Ecological Archives E095-014-A4
Nicole L. Goebel, Christopher A. Edwards, Michael J. Follows, Jonathan P. Zehr. 2014. Modeled diversity effects on microbial ecosystem functions of primary production, nutrient uptake, and remineralization. Ecology 95:153–163. http://dx.doi.org/10.1890/13-0421.1
Appendix D. Variation among model realizations and random selection of phytoplankton-types calculations.
In the baseline numerical experiment, phytoplankton types were drawn from one realization containing 78 types. In order to demonstrate that one model realization is a good representative of model behavior, we tested the sensitivity of ecosystem productivity to different model realizations and pool size of randomly selected phytoplankton types. Average productivity for two ensembles of ten different realizations containing 19 or 39 phytoplankton types were compared. Productivity of each model run was vertically integrated and averaged horizontally over the year 2000. Productivity for the 19-member ensemble ranged from 142.9 mg C·m-2·d-1, an outlier, to a maximum of 281.9 mg C·m-2·d-1, averaging 247.9 with a standard deviation of 39.1 mg C·m-2·d-1. Productivity for the 39-member ensemble averaged 265.0 with a standard deviation of 11.1 mg C·m-2·d-1, ranging from 246.9 to 283.6 mg C·m-2·d-1, with no outliers. Small variability in productivity and a nonsignificant difference (p = 0.20, n = 10) among ensembles demonstrates model robustness among different realizations and random selection of phytoplankton types.