From traits to flames: leaf traits, plant strategies, and plant flammability across a moisture gradient in a frequently burned subtropical landscape

The distribution of plant functional traits across environmental gradients can reflect species' adaptations to local abiotic conditions. Widely measured leaf traits such as leaf area (LA), specific leaf area (SLA), and leaf dry matter content (LDMC) indicate different life history strategies and often respond predictably to gradients of stress and disturbance. Mounting evidence suggests that leaf traits also covary with measures of plant flammability. Yet, whether plant flammability and leaf traits covary synchronously across environmental gradients remains unclear. Here, we examined plant community composition, leaf morphological traits, and shoot flammability along gradients of water depth and burn frequency between seasonally inundated marl prairie and dry pine rockland on Long Pine Key in Everglades National Park (ENP). We built generalized linear mixed models to test the strength and shape of trait‐environment relationships between leaf morphological traits, shoot flammability, and life history strategies, across these two environmental gradients. Additionally, we utilized general linear mixed models to test for relationships between leaf morphological traits and shoot flammability. We found that plants in the drier regions along the gradient (i.e. pine rockland) have high LDMC and moderate LA that reflect stress‐tolerant strategies. Conversely, plants in wetter parts of the gradient (i.e. marl prairies) have low LDMC and high LA that reflect disturbance‐tolerant strategies. We also found that plants in the pine rockland burn more completely, at higher temperatures, and for longer durations than those in the marl prairie. The paired distribution of leaf traits and shoot flammability along environmental gradients reflects significant correlations between shoot flammability and LA and LDMC. The results indicate that life history strategies, leaf morphological traits, and shoot flammability may prove useful in plant and landscape flammability models for the Everglades and other analogous ecosystems.