The impacts of changing disturbance regimes on serotinous plant populations and communities

Climatic change is anticipated to alter disturbance regimes for many ecosystems. Among the most important effects are changes in the frequency, size, and intensity of wildfires. Serotiny (long-term canopy storage and the heat-induced release of seeds) is a fire-resilience mechanism found in many globally important terrestrial ecosystems. Life-history traits and physiographic differences in ecosystems lead to variation in serotiny; therefore, some systems may exhibit greater resilience to shifting disturbances than others do. We present a conceptual framework to explore the consequences of changing disturbance regimes (such as mean and variance in fire severity or return intervals) to serotinous species and ecosystems and implications of altered serotinous resilience at local and regional scales. Four case studies are presented, and areas needing further research are highlighted. These studies illustrate that, despite the reputed fire resilience of serotiny, more fire does not necessarily mean more serotinous species across all systems in which they occur.