Species patch size at seeding affects diversity and productivity responses in establishing grasslands

1. Species interactions in diverse plant communities affect community-scale functions such as above-ground biomass production, diversity and invasion resistance. While the strength of these formative interactions can be affected by the balance of inter- and intraspecific interactions among the resident species, it is unclear over what distances individuals typically interact in grasslands and whether or not species interactions at seeding can be effectively manipulated to improve these responses. 2. In a three-year study, we tested whether manipulating the size of seeded species patches affected above-ground biomass, diversity and invasion resistance in experimentally restored grassland plots (16 m2). Plots were divided into patches that were 1, 0.5, 0.25 or 0.125 m on a side, and the equivalent of 1 m2 in each plot was seeded with one of 16 grassland species (1728 seeds/m2). A final treatment involved mixing and broadcasting all seeds into an undivided plot to mimic typical restoration...