Kirk W. Davies

Kirk W. Davies



Rangeland Scientist
U.S. Department of Agriculture, ARS


Dr. Davies is a Rangeland Scientist with the USDA-Agricultural Research Service at the Eastern Oregon Agricultural Research Center in Burns, OR. He received a dual B.S. (2000) in Rangeland Resources and Crop & Soil Science from Oregon State University and a Ph.D. (2005) in Rangeland Resources from Oregon State University. Dr. Davies joined the USDA-Agricultural Research Service as a Rangeland Scientist in October 2006.

Dr. Davies research focuses on vegetation patterns, disturbance ecology, climate and management influences on rangeland vegetation, sagebrush-bunchgrass community ecology, and invasive plant prevention, control, and ecology.

Current Research Projects:

  • Resource islands and vegetation heterogeneity in sagebrush plant communities
  • Ecology and prevention of exotic annual grass invasion
  • Impacts of exotic annual grass invasions
  • Identifying characteristics of invasion resistant plant communities
  • Revegetation of exotic annual grass invaded plant communities
  • Prior disturbance impacts on subsequent disturbances
  • Pre- and post-fire management influence on plant community ecology
  • Wyoming and mountain big sagebrush plan community ecology
  • Influence of disturbances on wildlife habitat in the sagebrush steppe
  • Insect response to distrubances in sagebrush plant communities
  • Feral (wild) horse impacts to riparian areas and adjacent uplands
  • Influence of climate and soils on native vegetation cover, density, and production

Recent Peer-Reviewed Journal Articles:

K.W. Davies, and D.D. Johnson.  2017.  Established perennial vegetation provides high resistance to reinvasion by exotic annual grasses.  Rangeland Ecology & Management 70:748-754.

K.W. Davies, C.S. Boyd, J.D. Bates and A. Gearhart.  2017.  Legacy microsite effect on survival of bitterbrush outplantings after prescribed fire: capitalizing on spatial variability to improve restoration.  Restoration Ecology 25:723-730

K.W. Davies, J.D. Bates, ad A. Hulet.  2017. Attempting to restore mountain big sagebrush four years after fire.  Restoration Ecology 25:717-722.

Bates, J.D. and K.W. Davies. 2017.  Data set on the effects of conifer control and slash burning on soil carbon, total N, organic matter and extractable micro-nutrients.  Data in Brief 14:515-523.

Boyd, C.S., J.D. Kerby, T.J. Svejcar, J.D. Bates, D.D. Johnson, & K.W. Davies.  2017.  The sage-grouse habitat mortgage: effective conifer management in space and time.  Rangeland Ecology & Management 70:141-148.

K.W. Davies, A. Gearhart, C.S. Boyd, J.D. Bates.  2017.  Fall and spring grazing influence fire ignitability and intial spread in shrub steppe communities.  International Journal of Wildland Fire 26:485-490.

K.W. Davies, M.D. Madsen, & A. Hulet.  2017.  Using activated carbon to limit herbicide effects to seeded bunchgrass when revegetating annual grass-invaded rangelands.  Rangeland Ecology & Management 70:604-608

C.S. Boyd, K.W. Davies, & G.H. Collins.  2017.  Impacts of feral horse use on herbaceous riparian vegetation within a sagebrush steppe ecosystem.  Rangeland Ecology & Management 70:411-417.

C.S. Boyd, K.W. Davies & J.A. Lemos.  2017.  Influence of soil color on seedbed microclimate and seedling demographics of a perennial bunchgrass.  Rangeland Ecology & Management 70:621-624.

Bates, J.D., T.S. Svejcar, R.F. Miller, & K.W. Davies.  2017.  Plant community dynamics 25 years after juniper control.  Rangeland Ecology & Management 70:356-362.

Bates, J.D. and K.W. Davies.  2017.  Effects of conifer treatments on soil nutrient availability and plant composition in sagebrush steppe.  Forest Ecology and Management 400:631-644.

Bates, J.D., and K.W. Davies.  2017.  Data set on the effects of conifer control and slash burning on soil carbon, total N, organic matter and extractable micro-nutrients. Data in Brief 14:515-523.

Davies, K.W. and J.D. Bates.  2017.   Restoring big sagebrush after controlling encroaching western juniper with fire: aspect and subspecies effects.  Restoration Ecology 25:33-41.

Svejcar, T.J., C.S. Boyd, K.W. Davies, E. Hamerlynck, and L. Svejcar.  2017.  Challenges and limitations to native species restoration in the Great Basin, USA.  Plant Ecology 218:81-94

Bates, J.D., K.W. Davies, A. Hulet, R.F. Miller, & B. Roundy.  2016.  Sage-grouse groceries: forb response to pinon-juniper treatments.  Rangeland Ecology & Management 70:106-115.

