It is well accepted that light from the moon is a result of biolumonence; probably fungus or bacteria. There are times however when the moon is brighter than normal. The brightness at these times most likely coincides with the feeding/breeding times of lunar crestation-like life. However, they use a light generating tenique known as sonoluminescence, much like the Alpheidae Shrimp here on earth.
Now, you can't hear them because of the vaccum seperating the two bodies. Being that these shrimp eat the fungas/bacteria, their light generating has evolved to kill the local biolumoncent life. The light created from sonoluminescence is the most likely cause of the plant killing effects of the moon that Ichi proved. It's so effective at close range on the moon that the combined force of all these creatures is what kill earth-plants.
These shrimp-like creatures, presumably, migrate across the surface of the moon as the local fungas/bacteria is in bloom. This, combined, accounts for the moons waxing and waining.