Early‐ and late‐flowering guilds respond differently to landscape spatial structure

Species with unique phenologies have distinct trait syndromes and environmental affinities, yet there has been little exploration of whether community assembly processes differ for plants with different phenologies. In this study, we ask whether early‐ and late‐blooming species differ in the ways that dispersal, persistence and resource acquisition traits shape plant occurrence patterns in patchy habitats. We sampled plant communities in 51 Ozark dolomite glade grasslands, which range in size from <1 ha to >100 ha. We modelled the occurrence of 71 spring‐ and 43 summer‐blooming grassland species in these patches, using as predictors both environmental variables (landscape structure, soil resources) and plant traits related to dispersal, longevity and resource acquisition. We were especially interested in how the environmental variables and plant traits interacted to determine the occurrence of phenological strategies in habitats that vary in size and isolation. Summer‐blooming species with better persistence and dispersal abilities had higher relative frequencies in smaller, more isolated habitat patches, and summer‐blooming species with higher specific leaf area—suggesting fast growth and low stress tolerance—were more likely to occur in patches with greater soil organic matter and clay content. However, spring‐blooming species showed much weaker interactions between functional traits and environmental gradients, perhaps because environmental conditions are less harsh in spring than in summer. Synthesis. Several axes of plant life‐history variation may simultaneously influence community responses to habitat connectivity. In this case, explicitly considering plant phenology helped identify generalizable relationships between functional traits and landscape spatial structure.