Displaying all posts in the The OTM Community category.

Launching a successful open data and citizen science initiative

As urban forest managers look for new ways to engage the public, many municipalities and non-profit groups are turning to citizen science and open data to connect with stakeholders. Citizen science generally refers to partnerships between the public and professional scientists to address real-world problems. The public can be involved in all stages of a project including formulating research questions, conducting scientific experiments, collecting and analyzing data, interpreting results, making new discoveries, and developing technologies and applications. Citizen science projects can generate public interest, but there are often concerns about the need for data coordination, quality control, open access, and long-term funding and resource commitment.

The OpenTreeMap mobile applications make it easy for citizen scientists to collect and update tree inventory information from their phones.

Many of our OpenTreeMap customers use citizen science to increase public awareness and support for community forestry and to collect quality data that can help drive management and policy decisions. This month’s Urban Forest Connections webinar, a webinar series sponsored by the U.S. Forest Service, highlights the challenges and opportunities surrounding citizen science in urban forestry. Lara Roman, Research Ecologist at the Philadelphia Field Station, presents findings from a study of volunteer data quality in urban tree inventories and implications for the use of citizen science for various urban forest data collection needs. OpenTreeMap Project Manager, Deb Boyer, shares lessons learned from citizen science and open data projects across the U.S. and discusses various technical approaches. You can watch the full recording here.

Since 1973, tens of thousands of volunteers have worked with Asheville GreenWorks to plant trees, clean rivers and improve the environment.

There are many other resources available to help you determine whether citizen science and open data projects are right for your community. We’ve listed a few below. We would also love to hear your stories about using citizen science.

Defining the Open in OpenTreeMap: What Does it Mean for OpenTreeMap to be Open Source?

Volunteers for Asheville GreenWorks at a tree planting event.

Volunteers for Asheville GreenWorks at a tree planting event.

Being an open source software means our source code is available for anyone to use and improve at no cost. Any software engineer whether or not they work at Azavea, the company that makes OpenTreeMap, can help us improve the software or take the code and create a custom tree map. The only requirement is that all changes are made freely available. In contrast, proprietary software has source code that only the original authors can legally copy and update. Because many groups do not have the time or resources required, we created a paid subscription service. In exchange for an annual fee, we host the map for you. We are able to spread out the hosting costs across our entire customer base, which for many makes purchasing a subscription less expensive than setting up and hosting a map.

Our goal is to make communities greener and more sustainable, and doing so is only possible if people around the world have the opportunity to build off the work we’ve done. Allowing software developers outside Azavea to contribute means we’re able to add new features and functionality more quickly than if we relied exclusively on our small but dedicated team of developers. Incorporating features built by people outside the company also ensures we continue to build a product that meets the needs of users worldwide.  

Many municipalities and nonprofit organizations, including the City of Asheville, North Carolina, have used OpenTreeMap code to build their own tree map. By using our code, the city saved time and resources that would have otherwise been spent building a tree mapping application from scratch. While Asheville’s map looks and functions very similarly to maps we host through our subscription service the city does not pay us.

The City of Asheville's tree map can be found at http://ashevilletreemap.org/.

You can access the City of Asheville’s tree at http://ashevilletreemap.org/.

The City of Asheville crowdsourced tree data in order to reduce the costs associated with an inventory and engage citizens in urban forestry efforts. Building an inventory for a city the size of Asheville can strain limited economic resources and be incredibly time consuming if done by the city’s small urban forestry staff. By creating a map the public could update, the city in conjunction with Asheville GreenWorks a local nonprofit, has engaged hundreds of volunteers and collected data on thousands of trees.

Today, the map is primarily managed by Asheville GreenWorks but continues to be maintained by the city’s Information Technology (IT) department. The nonprofit uses the map to fill out the city’s inventory, and track plantings and maintenance. Asheville’s Department of Parks and Recreation also adds data to the map on their new plantings. By collecting tree data in one centralized location, the city is better prepared to create an urban forest management plan. According to Rick Carpenter, the Urban Forest Coordinator for Asheville GreenWorks,

“You need an urban forest inventory analysis to create policy change and you need input and backing from citizens. We could hire a large tree corporation who for a lot of money would complete and analyze our inventory for us, however, this does not create a sense of place or vested interest from the community members. If you want to change policy you need the backing of people in the area and the best way to do that is by using OpenTreeMap.”

Carpenter has noticed that by mapping, volunteers feel a vested interest in the trees they survey and are more likely to support urban forestry initiatives in the future.

In order to receive funding from the city, Asheville GreenWorks must create site plans, planting plans and project proposals. Historically, they have prepared these reports using QGIS and SketchUp, but Asheville GreenWorks plans to begin using OpenTreeMap’s new modeling and prioritization module in the future. This new suite of features will allow them to more easily create deliverables they previously gathered from a variety of different sources.

Asheville GreenWorks engages students of all ages in their planting programs.

Asheville GreenWorks engages students of all ages in their planting programs.

