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Sara Hanna, Humboldt State University, Sara.Hanna@humboldt.edu (Presenter)
Ken Fulgham, Humboldt State University, kenneth.fulgham@humboldt.edu

 

The sagebrush steppe ecosystem of the Intermountain West has experienced a decline over 150 years due to changing fires regimes, invasive species and conifer encroachment. One species of concern is western juniper (Juniperus occidentalis), whose distribution and density has expanded dramatically. Additionally the invasion of exotic annual grasses like cheatgrass (Bromus tectorum) have led to reduced productivity, biodiversity and increased high severity fires. Prescribed fire is an effective management tool in the restoration of sagebrush habitats. We examined the long-term, post-fire vegetation dynamics of a sagebrush steppe and western juniper community at two study sites located in Modoc County California. The immediate post-fire plant communities at 10 years were dramatically different than those measured nearly thirty years after the fire. While invasive annual grasses dominated the area in the years immediately following fire, native perennial grasses and forbs began recovering after 10 post-fire growing seasons. Following nearly 30 growing seasons, perennial grass and forb cover and productivity were still greater than pre-fire levels. Sagebrush cover had also recovered to pre-fire levels, although decidedly slower than herbaceous recovery. Evidence of post-fire western juniper establishment was evident. There were significant differences in the post-fire vegetation between the sampling sites, confirming that the heterogeneity of sagebrush plant communities leads to differences in predicting post-fire succession.