Ecological site group DX035X01FESG16
Canyonlands - Deep Rocky - mid elevation
Last updated: 10/12/2022
Accessed: 05/02/2024
Ecological site group description
Key Characteristics
- Canyonlands
- Deep Rocky Soils
- Mid-elevation MAST < 54 degrees F.
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
These sites are found on many landforms with deep stony soils, including; mountain slopes, hillslopes, escarpments, slump blocks, structural benches, remnant alluvial fans, remnant stream terraces, landslides, and benches. Elevations range from 4700 to 7500 feet and slopes are between 2 and 80 percent. Runoff is typically very high.
Climate
The climate of this group is characterized by warm summers and cold winters. Average annual precipitation is 9 to 16 inches. Much of the summer moisture occurs as convective thunderstorms from July through October. May and June are typically the driest months during the growing season. Large fluctuations in daily temperatures are common, and precipitation varies greatly from month to month and from year to year.
Soil features
The soils are typically deep or very deep and well drained. They formed in slope alluvium and colluvium derived from sedimentary and igneous rocks; mainly sandstone, shale, limestone, and diorite. Surface textures are sandy loam or loam with 15 to 50 percent rock fragments. Subsurface textures are also loamy and average more than 35 percent rock fragments. Permeability is moderate and available water holding capacity ranges from 2 to 6 inches in the upper 40 inches of the soil profile. The soil moisture regime is ustic aridic or aridic ustic and the soil temperature regime is mesic.
Vegetation dynamics
These sites developed under Colorado Plateau climatic conditions and included natural influences of herbivory, and climate; however due to the remote location, broken topography, steep slopes (2-50%), and lack of perennial water sources this area rarely served as habitat for large herds of native herbivores. This site’s plant species composition is generally dominated by two-needle pinyon and Utah juniper, with some perennial grasses.
There is no evidence to indicate that this site historically maintained a short burn frequency. However, due to modern disturbances such as brush treatments, invasive species, and OHV use, the resilience of the plant communities may be reduced. Disturbances that reduce the presence of perennial grasses result in an opportunity for invasive annuals to enter into the system.
Drought and insects appear to be the main driving factors in many of the Pinyon/Juniper communities of Utah. Betancourt et al. (1993), noted that Pinyon and Juniper woodlands in the southwest appear to be more susceptible to large die offs during droughts, than in other locations. As severe droughts persist, the Pinyon trees, being more susceptible to drought and insects, seem to die out, while the Utah juniper trees survive.
The reference plant communities are dominated by two-needle pinyon and Utah juniper. Perennial grasses, especially blue grama, are present in the understory. Shrubs may also be abundant, but not in all areas.
Major Land Resource Area
MLRA 035X
Colorado Plateau
Subclasses
Correlated Map Unit Components
22594306, 22593834, 22594104, 22593841, 22594114, 22594122, 22598319, 22601600, 22966961, 22963654
Stage
Provisional
Contributors
Vic Parslow
Keith Crossland
Curtis Talbot
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