Rachel Keen, Assistant Professor
Contact information
103 Bushnell Hall
(785) 532-6615
rkeen@ksu.edu
Education
Ph.D. 2023, Kansas State University. Biology.
Area(s) of Specialization
Grassland/savanna ecohydrology, soil hydrology, plant ecophysiology
Research Focus
Research in our lab focuses on the interaction between ecological and hydrological systems in open ecosystems, including grasslands, savannas, and shrublands. Open ecosystems around the world are experiencing shifts in vegetation cover (e.g., grassland to woodland) that have the potential to drastically alter landscape-scale water fluxes. Much of our current work explores how vegetation impacts soil structure and mediates water fluxes, both above- and below-ground. These water fluxes influence carbon and nutrient cycling, plant productivity, local water yield, and ecosystem responses to drought and other disturbance events. The work we do is highly interdisciplinary, utilizing methods and experimental approaches from plant ecophysiology, hydrology, soil science, and atmospheric science to explore how vegetation influences critical zone function in open ecosystems, particularly in the context of changing climate, land-use, and land-cover.
Selected Publications
Li, B., Sprenger, M., Araki, R., Ajami, H.,, Rudisill, W., Crompton, O., Gimenez, D., Groh, J., Hirmas, D., Koop, Keen, R.M., et al. 2026. Dominant controls on preferential flow and their implications for future soil water fluxes. Earth's Future 14, e2026EF008296.
Sadayappan, K., Jarecke, K.M., Keen, R.M., Puthalalth, S., Dodds, W.K., Kirk, M.F., Sullivan, P.L., Nippert, J.B., Seybold, E.C. and Li, L. 2026. Flow or no-flow: Does discharge regulate water chemistry in intermittent streams? Water Resources Research 62, e2025WR040321.
Jarecke, K.M., Keen, R.M., Singha, K., Nippert, J.B., Billings, S.A., Zhang, X., Sadayappan, K., Kirk, M.F., Hirmas, D.R., Li, L., Ajami, H., Dumont, M., Flores, A.N. and Sullivan, P.L. 2025. Woody encroachment intensifies deep soil drying at daily, seasonal, and decadal scales. Ecosystems 28, 64.
Keen, R.M., Sadayappan, K., Jarecke, K., Li, L., Kirk, M.F., Sullivan, P.L., Nippert, J.B. 2024. Unexpected hydrologic response to ecosystem state change in tallgrass prairie. Journal of Hydrology 643,131937.
Keen, R.M., Helliker, B.R., McCulloh, K.A., and Nippert, J.B. 2024. Save or spend? Diverging water-use strategies of grasses and encroaching clonal shrubs. Journal of Ecology 112, 870–885.
Sadayappan, K., Keen, R.M., Jarecke, K.M., Moreno, V., Nippert, J.B., Kirk, M.F., Sullivan, P.L. and Li, L. 2023. Drier streams despite a wetter climate in woody-encroached grasslands. Journal of Hydrology 627, Part B,130388.
Dodds, W.K., Ratajczak, Z., Keen, R.M., Nippert, J.B., Grudinski, B., Veach, A., Taylor, J. and Kuhl, A. 2023. Trajectories and state changes of a tallgrass prairie stream and riparian zone after a decade of woody plant removal. Ecological Applications 33(4): e2830.
Keen, R.M., Nippert, J.B., Sullivan, P.L., Ratajczak, Z.R., Ritchey, B., O’Keefe, K. and Dodds, W.K., 2023. Impacts of riparian and non-riparian woody encroachment on tallgrass prairie ecohydrology. Ecosystems 26, 290–301.
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