–
	Forb, annual	2FA	Forb, annual	0–6	–
	Rocky Mountain zinnia	ZIGR	Zinnia grandiflora	2–5	–
	pale evening primrose	OEPA	Oenothera pallida	0–5	–
	Wright's bird's beak	COWR2	Cordylanthus wrightii	0–5	–
	cryptantha	CRYPT	Cryptantha	0–5	–
	hoary tansyaster	MACA2	Machaeranthera canescens	0–5	–
	fineleaf hymenopappus	HYFI	Hymenopappus filifolius	0–5	–
	flatspine stickseed	LAOC3	Lappula occidentalis	0–2	–
	pepperweed	LEPID	Lepidium	0–2	–
	sanddune linanthus	LIAR2	Linanthus arenicola	0–2	–
	shortstem lupine	LUBR2	Lupinus brevicaulis	0–2	–
	sand verbena	ABRON	Abronia	0–2	–
	whitemargin sandmat	CHAL11	Chamaesyce albomarginata	0–2	–
	rose heath	CHER2	Chaetopappa ericoides	0–2	–
	whitestem blazingstar	MEAL6	Mentzelia albicaulis	0–2	–
	touristplant	DIWI2	Dimorphocarpa wislizeni	0–2	–
	small wirelettuce	STEX	Stephanomeria exigua	0–2	–
	longbeak streptanthella	STLO4	Streptanthella longirostris	0–2	–
	annual Townsend daisy	TOAN	Townsendia annua	0–2	–
	phacelia	PHACE	Phacelia	0–2	–
	woolly plantain	PLPA2	Plantago patagonica	0–2	–
Shrub/Vine
6	Dominant shrubs			25–70
	fourwing saltbush	ATCA2	Atriplex canescens	7–30	–
	jointfir	EPHED	Ephedra	7–20	–
	sand sagebrush	ARFI2	Artemisia filifolia	7–20	–
	winterfat	KRLA2	Krascheninnikovia lanata	5–15	–
7	Misc. shrubs			25–50
	rabbitbrush	CHRYS9	Chrysothamnus	0–15	–
	snakeweed	GUTIE	Gutierrezia	0–15	–
	pricklypear	OPUNT	Opuntia	0–10	–
	yucca	YUCCA	Yucca	0–10	–
	common dunebroom	PAFI4	Parryella filifolia	0–5	–
	broadbeard beardtongue	PEAN4	Penstemon angustifolius	0–5	–
	sand buckwheat	ERLE9	Eriogonum leptocladon	0–5	–
	rubber rabbitbrush	ERNAB2	Ericameria nauseosa ssp. nauseosa var. bigelovii	0–5	–
	prairie sagewort	ARFR4	Artemisia frigida	0–5	–
Tree
8	Trees			25–55
	oneseed juniper	JUMO	Juniperus monosperma	0–25	–
	twoneedle pinyon	PIED	Pinus edulis	0–25	–

Interpretations

Animal community

This site is favorable for grazing throughout most of the year except when snow cover restricts availability of forage. With unmanaged grazing during winter and spring, the relatively scarce cool season grasses are replaced by rabbit brush, snakeweed and lower value forbs and grasses. Planned grazing systems adapt well to use on this site.

The potential plant community produced by this site provides food for those species of wildlife that utilize grass as a major portion of their diet. When vegetative retrogression occurs, unpalatable shrubby species increase and some wildlife species may be benefit.

Recreational uses

Site is located on gently rolling plains and mesa tops which lend themselves to activities such as horseback riding, wildlife observation and hunting.

Following good winter moisture a variety of spring and summer flowers which are particularly noticeable. It has good aesthetic appeal when not severely disturbed.

Winters are cold, however, relatively mild spring, fall and summer months are attractive to recreationists.

Other products

Personal firewood cutting when the tree canopy exceeds 15%.

Supporting information

Type locality

Location 1: Navajo County, AZ
General legal description	Petrified Forest, Painted Desert National Park.
Location 2: Apache County, AZ
General legal description	LDS Stake Ranch near St Johns(top of mesa).

Other references

Updates and revisions for this ESD were conducted as part of a 2007-2012 Interagency Technical Assistance Agreement between the Bureau of Indian Affairs–Navajo Region and the NRCS-Arizona.

