App of the Month: Urban forest monitoring in Montréal

Learn about the work of Margaux Dubé from the PaqLab research laboratory at the Université du Québec à Montréal and her app “Urban Forest Monitoring: Complexe des sciences Pierre-Dansereau, UQAM”, which was built using ArcGIS Web AppBuilder. Accessible to specialists as well as members of the public, this app provides information about every tree within a half-kilometre square of urban Montréal. It’s a valuable tool for educating a broad audience about the urban forest and its biodiversity.

Challenges and opportunities

The PaqLab research laboratory at the Université du Québec à Montréal (UQAM), headed by professor Alain Paquette, focuses on the connection between biodiversity and ecosystem functions. PaqLab’s researchers look at the ways that biodiversity affects the resilience of ecosystems as well as the mechanisms that make these processes work. They also examine the effects of urban green infrastructure—such as urban forests—on human wellbeing.

As part of PaqLab’s ongoing research, in summer 2019 a team of students began to conduct a complete survey of urban forests in a patch of urban landscape centered around the Complexe des sciences Pierre-Dansereau at UQAM, collecting data about tree species and tree dimensions. All trees in the area, which measures about a half-kilometre square, were included in the survey, for a total of 1,567 privately and publicly owned trees. Data from municipal trees was the easiest to collect, due to the City of Montréal's publicly available census data. However, for private trees, the team had to make numerous phone calls and knock on many doors to obtain access permissions.

In winter 2020, one of the lab’s researchers, Margaux Dubé, set out to complete and correct the survey, adding several new data to the trees such as postal codes and ownership types (including public, residential, institutional and commercial ownership). Margaux wanted to showcase the survey data within a simple, user-friendly interface so that specialists and non-specialists alike could learn from the research in the lab and from trees in downtown Montréal.

The solution

To present her data in as user-friendly a way as possible, Margaux needed to find the right software solution. She had used geographic information system (GIS) technology before and was already aware of Esri’s ArcGIS platform. Only once she had started conducting her research into app builders did she realize that the ArcGIS platform already contains several extensions that would achieve this for her. ArcGIS Web AppBuilder rose to the top because of its accessible, intuitive interface and the fact that it allows users to create apps that run on any device without needing to code.

With the data in hand, Margaux created the app itself between March and June 2020. After a two-week test phase, during which she and the PaqLab team made improvements to the app, the app was launched in late summer 2020.

Margaux learned important lessons from her work on the app:

“You have to be patient when you create. Sometimes, patterns that seem very complex to us are resolved very easily. You can spend a week working on a single problem and, after a few days of not thinking about it, find the solution in a few seconds.” —Margaux Dubé, student, Master of Environmental Sciences, UQAM

A tour of the app

When a user opens the app, they are greeted by a header featuring PaqLab’s customized branding, including their logo in the top left corner, the name of the app in French and English and links to associated websites. Below that, the app features three main content areas: information and a legend on the left, an interactive map in the centre and statistical summaries on the right. The “Conseils” tab in the top left pane instructs users on how to use the app, making it easier for members of the public who are fresh to the app to make use of its many features.

Margaux Dubé’s app, “Urban forest monitoring: Pierre-Dansereau Science Complex, UQAM”, showcases data about all the urban trees within a half-kilometre square of urban landscape in Montréal. There are 1,567 trees in the survey area from over 30 species. Most are concentrated in parklands, around major institutional buildings like churches and libraries, and along streets in low-density residential areas.

Each recorded tree within the survey area is numbered on the map and its crown is represented as a shape, allowing users to get a sense of relative tree size at a glance.

As a user zooms in, restricting their field of view, the widgets on the right side of the app change to reflect the trees that are visible. This allows users to get an immediate sense of their surroundings.

The Filter widget allows users to explore tree life by postal code, owner, family, genus, scientific name, common name, origin or functional group—that is, by the role they play in the urban forest. Multiple filters can be applied so that users can not only see what trees live near them, but what types of trees they are, and how they relate to the urban ecosystem.

To highlight specific tree species, users can either use the Filter widget in the top left corner of the map or they can interact with the pie chart in the right-hand pane, as above.

The “Inventaire” option in the lower left-hand pane can be used to locate exact specimens by identification number, family and scientific name.

A look to the future

This application not only completely identifies the urban forest in the Complexe des sciences Pierre-Dansereau, but it’s also easy to use and can help members of the public better understand the biodiversity of the world around them. A person using the map while they’re situated in the area will be able to easily identify the surrounding trees as well as their ownership. Margaux hopes that the app will highlight the importance of trees in an urban environment and provide a baseline for follow up by future researchers.

Several media outlets, including Radio-Canada and ACTUALITÉSUQAM (both articles available in French only), have seen the app and become aware of PaqLab’s work that way. Margaux and other members of the lab have taken this opportunity to promote their ongoing projects to a wider audience and educate the public about the benefits of the urban forest and the importance of good urban forest management. The app has also received attention on social media.

Now that PaqLab has this tool in place, lab members have something that they can work on, improve upon and add information to over time. In the long term, Margaux hopes that the results of the app will help develop better management strategies for Montréal's urban forests.

Interested in creating your own app? Explore ArcGIS Web AppBuilder.

This post was translated to French and can be viewed here.