Over the last several years, you've no doubt heard about or even participated in one of the many tree-planting campaigns embraced by cities like New York, Los Angeles and Philadelphia. The benefits are numerous, with trees responsible for lowering higher urban temperatures, reducing storm runoff, creating cleaner air and improving the natural beauty of neighborhoods. Who would honestly turn down the opportunity for a free tree planted in their own front yard?

As it turns out, a sizable portion of Detroit's urban residents. From 2011 to 2014, during a tree campaign spearheaded by the non-profit The Greening of Detroit, more than 1,800 of 7,425 eligible Detroit residents — roughly 25 percent — submitted "no-tree requests." The size of the negative number was so surprising that it inspired Christine Carmichael, a researcher at the University of Vermont, to take a closer look.

In a new study published in the journal Science and Natural Resources, Carmichael says people didn't reject trees out of some ill will towards nature, but from a lack of say in the re-planting initiatives.

"This research shows how local government actions can cause residents to reject environmental efforts — in this case, street trees — that would otherwise be in people's interests," she said in a statement.

The City of Trees

At the turn of the 20th century, Detroit had more trees per capita than any industrialized city in the world. At the turn of the 20th century, Detroit had more trees per capita than any industrialized city in the world. (Photo: xiquinhosilva/Flickr)

From the late 19th century until the mid-20th, Detroit was proudly known as the "City of Trees," with an estimated 250,000 shade trees towering over its streets. Over the decades that followed, however, budget cuts to tree services, as well as diseases such as Dutch elm and insects like the emerald ash borer, led to untold losses. Dead trees and all the dangerous issues that come with them were suddenly the remainder of a once-proud legacy that few, including the city's strapped budget, had the financial resources to remedy. As The New York Times notes:

Of the 20,000 trees marked dead or hazardous in 2014, when Dr. Carmichael’s study began, the city had removed only 2,000 or so.

So it's understandable that of the more than 150 Detroit residents that Carmichael interviewed, many of them viewed the trees as something that they themselves would have to one day take responsibility for.

"Even though it's city property, we're gonna end up having to care for it and raking leaves and God knows whatever else we might have to do," said one woman interviewed for the study.

Additional factors discovered by Carmichael over the course of her three-year study included distrust of any program tied to the city government as well as a lack of participation extended to residents by organizers of the tree planting initiative.

"What this study shows is why meaningful involvement is so important to making sure these tree-planting efforts are environmentally just," she told Earther. "And realizing that trees are living things. In urban environments, they do need care to live in some harmony with people."

Lessons for positive growth

After presenting her finding to officials at The Greening of Detroit, the group put in motion changes that included a focus on greater community engagement, choice and follow-up communication.

"As a result of our refined focus, [our program] has brought thousands of residents together to not only plant trees, but gain a greater understanding of the benefits of trees in their communities," Monica Tabares of The Greening of Detroit said.

Carmichael's study also offers important lessons for other municipalities considering launching their own tree-planting initiatives. The real success won't come from the number of young trees in the ground, but from the communities that embrace and nourish them in the decades and even centuries to come.

"Healthy urban forests cannot be measured just by the number of trees planted," she said. "We also have to capture who is involved, and how that involvement affects the well-being of people and trees in the long-term."

Michael d'Estries ( @michaeldestries ) covers science, technology, art, and the beautiful, unusual corners of our incredible world.

Why did so many Detroit residents turn down free trees?
It has to do with civic involvement and not an issue with nature.