Pre-disturbance plant condition drives intraspecific resprouting variability in Mediterranean shrubs

Many Mediterranean plants persist after disturbances by resprouting from dormant buds, and understanding factors driving variability in resprouting is crucial for predicting regeneration under global change. We hypothesized resprouting is influenced more by long-term environmental factors (e.g. historical aridity, fire history, soil nutrients) that shape pre-disturbance plant condition than by immediate water availability or local adaptations. We applied an experimental disturbance of two consecutive cuts in a short interval (i) in the field, targeting adult Anthyllis cytisoides and Globularia alypum plants along an environmental gradient (in Spain), and (ii) in a common garden, using A. cytisoides grown from seeds of contrasting aridity provenance and subjected to contrasting water treatments. Intraspecific variability in resprouting predominantly occurred within populations, and was primarily determined by pre-disturbance plant size, underscoring the importance of individual history. Secondarily, aridity had a positive effect on resprouting, while higher fire frequency and the second cut had negative effects. We found no evidence of local adaptations, but young plants in the garden were dependent on water availability. Adult plants may be resilient to disturbance under low water availability but sensitive to increased disturbance frequency, while young plants may be vulnerable in a drier world, emphasizing ontogenetic differences in resprouting vulnerabilities.