Carpenter has recruited students studying ecology and forestry at local universities to map trees. By engaging students the city gets additional data that helps them better manage their inventory and the students get an introduction to GIS and data collection. Students and other volunteers use a dichotomous key to identify tree species before entering information on the map. Carpenter fact checks random samples of data and has been impressed by the accuracy of the data. Click here for an summary of Asheville GreenWorks’ urban forestry initiatives and the impact they’ve had across the city.

We realize not all cities and organizations have the technical expertise of Asheville. There are many communities with OpenTreeMap subscriptions that want to see additional features added to the software, but do not have the time or resources to contribute code themselves. In cases where we think feature requests from individual customers would have utility for the broader OpenTreeMap community, we are able to cost share on software development. In other words, we discount the cost of building a feature in return for the ability to share that feature across the entire platform. If you are interested in seeing a particular feature built, please reach out.

Since 1973, tens of thousands of volunteers have worked with Asheville GreenWorks to plant trees, clean rivers and improve the environment.

Since the organization’s founding in 1973, tens of thousands of volunteers have worked with Asheville GreenWorks to plant trees, clean rivers and improve the environment.

In addition to bringing collaboration and transparency into our development process, we believe being open source gives us a competitive advantage. For this reason, the same principles that guide our product development help shape our business development efforts. We are committed to building a community of urban forestry practitioners and build a platform for people to share ideas and use those ideas to strengthen their own communities. To receive urban forestry news and product updates consider signing up for our newsletter here, or to have your work featured please get in touch with us directly.

To set up a “production” version of OpenTreeMap, we recommend reviewing our installation guide. If you want to set up OpenTreeMap for development and contribute to the open source project, additional information can be found here. To ask specific questions related to use of OpenTreeMap source code, please join the user group.

Azavea has made a demonstrated commitment to building and contributing to open source software beyond just OpenTreeMap. For a list of tools and libraries, you can check out our GitHub as well as the GeoTrellis, OpenDataPhilly and DistrictBuilder projects.

CITY OF TREES Film Tells the Story of Greening Efforts in DC

Washington Parks & People Executive Director Steve Coleman speaks with residents of Ward 8 in Oxon Run Park, Washington, DC in a scene from CITY OF TREES.

Washington Parks & People Executive Director Steve Coleman speaks with residents of Ward 8 in DC’s Run Park in a scene from CITY OF TREES.

Editor’s Note: We believe storytelling is a powerful tool for sharing the importance of maintaining, protecting and growing our urban forests. At OpenTreeMap, we’ve seen firsthand how storytelling can be used to recruit volunteers, garner support and secure funding. In addition to helping you manage your trees and green infrastructure, maps can help you tell your organization’s story. This month we wanted to share with you how one new documentary film is also working to share the story of urban trees and the people that plant and care for them. The following post is written by Lance Kramer of Meridian Hill Pictures. 

As documentary storytellers, we use film to share underrepresented perspectives, build empathy for people different from ourselves, and facilitate conversations about the complexities of the human experience. Our latest film CITY OF TREES is a story that challenges audiences to think deeply about the triumphs and struggles in making a long-term social impact within an environmental nonprofit.

CITY OF TREES follows the stories of trainees and staff in a stimulus-funded green job-training program, Washington Parks & People’s DC Green Corps, designed to put unemployed people back to work by planting and caring for trees in underserved communities in Washington, DC. The film follows its central participants navigating difficult issues: attempting to make change within a low-income urban community; fighting institutional poverty with short-term, non-renewable grant resources; creating environmental justice where it has been absent for decades.

In the process, CITY OF TREES thrusts viewers into the inspiring but messy world of job training and the struggles change makers face in urban communities everyday.

DC Green Corps trainee Michael Samuels and his mother Eleanor Barnett share the story of Michael's incarceration in a scene from CITY OF TREES.

DC Green Corps trainee Michael Samuels and his mother Eleanor Barnett share the story of Michael’s incarceration in a scene from CITY OF TREES.

Over the course of the five years we spent making CITY OF TREES, telling this kind of story required all parties — us as the filmmakers, the program staff and trainees, funders, and audiences — to embrace a certain unpredictability and complexity. Because our story centered on real people, we had to accept that any message about the impact of tree plantings or green job training would never be as tightly-crafted as a grant report or fundraising video. The goal of the film was not to solve unemployment or lack of canopy coverage in certain neighborhoods, but instead to explore the complexities that emerge when people with different backgrounds and perspectives work towards a common goal.

Stories that deepen public consciousness and promote productive discourse are increasingly important as cities become bigger and more diverse.

With nearly 50 screenings of CITY OF TREES at film festivals, conferences, nonprofits, universities, and public agencies last year, we saw how the film helped audiences develop a deeper understanding of the issues and possible solutions, and strengthen relationships with other stakeholders. At screenings we found that people have craved stories that seek deeper truths and raise hard questions.

Steve Coleman introduces a new cohort of DC Green Corps trainees in a scene from CITY OF TREES.

Steve Coleman introduces a new cohort of DC Green Corps trainees in a scene from CITY OF TREES.

