Look at a tree in your neighborhood and give it some thought.

Like us, a tree is a living, complex thing, too. It has roots that extend beneath the ground in all directions. They have two jobs: to absorb water and minerals from the soil, and to hold the tree in pace against winds and other weather. There is as much of a tree hidden below the ground as there is in sight above.

Trees can make their own food through photosynthesis in their green leaves. Trees use energy from sunlight, carbon dioxide from the air and water and element traces from the soil through the roots to produce food for growth and make oxygen. The process of photosynthesis makes the existence of all plant life (except a few species of bacteria) and animal life possible.

In recent years, as the effects of global warming have become clearer and deepened, trees have taken on a new level of environmental importance. Above and beyond their many practical virtues, trees are vital to life on the planet. They sustain our soil, moderate our climate, provide dwelling places for wildlife, conserve our water, clean our air, cool our streets and homes and smooth the edges of our lives. Perhaps of greater importance, they take in and use the main global warming gas, carbon dioxide.

Friday is National Arbor Day, the 147th anniversary of the first Arbor Day started by J. Sterling Morton from Nebraska in 1872. We continue to mark Arbor Day by reflecting on the importance of conservation, promoting the value of trees in our lives and renewing our commitment to tree planting and care.


Jim Gilbert’s Nature Notes are heard on WCCO Radio at 7:15 a.m. Sundays. His observations have been part of the Minnesota Weatherguide Environment Calendars since 1977, and he is the author of five books on nature in Minnesota. He taught and worked as a naturalist for 50 years.