The Great Lakes account for approximately 94% of North America’s fresh water[1] and is the largest fresh water system in the world. The quality of this resource affects the daily lives of residents who live, work and play within the Great Lakes region. The Great Lakes Restoration Initiative (GLRI) focuses on improving, protecting and restoring the integrity of this vital natural resource, in part, through grant-funded projects.
In 2019, ReLeaf Michigan, the Michigan Department of Natural Resources (MDNR), the Indiana Department of Natural Resources (IDNR), the St. Joseph River Basin Commission and Davey Resource Group, Inc. received a USDA Forest Service GLRI grant. |
Using 2018 aerial imagery, the level of tree canopy coverage in Angola, Buchanan, Coldwater, Middlebury, Sturgis and Syracuse ranges from 19% to 36% (Table 1). The communities participating in the 2019-2021 ReLeaf grant program have less overall canopy coverage, on average, when compared to previous year grant program participants (Table 2). As communities with primarily agricultural heritages, this is not an unexpected finding. Tree canopy is one of five land cover classifications analyzed for this project. The other four classes include: grass and other low-lying vegetation, impervious surfaces (e.g. concrete, buildings), bare soils, and water. Of these land cover classifications, impervious surface and tree canopy most directly impact the quantity and quality of stormwater runoff in a community. Table 3 displays the land cover levels for our three Indiana communities, and Table 4 exhibits the results for the Michigan communities. |
Trees improve a community’s air quality by capturing fine pollutants and particulate matter on the surfaces of their leaves. Recent studies have shown a strong correlation between total tree canopy and reduced rates of lower respiratory and cardiovascular disease. Every year, the community forests of these six communities collectively remove over 127 tons of pollutants from the air. These include: 3,855 pounds of carbon monoxide (CO), 25,520 pounds of nitrogen dioxide (NO2), 175,600 pounds of ozone (O3), 8,889 pounds of sulfur dioxide (SO2), and 41,459 pounds of dusts, soot, and other particulate matter. This equates to an annual monetary value of $85,591! |
Vacant planting sites present opportunities to plant trees, however, not all open spaces are candidates for tree plantings - like roads or sports/agricultural fields. Conversely, not all impervious areas remain impervious forever. Trees can be added in areas with impervious surface, for example by adding tree wells in sidewalks or landscape islands in parking lots. Since some locations are clearly better suited to meet community tree planting goals than others, this study attempted to eliminate areas unsuitable for planting and prioritize planting locations based on optimizing the ecosystem benefits that trees can provide to the community.
Final planting decisions should be made by each municipality. This report does not claim that all open locations should be planted with trees, but rather encourages that the prioritized planting areas provided in this study can be used to serve as a starting point and guideline for determining where future plantings may have the most impact on water quality and other tree benefits. |