Trees are often treated as mere lawn ornaments, but in reality they’re far more. They offer benefits to air quality, topsoil, climate, wildlife, and human health. In short, they improve our lives in ways most people neither appreciate nor understand.
Trees Provide Oxygen
In the process of photosynthesis, trees absorb water, carbon dioxide, and sunlight. From these ingredients, they produce glucose, which is their primary energy source.
But because both water (H2O) and carbon dioxide (CO2) contain oxygen, there’s a surplus which the tree has no need for. As a result, this surplus oxygen is released back into the atmosphere and helps to keep all of us breathing.
Trees Sequester Carbon
Another benefit trees provide is carbon sequestration–or, more simply, removal of carbon from the atmosphere.
As most people know by now, carbon dioxide is a greenhouse gas, acting as a kind of atmospheric insulation and increasing global temperatures. But when trees perform photosynthesis, they absorb carbon dioxide from the air, break it apart, and store the resulting carbon in their cells.
So what would have been a problem suddenly becomes a solution.
Trees Prevent Erosion
Topsoil is necessary for life. It gives nutrients to plants, which give nutrients to animals, which give nutrients to all of us.
But topsoil can be eroded very easily, especially by wind and rain. And in the absence of trees, this process can become so extreme that an entire region becomes desert–something which is happening as we speak with China’s Gobi Desert.
But when trees are clustered together in forests, they stop erosion in its tracks. They do this primarily in three ways: 1) by catching rain in their leaves and branches, 2) by storing water in their roots, and 3) by providing windbreaks.
Trees Support the Water Cycle
Because trees are composed of as much as 67% water by mass, they are understandably very thirsty. As such, they absorb large quantities of water through their roots, up to 11,000 gallons for a mature tree in a single growing season.
When trees grow together to form a forest, the effect is increased. One way in which this happens is by the accumulation of organic material in the soil (dead leaves, branches, bark), all of which acts like a sponge as it decomposes, increasing the soil’s water retention.
Once trees are done with water, they do something else of immense value: they release water vapor in a process called transpiration. At the same time, they release mineral salts–potassium in particular–which contribute to the formation of clouds, increase rainfall, and help to ensure that all of us have water to drink.
Trees Provide Food and Shelter
Whether feeding on leaves and fruit, preying on forest-dwelling animals, making nests out of hollow logs, or consuming nectar and pollen, many species of wildlife would not exist without trees and forests.
Here are a few examples: the American beaver (Castor canadensis) feeds on the wood, bark, leaves, and stems of maple, willow, poplar, birch, oak, and ash, among others. The great horned owl (Bubo virginianus) feeds on small mammals–especially rabbits, mice, and voles–and other birds, most of which derive some or all of their nutrition from forests. The snowshoe hare (Lepus americanus) feeds on the leaves, twigs, and stems of birch, willow, alder, and occasionally spruce.
And beyond that, trees provide basic materials for humans: wood, rubber, aspirin, chocolate, syrup, sponges, wax, gum, and latex, to name a few. And though all of these may have synthetic counterparts, they originated first and foremost with trees.
Trees Absorb Pollutants
Most people recognize basic ecological services that trees provide homeowners and city-dwellers alike: beautification and shade foremost among them.
But perhaps the greatest contribution trees make to human health is in reduction of atmospheric pollution. Whether mopping up sulfur dioxide (SO2), nitrogen dioxide (NO2), ozone (O3), or particulate matter less than 2.5 microns (PM2.5), trees help to keep our air clean and breathable. In fact, it’s estimated that in one year alone, trees in the continental US absorbed 17,400,000 tons of air pollutants, saving $6.8 billion dollars and more than 850 human lives.
And that’s all the more reason why we should be shutting down industries that contribute to our planet’s deforestation. Because a world without trees is a world without human life.
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