Are we underestimating the importance of trees?
I grew up playing in the woods, and spent my career as the horticulturist of Maymont, a public park with an amazing arboretum filled with national and state champion trees. I marveled at the majesty of the large old trees while finding joy in planting hundreds of young trees over the years.
Unfortunately, many people seem to forget that trees are living organisms and according to a March 2015 USDA blog called “The Power Of One Tree,” we need to give them more respect. Did you know one large mature tree can provide enough oxygen for up to four people per year? Trees are not only a source of oxygen; they clean the air by removing carbon dioxide, ozone, dust and other pollutants and they save energy.
Virginia Tech’s Energy Series publications promote improving the sustainability of your home by planting deciduous trees on the south or west sides of the house, and evergreen trees along the windward side of a landscape. Shade trees will cool a home in the summer, and once leafless, they will passively solar heat the house in the winter. Strategically placed evergreens will block the wind adding to the heating cost savings.
In addition to increasing the property value of your home by beautifying the landscape, trees can save between 8-12% in energy costs. Through evaporative transpiration they also cool the air by 5-10 degrees while creating a shady outdoor space for us to enjoy.
People say tree roots invade foundations and septic lines, and they remove healthy mature trees from their property. Since the early 1950s, rigid PVC pipe has replaced old cast iron piping and even older clay lines. A continuous run of PVC piping is unlike the fitted old pipes that had gaps in them where tree roots could grow in through. The glue used actually fuses the overlapping PVC pipe ends together.
As for foundations, tree roots will only grow where there is sufficient moisture and oxygen. In Central Virginia, this is within the top 12” - 18” of the soil profile. In my county, the building specifications state footing trench bottoms are to be a minimum of 18” below grade. Before cutting down a healthy tree out of unfounded fear, please check out the area building codes and pipes about which you are concerned.
When I take a walk in the woods, I think about the vitality of the natural forest and how a simple walk improves my state of mind. While running errands in town or walking on a city street, we need to realize our community of urban forests are equally important to our well-being.
Trees improve our way of life beyond our state of mind and shading our homes. Trees shade the streets and sidewalks; they create comfortable spaces in neighborhood parks for us to gather in and they aid in keeping us safe. In a U.S. Forest Service study completed in Baltimore,researchers concluded “a 10% increase in tree canopy resulted in a roughly 12% decrease in crime.” ( Our neighbors living in areas with low to no tree cover experience “increases in energy costs (e.g., for air conditioning), in air pollution levels, and in heat-related illness and mortality”. Trees make a difference, and simply supporting area municipal arborists and local tree planting programs will impact the lives of neighbors living in the heat islands within your community.
I have shared how the shade of a beautiful tree sustains our wellbeing, our health and safety, and how they save energy but trees also add significantly to the health of our environment. From the smallest organism at the bottom of the food chain up to the largest mammal, trees play a significant role in theecosystem.
Mind you, it’s not just any tree; Entomologist Doug Tallamy’s research confirms native treeshost hundreds of caterpillar species and other insects. In his book “Bringing Nature Home,”he explains how these insects are the food adult birds rear their young on. A reduction in caterpillar and insect populations directly affects the survival of bird species. The Cornel Lab shares the sad statistics on declining bird populations: since 1970 “the North American bird population is down by 2.9 billion breeding adults, with devastating losses among birds in every biome. Forests alone have lost 1 billion birds. Grassland bird populations collectively have declined by 53%, or another 720 million birds.”
How can we reverse this trend? Planting native trees and not cutting them down, is the step homeowners need to embrace and homeowners' associations s need to adopt. Trees planted in lawns do not mimic the natural environment. Trees with a generous layer of mulch within the drip line or better yet, with native shrubs and perennials planted underneath create great habitat for insects.
To create a significant impact within the ecosystem, we need to reduce the lawn and plant keystone species. Did you know keystone species of trees host more insects than other types of trees? In Central Virginia, the list of keystone species includes native oaks, Quercus spp., maples, Acer spp., river birches, Betula nigra, and black cherry trees, Prunus serotina, to name just a few. Keystone species for your area or ecoregion, can be found on the National Wildlife Federation’s website I hope you have a better understanding of the importance of the urban or community forest, the need to eliminate community heat islands, the role trees play in the sustainability of our home landscapes and the critical need for planting native trees to support the ecosystem.
Please stop cutting down healthy native trees; these vibrant living organisms are far more important than a sterile lawn.