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Expert Q&A: Morgan Grove, U.S. Forest Service

Social scientist Morgan Grove of the U.S. Forest Service shares insight into the social benefits of urban trees.

After studying architecture and environmental studies at Yale College, Morgan Grove joined the renowned architectural firm César Pelli & Associates (now Pelli Clarke Pelli Architects). There, he served as a liaison of sorts, connecting the firm’s architects and landscape architects on such notable projects as the Bank of America Center in Charlotte, NC. Struck by the lack of ecological knowledge he observed among landscape architects, and fueled by his own desire to work directly with land managers, Dr. Grove opted to continue his education, earning a Masters of Science in community forestry and a PhD in social ecology from the Yale School of Forestry & Environmental Studies. His graduate program focused on linking community land management with economic development, primarily in rural areas in the tropics. That is, until 1989 when Grove’s advisor, Bill Burch, sent him to Baltimore to see if similar linkages could be made in an urban environment in the U.S.


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Dr. Grove helped develop the Forest Service’s Urban Tree Canopy (UTC) Assessments Program, and he has authored numerous papers related to urban ecology, environmental justice, and the social aspects of urban forestry. He is co-author of The Baltimore School of Urban Ecology, a book which draws on two decades of pioneering social and ecological studies in Baltimore to propose a new way to think about cities and their social, political, and ecological complexity.

I have seen you referred to as an urban forester, a research scientist, and a social scientist. What do you call yourself?

I call myself a social scientist. Die-hard disciplinary social scientists might say that what I do doesn’t look like anything they do, but I am okay with that. My job is to do interdisciplinary work on things that are useful for people to make decisions. Many social scientists have done things that are not applied, and that is not something I aspire to do.

We are now at the point where we can model some of the ecosystem and public health services provided by trees in dollar amounts. How much do we really know about the social value of urban trees—how they contribute to things like community cohesion, education, safety, and quality of life?

The Chief of the Forest Service [Tom Tidwell] was here a couple of weeks ago talking about just that. He said that we need to feel more comfortable making the case for what we do in non-economic terms. We know a lot about the social value of trees. Tree-lined areas are shaded and attractive. They make it nicer and more comfortable for people to be outside, which then increases interactions among people. That is one mechanistic way that trees help build social capital and cohesion. Tree planting is also an organizing tool. Do we organize people to plant trees, or do we plant trees to organize people? It’s not an either-or question; the answer is “yes.”

Trees also have symbolic value. There are plenty of neighborhoods where crime is seen but not reported. A tree says “Hey, this is a nice neighborhood where people are organized.” A tree can be like a neighborhood watch sign that says to criminals, “If you try to do something here, you are likely to be seen and people will do something about it.”

Because trees are long-lived, they also help connect people to a place and to the past. If you say, “Let’s go clean up this forest patch, because it will be really important in the future,” the response is: crickets (silence). If you say, “This forest patch has been here for 150 years. Let’s go clean it up!” the response is, “Yeah!” Knowing the history of a place can be very motivating.

I was once showing a reporter from New Haven, CT some vacant lots that had been converted into community gardens, and he asked, “Are these gardens really addressing the food issue here? Why do this?” I said, “Look at your necktie. Why wear it? Maybe it keeps your shirt from getting stained by gravy, but really, it’s part of your outfit, your uniform. It makes you feel important. Well, this community garden is the neighborhood necktie. It helps people feel like their neighborhood is important and worth something.” Trees do the same thing.

That symbolic value seems like something that is hard to quantify, yet quantification might matter to a funder, no?

It might, but I think quantification can be a sloppy and lazy replacement for actually having a real conversation with that funder. We have been doing market behavior research on tree planting in Baltimore. We go into neighborhoods with trees and without trees and we ask people, “How do you feel about yourself? How do you feel about your neighborhood?” and we see differences. When we tease out other factors that may affect how they feel about their neighborhood, we see the environment coming out very strongly. Across the city, people in neighborhoods with tree plantings say things like, “When you have trees, it makes you feel good about yourself, and that your neighborhood should be respected.”

Let’s talk about some of the negative perceptions of urban trees. A colleague recently said, “Many people still don’t understand the value of trees in our cities. I’ve had residents in some neighborhoods tell me that they don’t want trees. Reasons range from ‘someone might hide behind it and shoot me’ to ‘it collects trash’ to ‘I don’t want bird crap on my car.’” What have you found to be the most common misperceptions or negative perceptions of urban trees?

