If you’re looking for a reason to care about tree loss, the nation’s latest heat wave might be it. Trees can lower summer daytime temperatures by as much as 10 degrees Fahrenheit, according to a recent study.
But tree cover in the United States is shrinking. A study published late last year by the US Forest Service found that we lost 36 million trees annually from urban and rural communities over a five-year period. That’s a 1% drop from 2009 to 2014.
If we continue on this path, “cities will become warmer, more polluted and generally more unhealthy for inhabitants,” said David Nowak, a senior US Forest Service scientist and co-author of the study.
Nowak says there are many reasons our tree canopy is declining, including hurricanes, tornadoes, fires, insects and disease. But the one reason for tree loss that humans can control is sensible development.
“We see the tree cover being swapped out for impervious cover, which means when we look at the photographs, what was there is now replaced with a parking lot or a building,” Nowak said.
More than 80% of the US population lives in urban areas, and most Americans live in forested regions along the East and West coasts, Nowak says.
“Every time we put a road down, we put a building and we cut a tree or add a tree, it not only affects that site, it affects the region.”
The study placed a value on tree loss based on trees’ role in air pollution removal and energy conservation.
The lost value amounted to $96 million a year.
Planning for trees
Nowak says there’s a downside to trees too, such as pollen allergies or large falling branches in storms, “and people don’t like raking leaves.” But, he says, there are ways cities and counties can manage trees to help communities thrive. “You can’t just say ‘we’re not going to have forests.’ We might as well manage and work with the trees.
“You don’t want a tree in the middle of a baseball field. It’s very difficult to play sports if you have trees in the way. Or trees in the middle of freeways.”
Nowak says we can design and manage tree canopies in our cities to help “affect the air, to affect the water, to affect our well-being.”
How you can help stop tree loss
Protect what you have: Nowak says the first step is caring for the trees on your own property. “We think we pay for our house, and so we must maintain it. But because we don’t pay for nature, we don’t need to. And that’s not necessarily true.”
Prune the dead limbs out of your trees: If they’re small enough, do it yourself or hire a company. The risk of limbs damaging your house is significantly lowered when there’s tree upkeep, Nowak said.
Notice where your trees may be in trouble: Often, you can observe when something’s wrong, such as when branches are losing leaves and breaking or when mushrooms are growing at the base or on the trees. You can also hire an arborist or tree canopy expert to assess the health of your trees on an annual basis. Or you can contact your local agricultural extension office for advice.
Don’t remove old trees if it’s not necessary: Instead, try taking smaller actions like removing branches. “It takes a long time for these big trees to get big: 50 to 100 years. And once they’re established, they can live a long time. But taking a big tree out and saying ‘we’ll replant,’ there’s no guarantee small trees will make it, and it will take a very long time to grow.”
Allow trees to grow on your property: Although everyone’s aesthetic is different, it’s the cheap way to get cooler yards and lower energy bills. It’s also an inexpensive approach to flood and noise control.
Nowak says he laughs when his neighbors wonder why their property doesn’t have more trees, because “I hear people running their lawn mowers.” Fallen seeds need a chance to implant, and constant mowing prevents that. If you don’t like where a seedling is growing, you can dig it up and plant it or a new tree where you like.
Educate yourself about trees and get involved: Many cities have tree ordinances that seek to protect very old, significant trees. You can get involved by attending city council meetings. You can also help your city plant trees by joining local nonprofit groups such as Arbor Day Foundation American Forests Trees AtlantaReLeaf Michigan Urban ReLeaf Sustainable Urban Forests Coalition
