Land-use legacies drive distinct recovery trajectories and persistently shape the taxonomic and functional composition of tree communities

Second-growth forests play a fundamental role in conserving biodiversity and maintaining ecosystem services in deforested tropical landscapes. However, land-use imposes constraints on forest restoration and ecosystem functioning, thereby posing challenges to the attainment of global restoration targets established by the UN-Decade on Ecosystem Restoration. Here, we investigated how contrasting land-use influences species composition and alpha taxonomic diversity, as well as taxonomic and functional β-diversity and local contributions to β-diversity, in second-growth forests regenerating on former plantations of Eucalyptus spp. and abandoned pasturelands within the Brazilian Atlantic Forest. We further examined whether the partitioning of β-diversity (turnover and nestedness) and functional trait composition reflected land-use legacies. The two forest types differed in species composition and showed high within-group variation in taxonomic and functional β-diversity. However, they had similar mean alpha taxonomic diversity, mean within-group β-diversity, and mean between-group local contributions to β-diversity. Furthermore, β-diversity patterns were primarily structured by turnover (heterogenisation) in former pasturelands and nestedness (homogenisation) in former plantations. This heterogenisation was linked to functional traits characteristic of early successional stages during ecosystem recomposition, whereas homogenisation corresponded to traits typical of more advanced successional stages. These findings suggest that, although overall β-diversity converges over time across different land-use types, marked variation in the composition of functional traits still persist, indicating that community reassembly processes remain strongly influenced by prior land-use. Importantly, the integration of commercial exotic – but non-invasive – species into restoration strategies may enhance ecological effectiveness, financial viability, and scalability, thereby supporting cost-effective large-scale reforestation initiatives.