The Tank_et_al_uptake_data.txt file contains 514 lines of tab-delimited data from the literature that was used to assess relationship between inorganic nitrogen uptake parameters and stream discharge, and to compare NO3-N uptake parameters with NH4-N uptake parameters. Parameter abbreviations are as follows: Cb = background concentration in µg/L; Cp = plateau concentration in µg/L; Sw = uptake length in meters; Vf = uptake velocity in mm/min. Missing values are indicated by a period (‘.’). Full citations associated with author_date_code in column 1 are given in Tank et al. Appendix A.