Drivers of post‐fire resprouting success in restored Banksia woodlands

Abstract

Disturbances can alter persistence trajectories of restored ecosystems. Resprouting is a common response of plants to disturbances such as fire or herbivory. Therefore, understanding a plant's resprouting response can inform successful restoration. We investigated patterns and drivers of resprouting following fire in fire‐prone Banksia woodlands restored after sand mining in the Mediterranean‐climate region of Western Australia. We applied experimental fire to samples of nine species with different resprouting types (rhizome, root crown, root sucker and lignotuber) across a 4‐ to 27‐year‐old restoration chronosequence. We investigated the influence of pre‐fire plant size, restoration age and soil conditions on resprouting success, defined by: (i) the probability of resprouting (measured ~5 months after fire), (ii) the probability of surviving the first summer and, (iii) vigour (both measured ~12 months post‐fire). We found that the probability of initial resprouting was high across most species, but summer survival was lower but comparable to that in other post‐mining restored ecosystems following fire. Generally, pre‐fire plant size did not influence probability of resprouting, while size and soil conditions were important for two species survival. Pre‐fire plant size was a significant predictor of vigour for all species with soil conditions influencing four species. Restoration age significantly influenced survival of three species. However, as our models explained low amounts of variation in probabilities of resprouting and survival (R2 = <0.11), other factors influencing resprouting success remain unidentified. Resprouting response to fire disturbance in restored Banksia woodlands are species and resprouter type specific, with plant size and soil conditions potentially more informative for understanding responses to disturbances than restoration age alone.