Year: 3 years of data collection Year: 2012,2013,2014 Blk: Experimental block Blk: 1 - 5 Plot: plot number. Only weeded plots were analyzed so numbers are not consecutive. Rich: planted species richness (4 levels): monoculture (1), 2, 4, 8 Even: 3 levels of plot level planted species evenness. Space: species pattern treatment ( 2 levels) 1 = randomly planted, 4 = aggregated planting pattern. Not applicable (NA) to monocultures. Weeded: if plot was weeded. Only weeded plots analyzed. Biomass: Total plot biomass PYP = previous year proportion (realized proportion). Proportion each species in a plot contributed to each plot biomass in the previous year. For year 1 (2012) PYP is the planted proportion. P = intial planted proportion _1 - _16 = The number after PYP and P is the species number: 1 -4 The warm-season grasses: 1) big bluestem (Andropogon gerardii), 2) little bluestem (Schizachyrium scoparium),3)Indian grass (Sorghastrum nutans) , and 4)switchgrass (Panicum virgatum). 5 - 8 The cool-season grasses: 5) Canada wildrye (Elymus canadensis), 6)slender wheatgrass (Elymus trachycaulus) , 7)western wheatgrass (Pascopyrum smithii), and 8) green needle grass (Nassella viridula). 9 - 12 The forbs: 9) wild bergamot (Monarda fistulosa), 10) stiff goldenrod (Solidago rigida), 11) maximilian sunflower (Helianthus maximiliani), 12) yellow coneflower (Ratibida columnifera). 13 - 16 The legumes: 13) showy tick trefoil (Desmodium canadense), 14) Canada milkvetch (Astragulus Canadensis), 15) purple prairie clover (Dalea purpurea), and 16) American licorice (Glycyrrhiza lepidota).