A meta‐analysis of responses of C₃ plants to atmospheric CO₂: dose–response curves for 85 traits ranging from the molecular to the whole‐plant level

Abstract

Generalised dose-response curves are essential to understand how plants acclimate to atmospheric CO 2 . We carried out a meta-analysis of 630 experiments in which C 3 plants were experimentally grown at different [CO 2 ] under relatively benign conditions, and derived dose-response curves for 85 phenotypic traits. These curves were characterised by form, plasticity, consistency and reliability. Considered over a range of 200-1200 µmol mol À1 CO 2 , some traits more than doubled (e.g. areabased photosynthesis; intrinsic water-use efficiency), whereas others more than halved (area-based transpiration). At current atmospheric [CO 2 ], 64% of the total stimulation in biomass over the 200-1200 µmol mol À1 range has already been realised. We also mapped the trait responses of plants to [CO 2 ] against those we have quantified before for light intensity. For most traits, CO 2 and light responses were of similar direction. However, some traits (such as reproductive effort) only responded to light, others (such as plant height) only to [CO 2 ], and some traits (such as area-based transpiration) responded in opposite directions. This synthesis provides a comprehensive picture of plant responses to [CO 2 ] at different integration levels and offers the quantitative dose-response curves that can be used to improve global change simulation models.

MetaPhenomics: quantifying the many ways plants respond to their abiotic environment, using light intensity as an example

“…5e, PI = 1.3), be it with a low consistency. This mirrors the effect of [CO 2 ], where leaf N/P decreases with increasing CO 2 levels (Poorter et al 2022), also with relatively low consistency. It would be interesting to test whether the opposing effects of light and [CO 2 ] on the transpiration rate differentially affects mass flow around the roots, thereby affecting the uptake of nitrate more than of phosphorous compounds.…”

“…Enzymes are major engines of cell metabolism, and the different chemical compounds produced may reflect the physiological status plants are in. So far, we have only been able to include Rubisco amount or activity as an important enzymatic factor in C-fixation, and chlorophyll, xanthophylls and other carotenoids, and soluble phenolics as relevant groups of specific metabolic compounds (Poorter et al 2019(Poorter et al , 2022. However, there is a wide range of enzymes and compounds that could be instructive for the physiological status of plants.…”

“…mol −1 for [CO 2]. The data pertaining to these distributions and the nomenclature followed are fromPoorter et al (2019Poorter et al ( , 2022…”

Rice increases phosphorus uptake in strongly sorbing soils by intra‐root facilitation

“…This gave b HS = 1 × 10 −5 mol cm −3 pH −1 . We took a typical value for CO 2 pressure in the soil air of 0.004 atm (Poorter et al, 2021).…”

Unexpected Responses of Bean Leaf Size to Elevated CO2

“…Yu and Korner [ 11 ] and Kizildeniz et al [ 12 ] found no effect of elevated CO 2 on leaf size in tomato and grape leaves, respectively. A recent meta-analysis of responses of C 3 plants indicated an average slight linear increase in leaf size with increasing CO 2 [ 13 ], but with relatively low consistency. Ultimately, leaf size is determined by the combination of cell numbers and cell size.…”