Multitaxa functional diversity increases the resilience of biological natural capital in the Amazon

Abstract The resilience of biological natural capital in the Amazon is strongly influenced by the functional diversity of multitaxa, which promotes the stability and sustainability of the ecosystem. However, biological natural capital, driven by multiple dimensions of biodiversity, is often underestimated by focusing on the taxonomic dimension, such as richness and abundance. We applied a multitaxa and trait‐based approach to assess how functional diversity supports natural capital. By using a dataset including woody plants, bees, frugivorous butterflies and songbirds, we created two indices: Biological Natural Capital Resilience (BNCR), the proportion of biological assets needed to maintain natural capital integrity, and Biological Natural Capital Uniqueness (BNCU), the proportion of natural capital sustained by species' functional uniqueness. BNCR results show that, in general, more than 80% of biological assets to maintain the integrity of natural capital, and that the BNCR index reached the highest value when all taxonomical groups are combined. These results reveal that natural capital strongly depends on biological assets and underscore the importance of multitaxa approaches for assessing ecosystem resilience. BNCU values show that a substantial portion of natural capital integrity (from 46.22% to 64.23%) depends on a small subset of functionally unique species, indicating that the loss of few species, which play irreplaceable ecological roles, rapidly reduces ecosystem functioning. Synthesis and applications . This study presents a trait‐based framework integrating functional diversity into biological natural capital accounting, capturing both ecosystem resilience and species uniqueness across multiple taxa. It provides ecologically grounded, standardized and reproducible indicators that move beyond single‐taxon or purely taxonomic approaches. By embedding these indicators into natural capital accounts, the framework supports conservation prioritization, restoration planning, impact assessment, trend monitoring and scenario testing, offering a practical methodology to evaluate and manage the multiple dimensions of biodiversity within natural capital assessments.