Trees that ease learning: when students open their school books this autumn, here's why you'll want greenery nearby. (Perspectives).

When the weather gets warm, students take to the outdoors for class. It's one reason the students in Lynn Speed's class at Wisconsin's Cedarburg High School raised an unprecedented $700 for AMERICAN FORESTS' "A Tree for Every Child" program. In addition to having their money plant trees in forest restoration projects nationwide, the students earned seven seedlings to plant on campus.

"A lot of the classes go outside during the summer, and we'll sit outside and we'll read books," says 12th-grader Brittney Haskey. "It's really nice having that space, it really breaks the day up nicely."

Turns out that in addition to helping the environment, the students may be improving the environment in which they learn.

A series of studies done by the University of Illinois' Human-Environment Research Laboratory has found that trees provide a number of direct benefits to children. The studies add to a growing body of research that shows that, in addition to being aesthetically pleasing and environmentally essential, trees have a significant impact on the physical well-being and mental health of their human neighbors.

NATURAL BENEFITS

The positive effects of nature extend into a myriad of different areas. A famous 1984 study conducted by University of Delaware professor Roger Ulrich found that hospital patients who could view trees and natural scenes out their windows recovered more quickly from surgery than patients with views of a brick wall. Other studies have found that prisoners whose cells face natural scenes have fewer health problems than those who can see only the prison yard, and that workers are more productive if their commutes pass by greenery-filled parks. Officials at the Centers for Disease Control in Atlanta are looking at nature as a way to promote exercise and fight childhood obesity.

Founded in 1984, the Human-Environment Research Laboratory at Illinois has been at the forefront of research showing trees are more than just beautiful. Led by Frances Kuo and William Sullivan, the lab has conducted 18 studies on a broad range of the effects nature has on humans and the communities they call home.

The results show that the presence of vegetation and green-spaces can strengthen social ties in a neighborhood, reduce levels of aggression and violence, and help people cope with everyday stress. In one of the more startling findings, researchers found that crime rates actually go down in neighborhoods with more vegetation--the opposite of what many poilcymakers had in mind when they ordered bushes cleared and trees cut down to decrease crime.

Some of the lab's most noteworthy research has shown that raising and teaching children in a green environment can put them on the path to success early in their lives. One study showed that interaction with nature significantly curtailed the symptoms of Attention Deficit Disorder (ADD). Another showed that girls who can see nature out their home windows are more capable of concentration, impulse inhibition, and self-discipline.

TREES, KIDS, AND A.D.D.

For the ADD experiment, the results of which were announced last year by Kuo, Sullivan, and their colleague Andrea Faber Taylor, questionnaires were completed by parents and guardians of children aged 7 to 12 who had been diagnosed with ADD. Parents were asked to name activities that either helped or worsened their children's symptoms.

"When you ask parents just to knock off the top of their heads things their children do that seem to be helpful, activities in green settings... show up disproportionately," Kuo says. "They show up disproportionately rarely when you ask parents, 'Now tell me what seems to exacerbate your kid's symptoms.'"

Researchers then asked parents to systematically rate how particular activities such as soccer, rollerblading, reading, and playing video games affected their children's symptoms--again, "green activities" came out on top. Finally, parents described how much greenery grew around their houses. Children with more trees and nature around where they lived had milder symptoms--just looking at a green view made a difference.

"Time is better spent if they go into the backyard or go down to the park for 30 minutes than if they go down into the basement with no windows and no views and focus on an attentionally demanding video game," Faber Taylor says.

The team explains these benefits using the theory of attention restoration first developed by University of Michigan researcher Steve Kaplan. As people live their lives, they frequently have to use "directed attention," the effortful task of paying attention. This tool becomes fatigued after much use and has to be restored. While sleep has some restorative value, researchers have found that being exposed to "fascinating" situations where attention is involuntary--such as a waterfall, crying baby, or fire--is the best way to restore attention. Natural scenes are a perfect fit for this category.

Reaction to the study has been very enthusiastic, especially from parents and overworked teachers who are desperate for help, Kuo says. Faber Taylor added that hearing the results of the study is often the last push parents need to realize the benefits of nature.

