Health Benefits of Urban Greening: A Q&A with Kathy Wolf

Dr. Kathleen Wolf
Dr. Kathleen Wolf

When launching our National Open Spaces Sacred Places Awards Initiative, our foundation wanted to make sure to include a research component and to engage a community of scientists to generate more complete knowledge about the benefits and impacts that result from user experiences of nature-based sacred spaces in cities.

We turned to Dr. Kathy Wolf and brought her on as our Research Advisor. Dr. Wolf is a Research Social Scientist with the College of the Environment, University of Washington. Her studies are based on the principles of environmental psychology; the research is an effort to better understand the human dimensions of urban forestry and urban ecosystems. Dr. Wolf’s mission is to discover, understand and communicate human behavior and benefits, as people experience nature in urban settings.

To learn more about Dr. Wolf, her studies, and her perceptions of the health benefits and necessities of urban greening, we sat down for an interview on urban landscapes, why trees aid cities in everything from transportation to shopping, and much more.

Open Voices: As a research scientist you investigate people’s perceptions about and behaviors in connection with urban landscapes. What central themes and ideas has your research revealed about these perceptions and behaviors?

Kathy Wolf: One central theme is that local decision makers seem to regard trees and landscapes as simply ways to make places more beautiful, and they do. But aesthetics, being pretty, that’s only the beginning. If we poke through those words of beauty and aesthetics . . . there is now scientific evidence of some really powerful, positive things that happen to people when they experience nature in cities. So that is one theme; nature in one’s everyday life is profoundly important.

The second theme is the universal need. The work that I do represents a community of science that’s been working for 40 years on these sorts of questions. We now know that positive responses to nearby nature are similar for people of all ages, in people of all cultural or ethnic backgrounds, and for people of different nations. The need for nature in our everyday environments applies to all humankind.

Open Voices: Many of your published articles deal with the positive benefits that trees can have on urban landscapes. What are some of those benefits and how do they affect individuals and communities?

Kathy Wolf: Within my personal research program, there are several themes that we’ve done repeated studies about. One is the presence of urban forest canopy in business districts. In our studies people tell us that the business district with [tree] canopy is more welcoming, is more beautiful, and there is greater visual quality. But then they infer other benefits and positive experiences because of the presence of trees. They tell us that products are probably of greater quality. They tell us that the merchants are probably more helpful and more pleasant. This positive relationship of trees and commerce, trees in the retail environment – we’ve seen it again and again.

The second is transportation. Tree-lined streets contribute to the character of our communities. If you remove those trees the result is really barren places that you would have to drive through. Yet transportation professionals often tell people who are advocates for trees, “no, you can’t have trees in the roadside because they cause accidents.”

But we’ve discovered in our research that much of the data that transportation officials are referring to have been derived from high speed rural roads. More recent studies focused on urban roads find that having trees sets up sort of a visual pattern at the edge of the road that may encourage people to travel at lower speeds and be safer.

Open Sacred: You’re the Research Advisor for the National Open Spaces Sacred Places Award Initiative. Can you tell us a little bit about your work with the foundation and how it will proceed going forward?

Kathy Wolf: The Foundation has been funding Open Spaces Sacred Places (OSSP) for over a decade and there are many OSSPs in the Baltimore to Washington D.C. corridor. TKF now has an interest in having good research done in companion with the design and implementation of additional OSSPs. My role is to help guide the process to achieve that good science. That has involved doing outreach within my professional and scientific networks. It has involved responding to requests for information and being a sounding board on occasion when questions come up about research. And so I see my role not only as research advisor, but as a research ambassador on behalf of the Foundation, in order to encourage the best possible science in the projects that are now being reviewed for grant awards.

Open Voices: The United States is in the midst of a health and health care crisis. You have said that parks and nature can be part of the public health solution. What role can they play in improving community health?

Kathy Wolf: There are a number of ways that this can happen. The first set of health benefits is from environmental services. Trees capture particulates out of the air. What’s important is all that leaf surface area – imagine taking all the leaves off the tree and laying them on the ground. There’s an incredible amount of surface area and scientists have learned that particles adhere to those surfaces, and consequently there’s a removal of particular matter which clears the air and makes us less likely to breathe in the bad stuff.