Those are not misperceptions. They are real, and you could add others. People also hate leaves because they don’t want to rake them, and they hate roots, because the roots get into their water lines. Other reasonable complaints include “Planting trees will lead to gentrification,” “Why are you planting trees when you can’t take care of the ones you already have?” and “Why are you spending all of this money on trees, when we have so many other social problems?”

All of those concerns are fair, and you can’t say, “Those concerns are irrelevant,” “Not my job,” or “I’m here to do the trees. Get with the program.” It all comes back to community development. You have to communicate that the trees are part of larger concerns, and that you are willing to take on the larger concerns.

With crime, we know from research that criminals do hide behind shrubs planted around foundations, so concerns about vegetation and crime are partially justifiable. But in many cases, trees reduce crime. You must be willing to talk about that, and even do some role play. I’ll actually go stand behind a tree and ask, “Can you see me? How am I doing on that hiding thing?” But if I go stand behind a pine tree with low branches, their concern is clear.

In 2012, you published a study on the relationships between tree canopy and crime rates. I was going to ask about your findings-if they were relevant to other cities and if they are getting out to the public. But it sounds like you’re saying that may not even matter. What matters is having conversations about this-with funders and with community members.

Yes, and there are two places where you have to be willing to have that conversation. One is when you’re working with the people in an individual community. The other is with the police department; talking about how a tree planting program is actually a crime prevention program.

Forestry divisions in cities need to be able to make the case that what they do is related to community and neighborhood development. This goes back to what our Chief was saying: have the conversation around what engages people. Rather than talking about data and the economic value of trees, which can be distancing, talk about these facts.

With this crime discussion, start with “We know you want a safe neighborhood, and we’re here to be part of that effort. Here are some of the ways we think we can help you make a safe neighborhood.”  You might even need to bring the regional police commander with you. With concerns about roots and water pipes, say, “Yes, the roots of these trees might get into your pipes, so that’s why it’s important to find out where the pipes are and not plant the tree over the pipes.” With leaves, say, “If leaves are a problem and you can’t rake them, let’s talk about how we can engage the Boy Scouts, or come up with some other neighborhood solution.”

You mentioned concerns about gentrification. A study published last summer in Ecological Economics showed that tree cover may contribute to increased property value. This seems like a good thing. But a in 2015 study you coauthored, which looked at distributional equity of urban tree canopy, states that “Residents in low income neighborhoods might reasonably resist increases in UTC cover to avoid gentrification and rising rent.” How do you deal with that?

So much of this is about process, and the need to approach tree planting as a community development conversation. There are some neighborhoods in Baltimore where community members say, “We need to diversify this neighborhood. We need younger families, more racial diversity, more affluent people, more businesses.” That sounds like gentrification, but it isn’t when the community has control over the process and the outcomes.


Whether purposely or part of a market process, gentrification is most often externally driven and done to the community, not with the community. The outcomes of gentrification and diversification may feel similar, but it’s who controls the process and outcomes that matters. Communities want control over what happens where they live. There are neighborhoods in Baltimore, particularly those that had been redlined, where the value of homes has not increased in over 80 years. Those residents may think “I’d love it if the value of my home went up $200,000, but I don’t want to be displaced by the taxes.” There are policy instruments to address these things.  If major investments are made with the community that produce increased economic value, there is no reason that a city can’t protect people it’s from becoming displaced.

As a forester, my job is not only to think and talk about these things, but to say, “Let’s work on it and take on these issues.” Currently, trees are not a huge player in neighborhood transformations, but as a forester, I can advocate with the community.

Let’s talk about your work to enhance urban tree canopy (UTC) in Baltimore, the subject of the book The Baltimore School of Urban Ecology. In April of 2005, the Maryland DNR invited Baltimore to participate in the UTC Goal setting process. This was done because of a riparian forest buffer directive from the Chesapeake Executive Council. Less than a year later, Baltimore had established a goal to increase UTC from 20% to 40% in 30 years. There were many cycles to that goal-setting process, and one of the first steps was to identify what you had. The book states that the data needed to be visually representative at the parcel level, and that “A tree should look like a tree.”  Why was this important?

People don’t think about their place or community as a pixel. If you want to engage people, your data should represent how people think about where they live. It should be visually attractive and look like the real thing. Too often, this is ignored by scientists, and the result is a sort of accidental distancing. We need to get people to connect with the science on their terms, not ours.

