Sagebrush

Sagebrush landscape of green shrubs and other plants on a sloping hill. A blue reservoir is beyond the sagebrush. Tall pinnacles are visible across the water on a mesa. — Sagebrush on the slopes above Blue Mesa Reservoir
NPS Photo

Sagebrush is a widespread shrub across the American West. It is considered the largest terrestrial (land) ecosystem in the United States. It has a vast range and exists in deserts, valleys, mesas, mountains, and plains. Today, sagebrush ecosystems cover over 175 million acres. The sagebrush ecosystem in the Gunnison Basin is one of the largest remaining in the country. Sagebrush is part of the semi-arid shrubland, one of the life zones at Curecanti.

Multiple brown mule deer graze on sagebrush shrubs. Other deer sit in deep snow surrounding the plants. Snow blankets most of the ground. — Sagebrush is an important food source for both mammals and birds, especially during winter.
NPS Photo

Sagebrush ecosystems are comprised of shrubs, wildflowers, and grasses; they are a critical habitat for many other plant species. These ecosystems are vital to carbon and water storage, promoting pollinator diversity, and providing shelter and food for animals. Evergreen leaves and seeds are an important food source in winter for both birds and large mammals (deer, elk, and bighorn sheep) at Curecanti. Sagebrush also give off a particular spicy, bitter smell - either when a leaf if crushed or as an aroma in areas densely vegetated with it.

There are various subspecies of Big sagebrush (Artemisia spp.). Wyoming big sagebrush (A. tridentata ssp. wyomingensis) is the dominant species at Curecanti. It is found at low to mid elevations on valley slopes and foothills. It overlaps with mountain big sagebrush, which is found at elevations between 7,000 to 10,000 feet (2134 to 3048 m). Wyoming big sagebrush is drought resistant and can grow in rocky or gravel filled soil.

Mountain big sagebrush (A. tridentata ssp. vaseyana) grow among other shrubs and trees like pinyon pine, juniper, rabbitbrush, Douglas-fir, and Gambel oak. Despite preferring higher elevations, this species can grow on shaded north-facing slopes or areas where snow drifts accumulate and increase moisture.

Ecosystem Impacts

Due to human development, recreation, grazing, invasive species, wildfire, and drought, these ecosystems are at risk. Loss of native species, recreation, and increased aridity (dryness) are the biggest impacts to sagebrush at Curecanti.

Heavy livestock grazing (both within and adjacent to the park) can be detrimental and take years for ecosystems to recover. Grazing management efforts by the National Park Service focus on approaches which consider the impacts of livestock grazing on native species and sagebrush ecosystems.

Habitat loss for birds and animals is a special concern. The federally threatened Gunnison Sage-grouse depends on sagebrush for food, cover, and mating grounds. Their popluations have decreased more than 50 percent since the 1950s due to habitat loss and habitat degradation.

Other rare native plants, such as milkvetch, also dependent on sagebrush habitats. Invasive grasses, such as cheatgrass, can outcompete native vegetation and change the dynamic of an ecosystem. They impact the available fuels and can increase wildlife potential or frequency.

Restoration and Protection Efforts

Curecanti National Recreation Area and Black Canyon of the Gunnison National Park are both part of the NPSage Initiative to restore sagebrush-steppe ecosystems. Curecanti is also involved with local partners in the Gunnison Basin focused on sagebrush protection. NPS staff participate in native seed collection for storage and future growing efforts. Interagency cheatgrass treatments are planned for Red Creek and Dillon Pinnacles areas. Vegetation crew regularly works to mitigate invasive species in sagebrush ecosystems.