Jennifer Pontius uses remote sensing and GIS (geographic information system) modeling and mapping tools to help understand, map, and predict changes in forested ecosystems across the Northern Forest and beyond. Her recent work focuses on the detection, mapping, and projection of forest disturbance resulting from invasive species, such as emerald ash borer and hemlock woolly adelgid; global climate change; acid deposition; and forest fragmentation.
With Northeastern States Research Cooperative (NSRC) funding, Jen has used remote sensing tools and satellite imagery to quantify and understand historical trends in forest health and forest land conversion.
“Forest health in the northeastern United States is of increasing concern due to climate change, fragmentation, and invasive pests and pathogens,” stated Jen. “The technologies I use provide valuable tools for early detection of new or existing stressors on forest ecosystems and will allow natural resource practitioners to focus management efforts and prioritize target areas across the landscape.”
Jen is a research associate professor in the University of Vermont Rubenstein School of Environment and Natural Resources with a joint position as a research ecologist with the USDA Forest Service Northern Research Station. In the Rubenstein School, Jen directs the Environmental Sciences undergraduate program and acts as faculty advisor in the Spatial Analysis Laboratory where, with the aid of graduate and undergraduate students, she conducts much of her research.
She is also principal investigator for the Forest Ecosystem Monitoring Cooperative (FEMC), a partnership among the University of Vermont, the State of Vermont Agency of Natural Resources, other northeastern state natural resource management agencies, and the USDA Forest Service. The FEMC brings together forest researchers, managers, and practitioners to share data and information needed to monitor, manage, and understand the health of the region’s forested ecosystems in a changing global environment.
With support from NSRC, Jen and colleague Mary Martin of the University of New Hampshire used satellite imagery of forest canopies from 1984 to 2009 to quantify 25 years of trends in forest health in the northeastern United States. The researchers applied a forest health rating, based on canopy “greenness,” photosynthetic capacity, canopy density, and water content, to the images to quantify yearly forest health. Their findings indicate that forest condition varied from year to year, primarily due to drought and insect pest outbreaks, but as a whole, the condition of forested ecosystems across the region stayed relatively stable over the 25-year period.
“The only signs of decline were in high elevation red spruce and paper birch forests,” pointed out Jen. “Possible causes might include the interacting effects of acid deposition and injury from extreme climate events, such as winter injury, late frost, and ice storms.”
“When monitoring trends in forest health, we don’t always know if the location or measurements used are really capturing how things are changing,” said Sandy Wilmot, retired Forest Health Specialist and Climate Change Coordinator for the State of Vermont. “The work that Jen Pontius has done to develop and use satellite imagery to evaluate forest conditions over time improves our confidence that the small scale forest health trends are also reflected when measured across the larger resource.”
With more recent NSRC funding, Jen teamed up with Gillian Galford of the University of Vermont’s Gund Institute for Ecological Economics to study 30 years of forest land conversion in the northeastern U.S. Once again using satellite imagery, this time from 1984 to 2014, the research team is examining patterns and rates of land cover change. These changes in land use and cover correspond to changes in availability of ecosystem services provided by the land and forests, such as carbon storage, timber production, and biodiversity. By linking the historical data to potential drivers of change, the researchers can project changes in forest structure and function into the future.
“Data and products from this research should help land managers, conservation organizations, and community planners to target forested areas for conservation,” Jen stated.
“Forest fragmentation is one of the critical forest health issues facing Vermont,” said Sandy. “Much attention was paid to this topic in our state legislature in 2016, and with the maps created from this research project, it will be possible to identify priority areas for conservation. This NSRC-funded research project will provide natural resource managers with the information and tools to assess current and future risks to our natural resources. Their results will be critical to understand where to invest our limited resources and management efforts in order to protect key ecosystem services, like clean water.”
Jen and Gillian also received NSRC funding to compare and improve model estimates of forest carbon storage in northeastern forests. The maps they produced will be used in a new decision support tool to allow land managers to highlight key conservation areas based on carbon storage and to better understand the role of northeastern forests in global carbon storage.
Beyond her research, Jen teaches undergraduate and graduate students how to apply remote sensing, statistical, mapping, and modeling tools to natural resources applications. She and her husband and two children enjoy Vermont and the Northern Forest region on their 40-acre Underhill, Vermont farm. While cows and chickens keep them busy at home, the Pontius family takes time to hike up Mount Mansfield’s summit trails or paddle on the Waterbury Reservoir.