Fires are common in drier regions of the world, and plants in such ecosystems have evolved traits to tolerate frequent burning and intense temperatures. The mechanisms involved in the evolution of fire-tolerance through e.g. thickened bark, however, are unknown.
In this study, researchers compiled a database of bark thickness for more than 500 woody plant species, and used GBIF-mediated occurrences combined with climate data to establish environmental niches for each species. By including a dataset on occurrences of fires, the researchers describe a strong, global link between fire frequency and bark thickness. On average, species found in fire-frequent savannas have bark three times thicker than species in fire-infrequent forests.
The researchers further assessed the vulnerability of communities under future scenarios, and found that seasonal forests and savannas are robust, while tropical rainforests may be especially vulnerable, as wildfires are expected to increase in frequency in warmer climates.