Postdoctoral Research

During my postdoc in the Environmental Science (ENVS) Program at Trinity College, my students and I had a plethora of diverse, but connected, research projects. The Ehlert lab at Trinity focused on ecologically based management of invasive plants, with a special focus on Berberis thunbergii, Japanese barberry. Specifically, we looked at the intersection between Japanese barberry and Ixodes scapularis (the black-legged tick). Forests invaded with Japanese barberry have twice as many ticks as those that aren’t; this is associated with the fact that Japanese barberry creates the ideal, humid environment that ticks need to avoid desiccation. Here’s a closer look at what we did:

  • Bailey D’Antonio ’18 spent summer 2017 along with Blair Frantz ’17 conducting Japanese barberry research. Bailey successfully defended her senior thesis in the Biology department, and was co-advised by Dr. Amber Pitt (Biology/ENVS) and I. Specifically, Bailey focused on the effect of microhabitat on black-legged tick abundance on the white-footed mouse, Peromyscus leucopus. White-footed mice are reservoirs of Borrelia burgdorferi, the bacteria that causes Lyme disease. Ticks feed on mice for one of their blood meals, become infected, and move on to their next blood meal – often a human, thereby transmitting Lyme disease. Bailey accomplished this research by using live-catch traps in the field, and counting tick load on each captured mouse; after counting was complete, the mice were released back into the wild.
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    Biology student Bailey D’Antonio ’18 (left) and Blair Frantz ’17 (right) in the field with a Japanese barberry shrub that has been uprooted.

  • ENVS alumna, Corinne Macaulay ’18 and I investigated the role of horses as potential vectors of invasive plant seeds. Corinne and I were interested in this research question because we each have a horse! Horses are able to transport invasive seeds not only through their digestive tract, with seeds ending up in their feces, but their manes, tails, and fur can also easily transport seeds. We focused on the latter for Corinne’s research. Corinne started her research by conducting a survey of Intercollegiate Horse Show Association (IHSA) horseback riders, to learn about their attitudes toward and knowledge of invasive plants. Corinne expanded upon the survey by conducting experiments with our own horses and others to investigate how far seeds can travel when attached to their fur.

Corinne Macaulay ’18 presenting the results of her survey at the student research colloquium in Spring 2017.


Corinne and her horse, “Pilgrim.”

  • ENVS alum, Adam Hammershoy ’17  assessed different survey methods of Japanese barberry in Simsbury, CT. Adam specifically used transects and GIS to quantify the extent of invasion at our study site. Along each 50 m transect, Adam utilized a quadrat to count Japanese barberry density and cover. With GIS, Adam downloaded NDVI (normalized difference vegetation index) satellite data to map Japanese barberry locations, as you can see below. The NDVI values closely align with the dense shrubbery that we associated with Japanese barberry from Adam’s transects.

Map displaying 2016 NDVI vegetation coverage and their equivalent values within the study site.


Adam Hammershoy ’17 trapped in the barberry with his quadrat.

  • ENVS alumna, Blair Frantz ’17 investigated the invasivore movement, specifically as it related to Japanese barberry. The invasivore movement is a means of eradicating invasive species through human consumption. In the past, the fruit of Japanese barberry has been used to make…jam! Blair went to work by first conducting a strong literature review of the invasivore movement and how it became popularized. Next, she spent time in the kitchen! Blair was able to successfully produce jam from Japanese barberry, providing an alternative means of controlling this insidious invader.

Blair Frantz ’17 holding the jam she produced from Japanese barberry fruit, alongside the poster she presented at the student research colloquium in Spring 2017.