Tissue non-structural carbohydrate concentrations of Fagus sylvatica juveniles before, during, and after experimental low CO₂ exposure

This dataset reports tissue non-structural carbohydrate (NSC) concentrations in European beech (Fagus sylvatica) juveniles subjected to experimental low atmospheric CO₂ and subsequent recovery. Samples were collected during a controlled climate chamber experiment conducted at the Karlsruhe Institute of Technology (KIT), Germany, in June 2025. NSC measurements were obtained at three discrete time points representing key experimental stages: pre-starvation, post-low CO₂ exposure, and post-recovery. Concentrations of starch, soluble sugars, and total NSC were quantified in leaf, stem, and root tissues. Tissue samples were enzymatically analyzed following standardized protocols, with soluble sugars and starch converted to glucose and quantified spectrophotometrically, and total NSC calculated as the sum of these fractions. The dataset provides insight into tissue-specific carbon allocation and storage dynamics under carbon limitation and recovery, and complements continuous physiological measurements of gas exchange and growth collected during the same experiment. These data are suitable for analyses of plant carbon balance, storage depletion and refilling, and organ-level responses to experimentally induced carbon starvation.