Anthropogenic carbon dioxide (CO2) is the main greenhouse gas driving change in the Earth’s climate. Rising CO2 is expected to stimulate photosynthesis, but limited studies have been conducted on mature or temperate forests. It is uncertain how mature temperate forest ecosystems may respond to the future CO2 emissions and what interacting environmental factors may influence this. This experiment has been conducted at the Birmingham Institute of Forest Research Free Air Carbon Enrichment Experiment (BIFoR-FACE). BIFoR-FACE is set in a mature oak (Quercus robur. L) woodland and provides additional CO2, to 30m diameter experimental plots, to simulate the future atmospheric conditions in 50 years’ time (+150ppm). Instantaneous gas exchange measurements have been conducted in the second year of CO2 fumigation (2018) in the upper canopy of Q.robur trees, from bud burst (June) to leaf fall (October). This study used a paired plot design (n=3) of elevated CO2 (eCO2)(550ppm) and ambient control plots (aCO2 )(400ppm). Measurements were taken using a Li-6800 portable photosynthesis machine (LICOR) to calculate leaf-level rates of photosynthesis (A), stomatal conductance (gsw) and intrinsic water use efficiency (iWUE) across the growing season. The results suggest an average of +24% increase in photosynthesis, seasonally variable decrease in gsw and increase in iWUE under eCO2 conditions. The effect of eCO2 varied depending on the prevailing seasonal and diurnal fluctuations in environmental variables, such as light and water availability. This data will help understand, and contribute, to the accurate modelling of canopy physiological responses to eCO2 for mature temperate forest ecosystems.
No datasets are available for this submission.