Who we are


 jesse headshot

Jesse Nippert
Associate Professor

My research focus is on plant eco-physiological responses to changes in water availability (spatially, temporally, or driven by climate changes). Particularly, I'm interested in the mechanims of drought tolerance by grassland and savanna species (structure / function) as well as the theory of competition/ facilitation for water between trees and grasses. Thus, I enjoy spending my time addressing questions linking resource availability - physiology - patterns of productivity, with the goal of improving our ability to scale energy dynamics and hydrological processes from the plant- to ecosystem-level.

I love spending time outdoors in the grasslands. These systems exist within an interface of climatic variability and frequent disturbance (fire and grazers). Grass species are deceptively simple, but their unique physiology and form is adapted to environmental stress and disturbance. Despite abiotic and biotic pressures, grasses are masters of growth efficiency and develop dense canopies and high biomass. The environmental and biotic complexity of grasslands provides a challenging (mentally and physically) and enjoyable system to study. For me, there is nothing better than spending a day in the sun of the Konza Prairie.

CV (last updated - Apr 2015)


Kim O'Keefe
PhD Candidate

My research investigates how physiological mechanisms of plant water-use drive larger scale ecological phenomena such as plant survival and productivity, patterns of species coexistence, and earth-atmosphere exchange of fluxes in grasslands. For example, I am linking root structure with water-use patterns (multi-scale hydrological fluxes), understanding mechanisms of competition and facilitation for water among coexisting species, and predicting the responses of these processes to hydrological variation associated with global climate change. For my dissertation I am using whole-plant sap flux and stable isotope techniques in a tallgrass prairie to ask the following questions: (1) What are the biological and/or environmental drivers of hydraulic redistribution? (2) Do patterns of hydraulic redistribution differ among functional types (shrubs, forbs, and grasses) and ecological gradients (topography and grazing treatments)? (3) How does this mechanism influence competition and facilitation for water among different functional types? (4) How does hydraulic redistribution influence landscape-level carbon and water fluxes? I am also intersted in other hydrological fluxes in this system (night-time transpiration), as well as identifying the adaptive significance of drought avoidance (hydraulic redistribution) versus drought tolerance strategies, particularly in the context of global climate change.

CV (last updated - Aug, 2013)


Rory O'Connor
PhD Student

My proposed research will investigate the mechanisms of woody plant establishment in grassland ecosystems. How do woody plants establish themselves in a fire prone environment and within the tightly-knit root matrix of grasses? What are the above ground constraints that restrict establishment? Likewise, what are the belowground constraints of establishing in grasslands? A lot of work has been done exploring this topic in arid and semi-arid grasslands and savannas. However, woody expansion and establishment by both native and exotic species in mesic grasslands is less developed. I plan on using roughleaf dogwood and smooth sumac as my model species because both are clonal, respond similarly to fire and are increasing in abundance in the tall grass prairie.


Seton Bachle
MS Student

Seton joins us from Nebraska - having earned his BS from Hastings College. Seton's thesis will focus on identifying physiological traits associated with drought tolerance in grass species. This work will use paired congeneric grasses in experimental dry-downs. In addition, he likely will be involved in drought tolerance experiments on Konza Prairie.


Rachel Keen
SIMSL Technician

Rachel started working with us in Jan., 2014 as a biology undergrad. Currently, she is working in the lab as the primary technician responsible for SIMSL (the stable isotope lab). In addition to these responsibilities, Rachel is conducting research on Konza comparing source-water use among trees and grasses in the riparian watersheds. Her research investigates the proportional releiance of these streamside trees on Konza stream water, in collaboration with Dr. Walter Dodds.


Lindsey Swartz
Undergrad - Junior
Major: Biology

Lindsey is the primary field assistant on Konza for all the shrub physiology work performed by Kim and Rory. She started working in the summer 2015 and we plan to keep her around for the foreseeable future!

Former Post-doctoral Scholars

Amy Concilio (2012-15)
Currently: Visiting Professor- Fort Lewis College, Durango, CO

Former Graduate Students

Zak Ratajczak (2011-2014) Ph.D. - Biology
Currently: NSF Post-doctoral Fellowship, University of Virginia and the Stockholm Resilience Center

Troy Ocheltree
(2008-12) Ph.D. - Agronomy and SIMSL Manager
Currently: Assistant Professor, Dept. Forestry and Rangeland Stewardship, Colorado State University

Jeff Hartman (2009-11) M.S. - Biology
PhD (2015): University of Nebraska-Lincoln (w/ David Wedin)
Currently: TBD

Sally Kittrell nee Tucker) (2009-10) M.S. - Biology
Currently: Oklahoma State University (w/ Gail Wilson & Janette Steets)

Jacob Carter (2008-10) M.S. - Biology
PhD (2015): University of Kansas (w/ Joy Ward)
Currently:Post-doctoral fellow with the EPA in Washington DC

Former Undergrads

K-State Students
Ben Ketter (2012-2014) - now MS student at U Missouri
Gracie Orozco (2009-2014) - Environmental Engineer, Victoria, TX
Laura Kemp (2011-2012) - scientist at The Land Institute in Salina, KS
Whitley Jackson (2008-2012) - now at KU-Med School in KC
Teall Culbertson (2008-2011) - now a VetMed student at K-State

REU Students
Braden Hoch (2015) from K-State
Andy Muench
(2014) from U Wisconsin-Madison
Ben Ketter
(2013) from K-State
Annie Klodd
(2011) from Grinnell College
Rachel Wieme (2010) from St. Olaf's College
Zak Ratajczak (2009) from Vassar College
Laura Kangas (2008) from Michigan Tech

  Last Update: 16-Dec-2015