Did you know that an average tree holds about 225,000 leaves? I am not sure who counted them, but that sure is a lot of leaves, so they must be useful for something. Autumn draws our attention to leaves like no other time of year because of their colors and because many of us must rake them!

Let’s take a closer look at leaves to find out why they are important. Leaves come in a variety of sizes and shapes. No matter their design, all leaves share a common function. They all manufacture food for their host plant by an amazing process called photosynthesis. They do this by using the sun’s energy to make sugars and starches that plants need to grow and reproduce.

For photosynthesis to occur, plants need water, carbon dioxide, sunlight, and a green pigment called chlorophyll found in their leaves. Plants obtain water through their roots. The water then rises to the leaves where, in the presence of chlorophyll, water is split into hydrogen and oxygen using the energy from the sun. Carbon dioxide in the air enters the leaves through leaf pores called stomata. The hydrogen gas available from the splitting of water combines with the carbon dioxide to form sugar, a compound containing carbon, hydrogen, and oxygen. The leftover oxygen is released to the air, replenishing what we and all other animals need for breathing. That is what I call a miracle. If it weren’t for leaves, none of us would be able to breathe.

Besides giving us life-giving oxygen and food, leaves provide us with shade and cooling temperatures during hot summers all the while producing buds containing new leaves and flower parts that will burst forth with new life the following spring, all protected overwinter by their buds. The opening of buds and the development of new leaves and flowers in spring is another miracle of Nature. So, let’s not take leaves for granted. Take a new look at leaves for all they do for us as our very lives depend upon them.

The private Nature Education Center in Fifield operated by Tom and Mary Lou Nicholls is open seasonally by appointment only. Nicholls can be reached at nicho002@umn.edu.