Central Shortgrass Prairie
Description & Physiography
A broad expanse of rolling plains and tablelands dissected by streams, canyons, badlands, and buttes, the Central Shortgrass Prairie ecoregion spans eight states on the west-central edge of the Great Plains. The dominant grasses of the semi-arid prairie include buffalo grass (Buchloe dactyloides), blue grama (Bouteloua gracilis), and western wheatgrass (Pascopyrum smithii).
The primary natural forces that shape the Central Shortgrass Prairie – grazing, drought, and wildfire – do so through patterns of disturbance that keeps woody plants from invading the grasslands and replacing it with forest. These disruptions are crucial to the health of the prairie’s upland ecosystems.
The region lies in the rain shadow of the Rocky Mountains, and as precipitation increases to the east – primarily in the form of summer rains – mixed-grass prairie communities also occur. Its cold, dry winters and warm to hot summers are frequently punctuated by extreme weather like hail, blizzards, tornadoes, and dust storms.
Plants and Animals
Large historic herds of grass-eating bison, elk, and pronghorn (Antilocapra americana) helped maintain the landscape’s diverse mosaic of systems and communities, along with vast “towns” of black-tailed prairie dogs and carnivorous predators like wolves, bears, lions. Periodic drought may drive many vegetation changes across the prairie, and natural wildfire regimes revitalize growth of wildflowers and grasses.
Humans & History
The Central Shortgrass Prairie has a long human history, with the Kiowas, Comanches, and Arapahoes once occupying much of the land to hunt bison and antelope and stage seasonal hunts into the adjacent mountains. These tribes and their predecessors likely used fire to manage the prairie, both to create fuel breaks around their settlements and to entice large herbivores to patches of fresh new growth.
Following quickly on the heels of the first Western explorers, trappers and fur traders developed an extractive economy that prefigured the later growth and industrialization of the region. In the mid- and late 19th century, the railroads expanded transportation networks and helped increase settlement, predominantly in rural and small towns, where the large-scale cattle and sheep ranching expanded with the support of rail and its ready access to distant markets, as did gold, silver, copper and other hardrock mining communities.
Much of the Central Shortgrass Prairie is currently cultivated or grazed by domestic livestock, with a human population that remains principally dependent on agriculture, although both energy exploration and mining have increased. Growth in the region follows two divergent growth trends, with population in the eastern portion declining and rapidly increasing in the west along the Front Range from Cheyenne, Wyoming, to Pueblo, Colorado. Nearly three-quarters of the region’s population now live in its metropolitan areas.
This growth has prompted changes in land use – particularly tilled agriculture, urban development, and industry – that have altered the character of the prairie’s grasslands and substantially decreased the number and diversity of native herbivores (like American bison and American elk), carnivores, and grassland birds. The decline of viable colonies of black-tailed prairie dogs is a notable because they support many other species native to the prairie. The overgrazing of rangeland damaged riparian zones, but management practices introduced in the early 20th century has limited further soil erosion and decline in the water table.
Despite the precipitous decline of many species, large blocks of the native prairie remain – more than 50% of the ecoregion, in fact. In many places, its history of use has not significantly altered the landscape, demonstrating that sound land management practices can help sustain the native species, natural communities, and ecosystems. Because the vast majority of land in the ecoregion is privately owned and managed, successful conservation will require engaging willing landowners, and tapping into funding sources that support private land-conservation initiatives and management practices – a tremendous opportunity for conservationists, ranchers, public agencies, farmers, and the inhabitants of the region.
Climate projections for the Great Plains suggest that extreme events might occur more frequently within the next century. A recent analysis of a global climate model projects a 12° F (6.7° C) warming for the Central Shortgrass Prairie in the next century, along with up to an 8% decrease in average annual precipitation. Increased predicted weather variability may also result in greater competition for water resources, particularly among farmers and urban communities. Legacies of past land use, combined with a changing climate and expanding urbanized footprint, may also lead to greater impacts to native biodiversity from invasive non-native species.