A Canopy Where it Counts

Cedar Rapids, Iowa, grabs the opportunity for more equity and biodiversity after a Derecho flattens more than half the urban trees.

By Kevan Klosterwill

On August 10, 2020, a massive storm ripped through Cedar Rapids, Iowa, and the surrounding area. The storm, called a derecho for the straightness of its 140-mile-per-hour winds (as compared with a twisting tornado), spent less than an hour over the city, but in the process devastated the city’s tree canopy.

Almost every street was blocked by trees, and many fell on homes and power lines. All told, hundreds of thousands of trees were estimated lost—about 65 percent of the city’s urban canopy. Across the storm’s entire path through the Midwest, the total likely exceeded four million, according to analysis of aerial photography before and after the derecho. “That doesn’t account for anything that came down after the survey from disease, dieback, stress,” explains Nick McGrath, the community disaster recovery coordinator for Iowa’s Department of Natural Resources. “I expect many more trees to be removed, unfortunately.”

The 2020 derecho took out trees across Cedar Rapids, Iowa’s parks and neighborhoods. Todd Bannor/Alamy Stock Photo.

Like many cities across the United States, Cedar Rapids’s urban forest was already suffering in some ways, due to urban growth, reduced planting and replanting because of limited municipal budgets, and the historical inequities that limited the provision of trees and other urban services for certain populations.

Faced with both long-standing and immediate challenges, the city of Cedar Rapids turned to the urban planner Jeff Speck, Honorary ASLA, who had previously provided a plan for converting the downtown’s streets from one-way to two-way traffic, and to the local landscape architecture firm Confluence to develop a new urban forestry plan to guide the renewal of the city’s urban forest—dubbed “ReLeaf Cedar Rapids.”

“We’ve always been proud of our tree canopy,” says the City Manager Jeff Pomeranz. The community’s namesake cedar is one of many affinities that mark its long-standing interest in trees. As Pomeranz explains, interest in restoring the city’s trees came even before the storm was over, with one local business owner calling him to help and offering $50,000 toward replanting the city’s trees.

The city has made its own commitment, planning to spend $10 million over the next 10 years to implement the ReLeaf plan and creating a new position to coordinate those activities across various city departments. Pomeranz is hoping to raise a matching amount from local donors.

Lost trees from Social Pinpoint site. Planners used social media to gather input from the community about tree losses and replanting goals. Image by Confluence.

Kicking off the planning process in the midst of the COVID-19 pandemic, the team took advantage of Social Pinpoint, an online mapping tool, to gather data from the community about where trees were lost or needed most and solicited input about guiding principles for the plan.

The city also conducted outreach outdoors in local parks with its Rollin’ Recmobile, a van operated by the city’s parks department that brings recreational programming to sites throughout the community. The priorities that emerged from these efforts included climate action and resilience, equity, and habitat for pollinators and other native species. Initial volunteer plantings have also helped to provide awareness about the effort, some conducted in the fall following the storm.

A year later, a drive through Cedar Rapids reveals the ongoing signs of damage, but also marks of renewal. While twisted and broken trunks stand in woodlands and backyards, the stumps of the 8,000 street trees lost during the storm are being systematically ground down, and new plantings are being installed in parks and rights-of-way, with guidance from Confluence.

Volunteer groups, many coordinated by Trees Forever, a regional nonprofit advocacy group based in nearby Marion, are taking to the streets and parks to plant trees. Local residents have also already adopted more than 6,000 trees provided by the organization for their own homes. These efforts have contributed momentum to the city’s recovery while the plan has been developed.

Regrowing hundreds of thousands of trees will present other logistical challenges, which the organization is taking on. “It’s going to take us until year 4 or 5 to scale up and peak,” says Trees Forever founder and ReLeaf plan director Shannon Ramsay. They are working to contract grow 5,000 trees per year, connecting with local nurseries and garden centers to encourage more supply of resilient native trees, and training volunteer TreeKeepers to tend to those trees after they’re planted.

Pre-derecho total street trees. Careful analysis of the city’s losses has informed an equity-driven approach to replanting. Image by Confluence.

While the linkage between more numerous or severe derechos and climate change is unclear, what is apparent is that the damage wrought by these storms has the potential to make cities and woodlands less resilient, with consequences that include removing shade, destabilizing forests, and creating openings for invasive species to thrive.

On the other hand, the areas that survived the storm best provide important clues about how to replant. The ReLeaf Cedar Rapids plan’s authors have drawn from that analysis, along with new forest science and a solid community input process, challenging conventional urban forestry wisdom in the process.

“Urban forestry as it’s practiced in most cities is based on an incomplete understanding of things…diversity, tree size, spacing,” says Speck, pointing to the writings of people such as the German forester Peter Wohlleben—the author of The Hidden Life of Trees—that illustrate the increasing awareness of social relationships between trees. The team responded to those ideas in many ways, from questioning the conventional spacing of street trees 40 feet apart to encouraging more mutualistic associations between urban trees.

