Natural Resources
Conservation Service

Ecological site R035XC302AZ

Sedimentary Cliffs 10-14" p.z.

Accessed: 12/22/2024

Home / Esd catalog / MLRA 035X / Ecological site R035XC302AZ

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.

Click to explore map

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 is found in Common Resource Area 35.3 – the Colorado Plateau Sagebrush – Grasslands.

The Common Resource Area occurs within the Colorado Plateau Physiographic Province. It is characterized by a sequence of flat to gently dipping sedimentary rocks eroded into plateaus, valleys and deep canyons. Elevations range from 4800 to 6700 feet and precipitation averages 10 to 14 inches. The elevation range is lower (about 4500 to 6000 ) on the western side of the Colorado Plateau along the Grand Canyon, and moves up about 500 to 800 feet higher on the eastern side in the areas of the Navajo and Hopi Indian Reservations due to rain shadow effects from the Kaibab Plateau and Mogollon Rim. Common vegetation in this region includes Wyoming big sagebrush, Utah juniper, Colorado pinyon - cliffrose, Mormon tea, fourwing saltbush, blackbrush Indian ricegrass, needle and thread, western wheatgrass Galleta, black grama, blue grama, and sand dropseed. Sedimentary rock classes dominate the plateau with volcanic fields occurring for the most part near its margin. The soil temperature regime is mesic and the soil moisture regime is ustic aridic.

Table 1. Dominant plant species

Tree	(1) Juniperus monosperma
Shrub	(1) Artemisia tridentata ssp. wyomingensis (2) Atriplex canescens
Herbaceous	(1) Hesperostipa comata (2) Poa fendleriana

Download full description

Physiographic features

This ecological site occurs as steep canyon walls, with small plateaus and ledges. It typically suffers from excessive drainage. Slopes are over 30 percent.

Table 2. Representative physiographic features

Landforms	(1) Cliff (2) Escarpment
Flooding frequency	None
Ponding frequency	None
Elevation	1,463 – 2,042 m
Slope	30 – 100%
Aspect	Aspect is not a significant factor

Climatic features

Winter summer moisture ratios range from 70:30 to 60:40. Late spring is usually the driest period, and early fall moisture can be sporadic. Summer rains fall from June through September; moisture originates in the Gulf of Mexico and creates convective, usually brief, intense thunderstorms. Cool season moisture from October through May tends to be frontal; it originates in the Pacific and the Gulf of California and falls in widespread storms with longer duration and lower intensity. Precipitation generally comes as snow from December through February. Accumulations above 12 inches are not common but can occur. Snow usually lasts for 3-4 days, but can persist much longer. Summer daytime temperatures are commonly 95 - 100 F and on occasion exceed 105 F. Winter air temperatures can regularly go below 10 F and have been recorded below - 20 F.

Table 3. Representative climatic features

Frost-free period (average)	168 days
Freeze-free period (average)	193 days
Precipitation total (average)	356 mm

Bar

Line

Figure 2. Monthly precipitation range

Bar

Line

Figure 3. Monthly average minimum and maximum temperature

Influencing water features

The soil moisture on this ecological site comes from precipitation. The site does not benefit significantly from run-on moisture from other sites. Shallow bedrock areas will concentrate water in deeper soil pockets on ledges, where most of the vegetation production occurs. Because of the shallow soils, larger rainfall events will not be captured by the site. This site contributes runoff to other ecological sites.

Soil features

The soils of this ecological site are very shallow to shallow. The complex geologic strata associated with the site has created a multitude of soil textures, and developments. There are also extreme differences in aspect which affect soil formation.

The soils range from coarse to fine loams. Parent material is typically limestone or sandstone with prominent calcium carbonate influence. Permeability is moderate to rapid, and the avaiable water capacity is very low.

Soil map units correlated to this ecological site include:

SSA 623 Shivwits Area MU's 45 Torriorthents & 51 Merwhitica;

SSA 625 Mohave County Area NE part MU 63
Torriorthents; SSA MU 48 Torriorthents;

SSA-629 Coconino County North Kaibab part MU 48 Torriorthents;

SSA 697 Mohave County Central part MU 126 Torriorthents;

SSA 701 Grand Canyon Area MU's 21 Chilton Puertecito family & Teesto family, 80 Meriwhitica,
112 Lithic Ustic torriorthents & Ustic torriorthents, 113 Seis family & Skos family, 158 Lithic Ustic Haplargids Lithic Ustic torriorthents & Ustic torriorthents;

SSA 707 Little Colorado River 42-Reef/Progresso, 46-Rock Outcrop/Mathis

SSA 711 Navajo Mountain Area 42-Rock Outcrop/Mathis, 67-Rock outcrop;

SSA 712 Canyon de Chelly NM 18-Ustic torriorthents;

SSA-713 Chinle Area MU's 61-Ustic Torriorthents, 63-Rock Outcrop;

SSA 714 Hopi Area MU's 28 Torriorthents, 35 Strych & 40 Ustic torriorthents;

SSA 715 Fort Defiance Area 82-Arches, 100-Teesto family, 101-Torriorthents, 127-Ustic Torriorthents

SSA 717 Shiprock Area 305 and 316 Strych, 311
and 320 Kinusta.

