In “Another View” for Feb. 22, Stacey Koch pushed for urgent action to counter climate change.
A part of this action should be the protection of the trees that we have across the state of Pennsylvania. Pennsylvania is “Penn’s Woods.” The people of our state cherish their properties, their trees, their shrubs. Would you want it to be otherwise?
We understand the need to cut trees to maintain the reliability of the electric grid and to generate lumber, but we would like to make a plea for less aggressive tree clearing by electricity and commercial logging companies. There also should be more re-planting, particularly of native trees.
Homeowners should be encouraged to trim large trees rather than cutting them down.
Trees absorb up to the first third of most precipitation through their trunk and leaf system. Rather than falling directly onto the ground, this moisture first lands on the leaves of the trees allowing it to gently drip and the rest to evaporate. Upon reaching the ground, the roots absorb the rain into the ground replenishing ground water and aquifer resources. Stormwater runoff and flooding potential to other properties is reduced, water is cleaner and water supplies are replenished.
Research indicates that 100 mature tree crowns intercept about 100,000 gallons of rainfall per year, reducing runoff and providing cleaner water. Forest soils generally have high infiltration capacities due to the porous nature of the upper organic layers. The leaf litter also contributes by absorbing the energy of raindrop impact which might otherwise close soil pore spaces. (Quoted from the South Mountain Report issued by the Joint Planning Commission For Lehigh and Northampton Counties pp 24-25)
Once a significant number of trees are removed from a wooded area, infiltration decreases and run-off increases. Peak flows during wet periods are therefore larger, resulting in more flooding downstream, while recharge of underground water supplies decreases, causing even lower stream flows in times of drought.
Trees, wildflowers and other plants don’t just look pretty along stream banks, they form a riparian buffer vital to the stream’s health. The vegetation absorbs pollutants before they enter the water, shades the water so animals have a cool place to live and sheds leaves that become cover for smaller species living in the creek. That is why the Monocacy Creek Watershed Association in 2005 secured a $70,000 growing greener state grant to develop a plan that restores the riparian buffer.
On steep slopes, as trees and vegetation are removed, heavy rains can cause water to cascade down, forming intense flash floods that have devastated towns. In one year, flooding in West Virginia has cost $1.5 billion in damages with taxpayers paying the clean-up expenses and not the coal mining companies causing the damage. In Allentown we have had significant damage to the banks of Trout Creek, which runs along Emaus Avenue, and that was repaired using state grant money.
Other than the obvious value of trees for their beauty, there are other significant benefits, according to various published reports. These include cooling the air, removing certain pollutants, particularly in urban areas, storing carbon and generating oxygen and of course providing habitat and protection for numerous birds and animals.
The net cooling effect of a young healthy tree is equivalent to 10 room size air conditioners operating 20 hours a day. Trees reduce noise pollution by absorbing sounds. A belt of trees 98 feet wide and 49 feet tall can reduce highway noise by 6 to 10 decibels.
Modest increases of 10 percent canopy cover in the New York City area were shown to reduce peak ozone levels by up to 4 part per billion or by nearly 3 percent of the maximum and 37 percent of the amount by which the area exceeded its air quality standard. Similar results were found in Los Angeles and along the East Coast from Baltimore to Boston.
A single mature tree can release enough oxygen back into the atmosphere to support two human beings. The burning of fossil fuels for heating, electricity generation, and transportation emits carbon dioxide into the air. Trees filter some of the carbon dioxide out of the air and store the carbon. The tree then releases oxygen into the air. As quoted from Science News (Dec. 1, 2007): “On average, North American ecosystems store more than 650 million metric tons of carbon each year,”
Andrew Jacobson an atmospheric scientist with the National Oceanic Atmospheric Administration in Boulder, Colo., said. About 32 percent of the carbon ended up in the deciduous forests of the Eastern United States.
Over a 50 year lifetime, a tree generates $31,250 worth of oxygen, provides $62,000 worth of air pollution control, and recycles $31,250 worth of soil erosion, according to calculations by USDA Forest Service. Trees are essential habitat and a source of food for songbirds and many other animals. Along with the usual deer, foxes, and indigenous birds, wooded areas and forest support migrating warblers and hawks. Many species migrate and breed in the Lehigh Valley area. For example, Baltimore orioles, yellow billed cuckoo, yellow throat warblers, towhees , pileated woodpeckers, vireos, indigo buntings, scarlet tanagers, ruby throated hummingbirds, and wood thrush. None of these are currently on the endangered species list, but some are on the threatened list. Damage to their habitat across our neighborhoods as well as miles of Pennsylvania would certainly be detrimental to them.
Having the right to take down the trees on your property doesn’t mean it is always the right thing to do for the health of the environment. They are a valuable resource for the future health of the planet.
Editor’s Note: Jane Benning has been active for years in South Mountain Preservation and Wildlands land acquisitions.