Madsen, M. D., A. Hulet,J.L. Staley, K.W. Davies, and Svejcar, T.J.  2016.  Extruded seed pellets: a novel approach to enhancing sagebrush seedling emergence.  Native Plants Journal 17:230-243.

Madsen, M.D., K.W. Davies, C.S. Boyd, J.D. Kerby, and T.J. Svejcar.  2016.  Emerging seed enhancement technologies for overcoming barriers to restoration.  Restoration Ecology 24:77-84.

Davies, K.W., A. Gearhart, M. Vavra, B.W. Schultz, and N. Rimbey.  2016.  Longer term rest from grazing: A response to Jones & Carter.  Journal of Rangeland Applications 3:9-15.

Nafus, A.M., T.J. Svejcar, and K.W. Davies.  2016.  Disturbance history, management, and seeding year precipitation influences vegetation characteristics of crested wheatgrass stands.  Rangeland Ecology & Management 69:248-256. ARIS 324635.

Hamerlynck, E.P., R.L. Sheley, K.W. Davies, and T.J. Svejcar.  2016.  Postdefoliation ecosystem carbon and water flux and canopy growth dynamics in sagebrush steppe bunchgrasses.  Ecosphere 7:e01376 (pages 1-21).

Davies, K.W., J.D. Bates, C.S. Boyd, and T.J. Svejcar.  2016.  Pre-fire grazing by cattle increases post-fire resistance to exotic annual grass (Bromus tectorum) invasion and dominance for decades. Ecology and Evolution 6:3356-3366.

Davies, K.W., J.D. Bates, and C.S. Boyd.  2016. Effects of intermediate-term grazing rest on sagebrush communities with depleted understories: evidence of a threshold.  Rangeland Ecology & Management 69:173-178.

Davies, K.W., A.M. Nafus, C.S. Boyd, A. Hulet, and J.D. Bates.  2016. Effects of using winter grazing as a fuel treatment on Wyoming big sagebrush plant communities.  Rangeland Ecology & Management  69: 179-184.

Davies, K.W., C.S. Boyd, J.D. Bates, and A. Hulet.  2016.  Winter grazing decreases the probability of fire-induced mortality of bunchgrasses and may reduce wildfire size: a response to Smith et al. (this issue).  International Journal of Wildland Fire 25:489-493.

Davies, K.W., C.S. Boyd, J.D. Bates, and A. Hulet. 2015.  Dormant Season Grazing May Decrease Wildfire Probability by Increasing Fuel Moisture and Reducing Fuel Amount and Continuity.  International Journal of Wildland Fire 24:849-856 (ARIS# 300256).

Davies, K.W., C.S. Boyd, J.D. Bates, and A. Hulet. 2015.  Winter Grazing Can Reduce Wildfire Size, Intensity and Behaviour in a Shrub-grassland International Journal of Wildland Fire.

Bates, J.D., and K.W. Davies. 2015. Seasonal Burning of Juniper Woodlands and Spatial Recovery of Herbaceous Vegetation.  Forest Ecology and Management 361 (2016), 117-130.

Hulet, A., C.S. Boyd, K.W. Davies, and T.J. Svejcar.  2015.  Prefire (Preemptive) Management to Decrease Fire-Induced Bunchgrass Mortality and Reduce Reliance on Postfire Seeding.  Rangeland Ecology and Management 68 (2015), 437-444.

Davies, K.W., C.S. Boyd, D.D. Johnson, A.M. Nafus, and M.D. Madsen.  2015. Success of Seeding Native Compared to Introduced Perennial Vegetation for Revegetating Medusahead-invaded Sagebrush Rangeland.  Rangeland Ecology & Management 68:224-230.

Nafus, A.M., T.J. Svejcar, D.C. Ganskopp, and K.W. Davies.  2015.  Abundances of Co-planted Native Bunchgrasses and Crested Wheatgrass After 13 Years.  Rangeland Ecology and Management 68:211-214.

Johnson, D.D., and K.W. Davies.  2014.  Effects of integrating mowing and imazapyr application on African rue (Peganum harmala L.) and native perennial grasses.  Invasive Plant Science and Management 7:617-623.

Bates, J.D., R. O’Connor and K.W. Davies.  2014.  Vegetation recovery and fuel reduction after seasonal burning of Western Juniper.  Fire Ecology, Vol 10, Issue 3: 27-48.

