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Ecological site R023XY100OR

LAKEBED

Accessed: 11/21/2024

Home / Esd catalog / MLRA 023X / Ecological site R023XY100OR

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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.

Associated sites

R023XY200OR	PONDED CLAY Ponded Clay (silver sage present, cyclic ponding duration shorter)

R023XY200OR

PONDED CLAY

Ponded Clay (silver sage present, cyclic ponding duration shorter)

Table 1. Dominant plant species

Tree	Not specified
Shrub	Not specified
Herbaceous	(1) Eleocharis (2) Rumex

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Physiographic features

This site occurs in small to large lake basins that receive additional moisture as runoff from surrounding uplands. Slopes range from 0 to 1 percent. Elevations range from 4000 to 5800 feet.

Table 2. Representative physiographic features

Landforms	(1) Lakebed
Ponding duration	Long (7 to 30 days)
Ponding frequency	Frequent
Elevation	1,219 – 1,768 m
Slope	0 – 1%
Aspect	Aspect is not a significant factor

Climatic features

The annual precipitation ranges from 8 to 12 inches, most of which occurs in the form of snow during the months of December through February. Additional moisture is supplied to the site by run-on from snow melt. Spring and fall rains are common. The soil temperature regime is frigid. Extreme air temperatures range from 110 degrees F. to -30 degrees F. The frost-free period is 60 to 100 days. The optimum period for plant growth is early May through July.

Table 3. Representative climatic features

Frost-free period (average)	100 days
Freeze-free period (average)	0 days
Precipitation total (average)	305 mm

Bar

Line

Figure 2. Monthly average minimum and maximum temperature

Soil features

The soils in this site are deep and poorly or very poorly drained. They are generally formed in fine textured alluvium. The surface layer is typically a silt loam to clay loam over a clay subsoil. Permeability is very slow. The available water holding capacity (AWC) is about 5 to 12 inches for the profile. The soil is subject to annual ponding in the spring and early summer. A high water table restricts the effective rooting depth. The hazard of water erosion is slight.

Table 4. Representative soil features

Surface texture	(1) Silty clay loam
Family particle size	(1) Clayey
Drainage class	Poorly drained to very poorly drained
Permeability class	Very slow
Soil depth	183 cm
Available water capacity (0-101.6cm)	20.32 – 30.48 cm

Ecological dynamics

The potential native plant community is dominated by spikerush, Baltic rush and dock. Mat muhly and bottlebrush squirreltail are common. Vegetative composition is about 65 percent grass and 35 percent forbs.

Range in Characteristics:
Variability in plant composition is dependent upon the depth and duration of standing water. Where sufficient water collects, the plant composition consists mainly of Baltic rush, spikerush and dock. Where little water collects povertyweed and bottlebrush squirreltail are dominant.

Response to Disturbance
If heavy grazing causes site deterioration, spikerush, mat muhly and dock decrease. Bottlebrush squirreltail, poveryweeed and knotweed will increase.

State and transition model

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Standard diagram

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Click on state and transition labels to scroll to the respective text

Ecosystem states

1. Historic Climax Plant Community

State 1 submodel, plant communities

1.1. Historic Climax Plant Community

State 1
Historic Climax Plant Community

Community 1.1
Historic Climax Plant Community

Figure 3. 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	729	1020	1457
Forb	392	549	785
Total	1121	1569	2242

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	Dominant, perennial, moderate rooted grasslike			471–785
	spikerush	ELEOC	Eleocharis	471–785	–
2	Sub-dominant, moderate rooted grass-like			157–314
	squirreltail	ELEL5	Elymus elymoides	62–123	–
3	Moderate rooted, perennial grasses			157–314
	squirreltail	ELEL5	Elymus elymoides	78–157	–
	mat muhly	MURI	Muhlenbergia richardsonis	78–157	–
4	Other perennial grass/grasslike			34–78
	sedge	CAREX	Carex	11–34	–
	saltgrass	DISP	Distichlis spicata	0–34	–
	beardless wildrye	LETR5	Leymus triticoides	11–34	–
Forb
5	Dominant, perennial forb			392–549
	dock	RUMEX	Rumex	392–549	–
6	Sub-dominant, perennial forb			78–157
	povertyweed	IVAX	Iva axillaris	78–157	–
7	Other perennial forbs			6–78
	arnica	ARNIC	Arnica	6–17	–
	evening primrose	OENOT	Oenothera	6–17	–
	knotweed	POLYG4	Polygonum	6–17	–
	candytuft	SMELO	Smelowskia	6–17	–
	fiveleaf clover	TRAN	Trifolium andersonii	6–17	–

Interpretations

Animal community

Livestock Grazing:
This site suited to grazing in late summer and fall under a planned grazing system.

Wildlife:
This site provides water for numerous species of wildlife and waterfowl when ponded. Antelope prefer this site and make excellent use of it when forage is readily available. Various species use this site during the fall and winter.

Hydrological functions

The soils of this site have slow infiltration rates and are ponded. The hydrologic soil group is D.

Other information

This site is classified as a Type I Wetland in USFWS Circular 39.

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)	Jeff Repp
Contact for lead author	Oregon NRCS State Rangeland Management Specialist
Date	08/09/2012
Approved by	Bob Gillaspy
Approval date
Composition (Indicators 10 and 12) based on	Annual Production

Indicators

Number and extent of rills:
None, slight sheet & rill erosion hazard
Presence of water flow patterns:
None
Number and height of erosional pedestals or terracettes:
None
Bare ground from Ecological Site Description or other studies (rock, litter, lichen, moss, plant canopy are not bare ground):
10-30%
Number of gullies and erosion associated with gullies:
None
Extent of wind scoured, blowouts and/or depositional areas:
None, slight wind erosion hazard
Amount of litter movement (describe size and distance expected to travel):
Fine - limited movement
Soil surface (top few mm) resistance to erosion (stability values are averages - most sites will show a range of values):
Moderately to significantly resistant to erosion: aggregate stability = 4-6
Soil surface structure and SOM content (include type of structure and A-horizon color and thickness):
Deep poorly drained silt loams: Moderate OM (2-4%)
Effect of community phase composition (relative proportion of different functional groups) and spatial distribution on infiltration and runoff:
Moderate ground cover (40-60%) and gentle slopes (0-1%) effectively limit rainfall impact and overland flow
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:
Spikerush > Dock > Baltic rush > Mat muhly = Povertyweed = Squirreltail > other grasses > other forbs

Sub-dominant:

Other:

Additional:
Amount of plant mortality and decadence (include which functional groups are expected to show mortality or decadence):
Normal decadence and mortality expected
Average percent litter cover (%) and depth ( in):
Expected annual annual-production (this is TOTAL above-ground annual-production, not just forage annual-production):
Favorable: 1600, Normal: 1100, Unfavorable: 700 lbs/acre/year at high RSI (HCPC)
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:
Squirreltail, povertyweed, and knotweed will increase with deterioration of plant community. Cheatgrass and Medusahead invade sites that have lost deep rooted perennial grass functional groups.
Perennial plant reproductive capability:
All species should be capable of reproducing annually

Download reference sheet