What causes fall colors?
The chemicals Four main groups of biochemicals are responsible for the various yellows, oranges, reds and browns that we see in the fall – chlorophyll, carotenoids, anthocyanins and tannins. Each has its own color and chemistry. Varying amounts of these chemicals will give subtle variations in color from one leaf to the next or even from tree-to-tree. Chlorophyll The green color that we see on most plant leaves throughout the spring and summer is due to the pigment called chlorophyll. Chlorophyll is one of several pigments that gather energy from sunlight in the process of photosynthesis. Chlorophyll absorbs both the blue and the red wavelengths from sunlight, and reflects the green wavelengths. Nitrogen is one of the main components of chlorophyll. As daylengths shorten and temperatures get cooler, chlorophyll is broken down faster than it’s produced. The majority of the nitrogen migrates back to the twigs, being placed in storage for next year’s new growth. As chlorophyll breaks down