We hope that when people watch City of Trees they’re able to draw connections to experiences in their own lives and step into the shoes of someone who is different from themselves. We also hope that the courage displayed by the people who shared their stories in CITY OF TREES — particularly the staff and trainees of Washington Parks & People — will help make it easier for others in urban forestry and environmental justice fields to think about the potential to use authentic storytelling in their own work. To help with this effort, we recently released the CITY OF TREES discussion guide which was made with support from the U.S. Forest Service. The guide is designed to help nonprofits facilitate dialogues around the film’s central themes: environmental justice, workforce development, community engagement and returning citizens.

It is more important than ever for people from all backgrounds to come together to confront some of our country’s most pressing issues. We hope through watching the film people can better understand the complex factors facing urban communities and engage in conversations that lead to positive change.

DC Green Corps community liaison James Magruder conducts outreach in DC's Oxon Run Park in a scene from CITY OF TREES.

DC Green Corps community liaison James Magruder conducts outreach in DC’s Oxon Run Park in a scene from CITY OF TREES.

Click here to find out how you can host a screening of CITY OF TREES. The film will also have its encore broadcast on PBS/WORLD Channel‘s America ReFramed on Tuesday, Jan. 17 in a lineup of films focused on the fights for income equality and racial justice.

For more information on accessing the discussion guide and Community Screening Kit, you can contact Lisa Allen at lisa@meridianhillpictures.comLance Kramer is the producer of CITY OF TREES and Executive Director of Meredian Hill Pictures.

How One Contractor is Helping to Ensure Durham, North Carolina Stays Leafy

Veteran willow oaks shade streets in Durham, North Carolina. (Source: News Observer)

Veteran willow oaks shade streets in Durham, North Carolina. (Source: News Observer)

Nearly 40 percent of Durham’s 108 square miles are covered by trees. However, without proper maintenance of the existing inventory and systematic replanting efforts, this percent is at risk of decreasing. The city must plant an estimated 1,680 new trees every year for the next 20 years in order to maintain the current canopy coverage.

For many Durham residents, the fragile state of thousands of willow and water oaks planted in the 1930s is all too familiar. Not only are the willow and oak populations near the end of their natural lifespans, construction, vehicle exhaust, improper pruning, and cankerworms have have also weakened the trees’ health. By some estimates, Durham will lose an average of 650 of these large trees and 100 smaller trees per year over the next 20 years due to storm damage, accident and natural attrition. Currently, the city removes 750 or more dead and dying trees annually, a number that can rise due to natural disaster, disease, and pests.

The City of Durham hired Raleigh-based Leaf & Limb to inventory the aging willow and water oak populations in the city rights-of-way in order to create a digital map of the trees. Katie Rose Levin, an arborist consultant with Leaf & Limb and manager of the project with the City of Durham, has extensive experience helping clients collect and leverage tree inventory data for prioritizing maintenance, long-term planning, and regulatory compliance.

While inventories can be expensive and time-consuming to complete, they are essential for allowing organizations to plan for losses and gains and performing a cost-benefit analysis on maintenance activities. “You cannot manage something if you don’t know what you’re managing,” said Levin. With consistent tracking of data, a tree inventory becomes a living document that you can use to develop a master plan, make data-driven management decisions and track maintenance work. “Every city should have an inventory of all its infrastructure. Just as other infrastructure records need to be updated by technicians following maintenance, trees must be mapped and tracked, too,” said Levin.


Map of Durham, NC.

A map from the Environmental Affairs Board ‘Recommendations On Sustaining a Healthy Urban Forest In Durham, N.C.” shows the percentage of tree-canopy coverage in different parts of Durham. (Source: News Observer)

Leaf & Limb worked closely with the City of Durham to define a list of data collection fields and develop a set of guidelines for assessing the trees. “It’s important to understand how the data collected is being used. The goals of the tree inventory will dictate what information is being collected,” said Levin. Levin trained staff to recognize insects and diseases specific to willow and water oaks before going out in the field to collect data. Collecting extraneous data increases inventory costs and total time required.

According to Levin, it often makes sense for a contractor to complete an inventory for a city. Inventories are time intensive and require a specialized set of knowledge and tech savvy, which can make it difficult for municipalities to complete while also staying on top of their routine activities. Leaf & Limb chose to collect the data using OpenTreeMap as it was customizable, mobile-friendly and could be easily added to Durham’s existing tree map. Alex Johnson, the City of Durham’s Urban Forestry Manager, also noted that he did not want the data collected in a proprietary platform that would make it difficult to use later. He wanted a platform that did not require technical expertise and could use used to engage the community in stewardship activities.

The city also plans on completing a canopy analysis to establish a baseline, and set a goal of what percentage canopy coverage they want to maintain across the city. It is important that the city continues to calculate canopy coverage on the neighborhood-level. Studies have highlighted the lack of tree planting in poorer neighborhood. In recent years unequal distribution of canopy in cities can be exacerbated by the fact that cities tend to plant trees where trees have been recently removed. Canopy coverage data can help the city more effectively close the gap.

