Floristic variation along landscape transformation gradients in successional tropical dry forests of the Colombian inter-Andean valleys

This study analyzed variation in the floristic composition of successional tropical dry forests (Bs-T) along a gradient of landscape transformation and environmental factors in the Colombian inter-Andean valleys. Using 45 permanent plots distributed across the Magdalena and Cauca river basins, floristic patterns were evaluated through analyses of diversity (Hill numbers), similarity (NMDS), and relationships with environmental variables (RDA). The results showed a clear floristic differentiation between watersheds, whereas the succession and transformation gradients were not significant in explaining compositional variation. The main variables associated with floristic composition were total annual precipitation, mean annual temperature, and edaphic properties (pH, texture, base content, and available phosphorus), showing that environmental and geomorphological heterogeneity is the main determinant of floristic patterns in these ecosystems. Although some plots exhibit structural features typical of late successional stages, floristic composition reflects species assemblages characteristic of early and intermediate stages, suggesting that Bs-T forests require periods exceeding 50 years to recover the typical composition of mature forests. Taken together, these results confirm that floristic variation in the inter-Andean valleys is primarily related to multiscale environmental gradients rather than to the direct effects of transformation or succession, highlighting the need to incorporate these factors into management, restoration, and conservation strategies for tropical dry forest.