Zac Freedman (Principal Investigator)
Zac is interested in the ecology and environmental significance of microorganisms in a changing world. He completed his postdoctoral training at the University of Michigan with Dr. Don Zak and his PhD at Rutgers University with Dr. Tamar Barkay. Zac is a native of Evanston, Illinois and enjoys long bike rides, discovering new music, and all things hockey. Before embarking on a career in science, Zac was a camp counselor, a hot dog vendor at Wrigley Field in Chicago and a security guard at the Gorge Amphitheater in Washington State.
Zac’s CV
Annalise Keaton (Research Specialist)
Annalise is a graduate from UW-Stevens Point where she focused her studies on Botany and Conservation Biology. Having lived in Wisconsin her whole life, she is passionate about conserving its beautiful ecosystems. She enjoys spending her time out in nature, in her garden or in local pottery studios.
Brooke Propson (PhD Student)
Brooke is a PhD student and NSF Graduate Research Fellow in the Department of Soil Science. She joined the Freedman Lab in 2021 after graduating with a B.S. from the University of Michigan in 2019. Brooke is a biogeochemist who studies the impacts of altered anthropogenic activity on nutrient cycling and storage via changes in the soil microbial community, focusing on responses to changes in atmospheric nitrogen deposition. Outside of science, she enjoys xc skiing, reading, and exploring coffee shops and breweries around Madison.
Brooke’s website
Twitter & Instagram: @bpropscience
Gwen Pipes (PhD Student) 
Gwen is a first year PhD student in the Freedman Lab. She earned a B.S. in Environmental Science and an M.S. in Natural Resources from Cornell University. Gwen is interested in studying restoration in anthropogenically degraded landscapes and its impact on soil carbon storage. In her free time, she enjoys spending time with her cat, Atlas, doing art, and running.
Hannah Anderson (PhD Student)
Hannah is a MS+PhD track student in the Soil Science program. She earned a B.S. in Environmental Sciences, Policy and Management from the University of Minnesota, Twin Cities with emphases in soil science and forestry. She is interested in the integration of methods in soil biology and biochemistry with proximal and remote soil sensing, in addition to classical soil science theory to improve our characterization and prediction of soil functioning. Her masters thesis is taking a multi-omics approach in soil microbiomics and metabolomics to investigate plant-soil interactions in organic vegetable systems. Her PhD will be investigating soil recovery from mining and agricultural disturbance through the lens of microbially mediated carbon processes, organic matter dynamics and soil sensing.
Hannah’s website
Soni Ghimire (PhD Student) 
Soni joined the Freedman lab in June 2023. She earned a B.S. in Agriculture from Agriculture and Forestry University, Nepal in 2019 and an M.S. from Virginia Tech in 2023. She is interested in Soil Science, Remote Sensing, and Data Analytics. Her previous work focused on estimating the contributions of soil and cover crop N mineralization for corn. Soni’s current work integrates the use of MIR spectroscopy and inexpensive soil sensing technologies to understand the crucial microbial processes, ultimately facilitating the improvement of next-generation biogeochemical models. She enjoys cooking, reading books, watching series, and spending time with her family during her leisure time.
Erica Shoenberger (Phd Student) 
Erica is a PhD student in the Freedman and Picasso labs. She is conducting on-farm research in WI with the dual-purpose, perennial grain and forage, crop Kernza intermediate wheatgrass. She is exploring how transitioning land from annual to perennial grain cropping systems impacts soil health, microbial communities, and carbon dynamics. She loves camping, skiing, hanging out with her niece and nephew, growing an abundance of vegetables, and playing the guitar.
Hannia Ramírez (MS Student) 
Hannia is an M.S. student in Agroecology and an AAUW and Fulbright Scholar. She joined the Freedman Lab in 2025 after earning a B.S. in Biotechnology from Tecnológico de Monterrey. Her research focuses on applied plant-microbe interactions to improve the resilience, performance, and sustainability of edible crops. Hannia is excited to explore her identity as a scientist and aims to integrate sociological and participatory research approaches into her work.
Linnea Pelto (Undergraduate Research Assistant) 
Linnea is a third-year student majoring in Biology and Spanish at UW-Madison. She is passionate about the connections between ecological processes and human life. She is excited about pursuing a career in medicine. In her free time, she likes running, reading, and spending time with her friends.
Lab Alumni
Postdoctoral Fellows
Grace Cagle (2022-2025)
Project: Using successional dynamics, biogeography, and experimental communities to examine mechanisms of plant‐microbiome functional interactions
Graduate Students
Tanner Judd (PhD, 2025)
Dissertation Title: Investigating Carbon and Nitrogen Cycling Across Agricultural Landscapes Through Probing of Microbial Mechanisms
Current Position: Assistant Professor of Plant and Soil Science at West Texas A&M University
Clare Tallamy (MS, 2025)
Dissertation Title: Exploring Dynamics of Rhizosphere Microbiome Assembly in Organic Carrots (Daucus carota subspecies.)
Salvador Grover (MS, 2023)
Dissertation Title: Early production of switchgrass (Panicum virgatum L.) and willow (Salix spp.) indicates carbon accumulation potential in Appalachian reclaimed mine and agricultural soil
Current Position: Air Pollution Specialist at the California Air Resources Board
Greg Martin (PhD, 2022)
Dissertation Title: Anthropogenic disturbance regimes impact the microbial and chemical composition of soils and sediments across ecosystems
Current Position: Postdoc at Pacific Northwest National Lab
Jen Kane (MS, 2019; PhD, 2022)
MS Thesis Title: Soil microbial succession following surface mining is governed primarily by deterministic factors
PhD Dissertation Title: Cross-kingdom interactions shape soil biogeochemistry in natural and agricultural ecosystems
Current Position: Postdoc at West Virginia University.
Brianna Mayfield (MS, 2019)
Thesis Title: Mine reclamation using biofuel crops: Insights into the microbial ecology of the switchgrass (Panicum virgatum) microbiome.
Current Position: Senior Research Services Professional at University of Colorado Denver.
Jordan Koos (MS, 2018)
Thesis Title: Prescribed defoliation strategies influence soil carbon storage and nitrous oxide emission potential in West Virginia pastures
Current Position: Soil Conservationist at the Natural Resources Conservation Service.
Undergraduate Students
Anella Cousin (Undergraduate Research Assistant, 2020-2022)
Annalisa Stevenson (Independent Study, 2020)
Amalia Petropoulos (Undergraduate Research Assistant, 2021-2022)
Jeremy Fleck (Undergraduate Research Assistant, 2021-2023)
Alessia Fucentese (Undergraduate Research Assistant, 2021-2023)
Mar Gut (Undergraduate Research Assistant, 2022-2023)
Emily Sautebin (Undergraduate Research Assistant, 2022-2024)
Ethan Krull (Undergraduate Research Assistant, 2023-2025)