Callie BlackHeading into my senior year as a Natural Resources and Environmental Science major at UK, I became interested in studying the Dahurian buckthorn (Rhamnus davurica), a woody invasive that is emerging in central Kentucky. This plant is extremely under-studied and could have tremendous impacts on our ecosystems if left untreated. My mentor, Dr. John Cox, and I want to learn more about this plant in order to gauge how extreme this invasive species is and how to manage it properly.
This past spring, we labeled 60 buckthorn, as well as 60 bush honeysuckle and 30 spicebush as our two control groups. Each week, I would check on the plants to see if the buckthorn would leaf out earlier than the other species. Understanding how fast this invasive emerges in the spring can tell us if it is phenotypically advantageous compared to other plants in its environment.
I am now a 2025 Summer Sustainability Research Fellow studying the fruit phenology of the Dahurian buckthorn. I regularly check all of the buckthorn samples that bear fruit and record the ripening stage. I collect 5 fruits from 10 trees, label them, then put them in the freezer that evening. We will use these samples to analyze the chemical composition of the buckthorn plants at various life stages.
Obtaining plot surveys to see the prevalence of Dahurian buckthorn across landscapes is another fundamental part of my research. I open Avenza, a geospatial mapping software, and locate my next plot survey point. I analyze all plants less than 1 inch in diameter at breast height (this is a standard for measuring the diameter of a standing tree trunk and is usually around 4.5 feet in the US) in a specific section of that plot, and then record all plants above 1 inch in that same section. After I complete all of the field work for the day, I go back and record all of my findings in excel.
Throughout my time researching this invasive, I have encountered lots of exciting finds. Seeing the differences between these species’ phenologies has been very rewarding. I have learned so much about the research process and how dedicated you need to be in order to have accurate and accountable results. Needless to say, the journey has been fascinating!
Knowing I am making a difference in my local ecosystems is my main motivation for this research. After studying the phenology of the plant, my interest will shift towards the wildlife impact of it. In the fall I plan on collecting deer scat samples to analyze if they’re eating the fruit, as well as setting out bird and mammal trays. I hope my research is used to implement conservation strategies in order to better manage this plant before it further disrupts Kentucky’s ecosystems.
