Guest Blogger: Hope Anderson, C’22 Biology Major “ArcGIS and the Arboretum: New Technology Contributes to our Understanding and Appreciation of Trees on Campus”

Hope Anderson is a senior biology major and mathematics minor from Carrboro, North Carolina. She currently serves as the co-Editor-in-Chief of the Davidsonian. She is also a member of Turner Eating House and on the Executive Board of Pre-PhDs of Davidson Science and Women in Math. 

Davidson community members walking across campus would be remiss not to notice the little silver tags adorning many of the trees along their path. These tags date back to 1982 when the college first received its designation as an arboretum (Dick, “The Davidson College Arboretum”).  As of 2005, the arboretum contained over 3000 individually labeled trees and shrubs (Davidson, “Arboretum”).

Figure 7: Collecting a DBH Measurement

Nearly forty years after its establishment, the arboretum’s records remain almost entirely on paper. The most current map, created by Physical Plant in the early 90s, is a huge printed poster divided into grids and subgrids. Since then, available technology has improved dramatically. My fall 2021 independent research with Dr. Susana Wadgymar and collaborator Chloe Fisher (‘23) aims to digitize and update the arboretum’s records for both community and scientific use. To visualize data in a spatial format, we created a map of campus using Geographic Information System (GIS), which permits the storage, visualization, and analysis of data as a map ( “What Is a Geographic Information System (GIS)? U.S. Geological Survey”). In specific, ArcGIS is a popular and powerful GIS software used to create interactive and customizable maps online. Our goal was to use ArcGIS to establish a database and store arboretum data for years to come.

The Davidson arboretum is significant for several reasons. First, trees play a large role in carbon sequestration, or keeping carbon dioxide out of the atmosphere. The arboretum also cools campus and creates shady areas. Finally, the diverse collection of trees represented help us study and preserve native and engaged species in our region. We created an ArcGIS map with the help of visiting assistant professor of anthropology Dr. Maxime Lamoureux-St-Hilaire. ArcGIS maps are primarily composed of a basemap and one or more layers of information. Our arboretum map includes two layers—a feature layer storing data points, each corresponding to a tree, and a grid to help us divide campus into useful 50 x 50 meter squares. See figures 1-4 for additional information on how ArcGIS layers and the basemap work together. 

 Figure 1: Arboretum map showing both the feature layer and grid layer. Green points represent tagged trees and red represent untagged.

Figure 2: Arboretum map with only the feature layer visible.
Figure 3: Arboretum map showing both feature layers turned off; only the basemap remains.
Figure 4: ArcGIS layers can be overlaid on a variety of preset basemaps which users can quickly toggle between. Users can also create their own basemap. 

Students in Dr. Lamoureux-St-Hilaire’s fall 2021 Imaging the Earth class collected the majority of the data thus far using the ArcGIS Field Maps app. Each student spent a week in October recording data, collecting information on a tree’s location, whether or not it is tagged, whether the tree is coniferous or deciduous (see figs. 5 and 6), and the tree’s diameter at breast height (DBH, see fig. 7 at the top of the post). DBH is a simple but powerful dendrological measurement often used as a proxy for biomass and can be analyzed alongside height to approximate a tree’s carbon sequestration. Find a video demonstrating how to collect all these measurements at the end of this post. 

Figure 5: An example of a deciduous tree on campus. 
Figure 6: An example of a coniferous tree on campus.

After the initial census, Chloe and I started auditing individual grid squares (see fig. 1) to fill in any missing trees. This project is far from over; next semester Chloe and I will continue to audit the current data and identify trees without tags. We also plan to revisit previously collected points to update data the anthropology students didn’t collect, such as height and species. We’re hoping to involve additional members of the Davidson community with an interest in the arboretum. In future years, students can use the same map to collect new measurements for each tree, in order to continually update the online version of the map and compare data across years. 

Thank you to Dr. Lamoureux-St-Hilaire, Dr. Susana Wadgymar, and Chloe Fisher for all their help this semester. I look forward to continuing this project in the spring and setting up future lab members for even more exciting research. 

