Response to elevated CO2 in the temperate C3 grass Festuca arundinaceae across a wide range of soils

Abstract

Soils vary widely in mineral nutrient availability and physical characteristics, but the influence of this variability on plant responses to elevated CO2 remains poorly understood. As a first approximation of the effect of global soil variability on plant growth response to CO2, we evaluated the effect of CO2 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 CO2 (800 ppm) increased plant biomass in the high-fertility control and in two of the more fertile soils. Elevated CO2 had variable effects on foliar mineral concentration—nitrogen was not altered by elevated CO2, and phosphorus and potassium were only affected by CO2 in a small number of soils. While leaf photosynthesis was stimulated by elevated CO2 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 CO2 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.

Plant growth responses to elevated atmospheric CO2are increased by phosphorus sufficiency but not by arbuscular mycorrhizas

“…Our finding that the CO 2 effect was enhanced at increasing soil P availability in B. distachyon and M. truncatula supports previous observations that plant growth responses to eCO 2 are lower under nutrient-limited conditions (Poorter and Perez-Soba, 2001; Nord et al , 2015; Pandey et al , 2015 b ), particularly in relation to N supply, which has been more extensively researched than P. The larger growth response to eCO 2 in B. distachyon than in M. truncatula accords with free-air CO 2 enrichment (FACE) studies showing a greater stimulation of photosynthetic C uptake in grasses than in legumes (summarized in Leakey et al , 2009). This would be expected from the long-established, but sometimes overlooked, ‘law of the minimum’ (Liebig, 1843) and more general principles of plant growth-limiting factors (Blackman, 1905).…”

Experimental warming in a dryland community reduced plant photosynthesis and soil CO2 efflux although the relationship between the fluxes remained unchanged

“…A reduction in CO 2 efflux with warming may be attributed to interacting factors, such as reduced root respiration and plant C allocation below-ground and/or increased soil moisture controls over heterotrophic respiration (Rustad et al 2001). While we observed a strong coupling of A net and soil respiration, Nord, Jaramillo & Lynch (2015) suggested that the coupling of A net and soil respiration may depend upon soil type and that for many of the most common soil types a change in A net may not necessarily affect soil respiration. The net soil CO 2 efflux rates we collected adjacent to the A. hymenoides target plants are the sum of multiple gross CO 2 fluxes, including root and heterotrophic respiration, and the reduction in the net flux of CO 2 could be related to changes in multiple gross fluxes.…”

Synergistic effects of abiotic stresses in plants: a case study of nitrogen limitation and saturating light intensity inArabidopsis thaliana

“…In fact, this stress combination can severely restrict plant productivity worldwide, as N availability is a limiting factor for plant growth in both natural and agricultural soils in many growth environments (Hirel et al , Nord et al ).…”