You can find more information on how technology can support the long-term monitoring of urban trees; assist with tree planting and maintenance data processes, and enable data to be organized and shared in a report prepared by Azavea for the Pennsylvania Horticultural Society and the USDA Forest Service Philadelphia Field Station.

Using Existing Data to Analyze and Plan your Urban Forest

Trees line a city street.

A new tool from OpenTreeMap allows communities to use existing sociodemographic and land-use data to make more informed planting decisions and estimate the future ecosystem benefits of those trees over a 30-year period.

Cities, non-profit organizations and other land-managing institutions face competing priorities when it comes to managing the urban forest. Many organizations want to incorporate data on urban heat island effect, air quality and population density into their planting decisions, but do not have the GIS expertise or data required to do so. With OpenTreeMap’s new modeling and prioritization tools, you can generate heat maps of optimal planting locations that are customized based on your selection criteria, and experiment with digitally planting trees of various species and sizes to model the growth and mortality rates of those trees.

We have included two data sets from the National Land Cover Database (NLCD) on tree canopy and impervious surface as well as additional data on population density, economics, and housing. In order to make the tool accessible to the widest audience, we only used data that is available in the continental U.S., does not have usage restrictions and has a level of geographic accuracy that makes it helpful in making planting decisions.

A screenshot of OpenTreeMap's prioritization tool.

OpenTreeMap allows you to prioritize your planting criterion by selecting custom weights. Shown here is a map created to identify optimal planting sites in Milwaukee based on population density, median household income and percent tree canopy coverage.

Your planting priorities may be dictated by other factors not yet included in the tool, which is why we can upload additional overlays to the map for you. For example, we can upload additional overlays with data on local zoning laws, soil quality, transit information, and funding restrictions. We can also upload higher resolution canopy and impervious surface data should it be available for your city or region.

We will incorporate additional information on health, water, temperature, wildfires and air pollution as it becomes available across the continental U.S. Unfortunately, much of the existing health data, including results from a recent study by the Nature Conservancy on the cooling and filtering effects of trees, is not geographically accurate enough to inform local planting decisions. That is to say data at the citywide or even zip code-level is not specific enough to help inform planting decisions at the neighborhood or street-level.

A screenshot demonstrating OpenTreeMap's modeling tool.

A sample tree-planting and the resulting ecosystem benefits projected over a 30-year period. We provide pre-set mortality rates based on tree species and size, that can be customization in the application.

A sample tree-planting and the resulting ecosystem benefits projected over a 30-year period. We provide pre-set mortality rates based on tree species and size, that can be customization in the application.

Once you’ve identified the optimal planting locations, you can model the outcome of your trees over time. Understanding tree growth and mortality rates can help inform management and allows you to demonstrate the long-term environmental and economic benefits of your tree plantings over a 30-year period.

We are in the final testing stages before making these tools available on the OpenTreeMap platform. Initially, the tool will only be available within the continental U.S., however, we plan to incorporate additional customization options including the ability to upload datasets to support groups outside the U.S.

In addition to OpenTreeMap, there are two other tools you use to help you prioritize plantings: iTree Landscape and the Trees and Health application. The U.S. Forest Service’s iTree Landscape helps you identify specific planting locations using land cover and census demographics, and explore existing canopy and ecosystem benefits. The Trees and Health application organized by Portland State University and the U.S. Forest Service includes data on neighborhood vulnerability as it relates to air quality in fourteen U.S. cities. You can use the application to identify planting locations that impact tree canopy and public health.

For additional information on the new forestry modeling and prioritization tools, we invite you to watch our recent webinar. The slides from this presentation can be found here.

Want to get in touch? We’d love to hear your questions and feedback: opentreemap@azavea.com.

How to Incorporate Natural Disaster Preparedness into your Management Plan

A tree-lined street in Philadelphia.

Each year, millions of urban trees are destroyed by storms and other natural disasters. With urban populations on the rise and the increasing role of climate change in natural disasters, it is critical that communities prepare for extreme weather as it relates to trees and green infrastructure. Preparing involves not only implementing effective mitigation strategies, but also developing response and recovery plans.

Take 2012 Hurricane Sandy, the deadliest and most destructive hurricane of the 2012 Atlantic hurricane season, and the second costliest hurricane in U.S. history. The hurricane affected 24 states and the devastation was widespread. Trees were especially vulnerable in regions not accustomed to storms of this magnitude. Nearly 20,000 public trees in New York City were destroyed in the wake of the hurricane, which amounts to more trees lost in the city than in any other storm for which tree damage was documented. The NYC Parks and Recreation Department estimated tens of thousands more trees were flooded, left partially uprooted or otherwise compromised in ways not visible to the naked eye. For years following Sandy work was still being done to clean up downed trees and replanting efforts continue into present day.

Communities with more advanced urban forestry programs typically have complete tree inventories, tree canopy goals and management plans to help sustain the tree population. These core components provide a solid foundation for developing hazard mitigation and response plans in the event of a storm or other disaster. There are many different strategies for reducing both the damage and costs associated with natural disasters without taking down trees. In fact, during most storms with winds below 40 mph, trees in good condition are a net benefit and help moderate climate extremes. We’ve outlined some key considerations and proposed actions below.


