Relationships between mycorrhizal type and leaf flammability in the Australian flora

Abstract

Mycorrhizal fungi have been linked to fire processes in natural ecosystems via their effects on litter decomposability but, to our knowledge, relationships between mycorrhizal fungi and leaf traits directly associated with aspects of flammability have not been studied. Here, we assessed the relationships among leaf traits and host mycorrhizal type for 77 species of Australian trees and shrubs to determine whether mycorrhizal type can explain variation in three aspects of leaf flammability (ignitability, fire duration, and smoulder duration). Several associations were observed between mycorrhizal type and leaf traits directly linked to flammability measures, including specific leaf area, leaf mass, leaf moisture content, and leaf chemistry. The observed patterns suggest that interactions between mycorrhizal fungi and their host plants during the growth and senescence of leaves may have subsequent effects on fire processes. However, further work is necessary to evaluate the importance of these effects in real ecosystems, including whether plants or fungi are responsible for these patterns, and we propose four questions that will further progress in this area.