Benthic primary production and elemental content Costello, Kulacki, McCarthy, Tiegs, and Cardinale. 2018. Ranking stressor impacts on periphyton structure and function with mesocosm experiments and environmental-change forecasts. PLOS One. doi: xxx Contact information: David Costello Kent State University dcostel3@kent.edu Context: Biofilm primary production and elemental content at the end of the stressor exposure experiment (56 day duration). The periphyton colonized flume mesocosms (periphyton inoculum from Huron River, MI, USA) were either under control conditions or exposed to one of six stressors along a concentration gradient (elevated temperature, extinction, sediment, nitrogen, phosphorus, or salt). Rates of primary production were estimated using a 13-C isotope tracer. Temporal coverage: The experiment was initiated on October 24, 2011 and ended on December 20, 2011 Geographic coverage: Experiment was completed in the Cardinale Lab experimental flume facility at the University of Michigan (Dana Building, University of Michigan, Ann Arbor, MI, USA). Stream water and algal inoculum for the streams was collected from the Huron River at the University of Michigan Nichols Arboretum in Ann Arbor, MI, USA (42°16′59.32″ N, 83°43′27.89″ W). Data codes: Temp - treatments with elevated temperature Ext - treatments with altered algal inoculum to simulate extinction. Inoculum in control streams had 43 total taxa Sed - treatments with elevated sedidment Nitrogen - treatments with elevated nitrogen Phosphorus - treatments with elevated phosphorus Cl - treatments with elevated salinity (NaCl) Control - flumes with no stressors added SRP - Soluble reactive phosphorus Attributes: Name Definition Type Units FLUME Unique flume ID Discrete TREAT Stressor treatment of flume Discrete TEMP Stream temperature Continuous degrees C EXT Number of taxa lost Count TSS Total suspended solids Continuous mg/L NIT Nitrate concentration Continuous µg/L PHOS SRP concentration Continuous µg/L Cl Chloride concentration Continuous mg/L Pn Photosynthetic rate Continuous µg C/cm^2/hr Biomass Periphyton biomass Continuous µg C/cm^2 Cmass Biofilm carbon content Continuous mg C/g dry mass Nmass Biofilm nitrogen content Continuous mg N/g dry mass Pmass Biofilm phosphorus content Continuous mg P/g dry mass