Acclimation of photosynthesis to elevated CO 2 and temperature in five British native species of contrasting functional type

• Published in: Global Change Biology
• Main Authors: STIRLING, C.M., DAVEY, P.A., WILLIAMS, T.G., LONG, S.P.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 1997
• Subjects: General Environmental Science; Ecology; Environmental Chemistry; Global and Planetary Change; Poa alpina
• Online Access: http://dx.doi.org/10.1046/j.1365-2486.1997.00071.x; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1046%2Fj.1365-2486.1997.00071.x; https://onlinelibrary.wiley.com/doi/pdf/10.1046/j.1365-2486.1997.00071.x

Acclimation of photosynthesis to growth at elevated CO 2 concentration varies markedly between species. Species functionally classified as stress‐tolerators (S) and ruderals (R), are thought to be incapable, or the least capable, of responding positively in terms of growth to elevated [CO 2 ]. Is this pattern of response also apparent in leaf photosynthesis of wild S‐ and R‐strategists? Acclimatory loss of a photosynthetic and growth response to elevated [CO 2 ] is assumed to reflect limitation on capacity to utilize additional photosynthate. The doubling of pre‐industrial global [CO 2 ] is expected to coincide with a 3 °C increase in mean temperature which could stimulate growth; will photosynthetic capacity at elevated [CO 2 ] be greater when the concurrent temperature increase is simulated? Five species from natural grassland of NW Europe and of contrasting ecological strategy were grown in hemispherical greenhouses, environmentally controlled to track the external microclimate. Within a replicated design, plants were grown at (i) current ambient [CO 2 ] and temperature, (ii) elevated [CO 2 ] (ambient + 340 μmol mol –1 ) and ambient temperature, (iii) ambient [CO 2 ] and elevated temperature (ambient + 3 °C), or (iv) elevated [CO 2 ] and elevated temperature. After 75–104 days, the CO 2 response of light‐saturated rates of photosynthesis (A sat ) was analysed in controlled‐environment cuvettes in a field laboratory. There was no acclimatory loss of photosynthetic capacity with growth in elevated [CO 2 ] or elevated temperature over this period in Poa alpina (S), Bellis perennis (R) or Plantago lanceolata (mixed C‐S‐R strategist), and a significant ( P ?ƒ?žbl 0.05) increase in capacity in Helianthemum nummularium (S) and Poa annua (R). Photosynthetic rates of leaves grown and measured in elevated [CO 2 ] were therefore significantly higher than rates for leaves grown and measured in ambient [CO 2 ], for all species. With the exception of Poa alpina , stomatal conductance and stomatal limitation on A sat showed ...