Mesa Verde National Park supports four major plant communities, all of which fall within the semi-arid Transitional and Upper Sonoran Live Zones.
Shrub-steppe community
The shrub-steppe community in the lower elevations is dominated by big sagebrush, rabbitbrush, and several herbaceous species. It flourishes in dry canyon bottoms, in burned areas, and in the transition zone between the mountain shrub community and the pinyon-juniper woodlands.
Pinyon-juniper woodland
The pinyon-juniper woodland is dominated by Utah juniper and Colorado pinyon pine. This community is also known as the “pygmy forest,” as both of these tree species rarely exceed 30 feet in height. This community at Mesa Verde includes champion sized and very old trees such as a Utah juniper tree with a trunk 52 inches in diameter, largest in all of Colorado, and another dated at 1,300 years old. Where the trees’ dense growth is sparse enough to permit an understory, it is largely composed of bunch grasses, broad-leafed yucca, and prickly pear cactus. Recent wildfires have degraded about half of the pinyon-juniper community acreage in the park transforming those areas into a herbaceous and shrub dominated community. The pinyon-juniper woodland covers the mesa tops and upper canyon slopes lying at or below 7,800 feet in elevation. For more information on this plant community, visit Series: Pinyon-Juniper Woodlands.
Mountain shrub community
The mountain shrub community stretches across the park from east to west, in a broad swath which extends several miles south from the north rim of the cuesta, at elevations above 7500 feet. Typical plant species here include Gambel oak, Utah serviceberry, mountain mahogany, cliff fendlerbush, and various bunch grasses and flowering perennials.
Gambel oak and Douglas-fir woodland
The Gambel oak-Douglas-fir woodland is found at higher elevations along the north rim and in sheltered areas in some canyons. A few relic stands of quaking aspen occur at higher elevations. Before the wildfires of the past decade, Ponderosa pines grew in areas of acidic soil in 45 localities throughout the park. The recent fires have heavily impacted both Douglas-fir and Ponderosa pines at Mesa Verde.
Seep spring near Spruce Tree House.
Although most of the land within the park boundaries is semi-arid to mesic, there is a riparian zone along both banks of the Mancos River which forms a 4.7-mile long moist corridor of the eastern boundary. Common species in this riparian zone include cottonwood, willow, and buffaloberry. There are also some 282 seep springs which flow from between the rock juncture of Cliff House sandstone and Menefee Formation shale. Many of these create moist microclimates for more moisture loving species including mosses, orchids, and ferns.
Since Mesa Verde has experienced a number of wildfires in the last decade, there is an opportunity to witness the role fire plays in resetting plant communities. For instance, pinyon-juniper woodlands usually turn over every 400 years. During a visit to the park you may notice burned pinyon-juniper environments that are currently dominated by grasses and weeds. It will take centuries for a mature pinyon-juniper forest to return to these areas. In the mountain shrub community, which takes up to 100 years to fully mature, Gambel oak is resprouting and making a come back.