Trees down on West 90th St. in New York during the brunt of Hurricane Sandy. Photo by Robert Caplin

Trees down on West 90th St. in New York during the brunt of Hurricane Sandy. (Photo by Robert Caplin)

We recommend implementing practices that reduce the potential for damage including annual inspections, structural pruning, selective removal and planting site-appropriate trees based on species, condition and location. These types of proactive management activities help communities more easily identify high-risk trees as part of day-to-day operations.

Tree inventories and canopy analyses are an important tool for communities to collect and manage data on the urban forest. Not only do inventories provide a baseline of tree and planting site-specific data, they can help communities identify mitigation strategies to improve resilience. The U.S. Forest Service (USFS) developed the iTree software to provide communities with a free tool for analysis and benefits assessment of the urban forest, which along with OpenTreeMap represent two of the inventory mapping solutions available today.

Additionally, many communities have development hazard mitigation guides. For example, New York City’s Emergency Management Department compiled a guide that outlines key features of the city’s risk vulnerability, assesses a range of hazards (i.e. flooding, earthquakes, water shortages, strong windstorms and the pandemic flu) and presents strategies for managing risks associated with those hazards.


While no disaster is the same, communities with post-disaster recovery plans and established contracts for required work can begin recovery efforts more quickly. Pre-planning ensures there is a process in place for debris estimation and management, hiring of contractors and restoration. By identifying and prioritizing the areas that present the highest risk – power lines, public rights-of-way, high traffic areas – cities can focus limited resources on work that will have the greatest impact.

Utility companies can also play a critical role by creating a Vegetation Risk Management Plan (VRMP), to ensure public safety, maintain optimum urban tree canopy, promote tree health and decrease emergency management costs.

Disaster Response

Over 300 trees were lost after Hurricane Sandy in Central Park in New York City.

Over 300 trees were lost after Hurricane Sandy in Central Park in New York City.
(Source: A Walk in the Park)

After Hurricane Sandy, New York City’s first priority was to clear trees from highways and streets to provide access to fire trucks and ambulances. Only after roads were clear did tree crews turn their attention to city trees that collapsed on houses and other buildings. Though some of the fallen wood was in good enough condition to be repurposed into building materials, much of it was shredded into mulch in an effort to expedite cleanup and avoid spreading invasive insects.

Less than a month following the Hurricane and ensuing northeaster, more than $12 million had already been spent on tree clean-up. Tree debris can be one of the most expensive aspects of storm response and if not addressed immediately can leave a community with even more expensive restoration costs. It’s important to note that costs can be exacerbated by unnecessary tree removal following a storm and by risks associated with damaged but not fallen trees.

A woman photographs a downed tree damaging several cars after Hurricane Sandy made its way through Brooklyn, New York. (Source: EPA)

A woman photographs a downed tree damaging several cars after Hurricane Sandy made its way through Brooklyn, New York. (Source: EPA)

The American Planning Association (APA) recommends developing a process for assessing debris with emergency management personnel to ensure the debris and wood residue is managed for its highest and best use. The APA also advises communities to require tree risk assessors during emergency response and recovery operation to have additional qualifications beyond those qualifications required for general pruning and removal contractors.

Post-Disaster Recovery

Crews from all over the country came to New York City to help remove fallen trees. Pictured here a crew from Gainesville, Florida clears a property in Queens. (Source: NYTimes/http://nyti.ms/2cDUymj)

Crews from all over the country came to New York City to help remove fallen trees. Pictured here a crew from Gainesville, Florida clears a property in Queens. (Source: Marcus Yam, The New York Times)

Hurricane Sandy marks the first time forest systems in the northeast experienced saltwater flooding. The long-term effects of both flood and structural damage are not always immediately visible. In New York City, for example, the parks department inspected inspected nearly 48,000 trees in flood zones in the spring following the storm. More than 6,500 trees showed signs of stress and abnormal leafing and another 2,000 were presumed dead; these trees were completely healthy the previous year.

Disaster recovery does not happen overnight and longitudinal studies are important to determining a storm’s long-term impact on the tree population. As recently as this year, NYC Parks is exploring whether stress on trees from saltwater damage left them more vulnerable to other pests and disease, including a fungal growth recently found on many London Plane trees. Across the Hudson River in New Jersey, state officials are partnering with municipalities to distribute free seedlings to replace trees destroyed in the hurricane.


Trees are a form of green infrastructure, and like all other city infrastructure they provide value to residents in this case in the form of environmental, economic and social benefits. However, unlike other infrastructure, trees grow over the course of many years yet can be destroyed in a single event. Furthermore, healthy trees increase in value with age. That is to say, as trees grow the ecosystem benefits they provide including improved air quality, reduced stormwater runoff and carbon dioxide removal increase. The increase in value of a tree overtime makes regeneration a critical issue following a natural disaster.