Davies, K.W., M.D. Madsen, A.M Nafus, C.S. Boyd, and D.D. Johnson.  2014.  Can imazapic and seeding be applied simultaneously to rehabilitate medusahead-invaded rangeland? Single vs. multiple entry.  Rangeland Ecology and Management 67:650-656.

Davies, K. W., G. Collins, and C. S. Boyd.  2014.  Effects of feral free-roaming horses on semi-arid rangeland ecosystems: an example from the sagebrush steppe.  Ecosphere 5(10):127.

Davies, K.W., and J.D. Bates.  2014.  Attempting to restore herbaceous understories in Wyoming big sagebrush communities with mowing and seeding.  Restoration Ecology 22:608-615.

Kyser, G.B., J.M. DiTomaso, K.W. Davies, J.S. Davy, and B.S. Smith.  2014.  Medusahead Management Guide for the Western States.  University of California, Weed Research and Information Center, Davis. 68 p. Available at:

Nafus, A.M. and K.W. Davies.  2014.  Medusahead Ecology and Management: California Annual Grasslands to the Intermountain West.  Invasive Plant Science and Management 2014 7:210-221.

Davies, K.W., D.D. Johnson, and A.M. Nafus. 2014. Restoration of Exotic Annual Grass-invaded Rangelands: Importance of Seed Mix Composition.  Invasive Plant Science and Management 7:247-256.

Boyd, C.S., D.D. Johnson, J.D. Kerby, T.J. Svejcar, and K.W. Davies.  2014.   Of Grouse and Golden Eggs: Can Ecosystems Be Managed Within a Species-Based Regulatory Framework?  Rangeland Ecol Manage 67:358-368.

Bates, J.D. and K.W. Davies.  2014.  Cattle Grazing and Vegetation Succession on Burned Sagebrush Steppe.  Rangeland Ecol Manage 67:412-422.

Davies, K.W., J.D. Bates, C.S. Boyd, and A.M. Nafus. 2014.  Is fire exclusion in mountain big sagebrush communities prudent? Soil nutrient, plant diversity, and arthropod response to burning.  International Journal of Wildland Fire 23:417-424.

 Davies, K.W., J.D. Bates, M.D. Madsen, and A.M. Nafus.  2014.  Restoration of Mountain Big Sagebrush steppe following prescribed burning to control western juniper.  Environmental Management 53:1015-1022.

Davies, K.W., M. Vavra, B. Schultz, and N. Rimbey.  2014.  Implications of longer term rest from grazing in the sagebrush steppe.  Journal of Rangeland Applications Vol. 1 (2014):14-34.

Madsen, M.D., K.W. Davies, D.L. Mummey and T.J. Svejcar.  2014.  Improving restoration of exotic annual grass-invaded rangelands through activated carbon seed enhancement technologies.  Rangeland Ecology and Management 67(1):61-67.

Bates, J.D., R.N. Sharp, and K.W. Davies. 2014.  Sagebrush steppe recovery after fire varies by development phase of Juniperus occidentalis woodland. International Journal of Wildland Fire 23:117-130.


Madsen, M.D., K.W. Davies, C.S. Boyd, J.D. Kerby, D.L. Carter, and T.J. Svejcar.  2013. Restoring North America’s Sagebrush Steppe Ecosystem Using Seed Enhancement Technologies.  Proceedings of the International Grassland Congress, Sydney, Australia – September 15-19, 2013. (Peer-Reviewed Conference Proceedings).

Davies, K.W., C.S. Boyd, and A.M. Nafus.  2013.  Restoring the Sagebrush Component in Crested Wheatgrass-Dominated Communities.  Rangeland Ecology & Management 66:472-478.

Davies, K.W. and A.M. Nafus.  2013. Exotic Annual Grass Invasion Alters Fuel Amounts, Continuity and Moisture Content.  International Journal of Wildland Fire 2013, 22: 353-358.

Davies, K.W., A.M. Nafus, and D.D. Johnson.  2013.  Are Early Summer Wildfires an Opportunity to Revegetate Exotic Annual Grass-Invaded Plant Communities?  Rangeland Ecology & Management, Society of Range Management, March 2013:66:234-240.

Davies, K.W., A.M. Nafus, and M.D. Madsen.  2013.  Medusahead Invasion Along Unimproved Roads, Animal Trails, and Random Transects.  Western North American Nauralist 73:54-59.


Davies, K.W., J.D. Bates, and A.M. Nafus.  2012.  Mowing Wyoming Big Sagebrush Communities with Degraded Herbaceous Understories:  Has a Threshold Been Crossed?  Rangeland Ecology & Management, 65 (5):  498-505.

