isocalcR

isocalcR calculates stable isotope-derived plant physiological indices and leaf gas exchange parameters from plant tissue δ13C and reference atmospheric data to support ecological and plant physiological research.

Key Features:

• Integrated functions: Computes leaf carbon isotope discrimination (∆13C), leaf intercellular [CO2] (ci), the ratio of leaf intercellular to atmospheric [CO2] (ci/ca), the difference between atmospheric and leaf intercellular [CO2] (ca−ci), and intrinsic water use efficiency.
• Standardized reference data: Provides recommended atmospheric [CO2] (ppm) and atmospheric δ13CO2 (‰) values spanning 0 to 2021 C.E. for use in calculations.
• Environmental parameterization: Accepts temperature and elevation inputs to adjust isotope-based calculations for study location.

Scientific Applications:

• Leaf gas exchange analysis: Derive ∆13C, ci, ci/ca, ca−ci, and intrinsic water use efficiency from plant tissue δ13C to infer leaf-level gas exchange processes.
• Ecosystem dynamics: Use isotope-derived physiological indices to study ecosystem carbon and water relations.
• Plant responses to environmental change: Investigate plant physiological responses to variation in atmospheric CO2, atmospheric δ13CO2, temperature, and elevation.

Methodology:

Implements theoretical formulations from stable isotope analysis to compute ∆13C, ci, ci/ca, ca−ci, and intrinsic water use efficiency using atmospheric [CO2] (ppm) and atmospheric δ13CO2 (‰) with temperature and elevation inputs.