Structural recovery and stable multidimensional diversity mask compositional shifts after selective logging in the Eastern Himalaya

Selective logging is among the most widespread anthropogenic disturbances in tropical forests. While its effects on forest structure and taxonomic diversity are well documented, its consequences for functional and phylogenetic diversity, species- and trait-mediated responses across logging chronosequences remain less studied. We examined tree communities across recently logged, old-logged (> 25 years), and unlogged forests in the Eastern Himalayan foothills. Using 90 vegetation plots (400 m² each), we quantified forest structure, species composition, taxonomic, functional, and phylogenetic diversity, along with species- and trait-level responses to logging. Recently logged forests had lower canopy cover, canopy height, and basal area of large trees than old-logged and unlogged forests. Total stem density and basal area were similar across all three forest categories, however, species composition remained distinct. Logged forests exhibited higher taxonomic diversity, whereas functional and phylogenetic diversity did not vary along the chronosequence. Species-specific analysis showed that logging resulted in both positive and negative impacts across different species. Trait-based analyses revealed that shade-adapted evergreen species were negatively impacted in logged forests. By integrating structural, multidimensional diversity, and species- and trait-specific perspectives, we show that selectively logged forests retain considerable ecological value but remain structurally and compositionally distinct after disturbance. Our findings demonstrate that the recovery or stability in diversity might mask underlying shifts in species composition and traits, highlighting the value of multidimensional assessments of logging impacts. These results underscore the importance of assisted natural regeneration focused on promoting evergreen tree species regeneration may accelerate compositional recovery and enhance long-term forest resilience.