Bedrock Hills Provisional Ecological Site Group

Description

The reference state for this ecological site is a mixed forest. No other states are identified at this time; as more data is collected, this is suspected to change. This state is dominated by a forest of paper birch (Betula papyrifera), white spruce (Picea glauca), and sometimes cottonwood (Populus balsamifera ssp. trichocarpa).

Drought or dry conditions can trigger the spruce bark beetle infestation. The spruce bark beetle will nest and kill mature white spruce. In some cases, the beetle will also invade younger spruce. When this happens, the overstory opens, causing an increase in understory vegetation such as bluejoint grass (Calamagrostis canadensis), especially if the grass is already a dominant species in the plant community.

Dead and dying spruce trees make this community highly susceptible to lightning-caused fire. This promotes aspen (Populus tremuloides) growth. Spruce will colonize and overtop aspen over time.

Dominant plant species

1. white spruce (Picea glauca), tree

2. paper birch (Betula papyrifera), tree

3. black cottonwood (Populus balsamifera ssp. trichocarpa), tree

Submodel