MS Reference Number: Oecologia (2007) 151:512–520 MS Dryad ID: xxxx MS Title: Biomass responses to elevated CO2, soil heterogeneity and diversity: an experimental assessment with grassland assemblages MS Authors: Fernando T. Maestre & James F. Reynolds MS Journal: Oecologia **FILE NAMES AND CONTENTS** Maestre_Oecol151.txt - Biomass and relative yield data from the harvesting of the experiment. **FILE STRUCTURE AND UNITS OF MEASUREMENTS** The file is a tab delimited text file. Column headings are in the following order and format: number - Microcosm number. code - Microcosm code. comp - Microcosm composition. 1=Plantato lanceolata monoculture, 2= Lolium perenne monoculture, 3= Holcus lanatus monoculture, 4= Lolium + Plantago mixtre, 5= Plantago + Holcus mixture, 6= Lolium + Holcus mixture, 7= Plantago + Lolium + Holcus mixture. rich - Species richness. co2 - Atmospheric co2 concentration. 1=375 ppm, 2 = 700 ppm. het - Nutrient heterogeneity treatment. 1=homogeneous nutrient supply, 2=heterogeneous nutrient supply. wa - Water availability treatment.1= 125 mL water added, 2=250 mL water added, 3=375 mL water added. ba - Aboveground biomass, in g·m-2. bs - Belowground biomass, in g·m-2. bt - Total biomass, in g·m-2. rs - Root-to-shoot ratio (bs/ba), unitless. cu - Roots harvested in the control cylinder, in g. nu - Roots harvested in the cylinder with nutrients, in g. rii - RII index with root data (nu-cu)/(nu+cu), unitless. dmax - Dmax, unitless. ryt - Relative yield total, unitless. **DATA COLLECTOR** All data were collected by Fernando T. Maestre (fernando.maestre@urjc.es).