The Dung Beetle & Climate Change
Morgan Fleming is a senior working in the Sheldon Lab. She has always loved the sciences and the outdoors, and quickly found her home in the EEB department after arriving at UT. Recently, Morgan completed an independent project investigating how early life stages of the dung beetle, Onthophagus taurus, change their metabolism in response to temperature, a key question in response to climate change. Specifically, she examined metabolic plasticity in response to increasing temperature mean and variance and potential fitness tradeoffs.
Dung beetles provide a variety of ecosystem services by removing and processing dung, including nutrient cycling, reduction of parasites, and secondary seed dispersal, that may be altered in a warming world. Understanding how dung beetles respond to temperature changes can thus lead to better predictions of how climate change may affect key ecosystem services. While there is abundant research on thermal responses of adult insects, less is known about physiological responses in earlier life stages that could help mitigate the impacts of climate change. Morgan reared beetles in incubation treatments that varied in temperature mean and fluctuation. She completed metabolic trials on beetle pupae and then measured body size of the beetles when they emerged as adults. Morgan found that pupae in the warmest, most variable temperatures reduced their energetic demands but had much smaller adult body sizes compared to pupae reared in other temperature treatments. Results of this study suggest that plasticity in early life stages could mitigate impacts of climate change on dung beetles, but this may come at a cost to fitness later in life since small-bodied adults have reduced reproductive success.
Earlier this year, Morgan received the EEB Outstanding Undergraduate Research Poster Award, the Award of Excellence at the EURēCA conference, and a summer research grant from the UT Office of Undergraduate Research. In August 2019, she presented her work at a national conference. She also won a prestigious National Science Foundation Graduate Research Fellowship. Morgan plans to continue on to EEB’s PhD program.
This regional biodiversity also faces local challenges such as increased urbanization and population density, fires, and global challenges such as climate change. Understanding and conserving the ecosystems and their functions are critical to safeguarding the many life sustaining and enhancing benefits people in the region derive from nature. For example, GSMNP is the most visited national park in the US, bringing more than $950 million in visitor spending in 2019 that supported 13,737 jobs in the local area, but overuse is a park management concern. Likewise, the mighty Tennessee River provides water to five million people and is home to more than 250 species of native fishes. East Tennessee is becoming increasingly important as a significant carbon sink because of its intensively managed, highly productive forests.
Susan Kalisz, the College of Arts and Sciences Excellence Professor and head of the Department of Ecology and Evolutionary Biology, is a newly elected member of the American Academy of Arts and Sciences class of 2020.