Flowering phenology as a functional trait in a tallgrass prairie

The timing of flowering is a critical component of the ecology of plants and has the potential to structure plant communities. Yet, we know little about how the timing of flowering relates to other functional traits, species abundance, and average environmental conditions. Here, we assessed first flowering dates (FFDs) in a North American tallgrass prairie (Konza Prairie) for 431 herbaceous species and compared them with a series of other functional traits, environmental metrics, and species abundance across ecological contrasts. The pattern of FFDs among the species of the Konza grassland was shaped by local climate, can be linked to resource use by species, and patterns of species abundance across the landscape. Peak FFD for the community occurred when soils were typically both warm and wet, while relatively few species began flowering when soils tended to be the driest. Compared with late-flowering species, species that flowered early had lower leaf tissue density and were more abundant on uplands than lowlands. Flowering phenology can contribute to the structuring of grassland communities, but was largely independent of most functional traits. Therefore, selection for flowering phenology may be independent of general resource strategies.