In order for the urban forest to be adequately addressed in disaster management and recovery, it needs to be a local priority. Education and community engagement at the local level further support the mitigation of urban forestry related hazards. Communities must also advocate on for increased funding and attention for urban forestry-related issues at the state level, as states ultimately are the primary decision maker in matters related to hazard mitigation.

Has your community experienced a significant storm or other natural disaster? What were some of your biggest challenges? We would love to hear from you and give people the opportunity to learn from your story.

Practical Methods for Reducing Urban Tree Mortality

2015_06_22_Street Foliage copy

Tree-lined streets like this one in Philadelphia, Pennsylvania cannot be created overnight. Trees must be monitored closely to ensure their long-term survival.

We recently hosted a webinar on practical methods for increasing the annual survival rates of young trees, a topic that is critical to ensuring the longterm growth of our urban forests. Urban forests provide environmental, health, economic benefits that motivate tree-planting programs. However, realizing these ecosystem benefits depends on tree survival. Overall canopy levels in major cities have been declining, and tree planting and regeneration do not offset current losses.

Small, young trees typically have highest mortality rates. However, accurate mortality data is hard to come by and the data that does exist suggests over a quarter of trees planted die within first 5 to 9 years.[1]  The lack of available information on mortality rates and causes demonstrates the need for standardized tree monitoring protocol. Collecting and analyzing longitudinal tree data will take years, but to assist in data collection efforts the Urban Tree Growth and Longevity Working Group developed a minimum data set necessary for any urban tree monitoring project. This data set includes field crew information, tree species, location, site type, mortality status, condition rating, and diameter at breast height (DBH).

Technology can be used to support effective, long-term monitoring of urban trees and assist with tree planting and maintenance data processes. Azavea prepared a report titled “Data Management for Urban Tree Monitoring” for the Pennsylvania Horticultural Society (PHS) and the USDA Forest Service on the requirements for ideal software monitoring system. The report is the culmination of over twenty interviews with researchers, practitioners from organizations throughout the US (federal agencies, academic researchers, municipal and nonprofit employees, volunteers, students). Included in the report are in-depth analyses of the software offerings currently on the market and whether they meet the features requirements that allow for successful monitoring.

Data-driven decisions can help you maximize limited resources and advocate for additional funding. Watch the video for more detail on the minimum data set and using technology to ensure the health of your urban forest.

Effective monitoring is not the only solution to increasing the mortality rates of young trees. TreePans, a family-run business based in Iowa, has designed a product that protect trees from mechanical damage and allows for more efficient watering. In the video below, Ben Brown of TreePans discusses the core functionality of the protect, how the implementation of TreePans at one university helped reduce mortality rates, and the importance of providing workers and community members alike with the requisite knowledge and resources for helping care for young trees.

Click here to sign up for future webinars, urban forestry news and product updates.

Building the Best Technology for the Longterm Monitoring of Urban Trees

A tree-lined street in Philadelphia's Fairmount neighborhood.

A tree-lined street in Philadelphia’s Fairmount neighborhood.

Trees in urban settings play a vital role in our communities. Whether newly planted or decades old, urban trees provide crucial environmental, economic, community, and aesthetic benefits. A healthy urban forest can assist with stormwater mitigation efforts, shade buildings to save energy, beautify neighborhoods, increase property values, positively impact human health, and encourage community members to spend time outdoors.

A new report prepared by Azavea for the Pennsylvania Horticultural Society and the USDA Forest Service Philadelphia Field Station explores how technology can be used to support the long-term systematic monitoring of urban trees; assist with tree planting and maintenance data processes; and enable data to be organized and shared between researchers and practitioners. Growing a vibrant urban forest requires maintenance, stewardship, and the regular planting of new trees.

Planting campaigns by governmental, non-profit, and community groups have resulted in millions of young trees added to cities throughout the U.S. in recent years. While many of these new trees are catalogued and counted as part of the planting initiative, less data is available about urban trees as they grow and die.

Information about stewardship activities such as pruning, watering, and planting site improvements is also seldom tracked consistently after trees are planted, despite research demonstrating that such activities may directly impact the health and growth of the tree. Long-term monitoring data related to urban tree health, growth and mortality rates, and longevity is useful to urban forestry professionals, scientists, and local community groups for four key purposes:

  • Gathering tree growth, mortality, and health data for planting programs as a means to evaluate performance, inform program management, and adapt practices over time
  • Coordinating community stewardship activities to encourage tree health and survival
  • Understanding how urban forests change through time in terms of population dynamics, including growth, mortality, and species diversity
  • Generating empirical data for use in accurately projecting urban tree populations and the related future estimated ecosystem services in order to demonstrate the value of planting campaigns toward environmental targets and goals

As part of long-term monitoring, it is essential to track longitudinal data about the same individual trees and planting sites. However, that process can be time-intensive, require extensive staffing resources, and result in large amounts of data that may be difficult to organize and quickly access or search. To increase the amount of available empirical data, it’s crucial to explore how to use technology to accurately gather tree data over time using field crews with varying levels of experience and then manage that data in a way that enables sharing information between groups. Through interviews with researchers and forestry practitioners, the authors built a list of the system requirements for an ideal software monitoring system, and evaluated 11 of the existing software platforms including OpenTreeMap.

