Maternal plant exposure to fire enhances offspring germination

Plants that resprout after fire experience drastically altered conditions in post-fire environments. However, the effects of plant exposure to fire on offspring traits remain understudied. Many resprouting species are herbaceous plants that flower and fruit rapidly after fire (i.e., fire-stimulated flowering), developing their seeds under increased resource availability and modified biotic interactions, particularly enhanced pollination. We hypothesize that these changes may improve early offspring development through maternal provisioning and increased quality of floral visitation and pollen deposition. To test this, we selected three Mediterranean geophytes (Asphodelus cerasifer, Drimia maritima, Narcissus assoanus) and compared seed mass (3161 seeds) and total germination (2262 seeds) between paired burned and adjacent unburned plants during the first post-fire fruiting season, sampling six populations over 4 years. Although responses varied among localities and species, on average, seeds from burned plants were 13.9% heavier and had a 16.9% higher germination than those from unburned plants. Our results demonstrate that plant exposure to fire can enhance seed mass and germination and suggest that these improvements may be largely influenced by maternal effects. These fire-driven increases in offspring performance may have important consequences for recruitment, regeneration dynamics, and the long-term persistence of plant populations in fire-prone ecosystems.