Zak Ratajczak, Assistant Professor

Zak Ratajczak

Contact information

218 Bushnell Hall

Lab website:


Ph.D. 2014, Kansas State University. Biology.

Area(s) of Specialization

Community Ecology, Fire, Grasslands & Savannas, and Resilience Theory

Research Focus

My goal is to better understand how ecosystems respond to changing climate and land management, with an emphasis on fire, large mammals, and climate extremes. I am particularly interested in resilience, which is a system's ability to maintain its identity, functions, and feedbacks, despite changes in disturbances and other environmental drivers. My work is rooted in tallgrass prairie of the central Great Plains, but often includes cross-site syntheses. I use the full suite of approaches in modern science: observational studies, experimental manipulations, theoretical models, and next-generation simulation models.

Research in the lab aims to address both pressing conservation issues and advancing ecological theory. Some of the questions we are working on are:

  • What types of climate extremes are more likely to exceed ecological resilience?
  • Do ecosystems have tipping points, where small changes in management, like fire or grazing, have large ecological consequences?
  • And can we identify climate and management tipping points before we cross them?
  • How does the reintroduction of extirpated animals and disturbances (e.g. fire) affect the resilience to projected changes in climate?

Selected Publications

Turner, M.G., Calder W.J., Cumming G.S., Hughes T.P., Jentsch A., LaDeau S.L., Lenton T.M., Shuman B.N., Turetsky M.R., Ratajczak Z., Williams J.W., Williams A.P., and Carpenter S.C. 2020. Climate Change, Ecosystems, and Abrupt Change: A Science Agenda. Proceedings of the Royal Society B Biological Sciences.

Ratajczak Z. and Ladwig L. 2019. Will climate change push grasslands past tipping points? Book chapter for "Grasslands and Climate Change" Gibson D. and Newman J. (eds) British Ecological Society and Cambridge University Press, Cambridge UK.

Ratajczak Z., Carpenter S., Ives A., Kucharik K., Ramiadantsoa T., Stegner A.M., Williams J., Zhang J., Turner M.G. 2018. Abrupt change in ecological systems: diagnosis and inference. Trends in Ecology and Evolution 33: 513-526.

Seakell D. Carr J., Dell'Angelo J., Gephart J., Kummu M., Magliocca N., Porkka M., Prell P., Puma M.J., Ratajczak Z., Rulli M.C., Seekell D.A., Suweis S., Tavoni A., D'Odorico P. 2017. Conceptualizing and quantifying resilience in the global food system. Environmental Research Letters 12: 025010.

Ratajczak Z., J.B. Nippert, J.C. Hartman, and T.W. Ocheltree. 2011. Positive feedbacks amplify rates of woody encroachment in tallgrass prairie. Ecosphere 2: art121.

View publication list on Google Scholar