Nitrogen and carbon isotopes and concentrations in ectomycorrhizal sporocarps and soil from two N addition experiments in Sweden, Norrliden and Rosinedalsheden

Data are carbon and nitrogen isotopes and concentrations in ectomycorrhizal sporocarps and soils. Soil data are by horizon. Data were from two long-running N deposition experiments in northern Sweden. We hypothesized that N additions would alter nitrogen concentrations in soil and fungi and that the source N for different fungal taxa (which horizon) could be estimated by comparing patterns between soil and sporocarps.

For the nine most common taxa, we provide estimates of the 15N enrichment of the taxa relative to the probable soil horizon of N uptake, as discussed in Hobbie, Chen, and Hasselquist (in final review, Fungal Ecology). Potential soil horizons of N uptake were the S (litter), F (fermentation), and H (humic).

Also included are results of two stepwise multiple regressions, corresponding to: (1) controls of the natural log of sporocarp C:N ratios for the nine most common taxa (Table 2 in Hobbie, Chen, and Hasselquist) and (2) controls of the 15N:14N ratio increase (15N enrichment) of sporocarps relative to the d15N of the probable soil horizon of N uptake for the nine most common taxa (Table 5 in Hobbie, Chen, and Hasselquist).