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

As a plant ecophysiologist, I am broadly interesting in studying the functional relationship between plants and their environment. My research focuses on three areas: 1) improving fine-scale spatiotemporal resolution of water movement through the soil-plant-atmosphere continuum; 2) elucidating physiological mechanisms of woody and herbaceous species coexistence in grasslands; and 3) understanding physiological responses of plants to climate variability. Understanding plant-water relations at fine spatiotemporal scales has been the primary focus my graduate research, and through this work I have investigated processes such as hydraulic redistribution, nocturnal transpiration, and source-water partitioning in grassland communities. I use a variety of techniques to address my research questions, including leaf gas exchange, sap flow sensors, stable isotope analyses, and hydraulic measurements. Although my research has primarily focused on grasslands, I am interested in addressing similar ecophysiological questions in other systems as well.

CV (last updated - Feb, 2016)


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 Lab Manager

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. Rachel will be leaving us in Jan. 2017, to begin a M.S. at Utah State University working with Prof. Steve Voelker.


Lindsey Swartz
Undergrad - Senior
Major: Biology

Lindsey started working in the lab during the summer of 2015, assisting Kim, Rory, and Braden on Konza with their work on shrub physiology. Since then, she's been a part-time lab assistant helping keep the lab and SIMSL running smoothly.


Aolani Zidek
Undergrad - Freshman
Major: Biology

Aolani brings tremendous enthusiasm to the lab. She spend the summer 2016 helping Rory and Mira with Konza fieldwork and helping Rachel in SIMSL. Aolani is still deciding what type of biologist she wants to become, but we will do our best to push her towards plant physiological ecology!

Former Post-doctoral Scholars

Amy Concilio (2012-15)
Currently: Assistant Professor, St. Edwards, Austin, TX

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
Mira Ensley-Field (2016) from Macalester College
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: 28-Aug-2016