10.1594/PANGAEA.971327Plum, ChristophChristophPlum0000-0002-2231-1315Institute for Chemistry and Biology of the Marine Environment, Carl von Ossietzky Universität OldenburgGerhard, MiriamMiriamGerhard0000-0002-0472-9435Universidad de la República UruguaySmykala, MikeMikeSmykala0009-0004-7439-8514Institute for Chemistry and Biology of the Marine Environment, Carl von Ossietzky Universität OldenburgPANGAEA2024Diatomecological stoichiometryGeminigera cryophilaLaboratory experimentNitrogenPhaeocystis antarcticaPhosphorusSouthern OceanTemperatureType of studyTaxon/taxaTreatment: temperatureTreatment: nitrogen/phosphorus ratioExperimental treatmentTreatment: nitrogenTreatment: phosphorusReplicateExpected growth rate, linearObserved growth rate, linearLog response ratio, observed versus expected growth rate, linearCalculatedDataset10.1594/PANGAEA.97132910.1002/lno.700451048 data pointstext/tab-separated-valuesCreative Commons Attribution 4.0 InternationalData were obtained from a laboratory growth experiment conducted from April to May 2021 at the Institute for Chemistry and Biology of the Marine Environment (University of Oldenburg). Three Antarctic phytoplankton species (Chaetoceros simplex, Phaeocystis antarctica (single cell culture) and Geminigera cryophila) were grown in monocultures and a mixture of all three species. We used a factorial design including four different N/P treatments (control plus three different N/P levels) and 10 different temperatures (-2, -1, 0, 1, 2, 3, 4, 6, 8 and 10°C). The detailed experimental setup is explained in doi:10.1594/PANGAEA.971329. In order to analyze whether the temperature and nutrient response of the mixed assemblage differs from expectations based on the monoculture performance, we calculated the log response ratio between the observed specific growth rate (µobs) of the mixed phytoplankton assemblage and the expected growth rate based on monocultures (µexp) as ln(µobs/µexp). Therefore we calculated an abundance weighted specific growth rate for the expected performance in the mixed assemblage (µexp) based on the monoculture performance as µexp = (a1*µ1) + (a2*µ2) + (a3*µ3) / (a1+a2+a3) where a is the abundance of each species at exponential growth in the mixed assemblage and µ is the specific growth rate of the corresponding monoculture. Positive deviations from 0 indicate higher observed growth in the mixed assemblage (µobs) than expected from monoculture performance (µexp).The experiment started at 2021-04-02T10:00 and ended at 2021-05-19T12:00 .German Research Foundationhttps://doi.org/10.13039/501100001659442927665Altered stoichiometry and species interactions in coastal Antarctic plankton communities under global climate change