Table 4. Representative soil features

Parent material	(1) Colluvium – limestone and sandstone
Surface texture	(1) Gravelly sand (2) Cobbly loam (3) Sandy clay loam
Family particle size	(1) Loamy
Drainage class	Well drained
Permeability class	Moderate
Soil depth	15 – 25 cm
Surface fragment cover <=3"	35 – 75%
Surface fragment cover >3"	45 – 65%
Available water capacity (0-101.6cm)	1.78 – 2.29 cm
Calcium carbonate equivalent (0-101.6cm)	5 – 35%
Electrical conductivity (0-101.6cm)	0 – 2 mmhos/cm
Sodium adsorption ratio (0-101.6cm)	0
Soil reaction (1:1 water) (0-101.6cm)	7.9 – 8.4
Subsurface fragment volume <=3" (Depth not specified)	45 – 65%
Subsurface fragment volume >3" (Depth not specified)	10 – 20%

Ecological dynamics

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 historic climax plant community for this ecological site has been described by sampling relict or relatively undisturbed sites and/or reviewing historic records. The historic climax plant community is the plant community that evolved over time with the soil forming process and long term changes in climatic conditions of the area. It is the plant community that was best adapted to the unique combination of environmental factors associated with the site.

Natural disturbances, such as drought, fire, grazing of native fauna, and insects, are inherent in the development and maintenance of these plant communities. The effects of these disturbances are part of the range of characteristics of the ecological site. Fluctuations in plant community structure and function caused by the effects of natural disturbances help establish the boundaries and characteristics of an ecological site. They are accounted for as part of the range of characteristics of the ecological site. Recognizable plant community phases are identified in the reference state of the ecological site. Some sites may have a small range of variation, while others have a large range. Some plant community phases may exist for long periods of time, while others may only occur for a couple of years after a disturbance.

Deterioration of the plant community, hydrology, or soil site stability on an ecological site can result in crossing a threshold or potentially irreversible boundary to another state, or equilibrium. This can occur as a result of the loss of soil surface through erosion, the loss of the stability of the site due to disturbances that cause active erosion on the site, increases in the amounts and/or patterns or runoff from rainstorms, changes in availability of surface and subsurface water, significant changes in plant structural and functional types, or the introduction of non-native species. When these thresholds are crossed, the potential of the ecological site to return to the historic climax plant community can be lost, or restoration will require significant inputs . There may be multiple states possible for an ecological site, determined by the type and or severity of disturbance.

The known states and transition pathways for this ecological site are described in the state and transition model. Within each state, there may be one or more known plant community phases. These community phases describe the different plant community that can be recognized and mapped across this ecological site. The state and transition model is intended to help land users recognize the current plant community on the ecological site, and the management options for improving the plant community to the desired plant community.

Plant production information in this site description is standardized to the annual production on an air-dry weight basis in near normal rainfall years.

State and transition model

Custom diagram

Standard diagram

Figure 4. R035XC302AZ ST 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

Community 1.1
Historic Climax Plant Community

Figure 5. 35.3 Sedimentary Cliffs

Figure 6. Lower Elevation, South Aspect Site

Figure 7. Higher Elevation Site

This site is a complex of trees, shrubs, forbs, and grasses. In the original plant community there is a mixture of cool and warm season plants. The plant community is composed of relatively equal amounts of shrubs, grasses, and forbs. It can be variable due to site conditions (aspect, soil depth, run-on & run-off areas). Plants most likely to increase or invade when the site deteriorates are big sagebrush, snakeweed, juniper and cacti. COMMUNITY PATHWAY: 1.1A – Drought, extended periods of winter dominated moisture, and loss of natural fire will reduce perennial grasses and increase woody species on the site.

Figure 8. Annual production by plant type (representative values) or group (midpoint values)

Table 5. Annual production by plant type

Plant type	Low (kg/hectare)	Representative value (kg/hectare)	High (kg/hectare)
Grass/Grasslike	224	392	504
Shrub/Vine	56	191	325
Tree	90	112	179
Forb	45	56	90
Total	415	751	1098

Figure 9. 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 10. Plant community growth curve (percent production by month). AZ3531, 35.3 10-14" p.z. all sites. Growth begins in the spring and continues through 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	1	3	17	18	10	19	20	10	1	1	0

Community 1.2
Composite Shrub, Succulents, and Annual Forbs

1.2 Composite Shrub, Succulents, and Annual Forbs – Composite shrubs such as broom snakeweed, and succulents such as prickly pear increase over Big sagebrush and other palatable shrubs. Perennial bunchgrasses decrease in relation to annual grasses and forbs. COMMUNITY PATHWAY: 1.2A – Managed grazing.

