Integrating Evolutionary Ecology into Urban Aerobiology: Temporal Dynamics and Drivers of Airborne Spore-Pollen Diversity

Abstract Urban airborne spores and pollen serve as valuable bioindicators for assessing biodiversity and ecosystem health. Traditional monitoring approaches predominantly correlate spore-pollen dispersal dynamics with meteorological variables, largely overlooking their intrinsic biological attributes and evolutionary context. This study adopted an evolutionary ecology framework to investigate the temporal dynamics of airborne spores and pollen in Kunming, a subtropical plateau city in China. Integrating one-year gravimetric sampling with eDNA metabarcoding, we analyzed how regional phylogenetic history, local vegetation structure, seasonal climate, and basin topography jointly shape urban spore-pollen spectra, assessed the relative contributions of biotic drivers versus abiotic factors in governing dispersal patterns, and evaluated whether phylogenetic diversity reflects biotic homogenization in airborne spore-pollen communities. Our findings demonstrated that biotic factors, especially spore-pollen grain morphology and floral traits, possessed greater explanatory power for dispersal dynamics than meteorological variables. The airborne spore-pollen assemblage exhibited remarkably high phylogenetic diversity, with a significant phylogenetic signal detected in key functional traits, suggesting limited community similarity and apparent evolutionary constraints. These results challenge the prevailing abiotic-centric perspective, repositioning airborne spores and pollen as evolutionarily constrained biological entities rather than passive atmospheric particles. This framework advances spore-pollen monitoring from descriptive abundance records to process-based evolutionary indicators, offering novel tools for urban biodiversity assessment and for forecasting plant community responses to ongoing climate and land use change.