Context‐dependent relationships between genomic traits and plant performance in temperate grasslands

Abstract Genome size and ploidy level affect fundamental processes in plants—including growth rate, stress tolerance and dispersal ability—and may play a critical role in shaping species responses to changing environmental conditions. Central European temperate grasslands, which are increasingly degraded by intensified land use and habitat fragmentation, provide a suitable system for investigating how these genomic traits mediate plant responses to human‐induced disturbances. We studied the relationship between genomic traits (genome size and ploidy) and species performance, measured as species cover from vegetation relevés, in a real‐world ecological context. The analyses involved data from 150 grassland plots located in three distinct regions in Central Europe. We performed species‐level and community‐level analyses to test whether genomic traits can predict plant performance across gradients of land‐use intensity and habitat fragmentation. Our results revealed distinct regional patterns of plant performance associated with genomic traits. In one region, species with larger genomes thrived in isolated, stable habitat patches, whereas species with smaller genomes thrived in fragmented, well‐connected habitats due to superior dispersal abilities. In the driest region, polyploid species performed better under mowing and in well‐connected habitats, potentially due to their enhanced drought tolerance. Additional region‐specific associations between genomic traits and land‐use practices may also reflect underlying climatic influences. No consistent associations were found across all three regions. These findings underscore the context‐dependent influence of genomic traits on temperate grassland species' responses to human‐induced disturbances. They further motivate the inclusion of genomic traits into ecological research and management to enhance predictions of plant responses. Long‐term, replicated studies remain vital for addressing the complex relationships between genomic traits, species performance and environmental change. Read the free Plain Language Summary for this article on the Journal blog.