From fire injury to tree death: insights into the physiological mechanisms of postfire tree mortality

Fire injury can cause immediate tree death, but it can also initiate physiological changes that affect a tree's ability to recover and survive. The mechanisms linking these injuries to postfire recovery or mortality remain poorly understood. Fire-induced injuries can disrupt tree carbon balance by reducing carbon acquisition, impairing carbohydrate transport, and increasing demands on nonstructural carbohydrates needed for recovery. Fire has also been hypothesized to cause mortality through hydraulic failure, although evidence for this mechanism in fire-exposed trees remains limited. Emerging evidence suggests that interactions between carbon balance and water transport may jointly influence postfire tree outcomes. Here, we synthesize current understanding of how fire affects tree carbon balance and water transport and offer pathways for future research.