John Day Fossil Beds National Monument

John Day Fossil Beds National Monument

Trees and Shrubs At John Day Fossil Beds National Monument

Trees and Shrubs

Water is definitely a limiting factor in the establishment of shrubs and trees on the John Day Fossil Beds National Monument.

Cottonwoods, willows, alder, and hawthorn grow only in a very restricted zone along the riparian courses. Only a few stately ponderosa pine can be found in the 9-16 inch precipitation zone that the three units of the monument find themselves in and these are usually tucked into a narrow ground with some moisture from a seep or spring close by.

Serviceberry and currant bushes can be found around rock slides where they seem to collect extra water from the rocks. And high up along the rocky escarpments surrounding the valleys are the mountain mahogany that get a little more rain due to elevation and who also take advantage of the water running off of the surrounding rock ledges.

Of course some shrubs just don't seem to need a lot of water or they have special adaptations that allow them to use available brackish water or to send roots down deep. Greasewood and rabbitbrush are good examples of these 2 adaptations.

Greasewood plants are able to draw up moisture high in salts and to distribute this out into the succulent leaves. This allows them to thrive in heavy, saline soils.

Rabbitbrush do well on the alluvial fans of dry water courses and send their roots down to subsurface moisture that maybe came as snow the winter before, melted with spring's coming, and disappeared into the soil high above on the hillside to then slowly move down the dry channel beneath the surface.

Other shrubs that have adapted well to these dry, xeric sites include big sagebrush, shadscale, broom snakeweed, antelope bitterbrush, and purple sage. Each has adaptations allowing it to grow, produce seed, and compete with its neighbors.

With the suppression of fire over the past century, there have been significant increases in the big sagebrush numbers found in the plant communities. The western juniper is a great example of a tree that can germinate and grow on very dry sites.

The small, young junipers may spend over 10 years developing large underground root masses before the tree really starts to grow upward. Juniper have taken full advantage of the suppression of fire by spreading out from historic areas in the rocky crags and small pockets typically protected from fire.

Entire landscapes around the region have been changed from grass and sagebrush to juniper with cheatgrass or bare ground understories. Juniper have extensive root systems with both deep roots and large amounts of very shallow roots so that the tree can quickly capture new moisture or can reach down to moisture stored in the soils.

The monument is pursuing an intensive effort to restore the natural process of fire to the landscape, not to eradicate junipers, but to maintain the natural checks and balances that prehistorically developed this region into a grass/sagebrush community.

Directions

The Visitor Center at the Sheep Rock Unit is located on Highway 19 between the towns of Dayville and Kimberly, 2 miles from the junction of Highway 26 and Highway 19.

The Painted Hills Unit is located 9 miles northwest of of the town of Mitchell, just off Highway 26. There is no visitor center at this unit.

The Clarno Unit is located 20 miles west of the town of Fossil. along Highway 218. There is no visitor center at this unit.