The OpenTreeMap iOS and Android applications are designed to allow for easy data collection and query in the field.

The OpenTreeMap iOS and Android applications are designed to allow for easy data collection and query in the field.

While developing software that meets data collection and management needs is a critical first step, caring for urban trees is a collaborative task. As non-profit groups, municipal foresters, researchers, student interns, citizen scientists, and others work together to grow and maintain our urban forests, technology can be a valuable tool to assist in gathering data, coordinating management and planting activities, and demonstrating the economic and ecological value of trees. The report advocates for continued innovation in urban forestry data monitoring and technology development to support collaboration among between the many individuals in involved in tracking tree health, growth, and longevity.

Improving the process of long-term tree monitoring is essential for creating high-quality data that can inform adaptive management decisions, guide future planting initiatives, and assist with research on understanding how urban forests change through time. By providing opportunities to share that data more widely, organizations can learn from other programs and work together to build stronger urban forests. We’re excited to be part of the ongoing conversation on how software can assist with long-term tree monitoring, and welcome your feedback and experiences using the tools available.

Parts of this post were republished with permission from the report, Data Management for Urban Tree Monitoring – Software Requirements.

“Trees in Trouble” highlights what we can do to mitigate the effects of EAB

An arborist removing ash trees in Madison Park, Cincinnati.

An arborist removing ash trees in Madison Park, Cincinnati.

In the past few years more than 12,000 dead Ash trees have been cut down in Cincinnati on publicly-owned land. According to documentary filmmaker Andrea Torrice, Cincinnati almost went broke trying to keep the invasion from damaging property and endangering citizens. In describing the infestation, she said, “It seemed to happen overnight.” Unfortunately, Cincinnati is not unique. Since emerald ash borer (EAB), an invasive Asian beetle, was first identified in 2002, communities all across the country have reported signs of EAB and face losing huge portions of their tree canopy. In total, it’s estimated EAB will kill between 50 to 100 million ash trees in the US and Canada.

A tree-lined street in Toledo, Ohio in 2006 before EAB arrived.

A tree-lined street in Toledo, Ohio in 2006 before EAB arrived.

The same tree-lined street in Toledo in 2008 after EAB had arrived.

The same tree-lined street in Toledo in 2008 after EAB had arrived.

The risk of emerald ash borer, however, is not just limited to canopy loss. The effects ripple through the ecosystem affecting other plants, animals and water supplies. Emerald ash borers eat tree bark and cut off access to the nutrients and water a tree needs to survive, and can kill an ash tree in as little as two years. Efforts aimed at reducing the spread of invasive species like EAB have proved costly for businesses that sell ash trees or wood products, property owners, and local and state governments alike.

We sat down with award-winning documentary filmmaker, Andrea Torrice to discuss her most recent film, Trees in Trouble. The film, which is set in Cincinnati, tells the story of America’s urban and community forests: their history, their importance to our health, economy and environment, and the threats they face today. Like many citizens, Torrice was not familiar with the spread of EAB and its impact on her neighborhood until she began to notice swaths of dead trees spray-painted for removal. Upon gaining a deeper understanding of the issue, she felt compelled to create a film that brought the issue to national attention. Torrice weaves together urban forestry history, public policy and science with personal stories to create a film designed to appeal to people of all ages.

Andrea Torrice, Producer and Director of "Trees in Trouble."

Andrea Torrice, Producer and Director of “Trees in Trouble.”

In addition to raising key questions about the challenges our forests face amidst climate change and the spread of invasive species, Trees in Trouble serves to educate citizens on the social, economic, environmental and health benefits trees provide. Throughout our conversation, Torrice was quick to highlight solutions communities can take to protect native trees such as increased monitoring and public awareness, all in an attempt to offer hope for the future. Torrice said, “Education about and awareness of EAB is a necessary first step in order to get citizens involved in the long-term preservation of our urban forests.” She encourages citizens to advocate for updated tree ordinances and to let their public officials know they support funding for the care and maintenance of our urban forests. At the same time, she acknowledges that local government cannot solve the problem alone.

Pleasant Ridge School in Cincinnati hosted a tree planted event in celebration of Arbor Day.

Pleasant Ridge School in Cincinnati hosted a tree planted event in celebration of Arbor Day.

In Cincinnati, for instance, a mandate requires the city to remove all infested ash trees on public land. The cost and scale of this removal project means the city can only afford to replant one tree for every three lost. Stories like this are not limited to Cincinnati, which is why Torrice believes the most successful initiatives to mitigate the effects of EAB are those that bring together multiple stakeholders.

The Taking Root initiative, which brought together 220 diverse organizations and partners across Ohio, Kentucky and Indiana, was started in response to the spread of EAB. The goal of the campaign is to address the current historic loss of our region’s tree canopy by planting trees, better managing local forests, promoting the benefits of healthy trees, and fostering a sense of stewardship among individuals and communities.

