Fire return intervals are very short at Niassa Special Reserve, Mozambique, especially in dry miombo woodlands—a survival analysis

Background Fire shapes savanna and woodland landscapes, but the temporal spacing of recurrent fires remains poorly quantified in African miombo ecosystems. Understanding how fire-return intervals vary across vegetation and landscape settings is important for interpreting fire-regime heterogeneity, vegetation recovery, and fire-management needs. We assessed Fire-return intervals across the Niassa Special Reserve, Mozambique, and evaluated whether fire recurrence differed among major vegetation types. Annual fire histories for 2013 to 2024 were reconstructed from Landsat-derived burned-area maps sampled on a 1-km grid across the reserve. Fire-return intervals were analysed using discrete-time survival analysis approaches that incorporated censored observations and vegetation-stratified comparisons. Results Recurrent burning dominated the landscape: 69.6% of the reserve burned more than six times during 2013–2024. Median Fire-return intervals were approximately 1 year across most major vegetation types. Dry lowland miombo had the shortest intervals, highest annual burned area, and lowest survival probabilities. Moist escarpment miombo had longer intervals, lower annual area burned, and higher probabilities of remaining fire-free. Among the candidate distributions evaluated, the discrete Weibull model provided the best fit across vegetation types. Hazard functions peaked at 1-year intervals and declined thereafter, indicating that reburning was concentrated soon after previous fires and that long fire-free periods were uncommon. Conclusions Fire recurrence in the Niassa Special Reserve is strongly structured by vegetation type and landscape heterogeneity. The dominance of short fire-return intervals, particularly in dry miombo woodlands, suggests that frequent reburning is a defining feature of this protected miombo landscape. Maintaining spatial variation in fire frequency, including areas with longer fire-free persistence and potential fire refugia, can support landscape-level fire management, vegetation recovery, and miombo woodland resilience.