Are you ready to “Go Green"?
Posted: April 2, 2012
Remember, we have only been celebrating Earth Day for 42 years. Arbor Day is truly an American holiday, started by J. Sterling Morton in Nebraska in 1872.
With today’s concerns about global climate change; increased energy consumption (and skyrocketing costs); air and water pollution; habitat loss; increased human health issues such as asthma, obesity and skin cancer; and declining quality of life in some of our communities, there is even more reason for us all to celebrate Arbor Day and embrace the largest “green” elements in our landscapes. Many think Arbor Day is just for kids, but I think we all need to take time to plant, care for, or just learn more about trees and the role they play in maintaining healthy environments in which we all live.
Consider this, as we continue to debate the need for energy in this country, increased urbanization over the past 50 years has led to increased temperatures within our communities averaging about 2 degrees Fahrenheit per decade. Meanwhile the demand for electricity increases by 3-4 % for every 2 degree F. increase. The average American uses about 1000-kilowatt hours per month. A study conducted by Dr. Greg McPherson of the USDA Forest Service in 1994 showed that if just 3 trees were planted for every two houses in the nation (a total of 100 million trees), we could reduce energy consumption for heating and cooling by 30 billion kilowatt hours. That would be enough energy to power the state of Maryland for six months (5 million people).
As we begin to remove trees and forest canopy and replace it with roads, parking lots, driveways, homes, patios, pools (impervious surfaces) and even grass, we immediately have impact on watersheds and streams (or lakes). As this ‘storm water runoff’ travels to the streams it collects pollutants and increases speed (causing stream bank erosion) and downstream flooding. Over 3000 miles of streams in Pennsylvania are polluted by stormwater runoff. Trees (especially large trees with large leafy canopies) play an incredible role in reducing stormwater runoff by intercepting rainfall, allowing for greater infiltration into soils, consuming and using stormwater for growth, preventing soil erosion (especially along streams), and removing pollutants that are in the stormwater. A single large deciduous tree can intercept about 700 gallons of precipitation in a year, while a mature evergreen can intercept more than 4,000 gallons that would otherwise become stormwater.
Those same trees that help us conserve energy and reduce stormwater (pollution and flooding) also sequester atmospheric carbon and remove airborne pollutants. Carbon dioxide, the greenhouse gas that is causing climate change, is removed by trees (and forests) and used to make plant food (photosynthesis) and wood. Forest Service research shows that 100 trees can remove 10,000 pounds of carbon dioxide from the atmosphere per year, and can remove about 1000 pounds of pollutants, including 400 pounds of ozone, and 300 pounds of particulates.
Trees in our communities not only help the local environment, they reduce traffic speeds; beautify our streets and homes; increase property values; and attract shoppers to business districts. Yes, trees have a positive impact on the economic viability of our community and the health of its downtown. National studies completed several years ago by Dr. Kathleen Wolf at the University of Washington showed that shoppers preferred trees in business districts and those shoppers were willing to travel farther, stay longer and spend more (up to 11%) in aesthetically pleasing commercial areas that had trees. In a time when our downtowns are struggling to survive and compete with the big box stores, merchants need to stop blaming trees for blocking signs and begin to work together with the municipalities to create destinations where shoppers will feel comfortable walking around and spending more time and money.
As all mounting research continues to recognize the important role that trees and forests play in providing us with clean air and water; removing pollutants from the atmosphere; reducing stormwater and flooding; reducing energy consumption, and moderating local temperatures, I continue to see more trees removed (and not replaced) and hear multiple excuses about how messy trees are, how they lifted sidewalks, blocked signs, drop leaves, shade the grass, and harbor wildlife or insects. I am also seeing more miniature trees and non-native, invasive trees planted in our landscapes, knowing that they will not provide the same benefits that a large native oak or maple would.
So it is not too late to truly “Go Green” this spring. Visit the www.patrees.org and learn more about trees and their care; attend a workshop in the future; volunteer to help plant trees in your community; or plant a tree or two on your property to help your local watershed, and the planet.
Extension Urban Forester