Citation

Bates JD, Sharp RN, Davies KW. Int. J. Wildland Fire 2014; 23(1): 117-130.

Copyright

(Copyright © 2014, International Association of Wildland Fire, Fire Research Institute, Publisher CSIRO Publishing)

DOI

10.1071/WF12206

PMID

unavailable

Abstract

Woodland ecosystems of the world have been changed by land use demands, altered fire regimes, invasive species and climate change. Reduced fire frequency is recognised as a main causative agent for Pinus-Juniperus L. (piñon-juniper) expansion in North American woodlands. Piñon-juniper control measures, including prescribed fire, are increasingly employed to restore sagebrush steppe communities. We compared vegetation recovery following prescribed fire on Phase 2 (mid-succession) and Phase 3 (late-succession) Juniperus occidentalis Hook. (western juniper) woodlands in Oregon. The herbaceous layer on Phase 2 sites was comprised of native perennial and annual vegetation before and after fire. On Phase 3 sites the herbaceous layer shifted from native species to dominance by invasive Bromus tectorum L. (cheatgrass). After fire, shrubs on Phase 2 sites were comprised of sprouting species and Ceanothus velutinus Dougl. (snowbrush). On Phase 3 woodland sites the shrub layer was dominated by C. velutinus. The results suggest that Phase 2 sites have a greater likelihood of recovery to native vegetation after fire and indicate that sites transitioning from Phase 2 to Phase 3 woodlands cross a recovery threshold where there is a greater potential for invasive weeds, rather than native vegetation, to dominate after fire.