Genome size mediates the effect of environmental filtering in
determining plant β-diversity across temperate grasslands
Abstract
Elucidating mechanisms underlying community assembly and biodiversity
patterns is central to ecology and evolution. Genome size (GS, i.e.
nuclear DNA content) determines species’ capacity to tolerate
environmental stress or to exploit new environments and therefore
potentially drive community assembly. However, its role in driving
β-diversity (i.e., the site-to-site variability in species composition)
remains unclear. We measured GS for 169 plant species and investigated
their occurrences within plant communities across 52 sites spanning a
3200-km transect in the temperate grasslands of China. We found
environmental factors showed larger effects on β-diversity of large-GS
than that of small-GS species. Community weighted mean GS increased with
mean annual precipitation, soil total nitrogen and phosphorus
concentrations, but decreased with mean annual temperature, suggesting a
negative selection against species with large GS in resources-limited or
warmer climates. These findings highlight the roles for GS in driving
community assembly and predicting species responses to climate change.