Young Researchers Help Track Nearly 1 Million New Trees in Maryland
Tree plantings in 2024 doubled compared to past years. High school interns at UMD are using data science to track and optimize every tree.
Kendi Gray, Endric Lotsch and Elizabeth Yoo spent their summer immersed in satellite imagery, mapping software and environmental data. As interns in the GEOG High School Program at the University of Maryland’s Department of Geographical Sciences, they weren’t just learning about environmental science—they were actively shaping the future of Maryland’s forests.
Their work was part of Maryland’s 5 Million Tree Initiative (5MT), a statewide effort to plant five million trees by 2031 led by the Maryland Department of the Environment (MDE) and supported by a network of agencies, nonprofits and research institutions.
Since the program’s launch in July 2021, 992,989 trees have been planted across the state—a significant step toward reducing carbon emissions, improving air quality, and addressing environmental justice concerns in underserved communities. In 2024 alone, 522,747 trees were planted, marking a remarkable 111% increase in the annual rate of tree plantings compared to the 470,242 trees planted from FY21 to FY23, according to its latest report.
Among the key contributors to this effort is the University of Maryland’s Department of Geographical Sciences (GEOG). In addition to educating the next generation of environmental scientists, GEOG is also using cutting-edge technology to track and validate these tree plantings, among other projects.
Using Remote Sensing and Ecosystem Modeling to Track Trees
Researchers at UMD are tracking the planting of trees over time. By combining remote sensing, ecosystem modeling and high-resolution mapping tools, they can assess where trees have been planted and monitor their growth.
One key tool is LiDAR, a laser-based mapping system that creates 3D images of landscapes, allowing scientists to measure tree height and density. Researchers also use aerial photos from the USDA’s National Agricultural Imagery Program (NAIP) and data from a UMD-led NASA Carbon Monitoring System project to build detailed forest maps. These high-tech methods help ensure Maryland’s reforestation efforts are both measurable and impactful.
“What surprised me the most was Maryland's role in leading the county in environmental science and research,” Yoo said. “I never realized how involved our state was in these sorts of matters.”
Under the mentorship of Professor and Associate Chair George Hurtt, students performed data analysis, graphing and GIS mapping. They analyzed the number of trees planted by county, species and agency, along with their estimated carbon sequestration. Using GIS and remote sensing and ecological modeling, they also identified areas where additional trees could be planted to maximize carbon capture and environmental benefits.
Beyond research and education, the Department of Geographical Sciences is committed to community engagement. Through its High School Program, students gain hands-on experience with geographical sciences, including GIS and remote sensing, as well as soft skills such as problem solving and communication—bridging learning with real-world applications.
“Student involvement was exceptional,” Hurtt said. “It is so gratifying to mentor students on state-of-the-art research with real-world applications.”
During their internship last summer, Yoo and Lotsch honed a range of skills involved with research and analytical abilities, learning to spot trends in data and interpret maps.
“Through analyzing the trees planted, their location and which organizations were responsible for the plantings, we were able to identify patterns and areas of improvement of the initiative,” said Lotsch. He explained how they discovered patterns in tree planting locations and analyzed density using Google Earth and an interactive map to pinpoint underserved areas in Maryland.
About the internship's impact, Lotsch added, “I feel accomplished knowing that the research I conducted has supported the 5 Million Tree Initiative in taking a step closer to its goals.”
This sense of accomplishment carried over to the students’ outlook on their futures and Maryland’s environmental progress. “Maryland’s leadership on the environment gives me hope and reassurance that I can turn this interest into a career,” Yoo shared.
Lotsch echoed a similar sentiment: “I was impressed to learn that the state of Maryland is committed to protecting our environment in the long term. This experience has also motivated me to focus on this field in college.”
Gray, who participated in the 2023 high school program, applied to UMD last year and returned to the project as an undergraduate research assistant.
Main image: Cover of the "Growing 5 Million Trees in Maryland Progress Report 2024." Student headshots courtesy of Elizabeth Yoo and Endric Lotsch.
Published on Mon, 02/24/2025 - 12:51