"They say, 'I've seen this and I just didn't put it together myself,' "Faber Taylor says. "Once it's made explicit to them, they make an effort. They do things with their child in green settings; they focus on that more."

The way exposure to nature can fit into an ADD treatment regimen differs for each child, the researchers stress. Some may be able to take less medicine, while others may see heightened attention with the same medication. And there is anecdotal evidence that for some kids, nature may he a cure.

"When you talk to parents about these findings, they say, 'When we do outdoor activities, he becomes a normal kid,' "Kuo said. "It does look like intense constant exposure to nature could actually remove the symptoms in some kids."

ROOMS WITH A VIEW

Intense exposure to nature helps attention, but any exposure at all can promote self-discipline. The second Illinois study found that girls with views of nature out their home windows were more likely to be able to inhibit impulses, delay gratification, and concentrate than similar girls with views of manmade settings.

Faber Taylor, Kuo, and Sullivan interviewed parents and children in a Chicago public housing development. The apartments were identical and families had been randomly assigned, so the only difference was their window view. Parents rated the amount of nature visible out the window, while children performed a series of tasks designed to test various aspects of self-discipline. Girls with views of nature performed better, a result Kuo attributed to a part of the brain that is active in both self-discipline and the appreciation of nature.

The correlation between home view of nature and self-discipline did not extend to boys, Kuo says, not because of any inherent gender difference, but because boys tend to play farther from home. She added that the amount of greenery in places where boys do spend their time has been shown to predict their ability to pay attention.

THE REAL WORLD

The series of experiments has been a large scholarly undertaking, but the researchers' interest in the subject isn't just academic. They would like to see certain policy changes and actions come about as a result of their work.

"We're very interested in seeing these findings make a difference in the real world," Kuo says.

Mary Ann Smith agrees. The Chicago alderman, who has been involved in a number of her city's greening initiatives, says the illinois research provides "backup data" for knowledge that most people already intuitively felt. The data will be helpful as Chicago continues with its plans to build a school with significant open spaces. The city has spent $1.25 million to acquire land and demolish existing buildings, Smith says, and construction of the school and removal of a street are imminent. Chicago is also building several school additions, one of which will include a park, Smith says, adding that her constituents have embraced the projects.

"The reaction has been very positive as long as the community is involved in planning," she says. "People understand the benefits of kids getting outside, but even children looking at a tree instead of a brick wall makes a difference."

The school projects are not Chicago's first greening campaigns. In 1997, the city embarked on a $10 million tree-planting venture to line the Windy City's streets and parks with 20,000 trees. In June, Mayor Richard M. Daley announced a plan to use landfill to create two miles of parkland along the shores of Lake Michigan.

Smith says she continues to fight for projects designed to increase Chicagoans' interaction with nature, such as rooftop gardens and transportation to parks for the elderly. But winning approval for those kinds of projects is not always easy, as there is much competition for social services funding.

"They said 'How can you spend money on trees and gardens when there's so much else to spend money on," Smith says. "They were brutal in challenging this strategy."

But she says research like that being done in Illinois helps convince people of the extended benefits. "There are so many other quality of life issues, like medicine and food," Smith says. "But we can show that [greenspaces] can actually reduce the need for medication."

The impact of the research is not limited to Chicago. Kuo says that within a few years of a talk she gave in Providence, Rhode Island, an urban forestry group had successfully pushed for more than a dozen municipal tree ordinances and the public housing authority had relandscaped public housing projects.

One policy change Kuo would like to see would alter how zoning codes are established. Right now, city design codes focus almost exclusively on everything but greenery," Kuo says, noting that the research shows nearly the opposite. "Almost nothing except trees really matters... what matters most is whether there's a tree in front of it."

Kuo, Faber Taylor, and Sullivan plan to continue their work and have several new experiments lined up. An ADD study extends the results of their original experiment to a national level. Faber Taylor is also taking children on controlled, identical 20-minute walks through different physical settings--a park, city streets with trees, and a city area with no trees--to see how the children's reactions change.

Faber Taylor says the public is starting to realize how many positive effects nature can have.

"We definitely want to continue pursuing this," she says. "It makes people appreciate nature as valuable and it has a positive impact on our health and our well being. They're starting to realize it's worth the effort." AF

Charles Enloe is an intern at American Forests magazine.