(Chamaebatiaria millefolium) D. Hays
The natural landscape at Lava Beds National Monument is divided into 23 of different vegetation associations. While there is a great deal of overlap between these different communities, and some plants and animals appear throughout the monument, there are certain key species that are more common in a specific community. There are three principle vegetation communities within the monument, along with the special environments in the surface lava flows and around lava tube caves.
The three plant communities are as follows:
(1) Bunchgrass-Sagebrush Grasslands,
(3) Pine Forest.
Sagebrush Grasslands occupy most of the northern half of the monument, generally at elevations between 4000 and 4500 feet above sea level. Although blue bunchgrass, northern wheatgrass and other grasses are the dominant plants in this community, there has been some incursion of woody shrubs and isolated junipers into this community over the last century. These changes have come about largely through suppression of natural fire. The grasslands are open, rolling country, and are generally drier than the other communities.
Brushlands community occupies most of the southern half of the monument, generally between elevations of 4500 to 5000 feet above sea level. Junipers, mountain mahogany and woody shrubs such as bitterbrush and gray and green rabbitbrush are the dominant plants in this community. The higher elevation also means this community receives more snowfall during the winter and more moisture generally than the grasslands below.
The Pine Forest community is largely confined to the southern end of the monument at elevations above 5000 feet, although patches of forest can extend downhill as low as 4600 feet. The Ponderosa pine and white fir become the dominant plant species, and the community can receive extensive snowfall over the winter. The high country serves as the summer range for many animal species, which then move to lower elevations for the winter.
In addition to the dominant communities, Lava Beds contains extensive lava flows and numerous lava tubes. These can be found at any elevation, and plant species partly reflect the elevation of the flow. The relative lack of productive soil limits plant growth, however. Lichens and mosses are the first pioneer plants over exposed lava, but grasses and even small shrubs and trees can colonize the flows over time. The cool, damp climate within the caves offers different plant and animal species a variety of microclimates that allow for their existence in near-desert conditions where they would not ordinarily survive. Lichens, mosses, ferns, tree frogs, and various insects are found in and around cave entrances. The deeper passages of the caves can harbor bats, woodrats, bacterial colonies (known as cave slime), and blind, colorless insects, as well as other creatures adapted to the cool, damp, dark conditions inside.
Finally, mention should be made of Tule Lake. Although this body of water heavily impacted by agricultural activity lies just outside the boundaries of the monument, it exerts an influence on the plants and animals within. The seasonal migration of waterfowl through the region provides a prey base for predators within the monument. The lakeshore also provides habitat for several of the animal species otherwise found in the lower elevations of the monument. These "partial residents" include skunks, porcupines and raccoons. There are also coyotes, bobcats, owls and hawks that use the lake and the lands immediately around it for hunting but build their dens or nests in the monument.
Bunchgrass-Sagebrush Grasslands: Sagebrush, Blue Bunchgrass, Indian Paintbrush, Mariposa Lily, Narrow-leaf Phacelia, Northern Wheatgrass, Thurber's Needlegrass
Juniper-Brushlands: Western Juniper, Mountain Mahogany, Bitterbrush, Rabbitbrush (several species), Bitter Cherry
Pine Forest: Ponderosa Pine, White Fir, Greenleaf Manzanita, Fireweed, Gentian
Rocky Lava Flows: Lichen (several species), Moss (several species)
Cave Mouths Interior Passages: Fernbush, Ferns (localized populations), Lichen (several species), Moss (several species), Liverwort, Bacterial slime colonies
Lake Shore Areas: Tule Reeds, Cattails, Stinging Nettle