The impact of fire on tree species diversity and natural regeneration in miombo woodlands in Chongoni Forest Reserve, Malawi

Abstract

The role of fire in Miombo forest ecosystems as an important forestry management tool for sustaining tree biodiversity has increasingly been recognized. In Malawi, there has been a limited or lack thereof of research conducted to date on the role of fire in Miombo forests, in particular focusing on the tree species diversity and natural regeneration. This study was conducted at Chongoni Forest Reserve (14 0 15 1 S, 34 0 12 1 E) to determine the effects of forest fire occurrence on tree species diversity and natural regeneration. Data on species occurrence, diameter at breast height, height, and regeneration were collected from a cluster of 3 concentric circular plots of sizes 0.01 ha, 0.04 ha, and 0.16 ha, assessed from 20 plots each in burnt and unburnt area. The data collected on the number of individual species and diameter at breast height were analyzed for tree species diversity, richness, and structure. The study has established that tree species in the reserve are differentiated in both burnt and unburnt plots in their richness. However, less significant differences are encountered on tree species and regenerants diversity values. More so, further analysis on frequency distribution among regenerants shows that relatively higher numbers are found in unburnt sites than in burnt sites. However, the existence of regenerants in both sites further indicates the resilient nature of Miombo woodland species to disturbances. In addition, Brachystegia floribunda and Uapaca kirkiana were identified as the two-key species in the forest. The study concluded that fire occurrence in the forest reserve has a role in maintaining the tree and regenerants species diversity and richness. Thus, the study recommends fire management, including monitoring routines to maintain species diversity.