Southern Aroostook Soil and Water Conservation District (SWCD) partnered with neighborhood residents to establish a tree inventory in Houlton, Maine, which will guide the district in future street tree diversity and help increase tree canopy.

The idea grew three years ago when District Manager Angie Wotton was talking with residents over coffee, and talk turned to observations of the number of trees being cut down along the streets of Houlton. Wotton asked if the residents would be willing to document what they saw over the summer of 2019.

The resulting list consisting of tree photos, locations, and observed conditions – including those that were damaged because of wire interference pruning – led to the SWCD applying for a Project Canopy planning grant from the Maine Forest Service. Funding was awarded in May 2020, and the district began recruiting volunteers from the targeted neighborhoods.

“My favorite comment from a survey volunteer was a woman who, after surveying her section with a friend, ‘complained’ to me that because of her participation, she was now unable to drive down a street in Houlton without assessing the street trees,” Wotton said.

“To me, that is exactly what we want to happen,” she said. “The more people are aware, the more we hope to get them involved.”

After training on measurements and what to look for in recording various data, 24 volunteers participated in surveying 20 sections in the Taking Stock: Planning Houlton’s Tree Growth project. The survey information then was transferred into a software program, i-Tree Eco, that provides various results for the surveyed project areas such as composition and structure, benefits, and costs.

Data also was used to develop an ArcGIS interactive map in partnership with Maine NRCS GIS Specialist Tara King. The interactive map shows an overview of the 20 sections surveyed along with snapshots of specific areas and various imagery layers.

One surprise from the survey, Wotton said, is the number of Norway maples throughout the area – it is the only species of 40 checked that is invasive, and Wotton found saplings growing in many spaces including amidst shrubbery.

“It made me realize it does pose a threat,” Wotton said, “but it also provides an opportunity for outreach and focus on native tree species.”

Another eye-opener was the limited number of northern red oak at just 4.6 percent. It is a species Wotton said will be a go-to in reestablishing treelined streets.

Other tree percentage findings include Norway maple, comprising 14.8 percent of the surveyed trees, sugar maple with the highest at 35.5 percent, and paper birch at 7.7 percent.

The SWCD recently submitted a new grant proposal under Project Canopy that targets three neighborhoods for tree plantings of sugar maple and northern red oak that will help it get started on replacement street trees.

King used the survey data to create a map based on street trees surveyed by address. Residents can visit the site and filter results by various criteria including species, diameter of trunk, crown health, and interference with utility lines.

Tags: Forestry