16,673 Trees and Counting!

The Care of the Urban Forest Project was a multi-year effort funded by the USDA Forest Service; the goal of the project was to strategically support 20 Vermont communities in moving their municipal tree programs forward through a three-pronged approach: 1) conducting a public tree inventory, 2) developing a strategic action plan or urban forest management plan, and 3) providing an in-house technical tree care training for Public Works and Parks Departments, as well as citizen volunteers.  The project has allowed VT UCF staff to provide direct assistance to municipal employees, tree board/conservation commission members, and engaged citizens in a concerted, effective manner, and we've thoroughly enjoyed having a greater presence at the local level.  Now at the tail end of the project, we're excited to share some results from the comprehensive tree inventory dataset.  

First, a little bit about our tree inventory tool.  We worked with the Agency of Natural Resource's GIS team to configure the ArcGIS Collector application to our tree inventory needs; the application is web-based, map-based, and allows us to collect a variety of point data (tree species, tree condition, tree size, closest building address, photos, etc.) on trees within the public right-of-way and on public land.  We use iPad Airs to collect the data and the user interface is easy (and fun!) to learn.  Once the data is collected, we sync it to the Agency of Natural Resources' Online Atlas tool so that the public can view all of the tree data.  We are able to export the information into an Excel spreadsheet so that we can analyze the data, create graphs, charts, and maps, and develop a public tree inventory report for each community; these reports are all available on our Public Tree Inventories page.  

In total, we've worked with 27 cities and towns throughout the state to inventory 16,673 public trees.  Of note:

  • 56 genera are represented in the dataset; the top 5 genera are: Acer (maple) at 34%, Malus (crabapple) at 10%, Fraxinus (ash) at 9%, Quercus (oak) at 6%, and Gleditsia (honeylocust) at 4%.
  • 112 species are represented in the dataset; the top five species are: Acer saccharum (sugar maple) at 11%, Acer platanoides (Norway maple) at 10%, Malus sp. (crabapple) at 10%, Acer rubrum (red maple) at 7%, and Fraxinus pennsylvanica (green ash) at 7%.
  • 80% of the public trees are in "Good" condition, 14% were rated "Fair", 5% are "Poor", and 1% (225) are "Dead" and are prioritized for removal.
  • Approximately 50% of the trees fall within the 6-18" diameter size class, and another 27% are under 6" in diameter; together, this means that over three-quarters of the inventoried public trees are under 18" and have not yet reached maturity.  This indicates a young urban forest; the lack of large public trees in our downtowns could be a result of the harsh growing conditions (soil compaction, road salt, etc.) or human-caused mortality, but it could also be a remnant of the impacts of Dutch elm disease which hit Vermont in the latter part of the 20th century and killed thousands upon thousdands of planted American elms -- historically the dominant mature shade tree in downtowns.  
  • We ran all but three of the tree inventory datasets through iTree Streets software to better understand the value of the ecosystem services provided by Vermont's public trees.  In total, over $1.2 million in benefits are provided by these trees annually, which breaks down to $100/tree (see image below).  As these trees grow and mature, the ecosystem services benefits that they provide will increase, and so investment in and proper care of these trees is paramount.  

PLANT. LIVE. GROW.