1. Dataset Title: Plant-soil feedbacks help explain plant community productivity 2. Name and contact information of PI: a. Name: Andrew Kulmatiski b. Institution: Utah State University c. Address: 5230 Old Main Hill, Logan UT 84322 d. Email: andrew.kulmatiski@usu.edu e. ORCiD ID: http://orcid.org/0000-0001-9977-5508 3. Name and contact information of Co-PI: a. Name: Jeanette Norton b. Institution: Utah State University c. Address: 4825 Old Main Hill, Logan, UT 84322 d. Email: jeanette.norton@usu.edu e. ORCiD ID: https://orcid.org/0000-0002-6596-8691 4. Name and contact information of Co-author: a. Name: Leslie E. Forero b. Institution: Utah State University c. Address: 5230 Old Main Hill, Logan UT 84322 d. Email: leslieeforero@gmail.com e. ORCiD ID: https://orcid.org/0000-0002-9577-8725 4. Name and contact information of Co-author: a. Name: Josephine Grenzer b. Institution: Utah State University c. Address: 5230 Old Main Hill, Logan UT 84322 d. Email: JosephineGrenzer@gmail.com e. ORCiD ID: https://orcid.org/0000-0002-2223-0566 5. Funding source: a. Funder: National Science Foundation Division of Environmental Biology; grant number: 1354129 6. Project abstract: Plant community productivity tends to increase as species richness increases, but the mechanisms behind this biodiversity-productivity relationship are not fully understood. Plant-soil feedbacks (PSF) are a compelling potential mechanism of the biodiversity-productivity relationship because they can explain patterns of both underyielding and overyielding in diverse plant communities. To test the role of plant-soil feedbacks in the biodiversity-productivity relationship we measured all possible plant-soil feedbacks for sixteen species, and used the measured plant-soil feedbacks to predict plant community biomass production. We compared the predicted plant community biomass production to observed biomass production in a paired biodiversity-productivity experiment. 7. Brief description of collection and processing of data: *****Cedar Creek Plant-Soil Feedback Greenhouse Experiment***** The greenhouse experiment was implemented at the Utah State University Crop Physiology Lab in Logan, UT. Soil from an area adjacent to Experiment 120 at Cedar Creek was dried in a 31° C room, and shipped to Logan, UT. A 6:1 mixture of loamy sand and sphagnum peat from Miller Companies, LLC in Hyrum UT was steam sterilized, and inoculated with 10% field soil. 2,720 1-L pots were planted with four seedlings, and then thinned down two seedlings after a one-month period. Plants were grown for a 6 month period, then killed by clipping. 2,466 pots had growth in phase I, and all other pots were discarded. Pots that realized growth were replanted with either the same (“self” treatment) or a different (“other” treatment) species, and grown for a 6 month period. At the end of the experiment, aboveground biomass was clipped, dried, and weighed. *****Cedar Creek Biodiversity-Productivity Greenhouse Experiment***** The greenhouse experiment was implemented at the Utah State University Crop Physiology Lab in Logan, UT. Soil from an area adjacent to Experiment 120 at Cedar Creek was dried in a 31° C room, and shipped to Logan, UT. A 6:1 mixture of loamy sand and sphagnum peat from Miller Companies, LLC in Hyrum UT was steam sterilized, and inoculated with 10% field soil. 190 12-L pots were planted with a total of sixteen seedlings with a species-richness level of either 1, 2, 4, 8, or 16 species. Plants were grown for an 8 month period, then killed by clipping. Clipped aboveground biomass was sorted to species, dried, and weighted. 8. Description of files (names, or if too numerous, number of files, file type(s): File name: “PlantSoilFeedback_Greenhouse2017.csv” Description of PlantSoilFeedback_Greenhouse2017.csv: This file includes the aboveground biomass in grams of plants growing on conditioned soils. File name: “BiodiversityProductivity_Greenhouse2017.csv” Description of BiodiversityProductivity_Greenhouse2017.csv: This file includes the aboveground biomass in grams of plants in biodiverse communities. 9. Definition of acronyms, codes, and abbreviations: Achmi - Achillea millefolium Agrsm - Pascopyrum smithii Amoca - Amorpha canescens Andge - Andropogon gerardii Elyca - Elymus canadensis Koecr - Koeleria macrantha Lesca - Lespedeza capitata Liaas - Liatris aspera Luppe - Lupinus perennis Monfi - Monarda fistulosa Panvi - Panicum virgatum Petpu - Dalea purpurea Poapr - Poa pratensis Schsc - Schizachyrium scoparium Solri - Solidago rigida Sornu - Sorghastrum nutans 10. Descriptions of parameters/variables: a. Temporal (beginning and end dates of data collection): *****Cedar Creek Plant-Soil Feedback Greenhouse Experiment***** Response data collected fall 2017. *****Cedar Creek Biodiversity-Productivity Greenhouse Experiment***** Response data collected fall 2017. b. Instruments used and units of measurements: Measured via scale in grams dried aboveground biomass c. Column headings of data files (for tabular data): *****Column headings in plant-soil feedback experiment CSV file***** Pot - Pot in the greenhouse housing the plant-soil feedback sample Initial Phase1 - initially assigned conditioning treatment Actual Phase1 - conditioning treatment assigned at the end of phase 1 P1abundance - percent cover in the field or grams biomass in the greenhouse realized at the end of the conditioning phase P2R - response treatment assigned at the beginning of phase 2 Treatment- whether the combined conditioning and response treatment is heterospecific ("other") or conspecific ("self) P2abundance - grams biomass of growth realized at the end of the response phase *****Column headings in biodiversity-productivity experiment CSV file***** Tag - Pot in the greenhouse housing the biodiversity-productivity feedback sample Com - Community number in the E120 Big Biodiversity experiment at Cedar Creek Treatment - list of species in the community Diversity - the total number of species assigned to the community RealDiv - the total number of species observed in the community Achmi - grams biomass of Achillea millefolium produced in pot Agrsm - grams biomass of Pascopyrum smithii produced in pot Amoca - grams biomass of Amorpha canescens produced in pot Andge - grams biomass of Andropogon gerardii produced in pot Elyca - grams biomass of Elymus canadensis produced in pot Koecr - grams biomass of Koeleria macrantha produced in pot Lesca - grams biomass of Lespedeza capitata produced in pot Liaas - grams biomass of Liatris aspera produced in pot Luppe - grams biomass of Lupinus perennis produced in pot Monfi - grams biomass of Monarda fistulosa produced in pot Panvi - grams biomass of Panicum virgatum produced in pot Petpu - grams biomass of Dalea purpurea produced in pot Poapr - grams biomass of Poa pratensis produced in pot Schsc - grams biomass of Schizachyrium scoparium produced in pot Solri - grams biomass of Solidago rigida produced in pot Sornu - grams biomass of Sorghastrum nutans produced in pot Sum - total grams biomass produced in pot d. Location/GIS Coverage (if applicable to data): Cedar Creek Greenhouse: 41.757954, -111.813309 Cedar Creek Soil Collection Site: 45.404189, -93.186820 e. Symbol used for missing data: Empty cells represent missing data. Dashes (-) represent unplanted species in a community. 11. Special software required to use data: No special software is required to use these data. ************************************************************************************************************************************