Functional traits and climate drive interspecific differences in disturbance-induced tree mortality

Area of Science:

• Forest Ecology
• Climate Change Impacts
• Disturbance Ecology

Background:

• Climate change is altering natural disturbance regimes (e.g., storms, fires), impacting forest dynamics.
• Predicting forest structure and composition shifts requires understanding species-specific sensitivities to disturbances.

Purpose of the Study:

• To investigate how functional traits and mean climate influence tree species' sensitivity to disturbances.
• To model annual mortality probability for 40 European tree species across various disturbance types.

Main Methods:

• Utilized data from 130,594 trees across 7,617 plots in French, Spanish, and Finnish National Forest Inventories.
• Modeled tree mortality probability considering tree size, dominance, disturbance type, and intensity.
• Correlated estimated species mortality probability with functional traits and mean climate niches.

Main Results:

• Distinct trait combinations determine species sensitivity: storm-sensitive species have high height-dbh ratio, low wood density, and high growth; fire-sensitive species have low bark thickness and high P50.
• Species adapted to warmer, drier climates showed higher fire resistance.
• Productive conifers were most sensitive, while Mediterranean oaks were least sensitive to disturbances.

Conclusions:

• Identified critical links between species functional traits and disturbance sensitivity.
• Provides a basis for more accurate predictions of future forest structure and composition under changing climate and disturbance regimes.