| Comments |
P.243 bottom paragraph: "The highest photon flux density normally encountered by plants occurs when the sun is directly overhead on a cloudless day, in which case the photosynthetic photon flux (PPF) for wavelengths from 400 to 700nm is about 2000 μmol/m^2/s on a horizontal plane (Chapter 4, Section 4.1D). The average chlorophyll concentration in chloroplasts is approximately 30 mol/m^3 (Chapter 4, Section 4.4D), and in passing through a chloroplast 2 μm thick about 30% of the incident PPF is absorbed." |