State 2
Native/ Introduced Annuals

Community 2.1
Native Overstory with Mixed Native – Exotic Understory

2.1 Native Overstory with Mixed Native – Exotic Understory – Exotic annual grasses are present in the plant community but the amount and composition of native perennial grasses remains unchanged. Introduced annuals can range in composition from 2-10 percent in the total plant community composition. COMMUNITY PATHWAY: 2.1A – Drought, extended periods of winter dominated moisture, and reduction in normal fire frequency will reduce perennial grasses and increase shrubs on the site.

Community 2.2
Native Overstory with Exotic Understory

Native Overstory with Exotic Understory Exotic annual grasses dominate understory within the plant community. Introduced annuals can range in composition from 2-20 percent in the total plant community composition. COMMUNITY PATHWAY: 2.2A – Normal precipitation patterns, periodic fires.

Transition T1A
State 1 to 2

Exotic grass species such as cheatgrass are introduced into the site.

Additional community tables

Table 6. Community 1.1 plant community composition

Group	Common name	Symbol	Scientific name	Annual production (kg/hectare)	Foliar cover (%)
Grass/Grasslike
1	Cool Season Grasses			112–224
	needle and thread	HECO26	Hesperostipa comata	22–90	–
	desert needlegrass	ACSP12	Achnatherum speciosum	22–90	–
	muttongrass	POFE	Poa fendleriana	22–56	–
	squirreltail	ELEL5	Elymus elymoides	22–45	–
2	Warm Season Grasses			112–280
	blue grama	BOGR2	Bouteloua gracilis	11–67	–
	bush muhly	MUPO2	Muhlenbergia porteri	0–28	–
	threeawn	ARIST	Aristida	0–28	–
	sideoats grama	BOCU	Bouteloua curtipendula	0–28	–
	black grama	BOER4	Bouteloua eriopoda	0–28	–
	James' galleta	PLJA	Pleuraphis jamesii	11–28	–
	spike dropseed	SPCO4	Sporobolus contractus	11–28	–
	sand dropseed	SPCR	Sporobolus cryptandrus	11–28	–
	mesa dropseed	SPFL2	Sporobolus flexuosus	11–28	–
	sandhill muhly	MUPU2	Muhlenbergia pungens	0–17	–
	ring muhly	MUTO2	Muhlenbergia torreyi	0–17	–
Forb
3	Forbs			45–90
	Indian ricegrass	ACHY	Achnatherum hymenoides	45–90	–
	Forb, annual	2FA	Forb, annual	11–45	–
	Forb, perennial	2FP	Forb, perennial	11–45	–
	prairie sagewort	ARFR4	Artemisia frigida	11–45	–
	buckwheat	ERIOG	Eriogonum	11–45	–
	globemallow	SPHAE	Sphaeralcea	11–45	–
Shrub/Vine
4	Shrubs			56–280
	serviceberry	AMELA	Amelanchier	0–45	–
	squirreltail	ELELE	Elymus elymoides ssp. elymoides	0–45	–
	Sonoran scrub oak	QUTU2	Quercus turbinella	0–45	–
	skunkbush sumac	RHTR	Rhus trilobata	0–45	–
	Wyoming big sagebrush	ARTRW8	Artemisia tridentata ssp. wyomingensis	22–45	–
	fourwing saltbush	ATCA2	Atriplex canescens	22–45	–
	rabbitbrush	CHRYS9	Chrysothamnus	0–45	–
	jointfir	EPHED	Ephedra	22–45	–
	broom snakeweed	GUSA2	Gutierrezia sarothrae	9–45	–
	Stansbury cliffrose	PUST	Purshia stansburiana	9–45	–
	bastardsage	ERWR	Eriogonum wrightii	0–27	–
	antelope bitterbrush	PUTR2	Purshia tridentata	0–22	–
	sand sagebrush	ARFI2	Artemisia filifolia	0–18	–
	brickellbush	BRICK	Brickellia	0–16	–
	manzanita	ARCTO3	Arctostaphylos	0–15	–
	roundleaf buffaloberry	SHRO	Shepherdia rotundifolia	0–9	–
5	cacti & succulents			6–34
	agave	AGAVE	Agave	18–45	–
	hedgehog cactus	ECHIN3	Echinocereus	18–45	–
	globe cactus	MAMMI	Mammillaria	18–45	–
	pricklypear	OPUNT	Opuntia	18–45	–
	yucca	YUCCA	Yucca	18–45	–
Tree
6	Trees			90–179
	juniper	JUNIP	Juniperus	90–179	–
	twoneedle pinyon	PIED	Pinus edulis	90–179	–
	blue grama	BOGR2	Bouteloua gracilis	45–90	–
	Gambel oak	QUGA	Quercus gambelii	0–45	–

Interpretations

Animal community

This site is typically quite steep which severely restricts use by livestock. Proper distribution is often impossible to attain, and heavy use occurs in the limited access areas frequented by livestock.

