(A) Plant carbon allocation after six growing seasons. Species differences in plant and soil response variables were examined using one-way ANOVA and letters represent significant differences from post hoc Tukey tests for the total plant carbon pool (P < 0.05). (B) Increase in plant nitrogen and decrease in surface soil nitrogen under each species over 6 years (depth, 0–10 cm), no species differences were found in lower soil depths. Species differences in plant and soil response variables were examined using one-way ANOVA and letters represent significant differences across species from post hoc Tukey tests (P < 0.05) for the change in the total plant nitrogen pool and the top 10 cm of the soil nitrogen pool. No species differences were found in the lower 40 cm of the mesocosm. Ps, Pinus strobus; Qe, Quercus ellipsoidalis; Qm, Q. macrocarpa; Lc, Lespedeza capitata; Pp, Poa pratensis; Ss, Schizachyrium scoparium; Sc, Solidago canadensis; BS, bare soil.