Baltimore Field Station

The Baltimore Old Forest Project -
Historical Aerial Imagery, Community Engagement and Citizen Science

We are working to understand the relationships among people, communities, and forests in Baltimore over the past 100 years. The distribution of landscapes that seem like “nature” or “wilderness” are actually the result of complex social histories. By examining urban forest environmental history we hope to gain a better understanding of historically-constituted mechanisms of racial and economic environmental inequalities. These insights will help contribute to local agency and non-profit goals for a more equitable future urban forest landscape for Baltimore City.

 

We are using several sources of historical aerial imagery to characterize change in the city’s forest patch ( >10,000 ft2) cover over time (1926-27, 1937-38, 1952-53, 1964, and 1972). This analysis of forest patch change allows us to determine which forest patches have been relatively stable, persisting through time, and which are much more dynamic. We have begun to analyze the earliest set of images, taken between 1926-27 and covering 210 mi2 (544km2) within and surrounding Baltimore City. This set comprises 93 individual images, or “tiles” taken from a bi-plane, and capture a moment of dynamic expansion in the city, just prior to the Great Depression. We obtained high-resolution scans of each image, which were geo-rectified to spatially align with current GIS data. This process converts the images from a disparate set of photographs into a seamless GIS dataset that can be used to observe changes in land patches over time—and ultimately to be integrated with other long-term social, economic, and ecological data.

[aerial photos:] St. Peter’s Cemetery, 1927 (left) and 2010 (right). In 1927, land on the western border of the cemetery was forested. Today, the property has become reforested, while lands outside the cemetery’s boundaries have been cleared.
St. Peter’s Cemetery, 1927 (left) and 2010 (right). In 1927, land on the western border of the cemetery was forested. Today, the property has become reforested, while lands outside the cemetery’s boundaries have been cleared.

 

Classifying land use is the first step toward analyzing change in forest cover. However, classifying land use, such as identifying forest patches on these historic photographs, cannot be automated. Thus, we have developed preliminary methods for landuse/landcover classification of historic imagery and are preparing to initiate the “ Baltimore Old Forest Project,” which will be a community-based collaborative research platform. Using a “crowd sourcing” approach, the Baltimore Old Forest Project will allow members of the community to classify the historic images through a web-based research platform. The non-profit land trust Baltimore Green Space is our partner in this project and will host the collaborative research platform on Zooniverse, a popular site for “people-powered research.” Zooniverse hosts similar projects that use archival material.

 

During the summer of 2017, we worked with Baltimore high school and college interns to develop the necessary methods for landuse and landcover classification, digitization, and quality assurance and quality control protocols of this imagery. We will further refine and document these protocols and convert them to the Zooniverse platform. From the Zooniverse platform, we will work with Baltimore Green Space to initiate the Baltimore Old Forest Project. Our team will work with Baltimore Green Space, local community members, schools, and organizations such as TreeBaltimore to classify the images in an online GIS database.  Many of these local participants are lifelong Baltimore residents and have in-depth knowledge of the green space in their neighborhoods, and how it may have changed over time. Participants will engage the scientific process while contributing their personal, in-depth knowledge of the “forest patches” that are part of their communities.

 

“Old Weather,” an example of “people-powered” research on Zooniverse. In this case, the public transcribes 19th century ships’ logs to help document Arctic climate change for a project co-sponsored by NOAA.
Old Weather,” an example of “people-powered” research on Zooniverse. In this case, the public transcribes 19th century ships’ logs to help document Arctic climate change for a project co-sponsored by NOAA.

Our preliminary analysis of this imagery suggests that this effort will reveal important insights into the relationships between property ownership and forest patch dynamics. For example, “Jonah House Forest” is an emergent forest within the historic St. Peter’s Cemetery. In 1996, the Archdiocese of Baltimore leased the overgrown and neglected cemetery property to Jonah House, a social justice religious community for $1 per year. Jonah House continues to manage the 22-acre forest patch because, as one of the caretakers mentioned in an interview, they believe in fostering a place of retreat for all forms of life. Over time, the ownership and land use of properties outside the cemetery have changed, as has the forest cover on these properties, while the cemetery, whose ownership has remained constant for well over a century, has become reforested.

 

In the future, we will extend the historic analysis through time by analyzing satellite imagery (1970-Present), which we can use to analyze the more recent 45 years of change over time. This research will help us determine patterns of change from which we can develop hypotheses about forest patch dynamics and ownership regimes. These insights may help inform future environmental planning, conservation, management, and stewardship goals for Baltimore City forest patches, and other cities throughout the region.

 

Contact: Morgan Grove, Team Leader, Baltimore Field Station,

 

Citation:

Grove, J.M., Cadenasso, M., Pickett, S.T., Burch, W.R. and Machlis, G.E., 2015. The Baltimore School of Urban Ecology: space, scale, and time for the study of cities. Yale University Press.

 

Last Modified: September 21, 2017