Green at Last!

Spring 2013

As spring brings longer days, the transformation of drab landscapes into lush, green environments begins. Our spirits soar.

Green is a fascinating color. Ruminations about it could fill volumes. Green is soothing and relaxing. As such, it is used by many to symbolize peace and ecology. (Ironically, green also may be the color some think of now that the log market is improving.) But most importantly, green drives the forest machine that gives us so many essential spiritual and material goods.

The pigment molecule chlorophyll is responsible for all this green. Chlorophyll uses the sun’s energy, CO2, and water to make chemical energy (carbohydrates) in the life sustaining miracle we call photosynthesis.

But why green? In terms of light waves, green is reflected back while higher energy blue/violet waves and lower energy yellow/red waves are absorbed. Green remains as unused light in the middle of the electromagnetic spectrum. So why don’t plants use more light energy and appear darker? I could find no definitive answer, only interesting theories.

One had its foundation in evolution. Chlorophyll has changed very little since its first appearance in the oceans as blue green algae. At that time it gained a competitive advantage over other organisms that were utilizing different portions of the light spectrum. It survived successfully and has little need for change.

Another belief is that plants intentionally do not utilize the full light spectrum to keep from frying themselves. Take a maple tree for example. The outer leaves exposed to direct sun are often bright green in summer, whereas the inner, shaded leaves are larger and darker in color.

As our landscapes come alive in spring, it is a time to ponder just how essential green is for growing our precious forests.