COLUMBIA — Two days. A thousand trees.
A team of urban foresters needed just a pair of 10-hour days to compile data on every tree in Stephens Lake Park.
The procedure is part of a tree inventory campaign designed to calculate each tree's approximate annual economic value — a value that extends far beyond aesthetics.
“The biggest reason we do these projects in urban settings is because we tend to look at trees as an aesthetic pleasantry,” said Josh Behounek, a project manager at Davey Resource Group. “By doing this, we can quantify the benefits that trees provide on a daily basis.”
Columbia Parks and Recreation is collaborating with Davey Resource Group on the project, which comes by way of a $10,000 Tree Resource Improvement Grant from the Missouri Department of Conservation.
Part of the campaign includes adorning various trees with “price tag” posters that demonstrate the cost benefits and environmental advantages of urban trees. These advantages range from easing stormwater runoff to reducing air pollution.
Columbia Parks and Recreation conducted a preliminary monetary evaluation of 14 different types of trees at Stephens Lake Park. Using the National Tree Benefit Calculator, the department found an annual cost benefit range of $4 for a small red maple to $425 on a sprawling silver maple. The latter provides a $75.58 increase in property value. The American sycamore examined in the study provides a yearly cost benefit of $330, including more than $180 in stormwater benefits for its ability to soak up rain.
Behounek thinks that attaching a quantifiable monetary amount to the benefits a community reaps from trees will help convey their value.
“We know trees pick up stormwater, and we know they sequester carbon dioxide, but until you quantify these things in actual numbers, people take them for granted,” Behounek said. “When we put a dollar sign on them it shows what they give us per year.”
The tree inventory, a week-long procedure that began Monday, is a data-gathering phase of the project.
“We use GPS units, measure the size of the tree, its condition, its location and what species it is,” Behounek said. “Then we enter this data into the Forest Service model, and it can extrapolate the environmental benefits based on the data fields and parameters.”
Brett O’Brien, natural resource supervisor for Columbia Parks and Recreation, said data gleaned from the inventory is highly specific — and vitally important to the analysis.
“For a complete picture of the tree’s benefits, you really need to have the data,” he said. “We identify each tree's exact location, its condition and assess its health and structure."
Another dimension of the inventory is the visual inspection, a process that consists of identifying dead limbs, cavities and decay, Ryan Gustafson, a project manager with Davey Resource Group, said.
"With this information, we can provide a risk rating for a tree or recommend maintenance," Gustafson said.
Once all information is obtained, the project can move to its next phase — the tree analysis. Organizers will use “i-Tree,” an analytical software program from the U.S. Department of Agriculture Forest Service, to compute the combined annual savings provided by the trees on Stephens Lake Park. The analysis will focus on six categories: air quality, stormwater run off, carbon dioxide sequestration, natural gas, property value and electrical savings.
Project organizers hope to instill in Columbia citizens an awareness of the quantifiable cost benefits supplied by trees. Behounek hopes the project will impart a sense of the communal value of trees in an urban setting.
"Trees have a collective benefit," Behounek said. "If a neighbor plants a tree, we all see the benefits."