You mentioned redlining. How was Baltimore’s history of segregation and environmental justice factored into the prioritization of UTC enhancement opportunities in Baltimore?

For the initial prioritization, we invited everyone interested in tree planting–city agencies, private sector, community associations, BGE [the utility]. About 20 organizations showed up. We laid out all of the reasons why you might want to plant trees or conserve trees, such as stormwater management, crime, environmental equity, etc. We asked everyone to vote on their top reasons, and we produced a prioritization map based on the votes. Was “environmental equity” as strong a driver as stormwater management? No, but…some of the places that had been redlined in the 1930s were some of the areas with the most impervious surface, so there was a lot of overlap and opportunity to address stormwater and environmental inequities.

The City’s Division of Forestry has asked us to work with all the stakeholders again to reprioritize planting areas now that we are 10 years into the process and we are getting new tree canopy data. What is so exciting is that our stakeholder organizations have grown, there are more of them, and they are much better networked. When I started working in Baltimore in 1989, I used to say you could get all the environmentalists together and fit them in a booth at Alonzo’s, a local pub. At a recent meeting about the UTC effort held by TreeBaltimore, the City’s organization coordinating tree plantings, we had over 200 people!

One of my doctoral students did a comparison of stewardship networks in Seattle and Baltimore. One of the interesting findings was that in Seattle, environmental activities are more related to conservation and “the environment” while in Baltimore, they are much more related to “social justice.”

In our initial UTC goal-setting and prioritization process, I don’t think we really understood the long history of segregation and its social, economic, and environmental consequences. The conversation will be different when we do this next prioritization.

Has that multi-cycle process of setting, prioritizing, and tweaking Baltimore’s UTC goal been formalized into a tool that is applicable to and can be used by other urban communities?
We developed a tool called UTC, which has four parts: assessment, prioritization, market analysis (which tracks all of the tree planting you’ve done to see how you are doing against your prioritization), and change analysis (which measures where you’re gaining and losing, and the social, economic, and environmental factors that may be impacting the gains and losses.) Change analysis is where we are with Baltimore. One of the most challenging parts of this effort is taking all the information and getting it into the form of a simple, four-page report. This will take a lot of work and iterative fine tuning, but once that is done, it can be replicated when this work is done for other municipalities and cities.

We did this same thing with the UTC assessment and prioritization reports. Our Forest Service staff at the University of Vermont have just used the UTC assessment tool to assess Detroit. When that report comes out, it will look a lot better than the very first report we did for Baltimore, because there have been about 50 of these assessments and reports done for different cities, and we’ve gotten better and better. The first UTC assessment we did was for Baltimore, which took six months. Then we did Annapolis, which took three months. Then New York City, which took five days. We are not only getting better and faster, but we have new communication tools, like a UTC assessment video that will soon be posted on the Forest Service YouTube channel which helps explain why it’s important to assess urban trees.

But using these tools is not like doing TurboTax. You don’t just put in your numbers and get a result. You need someone who knows GIS, you need to spend some money, and you need to understand that it is also a process-one that requires talking, being transparent, and staying flexible. For example, when we were working on the prioritization process in Baltimore, a lot of people said, “We want to prioritize all the pretty trees.” I’d say, “That is an important issue, but I do not have a database of pretty trees, so we’re not able to do that. But I have LiDAR data, so I can map out all of the big trees. If you’ll accept my use of LiDAR, and we can agree on the size we consider a big tree, we can prioritize big trees.” They agreed, so we changed the prioritization to account for that.

We found out that a Philadelphia firm, Azavea, has developed their own UTC prioritization tools. We asked how they developed them, and after a long pause, they said, “We’ve read all your papers, and we used your papers to write the software.” That is cool. If someone can develop a product off of what we’ve done, I call that a win!

Have the UTC tools been used outside of the US?

Yes. They have been used in a couple of cities in Canada, and in Beijing. We are an R&D operation. We develop the methods, and we publish how we do it, but we don’t want to be the bottleneck. We’re happy if someone can make a business off our work. We want cities to take this and run.

How did the City’s creation of a sustainability plan in 2009 impact UTC enhancement efforts? 

The UTC work simply got folded right into the Sustainability Plan. The sustainability plan has been helpful in raising the profile of the City’s Forestry Division and in justifying a complete street tree inventory, which is in the process of launching now. An important part of increasing UTC is knowing what you have, knowing what’s worth keeping.

The initiative is in its 10th year. What is working? What isn’t?

