Insights on the dynamics of Miombo woody vegetation in Niassa Special Reserve, northern Mozambique

Background Fire is a key ecological factor in the Miombo woodlands of southern Africa, but its role in tree dynamics has not been fully explored. Aim Investigate relationships between fire and forest dynamics and predict Miombo diameter distribution for the year 2033. Methods Tree data (growth, recruitment and mortality) were collected (2005, 2009, 2015 and 2019) along a fire frequency (ff) and severity (fs) gradient in 50 permanent plots in Niassa Special Reserve (NSR). A transition matrix was used to forecast forest structure for the year 2033. Main results Fire frequency (ff) and severity (fs) classes (low, medium and high) were associated with different tree species assemblages. High ff and fs had varied effects on tree mortality, recruitment, growth and carbon stocks. Julbernardia globiflora had higher mortality rate in high ff plots compared to other tree species. Projections indicated that, despite the regular distribution of diameter, high ff may reduce tree density in young cohorts. Conclusions A moderate fire regime is a determinant of sustaining the Miombo dynamics in NSR. Implications Fire management action through early dry season controlled burning is needed to prevent the impact of intense late dry season fire.