The second environmental service is temperature reduction. There’s now a lot of talk about climate change. I find it really interesting that there is this attention to climate change with regard to several degrees over decades. We have climate change happening today, right now, in many of our cities in the United States. Urban ground surfaces – building roofs, concrete, and so on – absorb heat, then readmit it as the day goes on. The result is localized higher temperatures. What is one of the best ways to reduce the heat effect? Planting trees, as tree canopy shades hard surfaces, and trees are constantly emitting moisture into the air through evapotranspiration and that cools the air. Why is this important? During really high temperature periods, particularly in the southern part of the United States, there are elevated mortalities because some people are very sensitive to extreme temperatures – the elderly, children, and people who are ill. So just bringing down the temperature in a city by a few degrees is a public health benefit.

The third public health solution relates to obesity and active living. We, as a nation, are not moving enough. We don’t get up off of the couch, or maybe more importantly, away from the table often enough. So the Centers for Disease Control and local health organizations first tackled this problem by understanding obesity in terms of caloric intake and activities. They asked, if you do this sort of activity, what is the calorie implication, and how might you reduce weight?

More recently there is interest in the influence of environment. You can’t be active if there isn’t a place to do things. So health officials have been looking at the direct physical settings that enable people to walk about, and do errands and what not – like having sidewalks. Even more recently there is awareness that just having the facility is not enough. You can put in a sidewalk, but if it’s uncomfortable or you feel like you’re really close to traffic, people are not going to use it. A recent surge of studies explores the influence of urban greening on physical activity. So, trees along sidewalks can provide a physical barrier and one feels more safe. Having adequate parks within a certain range, say a quarter mile, of every single front door of every single household, gives people a place to go, a welcoming place to go and be active.

Taking this idea another step, some communities are starting parks prescription programs. The medical community is teaming up with local parks organizations to prescribe outdoor activity. Imagine you’re in the doctor’s office and you’re carrying a few extra pounds; you might be put on a diet, you might get meds, but an alternative is to be advised to go walk in a park a certain amount of time each week. Parks departments are partnering in this effort by checking to make sure that people are safe and comfortable, and that trails and facilities are accessible. It’s a really interesting collaboration.

Open Voices: Do you have any thoughts on collaboration and how to make a public-private partnership come to life?

Kathy Wolf: First of all, collaboration and partnership are absolutely essential. In these times there are few public agencies that have the resources to carry out all that needs to happen to create and manage quality landscapes and green spaces in our cities. The private sector is looking at partnerships because of the health consequences; weight-related chronic diseases are very expensive to deal with. Businesses are recognizing that a modest investment in green can turn into a good bit of cost savings.

Really, getting into the details, what are the roles of different partners? Here’s one person’s view of what is happening. Local government and/or state or national government can build public awareness, can launch campaigns that call attention to a problem, and can set policy. But they may not be able to quickly put together resources and programs to make action happen. But local organizations, the private sector, and the nonprofit sector are nimble. If they see a need, if they see something that needs to be done, they’re far more able to change course in a hurry and respond to that need. So in these collaborations you see this kind of big picture role of government, recognizing a problem, doing the analytics of the problem, and then the quick-turn response that happens in other sectors. It’s exciting to see these collaborations happen and how community creativity and activity are applied to important issues.

Open Sacred: Any final words of wisdom?

Kathy Wolf: As a person with an interest in urban forestry, I get a lot of requests to travel around the country and present about the very things I’m talking about here. When in a new place I love to go out early in the morning and just walk around and learn about a community. Every once in a while I am literally stopped in my tracks by a huge beautiful tree that’s growing, despite all challenges, in the midst of sidewalks and streets and buildings. I feel like a tree whisperer. I stand there and I think – what could you tell me about this place? What changes have you seen in your lifetime? And that’s the power of trees even though we don’t often think about it, how they connect place across generations and change. But they need care, they need attention, and they need our protection, and that’s the good that communities can do to help both the trees and the people that live around them.

More information is available on the web about Dr. Wolf’s research program and about the health benefits of urban greening.

Additional reading: “Places of Urban Sanctuary for Humans”: A Q&A with TKF’s Tom Stoner

“Places of Urban Sanctuary for Humans”: A Q&A with TKF’s Tom Stoner