The City could best answer that question, but two areas they are focusing on now are getting more trees on private residential land and linking those trees to stormwater management, and tying fresh cut wood from Baltimore’s urban forest to local economic development. We want to handle the whole lifecycle of the tree-the planting, the care, and what we do with it when it dies. We want urban trees to be part of the community’s life cycle, too. We want the tree to be in front of your house, and the wood from which your dining room table is made.

In her forward to the book The Baltimore School of Urban Ecology, Dartmouth anthropologist Laura Ogden says that the work you and others have done in Baltimore is “of paradigm shifting significance,” because rather than looking at ecology in a city, it examines the ecology of a city and integrates many disciplines. When it comes to urban forestry, is this more holistic approach catching on?

I do think this idea of thinking of forestry as community development is catching on and has traction. We had a paper come out after the book that talks about ecology for the city, which is, in essence, this community development attitude. People think of urban ecology as synonymous with the Chicago School of the 1920s. We thought that it was time for a more contemporary view of ecology and the social sciences, and that’s one of the things this book tries to do.

I learned from Bill Burch that you must not only educate people, but empower them to have a voice to demand and defend their natural resources. Based on your experience, what have been the most effective ways to educate, inspire, and empower the people in the communities where you are trying to enhance UTC?

When I was running the project in Baltimore in the 1990s, when it was the URI program out of Yale, I got to spend a lot of time in neighborhoods. I learned that you need to communicate to people that you know things are tough, but that they are important, their place is important, and their community should reflect the greatness of its people. You also have to deliver. Our job is not to have endless planning meetings. My job is, frankly, to get stuff done—to do the science and develop tools that empower communities to control their own fate.

How can practitioners generate interest in environmental issues and careers among young people in cities…or at least be a better member of the urban communities in which our offices are located?

I’m a big believer in “start small and learn.” One thing that could be transformative would be to approach a nearby high school and offer to hire and pay for a few interns over the summer, and perhaps one or two during the school year. Teach those kids about your work and get them involved. When your work involves going to community meetings, take them with you.


What about working with kids on efforts to enhance urban tree canopy. Has that been done well in Baltimore?

Community members would say, “Don’t’ just do a program with my kid for one or two years and then abandon them. The drug dealers are really committed. Are you?” In Baltimore, the Parks & People Foundation has done a terrific job with this. They have what they call a “Green Career Ladder” where they get kids interested in the environment and they try to keep them interested and train them in green jobs. They not only have outdoor education programs, but a program called Branches, which provides summer environmental jobs and skills training for high school students.

The book includes the statement, “Our belief is that an interdisciplinary patch dynamics approach can invigorate studies of urban ecological systems and confront the essential issues of twenty-first century cities.” Can you unpack and explain that statement?

That statement means that we need to pay attention to all of the land in the city, and to understand all of those different places-your neighborhood, your yard, your watershed—from a social, economic, and environmental perspective. We need to understand how what you do may be affected by your neighbor, and how these interactions occur in terms of space, but also over time. Knowing the history of segregation in Baltimore, for example, can really help us understand how things have come to be and where they could go. In the last section of the book, we say that a land ethic that doesn’t include cities is not a land ethic; an urban land ethic would have concern not only for all of the city’s places, from an environmental perspective, but also for its people and their interactions.

Tell me about National Socio-Environmental Synthesis Center (SESYNC) and the program you are leading there.

SESYNC promotes social-environmental integration in terms of training and in addressing problems. A “Synthesis Center” means something very special to its funder, the National Science Foundation. As a Synthesis Center, we are dedicated to working with data that already exists. So in this case, synthesis refers to both the social-environmental integration and the synthesis of existing data. This is critical because there is already so much existing data that could be used to solve social-environmental problems. We need to develop our skills in using existing data that have been collected by others. I am also there to help mentor the postdoctoral students. For example, I’m working with a SESYNC postdoc on one project to try to understand how segregation creates its own ecologies. We have lands in the U.S. and in other post-colonial cities throughout the world where you find long histories of racial segregation. There are many ways that places become segregated. Even the treatment of tuberculosis was used to quarantine and segregate. If we want to produce sustainable, resilient cities, we need to acknowledge these historically segregated places, understand how they became that way, and address those places and people. For our project, we want to generate a framework to understand how places become segregated so that ultimately, we could better understand other cities, like Rio De Janeiro, New Delhi, and Bangkok. We have to understand how segregation systematically happens in order to systematically change it.

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