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Natural Resource Ecology and Management

NREM Faculty - Karen R. Hickman


Professor and Director, Environmental Science

365 Agricultural Hall
Stillwater, OK 74078

Educational Background
BS:1985 B.S., Oklahoma State University
PhD:1996 PhD., Kansas State University


Curriculum Vitae


  • NREM 4033/5033*: Ecology of Invasive Species

Research Interests:
My research program focuses primarily on addressing and understanding the effects of various management practices on plant and animal populations and communities within rangeland ecosystems of the Great Plains.  Native rangelands, grasslands, and pasturelands in Oklahoma as well as throughout the central and southern Great Plains are under new threats from invasion by exotic and native species and exurban sprawl, as well as traditional challenges associated with livestock and wildlife management.  My primary research goals are to further evaluate effects of management practices (e.g. grazing, patch burning, herbicide application, revegetation) on invasive species in Oklahoma grasslands, and to elucidate abiotic (e.g. fire, precipitation), plant-plant and plant-animal interactions that might be involved in limiting invasions of native systems by various invasive species.  Ultimately, my research goals are to establish collaborations with other researchers throughout the US and northern Mexico (i.e. Chihuahua) and continue to collaborate with researchers at OSU in order to conduct research whose results can be influential in the development and application of proper (and adoptable) land management practices.

Recent Publications (since 2005)

PEER-REVIEWED PUBLICATIONS:  (graduate students are preceded by *)

*Duell, E.B., G.W.T. Wilson, K.R. Hickman. 2016.  Above- and below-ground responses of native and invasive prairie grasses to future climate scenarios.  Botany 94:1-9.

**Claytor, M., & Hickman, K.R. 2015. Kudzu, Pueraria montana (Lour.) Merr. Abundance and distribution in Oklahoma. Oklahoma Native Plant Record 15:96-102.

*Winter, S. L., B.W. Allred, K.R. Hickman, and S.D. Fuhlendorf.  2015.  Tallgrass prairie vegetation response to spring fires and bison grazing.  Southwestern Naturalist 60:30-35.

**Keil, Katherine, K.R. Hickman.  2014. Mapping distribution in Oklahoma and raising awareness:  purple loosestrife (Lythrum salicaria); multiflora rose (Rosa multiflora), and Japanese honeysuckle (Lonicera japonica).  Oklahoma Native Plant Record 14:43-49.

*Greer, M.J., G.W.T. Wilson, K.R. Hickman, and S.M. Wilson.  2014.  Experimental evidence that invasive grasses use allelopathic biochemical as a potential mechanism for invasion: chemical warfare in nature.  Plant and Soil 385:165-179.

*George, A.D., T.J. O’Connell, K.R. Hickman and D.M. Leslie, Jr.  2013.  Food availability in exotic grasslands: a potential mechanism for depauperate breeding assemblages.  The Wilson Journal of Ornithology 125:526-533.

Fulbright, T.E., K.R. Hickman, and D.G. Hewitt.  2013.  Exotic grass invasion and wildlife abundance and diversity, south-central United States.  Wildlife Society Bulletin

*Beas, B.J., L.M. Smith, K.R. Hickman, T.G. LaGrange, and R. Stutheit. 2013. Seed bank responses to wetland restoration: do restored wetlands resemble reference wetland conditions following sediment removal? Aquatic Botany 108:7-15.

*Robertson, S., K.R. Hickman, K.R. Harmoney, D.M. Leslie, Jr. 2013.  Combining glyphosate with burning or mowing improves control of yellow bluestem (Bothriochloa iscahemum).  Rangeland Ecology and Management 66:376-381.

*Winter, S.L. K.R. Hickman, S.D. Fuhlendorf, and C.L. Goad.  2013.  Seasonal fires, bison grazing, and the tallgrass prairie forb Arnoglossum plantagineum Raf.  Natural Areas Journal 33:327-338.

*S. Robertson and K.R. Hickman.  2012.  Aboveground plant community and seed bank composition along an invasion gradient.  Plant Ecology 213:1461-1475.

Wilson, G.W.T., K.R. Hickman, M.M. Williamson.  2012.  Invasive warm-season grasses reduce mycorrhizal root colonization and biomass production of native prairie grasses.  Mycorrhiza 22:327-336.

Harmoney, K.R. and K.R. Hickman.  2012.  Comparing morphological development and nutritive value of Caucasian old world bluestem and native grasses.  Forage and Grazinglands (published online 27 Jan 2012).

*Winter, S.L, S.D. Fuhlendorf, C. Goad, C.A. Davis, and K.R. Hickman, David C. Leslie, Jr.   2012. Restoration of the fire-grazing interaction in Artemisia filifolia shrubland. Journal of Applied Ecology 49:242-250.

Derner, J.D.,  K.R. Hickman, and H.W. Polley. 2011.  Decreasing precipitation variability does not elicit aboveground biomass or plant diversity responses in mesic rangeland.  Rangeland Ecology and Management 64:352-357.

*Winter, S.L, S.D. Fuhlendorf, C. Goad, C.A. Davis, and K.R. Hickman.  2011.  Topoedaphic variability and patch burning in Sand Sagebrush Shrubland.  Rangeland Ecology and Management 64:633-640.

