Montana plant geography at elevations below montane forests broadly includes open shrub-grass or ponderosa pine dominated dry sites and riparian-wetland systems. In contrast to conventional wisdom, the floristic composition of these settings in eastern Montana does not reflect a strong Great Plains influence. State and county geographical distribution patterns suggestive of an influence of the Great Plains flora on that of eastern Montana involve only 52 species of mostly uncommon and narrowly distributed species of dicot forbs that do not compose a common type of characteristic Great Plains plant community in the state. In addition, the floristic similarity of the grass family, Poaceae, which is very diverse in open dry vegetation in Montana, reveals that Montana shares many more grass species in common with Utah than with the adjacent Great Plains state of South Dakota. Instead of the Great Plains biome, the low elevation flora and vegetation of Montana appears to be part of or influenced by the Pacific Northwest, Boreal, and the Intermountain biome. From the perspective of plant identification, the volumes of the Intermountain Flora works as well as or better across the state of Montana at low elevation dry settings compared to the Flora of the Great Plains or the Flora of the Pacific Northwest. The flora and vegetation of the open dry settings of eastern Montana is generally characteristic of the Intermountain sagebrush steppe and this should be considered in “prairie” restoration programs, especially when large ungulates like bison are proposed for reintroduction.
Lavin, Matt and Seibert, Catherine
"Great Plains Flora? Plant Geography of Eastern Montana's Lower Elevation Shrub-grass Dominated Vegetation,"
Natural Resources and Environmental Issues:
Vol. 16, Article 2.
Available at: http://digitalcommons.usu.edu/nrei/vol16/iss1/2