Video – “Collecting basic measurements using the ArcGIS Field Maps app” 

References 

Cottle, Jessica. “National Park and Recreation Month: Davidson College Arboretum.” Around the D: The Davidson College Archives & Special Collections blog (post), July 13, 2018. Accessed December 9, 2021. https://davidsonarchivesandspecialcollections.org/aroundthed/national-park-and-recreation-month-davidson-college-arboretum/.

Davidson, North Carolina 28035894-2000. “Arboretum.” Davidson. Accessed December 9, 2021. https://www.davidson.edu/offices-and-services/physical-plant/arboretum.

Dick, Lacy. “The Davidson College Arboretum: A Time Line | News of Davidson.” Accessed December 9, 2021. https://newsofdavidson.org/2018/07/29/7205/the-davidson-college-arboretum-a-time-line/.

“What Is a Geographic Information System (GIS)? | U.S. Geological Survey.” Accessed December 9, 2021. https://www.usgs.gov/faqs/what-geographic-information-system-gis.

National Park and Recreation Month: Davidson College Arboretum

Green brochure front with a cluster of leaves in the center, "arboretum" typed across the top, "Davidson College" written just below the leaves.

Arboretum Brochure, Front Page

Since 1985, the National Park and Recreation Association (NPRA) has promoted July as National Park and Recreation Month. As part of these efforts, the NPRA encourages people to appreciate the importance of parks and recreational facilities to STEM education, community gathering and engagement, wild life preservation, and public health – among others.

In recognition of this celebration, we invite you to learn more about the Davidson College campus, which is also a nationally recognized and protected working arboretum.

The campus earned this designation in 1982 when then college president Samuel Spencer received a letter from Henry Cathey, the director of the National Arboretum, requesting the grounds of the college be used as a working arboretum. With the addition of a generous donation from the estate of forestry enthusiast Edwin Latimer Douglass, Physical Plant led an aerial photography and mapping project of the campus to facilitate the preservation of the space.

Four men surround new aerial image of the college campus.

Four men surround new aerial image of the college campus, 1991

But how did the college’s landscape become so unique that it merited this recognition?

The first mention of intentional grounds planning occurs in the first volume of The Meetings of the Board of Trustees of Davidson College. The minutes for February 28, 1855 state: “A communication was read signed by a few ladies of Davidson College, earnestly requesting the Board to take into consideration the propriety of enclosing the college campus, and a general remodeling of college grounds.”

Feb 28, 1855 meeting minutes from the Board of Trustees. Discusses tree plantings.

Feb 28, 1855 meeting minutes from the Board of Trustees

 

This is followed up in the Annual Faculty Report of 1860 – 1861 which commented: “During last spring, the students, at the suggestion of the faculty, undertook to set out each a tree for the embellishment of the campus.” By 1869, reports indicated that such plantings would deliberately attempt to replicate the general forestry and botany of the state and region.

 

June 22, 1869 meeting minutes from the Board of Trustees discussing how the plants should reflect local botany.

June 22, 1869 meeting minutes from the Board of Trustees

 

Today, the college arboretum includes five tree species which were extinct on the North American continent sometime between 2 and 50 million years ago. Since their re-planting in Davidson, they have survived several hurricanes, ice storms, and campus landscaping alterations.

 

Descriptions of five extinct species in arboretum brochure, including Cunninghamia lanceolata, Koelreuteria paniculata, Metasequoia, glyptostroboides, Zelkova serrata, Ginko biloba.

Descriptions of extinct species in arboretum brochure

 

Umbrella Tree Poem from the 1909 Quips & Cranks, picture of the tree on top of the vertically oriented text.

Umbrella Tree Poem from the 1909 Quips & Cranks

 

Student relaxing against tree after Hurricane Hugo

Student relaxing against tree after Hurricane Hugo

 

So the next time you enjoy the shade provided by our carefully constructed and maintained landscape, stop and look for a small metal plaque where you will find information about the tree’s name and history. Want more information? The Archives holds several copies of the Elm Row Newsletter – a campus publication once dedicated to stories about the college grounds and distributed by campus staff.

1997 Elm Row newsletter, front page. Columns describe campus plants.

1997 Elm Row newsletter, front page

 

Related posts:
25th Anniversary of Hurricane Hugo
Campus Maps