Here’s a research report – from a British paper, no less – about the loss of trees in U.S. cities, and the negative impacts that loss is having. Suggestions follow.

•       •       •       •     •       •       •       •

US cities losing 36 million trees a year, researchers find

Scientists warn of environmental threats rising from trend

that is ‘likely to continue unless policies are altered’


Naomi Larsson


The Guardian

10 May 2018


Cities in the United States are increasingly seeing concrete in place of greenery as urban areas lose an estimated 36m trees annually, according to a study from the Forest Service.

Tree cover in urban areas has declined at a rate of around 175,000 acres per year, while impervious cover – such as roads and buildings – has increased significantly across the country. An estimated 40% of new impervious surfaces were in areas where trees used to grow, the study found.

The total loss of tree cover reached 1% across cities and surrounding areas in the five years between 2009-2014. As four-fifths of Americans live in urban areas, it has serious environmental, social and economic ramifications, warned researchers.


“Understanding where these losses are occurring

and the magnitude of change will hopefully facilitate

informed discussions on how much tree cover com-

munities want to have in the coming years, and

on the roles of urban trees in sustaining environ-

mental quality and human health and wellbeing,”


… said David Nowak, co-author of the study, published in the journal Urban Forestry and Urban Greening.

Urban forests moderate climate and reduce carbon emissions, improving the quality of air and water. Properly placed around buildings, trees can save energy by reducing the need for air conditioning by 30% and for heating by up to 50%. They also mitigate rainfall runoff, offering vital barriers in flood-prone cities. The estimated loss of these benefits – including carbon storage, pollution reduction, altered energy use in buildings – is valued at $96m (£71m) per year.

Urban trees also have social advantages, such as improving people’s mental and physical health. Rolf Skar, forest campaign director for Greenpeace USA, said …


“Trees in urban areas help ward off pol-

lution, providing a long list of benefits for

people and the planet. This news proves

once again that we need to prioritise

adding more green spaces to our cities.”


Researchers Nowak and Eric Greenfield analysed tree cover in US cities and surrounding areas between 2009 and 2014. They looked specifically at urban areas in all 50 states and the District of Columbia, and a broader category named “urban/community areas”, which includes both urban land and politically defined community areas.

They found that 45 states showed a net decline in urban tree cover, with 23 states experiencing significant decreases – resulting in an overall annual net loss of 0.12%, which is comparable to 175,000 acres of tree cover.

Alabama, Florida and Georgia were the states with the greatest annual net loss in tree cover in urban/community areas. Georgia saw the worst results, losing 18,830 acres of tree cover per year, and Florida showed a loss of 18,060 acres. Wyoming, Minnesota and Alaska were the only states to have no recorded change in urban/community tree cover over the five years.

In solely urban areas, the state of Oklahoma recorded the largest tree cover losses at a rate of 0.92%, followed by Washington DC at 0.44% per year.

While there was no significant increase in tree cover in US urban areas over five years, impervious surfaces such as concrete increased by 167,000 acres per year across the states. This represented an overall growth of 1% in urban areas. There was no impervious cover loss. Paul de Zylva, senior nature campaigner for Friends of the Earth, said …


“Trees improve city living. It’s worrying that

trends show so many are being lost in US

cities when leading cities worldwide are ex-

periencing the many benefits of investing in

trees as part of their plans to improve urban life.”


Nowak and Greenfield warn that tree loss will “likely continue into the future, unless forest management and/or urban development policies are altered, particularly given the threats to urban trees associated with development, climate change, insects and diseases, and fire”.

•       •       •       •     •       •       •       •

One additional positive I might add to this research:  A principal at Sasaki Associates, one of the world’s premier landscape architecture firms, gave a presentation concerning the impact of trees in communities.  Among the list of benefits – many of which are cited in this research report – was higher real estate values in communities with higher numbers of trees.  People want to live in neighborhoods that have an abundance of full-grown trees and lush, tree-lined streets.  And they’ll pay more to do so.

Your local nursery should be able to give you multiple examples of trees that do best in your area … and even on your specific home site. While I can’t simply advocate that everyone should rush out and buy a lot of new trees, I do think that each of us, once we know how much a tree that we want costs, can budget and plan for some amount of new tree planting.

In terms of space that’s not on our own property, check with whatever organization exists in your community. For example …

In historic Georgetown, there’s an established group, “Georgetown Trees,” that replaces fallen trees or adds trees in available unplanted spaces. They have an agreement with the city that allows for tree planting on public grounds.  Individual residents can participate in tree-planting efforts to whatever degree they’re able.

In my current community, a town of 11,000, we need city approval to plant trees in spaces such as the grass strip between the curb and sidewalk. It’ll make the “main street” walk infinitely more pleasant, add shade on hot summer days, influence drivers to automatically drive a bit more slowly, and jump the aesthetic quality of the town center.

(Our Garden Atrium sustainable development planted crepe myrtles – which provide pedestrian-level shade and three months of color – for about $50 apiece.  Buying a few for “main street” each year won’t break the bank.)

I think we can each identify readily affordable ways to add beauty and healthfulness to our environment. Given the trend suggested by the article, adding trees is more likely to be done by caring individuals than by our municipal governments.  And the increases in real estate values that accompany such efforts suggest there’s ample ROI for our efforts, as well.

Perhaps Joyce Kilmer’s “Trees” poem can abide a small variation …


“Blogs are written by fools like me,

But maybe each of us can plant a tree.”

Comments are closed.