Hagerman Fossil Beds National Monument - Plants

The predominant, natural vegetation on the Monument is sagebrush steppe plant communities, once common to much of the intermountain region of southern Idaho. These steppe communities include a dominant shrub, often sagebrush, interspersed with open, sparsely vegetated areas of grasses and forbs (broad-leaved herbaceous plants). The steep slopes of the Monument’s bluffs, west of the Snake River, provide an environment that contributes to the diversity of plant species. In addition, a riparian zone and localized wetlands occur along the Reservoir.

Livestock grazing prior to establishment of the Monument in 1988 also contributed to alteration of soils, loss of native grasses, and establishment of non-native plant species. Non-native plant species known to be present include Russian olive ( Eleagnus angustifolia ), Russian thistle ( Salsola kali ), quackgrass ( Agropyron repens ), cheat grass ( Bromus tectorum ), blue mustard ( Chorispora tenella ), tansymustard ( Descurainia sophia ), tumble-mustard ( Sisymbrium altissimum ), and medusa head (Taeniatherum caput-medusae ). These and other non-native species compete with the Monument"s native plant communities, disrupting ecosystem processes.