Patrick Alvord, ASLA, a landscape architect and principal at Confluence, explains, “How do you plant trees together such that their root systems grow together? Because that intertwining will help bind them together in a way that provides increased strength and resistance to overturning from strong winds.” One example is the white oak, which Alvord says is a fairly convivial species but notes it doesn’t do well alongside beeches or red oaks.

Addressing the lack of diversity in the Cedar Rapids canopy is another critical strategy. The team found that more than half of the city’s trees were either ashes or maples. With the emerald ash borer spreading rapidly through the region, that leaves the city with only one major genus as its primary canopy right now, something the plan seeks to address.

Among the native tree types encouraged are oaks, hickories, and walnuts—genera that are known not only for their size but also for their rich forage for wildlife and humans—as well as Midwestern familiars like cottonwood and Kentucky coffee tree. But while diversity at the city scale is beneficial, Speck notes that each block should nonetheless rely on those mutualistic associations where they can. “Localized homogeneity can be more healthy,” he says.

Pre-derecho tree coverage. Careful analysis of the city’s losses has informed an equity-driven approach to replanting. Image by Confluence.

A key aspect of the plan’s implementation will be addressing the historical inequities of street trees. Analysis of the city’s canopy conducted in the wake of the storm confirmed that Cedar Rapids, like many cities around the country, had fewer trees in poorer parts of the community, which in turn magnified the loss of the benefits that trees bring, such as improved air quality and its associated health contributions, lower summer temperatures that reduce energy costs, and higher property values.

These are the places that the plan calls for planting first. As the draft plan states, “These benefits matter everywhere, but are especially impactful in historically underserved neighborhoods, where investment in a robust tree canopy can balance out other disparities.” To develop that prioritization, the team drew on a number of resources, including census data, climate risk data, and the Centers for Disease Control and Prevention’s Social Vulnerability Index, which assesses communities’ capacity to respond to both natural and human-caused events by considering factors such as poverty, transportation access, and overcrowding.

Education about the benefits of trees in those areas and the provision of additional resources is a component of that planting focus. “We may have residents coming from other cultures who don’t have the same experience with trees that we have,” says Rachael Murtaugh, the city’s ReLeaf program manager. “Some communities may need a little [more] help to re-tree their neighborhoods than others might,” she says.

To guide the replanting, Confluence prepared plans for many of the city’s parks, siting tree plantings in ways that reflect the plan’s principles in terms of species selection and staging, in addition to the overall prioritization of sites. Among Confluence’s recommendations are staggered plantings to ensure an eventual diversity in the age of trees present. “Not everything goes in at the same time, matures at the same time, and dies at the same time,” Alvord says. That strategy also allows the community to scale up its planting capacity and local growers to develop the plant materials needed.

Those efforts are necessarily focused on public rights-of-way and parks, the land that the city controls, but another integral aspect of the urban forest’s recovery is what happens on private lands. Here, the program will require persuasion and education rather than direct planting. To help get the word out, the team is working with a graphic designer, aiming to produce a glossy, readable document that can educate and inspire homeowners to replant their yards and even shift their aesthetic preferences.

“You’re trying to find the sweet spot between size and canopy and convince homeowners that they should plant large canopy trees where they have room…after most homes were damaged after the derecho,” Ramsay says. That hesitancy comes on top of a preference for individual trees in grass around homes, which hardly creates the resilient forest stand that contemporary forestry scientists are investigating.

ReLeaf planners revised recommended tree lists with resilience, diversity, and support for native wildlife and pollinators in mind. Image by Confluence.

To communicate the broad principles of the effort, the plan includes a set of catchy “ReLeaf Rules” such as “Let Trees Mingle,” which encourages people to “Where possible, plant trees in groups and close together.” The last rule, “Break the Grass Habit,” encourages homeowners to move away from lawns and toward a more resilient landscape inspired by the prairies and woodlands of Eastern Iowa, one that recognizes that ground covers and the bugs that crawl in them can be just as important to urban forest health as the tree canopy above.

Changing homeowner preferences and garden center inventories is a bit of a catch-22, as some growers and suppliers are hesitant to stock natives homeowners won’t buy, but homeowners may not know about natives when all that’s for sale are flashy ornamentals. Communicating these principles effectively, whether through educational media or demonstration planting, may be essential to restoring the city’s canopy as a whole. The ReLeaf plan can also serve as a more general resource to communities across the region hit by the storm, and to cities more broadly that are interested in updating their urban forestry approaches.

But as much as there’s hope for the ReLeaf plan to be a model, much of the success will emerge from the place-based nature of the project. One of the strengths came from Confluence’s long-standing presence in the community. “Landscape architects and planners based in the community in which you work have a clear advantage over those coming in from out of town,” Alvord says. “If you don’t know the people that are working in the community to recover from something like this, I think it would be a lot more challenging to build those trusting relationships in a time of duress.”

Kevan Klosterwill is a landscape historian based in the Driftless Region of Iowa.

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