Ecological site group DX035X01IESG07
Little Colorado River Basin-sandy soils-non-run in moisture
Last updated: 10/12/2022
Accessed: 05/02/2024
Ecological site group description
Key Characteristics
- Little Colorado River Basin
- Sandy
- Do not receive extra moisture from run-in
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.
Physiography
This ecological site is found on nearly level to gently rolling uplands to partially stabilized or stabilized dunes on plateaus, fans and abandonded stream terraces. The soils are deep to very deep to any plant root restricting layer. The texture of the soil throughout the profile is generally sandy loams to loamy coarse sand. The slope of the site is generally 1 to 10 percent, but may be as high as 15 percent.
Climate
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.
Soil features
The soils associated with this ecological site are deep to very deep to any plant root restricting layer. The soil textures throughout the profile range from loamy fine sands to coarse sands. Where the site has been stable for long periods of time, there may be some accumulation of carbonates at moderate depths that can help the site retain more soil moisture within the root zone. The soil ranges from neutral to moderately alkaline (pH 6.6 to 8.4). The permeability is rapid to very rapid and the soil profile can capture both gentle winter rains and intense summer thunderstorms. The available water capacity is low. Wind erosion is a severe problem if the vegetative cover is lost.
Vegetation dynamics
The reference community is composed of mid and short grasses with a moderate percentage of forbs and shrubs. There is a mixture of both cool and warm season grasses and half-shrubs.
Plant species most likely to invade or increase on this site when it deteriorates are sand sagebrush, big sagebrush, rabbitbrush, annuals, sandhill muhly, wooly groundsel, and snakeweed.
Shrubland with Grasses
This plant community is characterized by a mix of shrubs and grasses. There is a slight increase of large and half shrubs, decrease in perennial grasses, especially cool season grasses. Grasses in decline include black grama, needle and thread and Indian rice-grass.
Unmanaged grazing, long term winter dominated precipitation, and/or drought that reduces perennial warm and cool season grasses.
Major Land Resource Area
MLRA 035X
Colorado Plateau
Subclasses
- R035XA118AZ–Sandy Upland 10-14" p.z.
- R035XB206AZ–Sandy Upland 6-10" p.z. Warm
- R035XB217AZ–Sandy Upland 6-10" p.z.
- R035XB222AZ–Sandy Terrace 6-10" p.z.
- R035XC315AZ–Sandy Upland 10-14" p.z.
- R035XC371AZ–Sandy Slopes 10-14" p.z. Bouldery
- R035XC373AZ–Sandy Upland 10-14" p.z. Warm
- R035XC377AZ–Sandy Slopes 10-14" p.z.
Correlated Map Unit Components
22341121, 22353951, 22353993, 22353995, 22396751, 22396738, 22396830, 22396833, 22396767, 22396771, 22396773, 22396650, 22396643, 22396837, 22396736, 22396730, 22396634, 22396633, 22396783, 22396850, 22396851, 22484757, 22484738, 22484742, 22484721, 22484744, 22484776, 22484768, 22484736, 22484772, 22484750
Stage
Provisional
Contributors
Curtis Talbot
Click on box and path labels to scroll to the respective text.