The formula to calculate the Light Sum (\(µmol m^{-2}\)) from Light Intensity (\(µmol m^{-2} s^{-1}\)) and Duration (hours) is:

\[ Light\ Sum = Light\ Intensity \times Duration \times 3600 \]

Where:

• \(Light\ Sum\) is the total amount of light received.
• \(Light\ Intensity\) is the intensity of light in µmol m⁻² s⁻¹.
• \(Duration\) is the duration in hours.
• 3600 is the conversion factor from hours to seconds.