2024/08/02 by A. Hope Jahren, Brian A. Schubert · 1 voice
Agricultural and Biological Sciences · Environmental Science · #Plant responses to elevated CO2 #Plant Water Relations and Carbon Dynamics #Climate variability and models
paper · pdf · doi:10.1038/s43247-024-01576-4
openalex publication_date 2024/08/02 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/23
Widespread drought driven by global warming is predicted across the 21st century, just as CO2 level is projected to as much as double over the same time period. However, the potential interplay between increasing CO2 and decreasing soil moisture on plant function is uncertain, as previous works have not successfully separated and quantified these two competing effects. Here we evaluated the interaction between soil moisture and CO2 using stable carbon isotope measurements of Arabidopsis grown under the simultaneous modulation of an exhaustive range of both variables. Results showed that both increasing soil water content and increasing CO2 increased isotopic discrimination, and that the soil moisture effect was not influenced by the CO2 level and vice versa. Our data confirm that changes in the carbon isotope record of terrestrial organic matter preserved within the geologic record are best interpreted as deriving from changes in atmospheric CO2. Soil moisture and atmospheric carbon dioxide levels both affect plant isotope discrimination, and the two effects are independent, which must be accounted for when interpreting photosynthetic carbon assimilation, according to stable carbon isotope measurements of Arabidopsis grown under a range of conditions.