Forests exhibit thresholds in disturbance intervals that influence sustainability of production and natural values including sawlog production, species existence and habitat attributes. Fire is a key disturbance agent in temperate forests and frequency of fire is increasing, threatening sustainability of these forest values. We used mechanistically diverse, theoretical fire interval distributions for mountain ash forest in Victoria, Australia, in the recent past and future to estimate the probability of realising: (i) minimum sawlog harvesting rotation time; (ii) canopy species maturation; and (iii) adequate habitat hollows for fauna. The likelihood of realising fire intervals exceeding these key stand age thresholds diminishes markedly for the future fire regime compared with the recent past. For example, we estimate that only one in five future fire intervals will be sufficiently long (~80 years) to grow sawlogs in this forest type, and that the probability of forests developing adequate habitat hollows (~180 years) could be as low as 0.03 (3% of fire intervals). Therefore, there is a need to rethink where sawlogs can be sourced sustainably, such as from fast-growing plantations that can be harvested and then regrown rapidly, and to reserve large areas of existing 80-year-old forest from timber harvesting.

森林在干扰间隔中表现出阈值，影响生产的可持续性和自然价值，包括锯木产量，物种生存和生境属性。火灾是温带森林的主要干扰因素，火灾频率在增加，威胁着这些森林价值的可持续性。在最近和将来，我们使用了机械多样性的理论火间隔时间分布，用于澳大利亚维多利亚州的山灰森林，以估算实现以下目标的可能性：（i）最小锯木采伐轮换时间；（ii）冠层物种成熟；（iii）为动物群提供足够的栖息地空洞。与最近的火灾相比，未来火灾情况下实现火灾间隔超过这些关键林分年龄阈值的可能性显着降低。例如，我们估计未来五分之一的火灾间隔将足够长（〜80年）以生长这种森林类型的锯木，并且森林形成足够的栖息地空洞（〜180年）的可能性可能低至0.03（3火灾间隔的百分比）。因此，有必要重新考虑可可持续采伐锯木的地方，例如可采伐的快速生长的人工林，然后迅速重新长成，并从木材采伐中保留现有的已有80年历史的大片森林。