Autumn View Over Cortland County NYS Hills During Autumn Stock Photo

The timing of color changes and the onset of falling leaves is primarily regulated by the calendar as nights become longer. None of the other environmental influences – such as temperature, rainfall, food supply – are as unvarying as the steadily increasing length of night during autumn. As days grow shorter, and nights grow longer and cooler, biochemical processes in the leaf begin to paint the landscape with Nature`s autumn palette. Corn harvest field in foreground.