Citizens and scientists in Cincinnati learning about invasive pests.

Citizens and scientists in Cincinnati learning about invasive pests.

Ultimately, better management of our urban forests starts with a clear understanding of the trees in your inventory. Information on tree condition and biodiversity as well as ecosystem benefit calculations provide actionable insights for municipalities on where to focus finite resources, and can help local governments advocate for budget increases. Our urban canopy is a testament to the foresight and commitment of past generations, and without proper attention to the long-term care of trees we risk leaving future generations with substantially fewer trees.

Click here to see when Trees in Trouble is airing in your area.

Transplanting Large Caliper Trees in Goderich, Ontario

The original article was written by Michael Ormston-Holloway BSc, MScP, GDHort, MLA, ASLA, CNLA, ISA Certified Arborist of The Planning Partnership (TPP) for Cabbagetown ReLeafMichael is a Partner at The Planning Partnership (TPP) and works in both landscape and urban ecology. In addition to his work at TPP, he lectures at the University of Toronto in the Daniel’s Faculty of Architecture, Landscape and Design, the University of Waterloo in the School of Planning division of the Faculty of Environment, the University of Guelph, and OCAD University.

Mature trees provide ecosystem benefits that help reduce pollution, lower energy costs, increase property values and reduce stormwater runoff. Moving large trees can be a good strategy for building momentum around an urban forestry project and for preserving large trees that would otherwise be removed due to development. Unlike mature trees, young specimens take years to reach a size that would provide equivalent ecosystem benefits to those of a large canopy tree.

Moving a large beech tree (1850)

Moving a large beech tree (1850)

People have been moving large trees since the 1850s, if not earlier, in fact, there is evidence of the ancient Egyptians transplanting large trees almost 4000 years ago. More likely than not, the Egyptians discovered that to transplant a tree, the size of a tree’s root ball must correspond to the caliper of the tree. Larger trees require a larger root ball in order to transplant. With that said, the physiological changes that affect a tree during transplant are similar regardless of the size or age of the tree.

Moving a tree (1930)

Moving a tree (1930)

A tree that has been planted for three or more years has roots that extend well beyond the drip line of the tree. Generally, 60 to 75 percent of an established tree’s root biomass is outside the drip line, meaning that a fully grown tree has roots branching out in diameter equal to two to three times its height.

During transplant, roots are often purposely trimmed back to lateral roots.  In response to this pruning, the tree produces more roots and root hairs, increasing the total size of the root ball. Thus, the process of root pruning helps increase the integrity and volume of the root ball, and helps the tree better acclimate to new surroundings, however, root pruning is more widely used on smaller trees. Since roots provide water, minerals and physical support for a tree, problems can arise when the root system of a tree, particularly a large tree, is improperly cut during prior to transplant.

AmericanHort (formerly the American Nursery and Landscape Association) set standards for root ball moving. In general, needled evergreens require a minimum of eight inches of root ball for each inch of trunk caliper and deciduous trees require nine inches of root ball per inch of caliper. After determining the root ball diameter, digging, balling and burlapping by hand help ensure the root ball remains intact.

Hand burlapping and balling large trees in preparation for tranplant in Goderich, Ontario.

Hand burlapping and balling large trees in preparation for transplant in Goderich, Ontario.

The Planning Partnership (TPP) is a leading expert in large-tree transplanting methods and has worked with various tree contractors throughout Southern Ontario to move trees 60 ft in height and greater. They worked with the Town of Goderich to redesign and replant their town square park following the F3 (on the Fugita scale) tornado that hit in August, 2011. Goderich, located on the eastern shore of Lake Huron, is home to fewer than 10,000 residents. The 2011 tornado was the strongest tornado Ontario had seen in more than 15 years with wind speeds at 280 kmh (174 mph). While the tornado only lasted 12 seconds, buildings were leveled and trees uprooted or split, leaving the town with $130 million in damages. It’s estimated the town lost more than 90 percent of it’s total tree canopy.

Transplanting a large Metasequoia in Goderich.

Transplanting a large Metasequoia in Goderich.

Following the tornado, the town worked with TPP to develop a master plan to combat lost tree canopy on public land. As part of their redesign of the central square, TPP transplanted more than 150 (44 small, 93 medium and 20 large) mature trees from around the region. The transformation of the town center following the tornado included the planting of 60′ tall trees with 30′ canopies. In addition to donations from the community, the trees came with an unusually long warranty, which was critical to the Town’s ability to afford mature trees. The successful transplant of the trees was just the first step to ensuring they thrived in their new home. The Town was committed to helping the trees adapt to the new environment through consistent fertilizing and soil treatment.

Did you recently transplant a tree in your town or city? We’d love to hear about it. Send us your story at opentreemap@azavea.com.

Additional resources on transplanting trees:

American Standard for Nursery Stock

Colorado Master Gardener Notes on Tree Planting

Clemson Cooperative Extension: Transplanting Established Trees & Shrubs

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