Why we’re still celebrating trees after 150 years

April marks the 150th anniversary of Arbor Day, the national holiday dedicated to planting trees. It’s the perfect occasion to discuss the importance of maintaining the health of trees in our natural areas and adding trees to our home landscapes.

The leaves of trees provide oxygen we breathe and play a critical role in the world’s water cycle, by releasing water vapor into the atmosphere. Leaves also provide cooling shade as a relief from heat in the summer. In urban areas with lots of paved surfaces, trees can reduce the effect of heat islands. When appropriately sited near our homes, they can help reduce energy use. Trees shading houses can reduce cooling costs by 20 to 30 percent in the summer, and evergreen trees can block the wind in winter, reducing heating costs. Finally, leaves filter pollutants from our air, soak up greenhouse gasses, and buffer the impact of rainfall on the ground.

The branches, trunks, and roots of trees sequester carbon. Roots also help to build good soil structure through their relationship with beneficial microorganisms. Additionally, root systems of trees reach well beyond the outside line of their branches, preventing erosion and absorbing and cleaning stormwater to prevent pollutants and sediment in runoff from reaching streams.

Trees release essential oils, called phytoncides, which have been shown to benefit human health by improving immune response, decreasing inflammation, and reducing cortisol levels. Studies have demonstrated that even having views of trees can speed patients’ recovery from illness and surgery in hospital settings.

Native trees add beauty to our landscapes with their ornamental traits, such as spring flowers, unusual foliage, interesting bark, and fall color. Healthy, mature trees can increase property value by seven to 19 percent by providing privacy and energy savings.

Native trees make it easy. When considering adding trees to our properties, there are excellent reasons for considering native tree species. These plants have evolved within a particular ecosystem, meaning they have adapted to our local soil and water patterns. When properly sited for sun and moisture preferences, they are likely to do well without our resorting to fertilizers and pesticides.

Something for everyone. Native trees have long-standing relationships with local wildlife, providing food, cover, and nesting sites for a wide range of animals from insects to birds and mammals. Planting one oak tree, for example, can offer critical support to our dwindling populations of butterflies and moths whose caterpillars are, in turn, essential food for baby birds. (Non-natives provide little or no food for native animals.)

Need help getting started? You can find links to other resources here: www.plantnovatrees.org/finding-help