Pinyon and juniper have been expanding into sagebrush (Artemisia tridentata) ecosystems since settlement of the Great Basin around 1860. Herbaceous understory vegetation is eliminated as stand densities increase and the potential for catastrophic fires increases. Prescribed fire is increasingly used to remove trees and promote recovery of sagebrush ecosystems.
Rau, B. M.; Blank, R. R.; Chambers, J. C.; Johnson, D. W. 2007. Prescribed fire in a Great Basin sagebrush ecosystem: Dynamics of soil extractable nitrogen and phosphorus. Journal of Arid Environments. 71: 362-375.