Biodiversity restoration potential: a comparative study of native species regeneration in natural forests and Liquidambar excelsa plantation forests

The identification of natural succession and regeneration processes is crucial for the preservation of biodiversity and ecosystem stability in sustainable forest management. This study investigated the biodiversity and regeneration of natural forests and Liquidambar excelsa (Noronha) Oken plantations. Tree species richness (dbh ≥ 10 cm) in natural forests was found to be significantly higher (44 species) than in plantation forests (5 species, 4 of which were natural recruits). Although tree density was higher in natural forests, basal area was lower than in plantations. At the regeneration (sapling) level, species richness did not differ significantly between the two forest types, with a moderate diversity index and high evenness, and a species similarity of 60.7%. However, sapling density and basal area were higher in the plantation forests. For understory vegetation, species richness was also not significantly different, but the diversity index was higher in the natural forests. Both shared a very high species similarity (75.6%), despite the greater density and cover in the natural forests. The successful recruitment of native species into plantations is more influenced by environmental factors such as proximity to natural forest seed sources and topography, rather than by the forest type itself. This is demonstrated by the discovery of L. excelsa seedlings in natural forests and the presence of several native species that have successfully regenerated in plantation forests, indicating the potential for biodiversity restoration.