© Jeremy Emmi
A Unique Environment
Vegetation at the top of Brockway Mountain is dwarfed by the grueling winds and inhospitable climate. The semi-alpine habitat has a magnificent covering of plant species that thrive in the full sunlight.
© Marianne Glosenger
The top of Brockway Mountain, including the new Helstrom Sanctuary, is a unique environment in Michigan and very rare in the Great Lakes region due to the thin soils, harsh climate and grueling winds. These conditions are produced by the mountain’s elevation and 300 foot volcanic cliff, its unique location near the tip of the Keweenaw Peninsula and its close proximity to the largest freshwater lake on earth, Lake Superior. The vegetation found on Brockway Mountain is significantly impacted (stunted, or “dwarfed”) by these conditions, resulting in pockets of remarkable semi-alpine habitat covered in grasses, sedges, creeping forbs, and small shrubs which thrive in the full sunlight. The natural communities exhibiting these conditions on the new sanctuary include volcanic bedrock cliff, dry-mesic northern forest and some small volcanic bedrock glades. These stunted bedrockoriented communities contain numerous species listed by the State of Michigan as Endangered, Threatened, or Species of Special Concern and an impressive concentration of these rarities are known to occur on Brockway Mountain.
The Valley Floor MNA’s protected lands incorporate a portion of the southern valley floor at the base of the volcanic bedrock cliff. The valley, sheltered from the harsh winds, includes exceptionally large trees. Northern mesic forest and mixed conifer swamp are found at the bottom of the cliff and in the southern third of the Helstrom sanctuary. The dry mesic northern forest slowly transforms into mesic northern forest near the northern boundary as well. These forests include birch, oak, maple, spruce and balsam fir with an understory including species such as bigleaved aster and bracken fern. The wetlands south of the 300 foot cliff are the headwaters for the Garden Brook as it flows toward Copper Harbor and Lake Fanny Hooe. The sanctuary also protects Beauty Pond, which is used by ducks, such as hooded merganser, and provides excellent breeding habitat for frogs, including spring peepers. 22
michigan nature | spring 2017
Northern mesic forest and mixed conifer swamp are found at the bottom of the cliff.
Spring 2017 issue of Michigan Nature magazine