Taxa assembly and trait partitioning contribute similarly to soil invertebrate functional diversity along secondary succession in the eastern Tibetan Plateau
Description
Destroyed and abandoned forests have driven extensive secondary succession. Yet how functional diversity emerges in soil invertebrate communities, particularly the roles of taxa assembly and trait partitioning in shaping it along secondary succession remains unclear. To address this gap, we developed a novel “taxonomic diversity-functional distance” analytical approach. We applied this approach to examine soil invertebrate functional diversity and its links to environments and soil functioning across secondary succession in the eastern Tibetan Plateau, including secondary grassland, shrubland, arboreal forest, and primary forest. We found that soil invertebrate functional α diversity (functional richness within plots) generally increased with succession, though it fluctuated with tree identity in the arbor forest stage. Functional β diversity (functional dissimilarity among plots) showed the opposite trend. This functional diversity was jointly shaped by taxonomic α/β diversity (taxonomic richness/dissimilarity) and functional α/β distance (trait partition within/among plots), with comparable contributions. Plant resources and soil microhabitats not only positively related to taxa assembly but also enhanced trait partitioning within plots. These processes collectively expanded functional space (functional α diversity) and subsequently supported soil multifunctionality across succession. Our study advances trait-based soil invertebrate ecology by elucidating dual recovery pathways for invertebrate functionality. It highlights that trait partitioning underlies soil ecosystem functioning, complementing the previous focus on taxa assembly. Testing these mechanisms across biomes and scales will inform targeted ecosystem management, enhancing the functional benefits of soil biology conservation in global restoration. Description of the data and file structure The dataset includes soil invertebrate indices, environmental factors related to soil invertebrates, and soil functions. The data used for statistical modeling were integrated into the Finaldata spreadsheet. Files and variables Invertebrate indices.xlsx: Taxonomic diversity, functional distances, and functional diversity of soil nematodes and arthropods. Environments.xlsx: Microhabitats required by soil invertebrates, microbial biomass as prey, and plant attributes reflecting primary resources. Finaldata.xlsx: Dimension-reduced environmental factors and heterogeneity, average soil invertebrate alpha and beta diversity (from nematodes and arthropods), and soil alpha and beta multifunctionality.