Grasslands, often overlooked, matter in Colorado

Their flowers lack the exuberant expressions of form and of color that we associate with wildflowers, but grasses do indeed bear flowers that produce fruits that bear seeds. So they are flowering plants; we just don’t think of them as wildflowers.

Disregarding our human sense of visual esthetics, we must embrace grasses for what they truly are — ecologically vital.

Grasses form the third of three dominant vegetation types that collectively form the lifescapes of Colorado. Just as we call shrub-dominated vegetation “shrublands” and tree-dominated vegetation “treelands,” we call grass-dominated vegetation “grasslands.”

Only a few of our grasses dominate vegetation. Of the world’s 11,783 grass species, just 326 of them grow wild in Colorado. Of these only western wheatgrass, Indian ricegrass and cheatgrass have been documented growing in all 64 Colorado counties. Foxtail barley, needle-and-thread and blue grama have been found in all but two or three counties.

Of all our grass species, buffalograss qualifies as the quintessential storyteller.

It grows throughout all the eastern counties, Wyoming to Oklahoma and from all the foothills to Kansas and Nebraska. Where it grows naturally in areas not altered by human activity, it dominates the vegetation.

Though short in height — mostly less than 10 inches tall — it grows deep roots and forms expansive mats. In this detail the story of buffalograss comes to matter.

Culturally, the words “plains” and “prairie” routinely get used as synonyms even though they are quite different. “Plain” is a geological term that refers to landform, and “prairie” is a botanical term that refers to a specific kind of grassland.

And here two essential principles must be understood. First, all plains are not grown with prairie; and second, all prairies are grasslands but all grasslands are not prairies.

Buffalograss makes the point.

Prairie grasslands require 24 inches or more of precipitation annually; prairie grasses grow well beyond 4 feet high, some reaching 15 or more feet; and prairie grasslands have no shrubs.

Buffalograss thrives at as little as 6 inches of precipitation a year; it grows less than a foot tall; and it grows interspersed with a variety of shrubs.

By definitions used in the disciplines of biogeography and plant ecology, grasslands grown with buffalograss are defined as “steppe.”

Some wildlife thrives in prairie grasslands; some wildlife thrives in steppe grassland.

Colorado’s precipitation pattern does not support prairie; it supports steppe. We have no prairie wildlife, but we have lots of steppe wildlife.

Such distinctions explain why grasslands matter.