Response to elevated CO(2) in the temperate C3 grass Festuca arundinaceae across a wide range of soils

Soils vary widely in mineral nutrient availability and physical characteristics, but the influence of this variability on plant responses to elevated CO(2) remains poorly understood. As a first approximation of the effect of global soil variability on plant growth response to CO(2), we evaluated the effect of CO(2) on tall fescue (Festuca arundinacea) grown in soils representing 10 of the 12 global soil orders plus a high-fertility control. Plants were grown in small pots in continuously stirred reactor tanks in a greenhouse. Elevated CO(2) (800 ppm) increased plant biomass in the high-fertility control and in two of the more fertile soils. Elevated CO(2) had variable effects on foliar mineral concentration—nitrogen was not altered by elevated CO(2), and phosphorus and potassium were only affected by CO(2) in a small number of soils. While leaf photosynthesis was stimulated by elevated CO(2) in six soils, canopy photosynthesis was not stimulated. Four principle components were identified; the first was associated with foliar minerals and soil clay, and the second with soil acidity and foliar manganese concentration. The third principle component was associated with gas exchange, and the fourth with plant biomass and soil minerals. Soils in which tall fescue did not respond to elevated CO(2) account for 83% of global land area. These results show that variation in soil physical and chemical properties have important implications for plant responses to global change, and highlight the need to consider soil variability in models of vegetation response to global change.