Highland Cool Valley Slopes and Depressions

Description

The reference state (1.0) is a dense closed canopy forest dominated by white spruce with the occasional ponderosa pine, aspen, or paper birch The hardwood and ponderosa pine components will be more heavily present in younger stands and eventually be out competed by the spruce and become less prevalent as the stand ages.

The understory can be very diverse from one site to another but may include a twinflower dominated community on run in landforms or a grouse whortleberry dominated community on run off landforms. In run in landscape positions, the twinflower community consists of common juniper, Oregon grape, and spirea. In run off landscape positions, the grouse whortleberry community consists of rough-leaf ricegrass, rock clematis, false melic, creeping dogwood and bracken fern.

In addition to downed woody debris, often times more than 25% of the ground cover is mosses and lichens along with 15-35% downed woody debris.

Structural variation within this reference state is driven by type of disturbance and time between disturbances. High severity disturbance such as stand replacing fires results in an early seral hardwood community of aspen and paper birch with a small component of ponderosa pine and white spruce. Due to the shade intolerance of the hardwood species immature white spruce and ponderosa pine are able to dominate the community. Because spruce are more tolerant than pine and are capable of faster height growth during its early life, it eventually dominates with greater than 80%. This dynamic will take up to 80 years to play out. Due to a long fire return interval this system will eventually result in an even-aged forest of mostly white spruce. As these trees age and become decadent they become more susceptible to windthrow from severe weather, bark beetles and root diseases. These eventual disturbances kill individual trees or small patches (0-20) acres, which regenerate with additional white spruce. This process creates a gap dynamic and produces an uneven age structure. This system is able to persist until the next high severity disturbance occurs for up to 300 years.

Dominant plant species

1. white spruce (Picea glauca), tree

2. ponderosa pine (Pinus ponderosa), tree

3. quaking aspen (Populus tremuloides), tree

4. paper birch (Betula papyrifera), tree

5. grouse whortleberry (Vaccinium scoparium), shrub

6. roughleaf ricegrass (Oryzopsis asperifolia), grass

7. sedge (Carex), grass

8. (Stipa), grass

9. western brackenfern (Pteridium aquilinum), grass

10. Forb (herbaceous, not grass nor grass-like) (Forb (herbaceous, not grass nor grass-like)), grass

11. twinflower (Linnaea borealis), grass

Submodel

Description

The Timber managed state is largely the result of forest management activities. Fire suppression was common throughout recent history removing one of the primary ecological drivers of this system. The removal of fire from the system left many of the spruce stands decadent and declining in health. This created a need for timber management to be used to sustain or create regeneration within these spruce systems.

Dominant plant species

1. white spruce (Picea glauca), tree

2. ponderosa pine (Pinus ponderosa), tree

Submodel