Pyrodiversity and Phylodiversity: Insights on Post-Fire Forest Communities

Fire is a fundamental process that structures community assembly and biodiversity patterns; however, altered disturbance regimes associated with anthropogenic change present a major threat to fire-adapted systems. Reintroducing fire to increase pyrodiversity (spatiotemporal diversity in fire) has been identified as an important step in restoring fire-adapted western temperate forests. Here, we utilize phylogenetic and taxonomic metrics to assess how pyrodiversity influences plant community assembly dynamics and diversity patterns in the central Sierra Nevada, California, USA. Compared to fire exclusion, regional taxonomic and phylogenetic diversity generally increased after fire. Further, with increased pyrodiversity, community assembly mechanisms diversified and occurrences of diverse plant lineages and local phylogenetic endemism increased, illustrating how evolutionary history influences responses of plants to pyrodiversity. These results demonstrate the importance of restoring mixed-severity fire to these systems and how phylogenetic tools can provide a valuable way to understand and monitor restoration impacts.