Shallow Stony, South Aspect, Columbia Hills

Description

Note: most sites on the south side of Columbia Hills have already crossed the threshold into State 3. But this is not true for Shallow stony, south aspect, Columbia Hills.

State 1 Narrative:
State 1 represents grassland steppe with no invasive or exotic weed species. Each functional, structural group has one or more native species. Communities with a dominance of annual grasses have never been seen on Shallow Stony, south aspect, Columbia Hills. The south side of the Columbia Hills has no sagebrush or bitterbrush, and except for a spot along the Columbia River, the south side of the Columbia Hills also has no rabbitbrush.

The Reference Community 1.1 is dominated by bluebunch wheatgrass with native buckwheat species prominent.

Reference State Community Phases:
1.1 Reference Bluebunch wheatgrass-Eriogonum species

At-risk Communities:
• Any community in the reference state is at risk of moving to State 2. The seed source of cheatgrass is nearby and blowing onto most sites annually.
• Reference community is quite stable as it receives limited grazing pressure and rarely burns
• State 3 has not been seen on Shallow Stony sites in the Columbia Hills

Submodel

Description

Note: most sites on the south side of Columbia Hills have already crossed the threshold into State 3. But this is not true for Shallow Stony, south aspect, Columbia Hills.

State 2 Narrative:
State 2 represents grassland steppe with minor inclusion of invasive annual grasses such as cheatgrass. All the native functional, structural groups would be represented by one or more species.

Cheatgrass will colonize Shallow Stony, south aspect, Columbia Hills sites on the south side of the Columbia Hills, and retain, a presence in the community. In State 2 cheatgrass in a minor component. But once a community has been invaded by cheatgrass the chance of going back to State 1 is small.

Community Phases for State 2:
2.1 Bunchgrass Bluebunch wheatgrass

Dominate Species in State 2: bluebunch wheatgrass and buckwheat species

Submodel

Description

State 3: Annual Grasses

Note: most sites on the south side of Columbia Hills have already crossed the threshold into State 3. But this has not been seen for Shallow Stony, south aspect, Columbia Hills.

State 3 Narrative:
State 3 represents sites that are dominated by invasive annual species and has crossed a biological threshold. State 3 is rare for Shallow stony, south aspect, Columbia Hills sites. The main species include cheatgrass, mustard, prickly lettuce and diffuse knapweed.

Community Phases for State 3:
3.1 Annual Grass cheatgrass

Submodel