Fighting climate change one tree at a time

| 27 Dec 2016 | 03:50

By Madeleine Thompson

Jill Jonnes wants New Yorkers to know they may be planting trees incorrectly. Jonnes' recent book, “Urban Forests: A Natural History of Trees and People in the American Cityscape” (Viking), presents a comprehensive study of city trees that spares few details, except that the way they are planted on streets is doing more harm than good. “That's the one thing I didn't get in [the book],” Jonnes said. “A very common thing that you see in New York is that people think they're doing a huge favor to their beloved street tree by building a box and filling it with dirt, when actually they're slowly suffocating their tree.” Instead of piling dirt around the flared bottom of a tree, she suggests that arborists leave more of the tree above ground so it can breathe.

“Urban Forests,” which came out in September, is the product of eight years of off-and-on research Jonnes conducted out a desire to lend her writing skills to a topic she cares greatly about: climate change. “Most people live in cities, and I thought 'what could you do if you're living in the city and you're just an ordinary mortal?'” she said. “It seemed to me that the thing people could do is to plant trees or care more for trees, or even just be aware of them. Honestly I didn't know more than any other person about trees.”

Starting in 1806 with Philadelphia plant collector William Hamilton's correspondence with fellow enthusiast President Thomas Jefferson, the book touches on the invention of Arbor Day, specific tree species that thrive in cities and the pests that have plagued them.

New York City, which Jonnes described as a “template for how to go about really restoring your urban forest in a very strategic way,” is featured heavily in the book. Between the MillionTreesNYC and PlaNYC initiatives, Jonnes writes that “no other American metropolis matched the scale of New York City's efforts.”

She also praises the Parks Department's city tree census and map , which document each of the 684,440 trees of 210 species throughout the five boroughs. According to the 2015 tree count, more than $110 million worth of energy conservation and intercepted stormwater, among other benefits, was saved thanks to New York City's green guardians. In 2008, its first year, Jonnes writes, MillionTreesNYC could take credit for the planting of more than 110,000 trees in the city as well as the “greening of city laws.” May of that year saw new zoning changes that required developers to plant and care for more trees and build greener parking lots, aiming to add 10,000 trees annually.

Jonnes' research highlights the career of former parks commissioner Henry J. Stern, who was a master of city laws and ordinances, and who had “an amazing natural talent for stunts and silliness, such as showing up in a spacesuit to view the lunar eclipse in Central Park.” Other prominent trees and characters that might be familiar to New Yorkers include the Callery pear tree that was salvaged from the wreckage of 9/11, Bette Midler and former president Theodore Roosevelt, whose family motto was apparently “He who has planted will preserve.”

Trees, wrote biologist Bernd Heinrich, are shaped by their experiences. In “Urban Forests” it becomes clear that cities are shaped just as much by their trees. “I've really come to feel that because so many of us live in the city and it's clear that nature just is so key to our health and happiness, I feel like cities really need to be retrofitted with nature,” Jonnes said. “It needs to be strategic and thought out.”

Madeleine Thompson can be reached at