This site provides a great deal of habitat diversity because of the topography, exposures, plant community variation, and rockiness. Permanent waters are lacking however. It is very important cover for many wildlife species.

Recreational uses

This site consists of canyon walls and plateau breaks. It has a highly diversified plant complex including trees, grasses, forbs, and shrubs. Winters are cold and spring is dry and windy. Late spring, summer, and fall provide pleasant recreation weather. Sport hunting is the major recreation activity of the site.

Supporting information

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
Stephen Cassady
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)	Kevin Williams
Contact for lead author	NRCS State Rangeland Management Specialist, Phoenix AZ
Date	01/09/2007
Approved by	Steve Barker
Approval date
Composition (Indicators 10 and 12) based on	Annual Production

Indicators

Number and extent of rills:
Rills may be common on talus slopes and other areas of soil accumulation due to runoff from adjacent rock outcrop and steep slopes. Much of the soil surface on talus slopes is armored by rock fragments.
Presence of water flow patterns:
Water flow patterns are occasional but may be common on talus slopes and other areas of soil accumulation due to runoff from adjacent rock outcrop and steep slopes. These patterns are usually short and discontinuous due to the frequency of rock fragments on the surface.
Number and height of erosional pedestals or terracettes:
Pedestals and terracettes are occasional but may be common on talus slopes and other areas of soil accumulation due to runoff from adjacent rock outcrop and steep slopes. Much of the soil surface on talus slopes is armored by rock fragments.
Bare ground from Ecological Site Description or other studies (rock, litter, lichen, moss, plant canopy are not bare ground):
Bare ground ranges from 5-10%. Areas with a greater cover of rock fragments and/or rock outcrop will have less bare ground. Drought may cause an increase in bare ground. The talus slopes have 3.7 inches of available water capacity (rock outcrop would have close to 0), so the potential to produce plant cover is low.
Number of gullies and erosion associated with gullies:
None
Extent of wind scoured, blowouts and/or depositional areas:
None
Amount of litter movement (describe size and distance expected to travel):
Herbaceous, fine woody, and some course woody litter will be transported in water flow pathways. Most coarse woody litter will remain under shrub and tree canopies. There may be more litter movement in areas that are adjacent to large expanses of rock outcrop.
Soil surface (top few mm) resistance to erosion (stability values are averages - most sites will show a range of values):
Soil surface textures are variable on the site. All surface horizons contain a significant amount of rock outcrops(gravel and/or boulders). Most soils have 40-80% ground cover of rock fragments (mostly gravels and boulders with some cobbles and stones). When well vegetated or covered with rock armor, the soils have a high resistance to both water an wind erosion. When well vegetated, these soils have a low to moderate resistance to water erosion depending on amount of rock fragment and vegetative cover.
Soil surface structure and SOM content (include type of structure and A-horizon color and thickness):
Soil surface structure is strong fine granular. The thickness of the A-horizon is 1 inch. The color of the A-horizon is not significantly different from the subsurface soil horizons.
Effect of community phase composition (relative proportion of different functional groups) and spatial distribution on infiltration and runoff:
The vegetation communities on this site are scattered and patchy. They are present where there has been some accumulation of soil, such as a talus slope, or in cracks in the bedrock where they can access water. This site is characterized by shrubs, grasses, then forbs, in descending order of dominance. There may be an occasional overstory of trees. Vegetative canopy cover ranges from 5-10% (grasses > forbs = shrubs > trees). Basal cover ranges 0-2% (shrubs > grasses = forbs > trees) for vascular plants and 0-1% for biological crust (cyanobacteria > lichen > moss). Both canopy and basal cover values decrease during a prolonged drought.
Presence and thickness of compaction layer (usually none; describe soil profile features which may be mistaken for compaction on this site):
None. Most of the soils are not easily compacted. Rock fragments are common on the soil surface and within the soil profile.
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:
none

Sub-dominant:
shrubs > perennial bunchgrasses > perenial colonizing grasses

Other:
forbs > trees > annual forbs > annual grasses

Additional:
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 shrubs andtrees the 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 amounts 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 dry years; 100-200 lbs/ac median years; 200-300 lbs/ac 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:
Pricklypear, Whipple''s cholla and Broom snakeweed are native to the site and have the potential to increase and dominate after heavy grazing. Cheatgrass is an exotic grass that has the potential to invade this site, with or without heavy grazing.
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 most severe droughts.

Download reference sheet

Search

Natural ResourcesConservation Service