Contributors

Ken Gishi
Larry D. Ellicott
Steve Barker

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)	Ken Gishi, Dean Schlichting, Dan Carroll
Contact for lead author	State Rangeland Management Specialist, NRCS-Arizona State Office, Phoenix, AZ
Date	11/13/2008
Approved by	Steve Cassady
Approval date
Composition (Indicators 10 and 12) based on	Annual Production

Indicators

Number and extent of rills:
None. The sandy surface textures and well drained nature of the soils should preclude the presence of rills.
Presence of water flow patterns:
A very few scattered water flow patterns may be present on steepest slopes. Water Flow patterns on these soils are commonly 1 to 2 meters long, generally occupying < 5% of the ground cover.
Number and height of erosional pedestals or terracettes:
Uncommon. If present pedestals typically less than 1” in height often associated with deposition areas and water flow patterns. Terracettes are absent. This site has potential for significant developement of biological crust. Well developed biological crust should bot be confused with pedastals.
Bare ground from Ecological Site Description or other studies (rock, litter, lichen, moss, plant canopy are not bare ground):
Bare ground averages 35-55%. Drought may cause an increase in bare ground.
Number of gullies and erosion associated with gullies:
None.
Extent of wind scoured, blowouts and/or depositional areas:
Wind scoured areas, blowouts, and/or depositional areas are mostly uncommon in well vegetated herbaceous plant communities(1.1 & 1.2). However, in certain plant communities (1.3 & 1.4) some deposition and wind scour may occur, especially during droughts, due to high wind erosion hazard of the soil. Sites dominated by sand sage and juniper are most likely to suffer from excessive blowouts and depositions
Amount of litter movement (describe size and distance expected to travel):
Most herbaceous and fine woody litter will be transported by wind and in water flow pathways, while a small percentage stays in place. Coarse woody litter and duff will accumulate under shrub and tree canopies.
Soil surface (top few mm) resistance to erosion (stability values are averages - most sites will show a range of values):
Expected soil aggregate stability ranges from 2 to 4. Under canopies the range is 3 to 4 and 2 to 3 in the interspaces. When well vegetated, these soils have a moderate to high resistance to water erosion, but only a low resistance to wind erosion.
Soil surface structure and SOM content (include type of structure and A-horizon color and thickness):
Soil surface structure is loose granular, with a weak physical crust. Surface thickness range from 3-6 inches. Color is variable depending on parent material.
Effect of community phase composition (relative proportion of different functional groups) and spatial distribution on infiltration and runoff:
This grassland community consists of about 70 percent grasses, 25 percent shrubs and 5 percent composition of forbs and promotes infiltration and reduces runoff.
Presence and thickness of compaction layer (usually none; describe soil profile features which may be mistaken for compaction on this site):
None.
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:
cool season grasses (35-45%) > warm season grasses (30-40%)

Sub-dominant:
shrubs (15-25%)

Other:
Forbs (5-10%) > Trees (1-5%)

Additional:
Amount of plant mortality and decadence (include which functional groups are expected to show mortality or decadence):
In a normal year up to 10% of grasses and shrubs die off. During and after drought years there can be from 10 to 20% die off of shrubs and grasses. Severe winter droughts affect shrubs, trees and cool season grasses the most. Severe summer droughts affect the warm season grasses the most.
Average percent litter cover (%) and depth ( in):
Within plant interspaces litter ranges from 10 to 20% cover, while under shrub and tree canopies it ranges from 25 to 60% cover with depths from 1/8 to 1/4 inch thick.
Expected annual annual-production (this is TOTAL above-ground annual-production, not just forage annual-production):
250-350 pounds per acre (dry weight) in drought years, 450-550 pounds per acre in normal years, 600-700 pounds per acre 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:
Mormon tea, Broom snakeweed, sand sagebrush and rabbitbrush are all native to the site, but have the ability to increase and dominate the area after disturbance. Oneseed juniper (JUMO) is native to the site, but has the ability to increase and dominate the site after unmanaged grazing and/or fire exclusion. Introduced annuals that have the ability to increase and dominate the site after unmanaged grazing and/or ground disturbance include cheatgrass and Russian thistle
Perennial plant reproductive capability:
All plants native to this site are adapted to the climate and are capable of producing seeds, stolons and rhizomes except during the most severe droughts.

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Natural ResourcesConservation Service

Ecological site R035XA118AZ

Sandy Upland 10-14" p.z.

Accessed: 04/25/2024

General information

Figure 1. Mapped extent

MLRA notes

Table 1. Dominant plant species

Ecosystem states

State 1 submodel, plant communities

Communities 1, 5 and 2 (additional pathways)

State 2 submodel, plant communities

State 3 submodel, plant communities

State 4 submodel, plant communities

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Conservation Service