Decoupling of Taxonomic and Functional Recovery in a Multi‐Decadal Mixed Araucaria Forest Chronosequence

ABSTRACT

Understanding how different biodiversity dimensions recover following disturbance is critical for interpreting forest successional trajectories. We examined this question in a protected remnant of Araucaria Mixed Forest (AMF) in subtropical southern Brazil, a frost‐prone montane system with multiple anthropogenic disturbance legacies. We established 32 permanent plots spanning a 40+ year post‐disturbance chronosequence and assessed taxonomic composition, species richness, functional diversity and functional trait composition across young (< 15 years), intermediate (15–39 years) and old (≥ 40 years) successional stands. Species richness showed no age‐related trend ( p  = 0.64), whereas functional diversity increased with stand age ( p  = 0.007) and reached its highest values in old stands. Floristic composition differed significantly among successional stages ( p  < 0.001), indicating species replacement without corresponding richness gains. Functional composition shifted towards more resource‐conservative trait strategies in older stands, although substantial heterogeneity persisted among old forest plots. These results indicate a decoupling between taxonomic and functional recovery trajectories, cautioning against the use of species richness alone as a recovery indicator. The delayed increase in functional diversity suggests that short monitoring windows may fail to capture important dimensions of forest recovery. Our findings underscore the conservation value of older forest stands and support the inclusion of functional indicators in long‐term assessments of forest recovery.