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:

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.

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).

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

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

Share this