Data from: Tracking plant preference for higher-quality mycorrhizal symbionts under varying CO conditions over multiple generations

The symbiosis between plants and root-colonizing arbuscular mycorrhizal (AM) fungi is one of the most ecologically important examples of interspecific cooperation in the world. AM fungi provide benefits to plants; in return plants allocate carbon resources to fungi, preferentially allocating more resources to higher-quality fungi. However, preferential allocations from plants to symbionts may vary with environmental context, particularly when resource availability affects the relative value of symbiotic services. We ask how differences in atmospheric CO2-levels influence root colonization dynamics between AMF species that differ in their quality as symbiotic partners. We find that with increasing CO2-conditions and over multiple plant generations, the more beneficial fungal species is able to achieve a relatively higher abundance. This suggests that increasing atmospheric carbon supply enables plants to more effectively allocate carbon to higher-quality mutualists, and over time helps reduce lower-quality AM abundance. Our results illustrate how environmental context may affect the extent to which organisms structure interactions with their mutualistic partners and have potential implications for mutualism stability and persistence under global change.,Full Experimental DataThis file contains the full experimental data analysed, specifically: Plant Number (plantnr), Generation (gen), CO2-level (co2), AMF inoculation (amf), full plant weight (fpw), G. aggregatum copy number (agg_cp), R. irregularis copy number (irr_cp), G. aggregatum copy number at detection limit (agg_cp_det_lim) and R. irregularis copy numbers at detection limit (irr_cp_det_lim). We analysed copy numbers below the detection limit at the detection limit, i.e. we used the agg/irr_cp_det_lim columns (see Methods for full justification), but additionally we provide full copy number data here including the uncorrected copy numbers (agg/irr_cp).Werner_CO2_Data.csvPilot Study DataThis data file contains the data for the pilot study performed, i.e. Plant Number (plantnr), AMF treatment (treatment), generation (generation) and AMF copy number (amf_cp).Werner_CO2_PilotData.csvAnalyses R-ScriptThis R-script performs the analyses presented in Werner et al. (2017), and generates the associated Figures presented in the manuscript. Use with the two data files provided in DataDryad.Werner_EE_CO2_Analyses.R,