Cities and communities in the US losing 36 million trees a year

April 18, 2018, USDA Forest Service
Scientists with the USDA Forest Service estimate that between 2009 and 2014, tree cover in the Nation's urban/community areas declined by 0.7 percent, which translates to losing an estimated 36 million trees or approximately 175,000 acres of tree cover annually. Credit: Creative Commons

Scientists with the USDA Forest Service estimate that between 2009 and 2014, tree cover in the Nation's urban/community areas declined by 0.7 percent, which translates to losing an estimated 36 million trees or approximately 175,000 acres of tree cover annually. Pavement and other impervious cover increased at a rate of about 167,000 acres a year during the same period, according to research by USDA Forest Service scientists.

Nationally, urban/community tree cover declined from 42.9 percent to 42.2 percent. Twenty-three had a statistically significant decrease in tree cover, with a total of 45 states showing a net decline. Trees improve air and water quality, reduce summer energy costs by cooling homes, reduce noise, mitigate runoff and flooding, and enhance human health and well-being, making them important to human health and urban and community infrastructure. The annual benefits derived from U.S. urban forests due to air pollution removal, carbon sequestration, and lowered building energy use and consequent altered power plant emissions are estimated at $18 billion.

The study by Dave Nowak and Eric Greenfield of the USDA Forest Service's Northern Research Station, "Declining urban and community tree cover in the United States," was published in the journal Urban Forestry and Urban Greening and is available at: https://www.nrs.fs.fed.us/pubs/55941

A table showing tree cover and impervious cover change by state is available at: https://www.nrs.fs.fed.us/news/release/resources/cities-communities-losing-tree-cover/

"Urban forests are a vital part of the nation's landscape," said Tony Ferguson, Director of the Forest Service's Northern Research Station and the Forest Products Laboratory. "Forest Service research puts knowledge and tools into the hands of urban managers that supports stewardship and the wise allocation of resources."

States or districts with the greatest annual net percent loss in urban/community tree cover were Rhode Island and the District of Columbia (minus 0.44 percent), Georgia (minus 0.40 percent), and Alabama and Nebraska (minus 0.32 percent each). States with the greatest annual net loss in tree cover were Georgia (minus 18,830 acre/year), Florida (minus 18,060 acre/year) and Alabama (minus 12,890 acre/year).

Three states - Mississippi, Montana and New Mexico - had slight, non-significant increases in urban/community tree cover. Nationally, Maine has the highest percent tree cover in urban/community areas with 68 percent tree cover. At 10 percent tree cover, North Dakota ranked as having the lowest percent urban/community tree cover.

"Urban forests are an important resource," said Nowak. "Urban foresters, planners and decision-makers need to understand trends in so they can develop and maintain sufficient levels of - and the accompanying forest benefits - for current and future generations of citizens."

As of 2010, urban land occupied 3 percent, or 68 million acres, of the United States, while urban/community land occupied just over 6 percent of the United States, or 141 million acres.

Overall, urban/community impervious cover had a statistically significant increase from 14.5 percent to 15.1 percent (an increase of 0.6 percent), States with the greatest annual net percent increase in impervious cover were Delaware (0.28 percent), Iowa (0.26 percent), and Colorado, Kansas and Ohio (0.24 percent each). States with the greatest annual net increase in impervious cover were Texas (17,590 acre/year), Florida (13,900 acre/year) and Ohio (8,670 acre/year).

Explore further: New Hampshire leads nation in percent tree cover

More information: David J. Nowak et al, Declining urban and community tree cover in the United States, Urban Forestry & Urban Greening (2018). DOI: 10.1016/j.ufug.2018.03.006

Related Stories

New Hampshire leads nation in percent tree cover

August 6, 2012

Tree cover in the nation's Lower 48 states covers 659 million acres, more than one-third of the nation, according to a U.S. Forest Service study of national tree cover and impervious surfaces. New Hampshire leads the nation ...

Growing need for urban forests as urban land expands

March 14, 2018

A new USDA Forest Service study projects that urban land in Lower 48 states will more than double between 2010 and 2060, which will affect forest and agricultural lands that are being converted to urban uses as well as expand ...

Study: Nation's urban forests losing ground

February 23, 2012

National results indicate that tree cover in urban areas of the United States is declining at a rate of about 4 million trees per year, according to a U.S. Forest Service study published recently in Urban Forestry & Urban ...

Recommended for you

Sahara dust may make you cough, but it's a storm killer

July 20, 2018

The bad news: Dust from the Sahara Desert in Africa—totaling a staggering 2 to 9 trillion pounds worldwide—has been almost a biblical plague on Texas and much of the Southern United States in recent weeks. The good news: ...

Human influence detected in changing seasons

July 20, 2018

For the first time, scientists from Lawrence Livermore National Laboratory (LLNL) and five other organizations have shown that human influences significantly impact the size of the seasonal cycle of temperature in the lowest ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.