Boyd, C.S. and K.W. Davies.  2012.  Differential Seedling Performance and Environmental Correlates in Shrub Canopy vs. Interspace Microsites.  Journal of Arid Environmental 87 (2012) 50-57.

Boyd, C.S. and K.W. Davies.  2012.  Spatial Variability in Cost and Success of Revegetation in a Wyoming Big Sagebrush Community.  Environmental Management (2012) 50: 441-450.

Davies, K.W., J.D. Bates and A.M. Nafus. 2012. Comparing Burned and Mowed Treatments in Mountain Big Sagebrush Steppe.  Environmental Management (2012) 50:451-461.

Davies, K.W., J.D. Bates, and A.M. Nafus. 2012. Vegetation response to mowing dense mountain big sagebrush stands. Rangeland Ecology and Management 65:268-276.

Madsen, M.D., K.W. Davies, C.J. Williams, T.J. Svejcar. 2012. Agglomerating seeds to enhance native seedling emergence and growth. Journal of Applied Ecology 49:431-438.

Johnson, D.D. and K.W. Davies. 2012. Medusahead Management in Sagebrush-Steppe Rangelands: Prevention, Control, and Revegetation.  Society of Range Management, Rangelands, 34(1):32-38.


Johnson, D.D., K.W. Davies, P.T. Schreder and A.M. Chamberlain. 2011.  Perceptions of Ranchers About Medusahead Management on Sagebrush Steppe Rangelands.  Environmental Management 48:400-417. 

Davies, K.W., J.D. Bates, and A.M. Nafus. 2011.  Are There Benefits to Mowing Wyoming Big Sagebrush Plant Communities? An Evaluation in Southeastern Oregon.  Environmental Management 48:539-546 .

Davies, K.W. 2011.  Plant community diversity and native plant abundance decline with increasing abundance of an exotic annual grass.  Oecologia 167:481-491. 

Davies, K.W., C.S. Boyd, J.L. Beck, J.D. Bates, T.J. Svejcar, and M.A. Gregg. 2011.  Saving the sagebrush sea: An ecosystem conservation plan for big sagebrush plant communities.  Biological Conservation 144: 2573-2584.

Bates, J.D., K.W. Davies, and R.N. Sharp. 2011. Shrub-steppe early succession following invasive juniper cutting and prescribed fire. Environmental Management 47:468-481.

Davies, K.W. and D.D. Johnson. 2011. Are we “missing the boat” on preventing the spread of invasive plants in rangelands. Invasive Plant Science and Management 4:166-171.

Davies, K.W. and R.L. Sheley. 2011. Promoting native vegetation and diversity in exotic annual grass infestations. Restoration Ecology 19:159-165.


Davies, K.W., J.D. Bates, T.J. Svejcar, and C.S. Boyd. 2010. Effects of long-term livestock grazing on fuel characteristics in rangelands: an example from the sagebrush steppe. Rangeland Ecology & Management 63:662-669.

Davies, K.W., S.L. Petersen, D.D. Johnson, D.B. Davis, M.D. Madsen, D.L. Zvirzdin, and J.D Bates. 2010. Estimating juniper cover from NAIP imagery and evaluating relationships between potential cover and environmental variables. Rangeland Ecology & Management 63:630-637.

Davies, K.W. 2010. Revegetation of medusahead-invaded sagebrush steppe. Rangeland Ecology and Management 63:564-571.

Davies, K.W., and J.D. Bates. 2010. Native perennial forb variation between mountain big sagebrush and Wyoming big sagebrush plant communities. Environmental Management 46:452-458. 

Davies, K.W., A.M. Nafus, and R.L. Sheley. 2010. Non-native competitive perennial grass impedes the spread of an invasive annual grass. Biological Invasions 12:3187-3194

Davies, K.W. and J.D. Bates.  2010.  Vegetation characteristics of mountain and Wyoming big sagebrush plant communities in the northern Great Basin.  Rangeland Ecology & Management 63:461-466

Rhodes, E.C., J.D. Bates, R.N. Sharp, and K.W. Davies.  2010.  Fire effects on cover and dietary resources of sage-grouse habitat.  Journal of Wildlife Management 74:755-765

Boyd, C.S., and K.W. Davies.  2010.  Shrub microsite influences post-fire perennial grass establishment.  Rangeland Ecology & Management 63:248-252 


For more information phone or email Dr. Davies at:

(541) 573-4074 or Kirk Davies

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