Much of the geological history of the Klamath Basin is one of new landscapes being built by volcanism. Between 2 and 5 million years ago, more than 400 eruptive vents spewed molten lava over much of the basin. Now weathering dominates. These two processes have had a major effect on plant communities and weathering continues to affect them. To demonstrate this we have selected two volcanic landscapes, one old and one new, to show how lichens and higher plants have adapted to these areas.
Lava Beds is an example of a young volcanic landscape with some lava flows being only a little over one thousand years old and showing little evidence of weathering. Lichens, mosses, and a few drought-adapted higher plants like rabbit brush and western juniper are the dominant plants.
Much older, perhaps 4 million years old, are the hydrovolcanoes that erupted under lakes or in wetlands. Devil’s Garden near the town of Sprague River, and Paiute Rock north of Beatty, are examples of hydrovolcanoes. Their rocks have weathered forming a variety of xeric habitats having little soil development. These habitats have plant communities adapted to dry conditions and appear to be comprised of species that spread west from eastern Oregon and may be relicts of much older plant communities that adapted to harsh conditions present in the early evolution of these volcanic landscapes.