Drivers of understory plant communities in Sierra Nevada mixed conifer forests with pyrodiversity

Abstract Background Fire suppression in western North America increased and homogenized overstory cover conifer forests, which likely affected understory plant communities. We sought to characterize communities their drivers using plot-based observations from two contemporary reference sites the Sierra Nevada, USA. These had long-established natural fire programs, have resulted restored regimes. In this study, we investigated how pyrodiversity—the diversity of size, severity, season, frequency—and other environment factors influenced species composition forest Results Understory were by a combination environmental, plot-scale recent history, plot-neighborhood pyrodiversity within 50 m. Canopy was inversely proportional cover, Simpson’s diversity, evenness. Species richness strongly interaction experience Conclusions Pyrodiversity appears contribute both directly indirectly diverse Nevada mixed forests. The indirect influence is mediated through variability tree canopy partially related variation while direct an between local neighborhood activity.