Cross-Taxa Analysis of Long-Term Data Reveals a Positive Biodiversity-Stability Relationship With Taxon-Specific Mechanistic Underpinning

Anthropogenic environmental change is altering biodiversity at unprecedented rates, threatening the stability of ecosystem services on which humans depend. However, most of what is known about biodiversity–stability relationships comes from experimental studies making extrapolation to real ecosystems difficult. Here, we ask whether the shape and underlying mechanisms of the biodiversity–stability relationship vary among taxa in real-world communities. Our study harnesses the power of six terrestrial and aquatic long-term monitoring datasets, encompassing entire assemblages at hundreds of georeferenced sites providing 20 years long community measurements, covering a 1200 km latitudinal gradient across Finland. In general, we detect a positive relationship between species richness and stability. Structural equation modelling reveals that this relationship is modified by functional trait community composition, with specific mechanisms varying among the taxa. Our study is among the first to highlight the importance of functional traits in elucidating both general and taxon-specific impacts of biodiversity on community stability.