*Winter, S.L, S.D. Fuhlendorf, C. Goad, C.A. Davis, K.R. Hickman, and D.C. Leslie, Jr.  2011.  Fire tolerance of a Resprouting Artemesia (Asteraceae) Shrub. Plant Ecology 212:2085-2094.

Harmoney, K.R., P. Stahlman, P. Geier, K.R. Hickman.  2010.  Rate and timing of glyphosate application to control Caucasian Old World bluestem (Bothriochloa bladhii).  Invasive Plant Science and Management.  3: 310-314.

*van Els, P., R. E. Will, M. W. Palmer and K. R. Hickman.  2010. Changes in forest understory associated with Juniperus encroachment in Oklahoma, USA. Applied Vegetation Science 13: 356-368.

Davis, C., J. Bidwell, K.R. Hickman.  2009.  Effects of hydrological regimes on competitive interactions of Schoenoplectus fluviatilis and two co-occurring wetland plants.  Aquatic Botany 91:267-272.

*George, A.D., T.J. O’Connell, K.R. Hickman and D.M Leslie, Jr.  2009.  Influence of Old World Bluestem (Bothriochloa iscahemum) monoculture on breeding density of three grassland songbirds in Oklahoma. Proceedings of the Fourth International Partners in Flight Conference. Pages 691-697.

*Schmidt, C.D., K.R. Hickman, R. Channell, W.J. Stark, and K.R. Harmoney.  2008.  Competitive ability of native grasses and non-native (Old World Bluestems; Bothriochloa spp.) grasses.  Plant Ecology 197:69-80.

*Limb, R.F., K.R. Hickman, J. Norland, T.G. Bidwell, D.M. Engle, A. Alford.  2007.  Digital Photography: Reduced Investigator Variation in Visual Obstruction Measurements for Southern Tallgrass Prairie.  Rangeland Ecology and Management.  60:548-552.

Hickman, K.R. and J.D. Derner. 2007.  Vegetation change after cessation of herbicide application in Blackland Tallgrass Prairie.  Rangeland Ecology and Management. 60:186-190.

Harmoney, K.R., P.W. Stahlman, and K.R. Hickman. 2007.  Suppression of Caucasian Old World Bluestem by Split Application of Herbicides.  Journal of Weed Technology.  21:573-577.

Hickman, K. R., G. H. Farley, R. Channell, and *J E. Steier.   2006.  Effects of Old World Bluestem (Bothriochloa ischaemum) on food availability and avian community composition within the mixed-grass prairie. Southwestern Naturalists. 51:524-530.

*Schmidt, C.D. and K.R. Hickman. 2006.  Stolon production in Caucasian old world bluestem.  Transactions of the Kansas Academy of Science. 109:74-76.

Harmoney K.R. and K.R. Hickman.  2004.  Comparative Morphology of Caucasian Old World Bluestem (Bothriochloa bladhii) and Native Grasses.  Agronomy Journal.  96:1540-1544.

Harmoney, K.R., P.W. Stahlman, and K.R. Hickman. 2004. Herbicide Effects on Established Yellow Bluestem (Bothriochloa ischaemum).  Journal of Weed Technology.  18:545-550.

Hickman, K.R., D.C. Hartnett, R.C. Cochran, and C.E. Owensby.  2004.  Grazing management effects of plant species composition and diversity in tallgrass prairie.  Journal of Range Management. 57:58-65.

Hickman, K.R. and D.C. Hartnett.  2002.  Effects of grazing intensity on growth, reproduction, and abundance of three palatable forbs in Kansas Tallgrass Prairie.  Plant Ecology. 159:23-33.

Hartnett, D.C., A. Steuter and K.R. Hickman.  1997.  Comparative ecology of native and introduced ungulates.

IN:  Ecology and Conservation of Great Plains Vertebrates.  Springer-Verlag.

Hartnett, D.C.,  K.R. Hickman, L.E. Fischer Walter.  1996.  Effects of bison grazing, fire, and topography on floristic diversity in tallgrass prairie.  Journal of Range Management.  49:413-420.



2017     Options for Expiring Conservation Reserve Program (CRP) Land (NREM-9016). D. Elmore, L. Goodman, K.R. Hickman, and K.. Alspach.

2015     Problem Horticultural Plants (NREM-2895).  D. Elmore, K.R. Hickman, and K. Holmes.

2012     Stocking Rate Determination on Native Rangeland (NREM-2886). T.G. Bidwell, D. Elmore, K.R.Hickman.

2010     Options for Expiring Conservation Reserve Program (CRP) (NREM-9016).  D. Elmore, T.G. Bidwell, K.R. Hickman, R. Wanger.  Oklahoma Cooperative Extension Service Publication.

2010     Old World Bluestems are Invading the Central and Southern Great Plains.  M. Greer, G.W.T. Wilson, and K.R. Hickman. South Texas Natives Fall Newsletter:  A publication of the Caesar Kleberg Wildlife Research Institute at Texas A & M University—Kingsville.

2009     Weed Control on Rangelands (NREM-2882).  J. Weir, T.G. Bidwell, D. Elmore, K.R. Hickman, S.D. Fuhlendorf, D.M. Engle.  Oklahoma Cooperative Extension Service Publication.