A trait-based approach to assessing resistance and resilience to wildfire in two iconic North American conifers

Ongoing changes in fire activity have the potential to drive widespread shifts in Earth’s vegetation. Plant traits and vital rates can be indicators of the ability of individuals to survive fire (resistance) and populations to persist (resilience) following fire and provide a method to assess vulnerability to fire-driven vegetation shifts.
In 15 study sites spanning climatic gradients in the southern Rocky Mountains, U.S.A., we quantified variation in key traits and vital rates of two co-occurring, widely-distributed conifers (Pinus ponderosa Douglas ex. P. Lawson & C. Lawson and Pseudotsuga menziesii (Mirb.) Franco). We used mixed models to explain inter- and intraspecific variation in tree growth, survival, bark thickness, and seed cone production, as a function of species, tree life stage (i.e., diameter, height, and age), average climate, local competition, and site conditions.
P. ponderosa was predicted to survive low-severity fire at a 23% earlier age than P. menziesii....