Data from:Temporal stabilizing effects of species richness and seed arrangement on grassland biomass production Haiyan Ren College of Agro-grassland Science, Nanjing Agricultural University, Nanjing, China https://orcid.org/0000-0003-0745-4438 Kathryn A. Yurkonis Department of Biology, University of North Dakota, Grand Forks, USA Iris Vogeler Department of Agroecology, Aarhus University, Tjele, Denmark Dima Chen College of Biological and Pharmaceutical Sciences, China Three Gorges University, Yichang, China Manqiang Liu Soil Ecology Lab, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, China Qiang Yu National Hulunber Grassland Ecosystem Observation and Research Station,Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, China Haiyan Ren hren@njau.edu.cn Publish time: 19.April, 2022 Publisher: Dryad https://doi.org/10.5061/dryad.47d7wm3gf Citation HAIYAN REN et al., 2022 Data from: TEMPORAL STABILIZIING EFFECTS OF SPECIES RICHNESS AND SEED ARRANGEMENT ON GRASSLAND BIOMASS PRODUCTION. Dryad Digital Repository. Dryad,Dataset: https://doi.org/10.5061/dryad.47d7wm3gf (Haiyan Ren et al., 2022). More information about depositing data in Dryad is available at http://www.datadryad.org/depositing Abstract 1. The extent to which individuals experience inter- and intraspecific interactions through their spatial arrangements within diverse plant communities, whether because of confounding effects of species richness, evenness, or direct changes in species patch sizes on their neighborhood relationships, could affect grassland biomass production and its stability at community scales. Elucidating the ways in which neighborhood effects and species richness contribute to such community responses has important implications for how practitioners establish grasslands to meet forage production and conservation goals. 2. We assessed the effects of altering plant species richness (3 levels: 2, 4, or 8 forage species per plot) and seed arrangements (4 levels: species mixed and seeded or seeded in 0.0625 m2, 0.25 m2, or 1.0 m2 single-species patches while maintaining plot-scale species evenness) on aboveground biomass production and its temporal stability in developing grasslands seeded with a suite of globally common forage species (three legumes, three cool-season grasses, two warm-season grasses). 3. Communities seeded with more species and those with their seeds arranged into smaller conspecific patches produced more biomass and were more temporally stable than those seeded with fewer species and larger conspecific patches. The effect of manipulating species arrangements is attributable to greater neighborhood scale interspecific interactions and stronger complementary effects. Furthermore, seeding species into conspecific patches resulted in communities that were 34% more productive, that were just as temporally stable, and that had similar diversity effects as those seeded with a species mixture, as is common in grassland reconstruction efforts. 4. Synthesis. In comparison with conventional mixed-seeding methods, seeding grasslands with high species richness and small, single-species patches may promote grassland reconstruction through increased biomass production, temporal stability, and complementarity effects. Our study highlights the importance of regulating intraspecific interactions within diverse communities for improving grassland biomass production and suggests that efforts to reevaluate methods used to establish forage and conservation grasslands could result in greater biomass production and stability in these systems. Methods 112 plots (2 × 4 m; separated by 1 m aisles) were laid out in a completely randomized design on the site. The experiment included monoculture plots of eight study species (8 species × 4 replicates = 32 monoculture plots) and mixture plots of these species seeded in all combinations of three species richness levels (2, 4, or 8 species in equal abundances) and four seed arrangement levels (mixed, 0.0625 m2, 0.25 m2, or 1.0 m2 single-species patches in equal areas across species).The requisite seeds for a plot were either completely mixed and uniformly hand broadcast over the entire plot (mixed; no a priori seed arrangement) or they were arranged into 128 – 0.0625 m2, 32 – 0.25 m2, or 8 – 1.0 m2 single-species patches (patch seeding; Fig. S1). The mixed seed arrangement replicated conventional grassland seeding practices. In the patch seeded plots, species were randomly assigned to and seeded in patches within each replicate depending on the richness level assigned to the plot. Species were seeded in equal proportions in all mixed-species communities such that they were similarly even at the plot-scale at seeding. Funding National Natural Science Foundation of China-Key Program (31830092) The dataset was collected at the White-Horse Research Station, Nanjing Agriculture University (32o 32’ 56” N, 118o 12’ 39” E) over three years aboveground biomass from 2016 to 2018, also with 8 monoculture species along with 4 seeds arrangements and 3 species richness 4 replicates A Trifolium repens B Festuca rubra C Dactylis glomerata D Medicago sativa E Poa annua F Cynodon dactylon G Zoysia japonica H Trifolium pratense ANPP Aboveground net primary production Biomass Unit: g/m2