Previous studies have primarily concentrated on elucidating the patterns and determinants of biodiversity-ecosystem function (BEF) relationships, predominantly in terrestrial plant systems and a limited number of freshwater ecosystems. However, there has been a notable lack of research addressing the modulation of marine ecosystems, benthic communities, and the impact of anthropogenic factors such as heavy metal pollution. We examined the relationship between multidimensional biodiversity of macrofauna and and both primary productivity and community stability within the intertidal ecosystem of Qingdao, China, which is deeply threatened by impacted by heavy metal pollution, and further revealed the specific driving process of heavy metal factors on these two relationships from the perspective of macrofaunal functional traits. The results showed that there were positive correlations among species diversity, functional diversity, and phylogenetic diversity with both community stability and primary productivity. Furthermore, functional-phylogenetic diversity and species diversity may serve as indicators for primary productivity and community stability, respectively. Additionally, MD, a multidimensional indicator of biodiversity, could indicate heavy metal pollution. Heavy metals, particularly As and Zn, could drive the BEF relationships through functional traits. High As pollution shifted functional traits from infauna and burrower to epifauna, filter feeding, swimmer, and cylindrical body form, changing species composition and increasing the consumption of benthic algae by macrofauna, which may lead to the decrease of biodiversity, stability, and ecosystem functioning. In contrast, lower Zn concentrations may promote community stability and enhance primary productivity, indicating that As and Zn could be useful indicators of intertidal ecosystem health. This study could provide valuable insights into the relationship between macrofaunal biodiversity, stability, and ecosystem functioning in neglected intertidal ecosystems, contributing to the sustainable development of marine ecosystems and the monitoring of ecological health status.
 

heavy metal pollution, macrofauna, functional traits, multi-dimensional biodiversity, ecosystem function