Energy balance at the target — “How can plants grow in the shade?” The answer is implied by this slide: diffuse/scattered light is still energy, and even shaded canopies receive enough for photosynthesis.

• Energy incident on any body is either reflected, absorbed, or transmitted.
• The proportions depend on:
  • The feature (leaf, water, concrete — each has its own spectral signature).
  • The wavelength (a leaf reflects little red, lots of NIR; a lake does the opposite).
• Conservation: reflected + absorbed + transmitted = total incident energy (see slide 18).