Grasses

Blue Grama grass seed head

NPS Photo/ Jonah Snead

Native Grasses of the Gila Cliff Dwellings National Monument

The Gila Cliff Dwellings National Monument is home to a diverse array of native grasses, each adapted to the unique environmental conditions of the region. These grasses not only contribute to the ecological health of the area but also support a variety of wildlife and plant communities.

Blue Grama (Bouteloua gracilis)

Description:
Blue Grama is a short, perennial grass that is one of the dominant species in the grasslands of the southwestern United States. It typically grows to about 6-12 inches in height, with slender, wiry stems that support distinctive seed heads resembling small combs or eyelashes.

Ecological Role:
Blue Grama is highly drought-tolerant and thrives in arid environments, making it well-suited to the dry conditions of the Gila region. It is a crucial forage species for wildlife such as deer and small mammals, as well as for livestock. The dense tufts formed by Blue Grama help prevent soil erosion, making it an important species for maintaining soil health in the monument.

Adaptations:
Blue Grama has deep roots that allow it to access moisture stored deep in the soil, making it resilient during dry periods. Its seed heads are adapted to disperse seeds effectively, ensuring its propagation across the landscape.

 

Side oats grama growing a seed stalk with seed heads.

NPS Photo/Jonah Snead

Sideoats Grama (Bouteloua curtipendula)

Description:
Sideoats Grama is a mid-sized perennial grass that typically reaches heights of 12-30 inches. It is easily recognizable by its oat-like seeds, which hang down along one side of the stem, giving the plant its name. The leaves are narrow and often have a bluish-green tint.

Ecological Role:
Sideoats Grama is a keystone species in the Gila’s grassland ecosystems, providing food and habitat for numerous species of insects, birds, and mammals. It is particularly valuable as a forage grass for grazing animals, offering high nutritional value. Additionally, Sideoats Grama plays a critical role in stabilizing soil, especially in open, dry areas.

Adaptations:
This grass is highly adaptable to a range of soil types, from rocky outcrops to sandy soils. It is also drought-resistant, with the ability to remain dormant during prolonged dry spells and quickly resume growth when moisture is available.

 

Cane Bluestem (Bothriochloa barbinodis)

Description:
Cane Bluestem is a tall, warm-season perennial grass that can grow up to 3-5 feet in height. It has a distinctive appearance with its cane-like stems and soft, fluffy seed heads that turn a silvery white as they mature. The leaves are long, narrow, and usually a vibrant green during the growing season.

Ecological Role:
Cane Bluestem is an important forage grass, particularly valued for its high nutritional content during the summer months. It provides excellent cover and nesting material for wildlife, including ground-nesting birds. The tall stature of Cane Bluestem also helps protect soil from erosion by slowing down wind and water movement across the landscape.

Adaptations:
Cane Bluestem is well-adapted to the variable rainfall patterns of the Gila region. It can thrive in both well-drained uplands and low-lying areas that may retain moisture longer. Its robust root system anchors the plant firmly in the soil, allowing it to survive in windy and exposed conditions.

Green Sprangletop (Leptochloa dubia)

Description:
Green Sprangletop is a perennial bunchgrass that typically grows 1-3 feet tall. It is characterized by its bright green, arching leaves and delicate, open seed heads that give the plant a graceful appearance. The seeds are small and borne on slender branches that spread out from the main stem.

Ecological Role:
Green Sprangletop is an essential component of the grasslands within the Gila Cliff Dwellings National Monument. It provides forage for a wide range of wildlife, including deer, rabbits, and birds, as well as for grazing livestock. The plant’s structure also offers protection and habitat for smaller creatures, such as insects and ground-nesting birds.

Adaptations:
This grass is highly tolerant of heat and drought, making it well-suited to the harsh climate of the region. It grows rapidly following summer rains, providing a quick and reliable source of forage. Green Sprangletop’s seeds are dispersed by wind and animals, allowing it to colonize new areas efficiently.

Invasive Grasses

Invasive grasses pose a significant threat to the native plant communities within the Gila Cliff Dwellings National Monument. These non-native species often outcompete native grasses, leading to reduced biodiversity and altering the structure of the ecosystem. Some of the most problematic invasive grasses include:

1. Weeping Lovegrass (Eragrostis curvula): Originally introduced for erosion control, this grass has become invasive in many areas, including the Gila. It spreads rapidly and forms dense stands that displace native vegetation.

2. Smooth Brome (Bromus inermis): A highly competitive grass that invades meadows and open areas, Smooth Brome can form monocultures, reducing the diversity of native plant species and negatively impacting wildlife habitat.

3. Cheatgrass (Bromus tectorum): Although more commonly associated with other parts of the Southwest, Cheatgrass can be found in disturbed areas within the monument. It is highly flammable and increases the risk of wildfires, further threatening native ecosystems.

Efforts are ongoing to manage and control these invasive species within the monument. The removal of invasive grasses and the reseeding of native species are critical components of preserving the ecological integrity of the Gila Cliff Dwellings National Monument.