Authors: Lucas Harris; Alan H TaylorFuture change in dry forest systems is likely to be abrupt and nonlinear, with severe disturbance potentially causing persistent changes in vegetation types. A gridded network of field plots (n = 342) was surveyed at four sites on the east side of the Sierra Nevada, California, in areas burned between 2002 and 2008 to evaluate post-fire tree regeneration and its drivers and the potential for fire-originated alternative vegetation states. Each site encompassed the elevational range of Jeffrey pine forest from sagebrush steppe and pinyon-juniper woodland at the lower end to mixed-conifer forest at the upper end. At each site 20th century expansion and infilling of Jeffrey pine and pinyon-juniper woodland, as assessed by aerial photographs, was followed by a wildfire with mixed-severity effects. Jeffrey pine regeneration was absent or nearly absent at two sites. At the other two sites topographic controls dictated Jeffrey pine regeneration, with most regeneration in gullies and at higher elevations. Severely burned areas tended to have abundant cheatgrass at low elevations and high shrub cover at higher elevations. These results suggest a potential fire-catalyzed range shift in Jeffrey pine distribution.
Add to my schedule
Create your personal schedule through the official app, Whova!Get Started