Potential of native tree species regeneration and establishment in exotic tree plantations: The case of Bellefoungou Forest Reserve in Northern Benin

Abstract

While natural forest losses occur continuously, the extent of forest plantations has increased worldwide. These plantations, in addition to their role in timber production, also support forest restoration by fostering native species regeneration under their canopies. However, little is known about native species regeneration in exotic tree plantations of Benin. This study assessed the potential of native species regeneration and establishment in exotic tree plantations. Specifically, it assessed tree species composition and diversity across different vegetation types, the species assemblage and similarity patterns between vegetation types across successional stages and whether and how functional traits explain native species plants establishment in exotic tree plantations of Bellefoungou Forest Reserve. A floristic survey using systematic randomizing technique design was conducted to collect data on the species composition in different vegetation types. Besides, some secondary data was extracted online on functional plant traits. Taxonomic diversity was assessed using species richness, Shannon-Wiener Index and Simpson Index for alpha diversity while Jaccard Coefficient and Sorenson Coefficient for beta diversity. Further, the following were estimated: functional diversity components (functional richness, functional evenness, functional divergence and functional dispersion) using FD package in R software. Non-Metric Dimensional Scaling (NMDS) analysis was done for assessment of similarity and assemblage patterns across vegetation types. Results showed that 55 tree species belonging to 19 families in the entire forest reserve were recorded while 21 of these were found across the canopies of Mixed Plantation (MP). The NMDS analysis showed that the MP is more similar to the woodland (WL) and Tree/Shrubs Savannah (TSS) than Gallery Forest (GF) which could be due the dispersal distance. Across the vegetation types, more than 80% of species have been dispersed by animals and wind in MP and natural forest stands. Further, it was found that the functional richness, eveness and dispersion were lower in MP compared to natural forest stands showing the availability of resources beneath the MP. The results of this study also suggest that tree plantations participate in the conservation of rare and vulnerable tree species of natural forests. This study therefore, informs the Ministry of Environment and other actors focused on conservation of biodiversity and restoration to promote interventions that facilitate degraded forest landscapes restoration in Benin.