Montana State University

Department of Animal & Range Sciences

P.O. Box 172900
Bozeman, MT 59717-2900
Email: animalrange@montana.edu

Tel: (406) 994-3722
Fax: (406) 994-5589
Location: 103 Animal Bioscience Building

Department Head:

Dr. Glenn Duff

Dr. Bret E. Olson

Photo of Bret Olson
Dr. Olson

Professor of Range Ecology
313 Animal Bioscience Building; MSU-Bozeman
Bozeman, MT 59717
Phone: (406) 994-3721
Fax: (406) 994-5589
Email: bolson@montana.edu

Education

B.A. University of California, Berkeley, Botany, 1977
M.S. University of California, Berkeley, Range Management, 1982
Ph.D. Utah State University, Range Ecology, 1987

Classes

NRSM 240 Natural Resource Ecology
NRSM 453 Habitat Inventory and Analysis
ARNR 541 Range Ecophysiology

Research Interests

  • Determine how livestock use the landscape on winter range.
  • Develop effective grazing recommendations for controlling noxious weeds.
  • Determine metabolic rates and heart rates of beef cattle as they change seasonally, and in response to different management scenarios.

Accomplishments and Interests

  • Assessed cattle use patterns on winter range to identify how to minimize weight loss
  • Identified effects of sheep grazing on two noxious weeds in Montana, using several approaches from basic plant biology to animal behavior and nutrition
  • Conducted a unique, longterm study to assess effects of livestock grazing on grasshoppers, and cumulative effects of livestock grazing and grasshopper herbivory on plant communities
  • Used the stable 13C isotope as a tracer to assess carbon allocation in plants, and used background levels of 13C/12C in plant tissues to indicate water use efficiency of leafy spurge and spotted knapweed and native grasses
  • Using 15N isotope as a tracer to assess N uptake in spotted knapweed and native plants
  • Conduct studies and develop models that indicate the importance of solar radiation for the thermal balance beef cattle grazing winter rangeland

Recent Publications

  • O'Neill, K. M., Olson, B. E., Wallander, R. T., Rolston, M. G., Seibert, C. E.  2010.  Effects of livestock grazing on grasshopper abundance on a native rangeland in Montana.  Environ. Ento.  39:775-786.
  • Whitney, T. R., Olson, B. E.  2010.  Can sheep and cattle rumen microorganisms be conditioned to invasive weeds?  Sheep and Goat Res. J.  25:26-31.
  • O’Neill, K. M., S. Blodgett, B. E. Olson, and R. S. Miller.  2008.  Impact of livestock grazing on abundance of Miridae and Reduviidae (Hemiptera) in crested wheatgrass pastures.  J. Econ. Entom.  101:309-313.
  • Thrift, B. D., J. C. Mosley, T. K. Brewer, B. L. Roeder, B. E. Olson, and R. W. Kott.  2008.  Prescribed sheep grazing to suppress spotted knapweed on foothill rangeland.  Rangeland Ecol. Manage.  61:18-25.
  • Keren, I. N. and Olson, B. E.  2007.  Applying thermal imaging software to cattle grazing winter range.  J. Ther. Biol.  32:204-211.
  • Whitney, T. R. and Olson, B. E.  2007.  Will molasses or conditioning increase consumption of spotted knapweed by sheep?  Rangeland Ecol. Manage.  60:533-537.
  • Hill, J. P., Germino, M. J., Wraith, J. M., Olson, B. E., Swan, M. B.  2006.  Advantages in water relations contribute to greater photosynthesis in Centaurea maculosa compared with established grasses.  Inter. J. Plant Sci.  167:269-277.
  • Keren, I. N., and Olson, B. E.  2006.  Thermal balance of cattle grazing winter range: model development.  J. Ther. Biol.  31:371-377.
  • Keren. I. N., and Olson, B. E.  2006.  Thermal balance of cattle grazing winter range: model application.  J. Anim. Sci.  84:1238-1247.
  • Whitney, T. R., and Olson, B. E.  2006.  Conditioning ewes and lambs to increase consumption of spotted knapweed.  Appl. Anim. Behav. Sci.  100:193-206.
  • Olson, B. E., and K. Launchbaugh.  2006.  Managing herbaceous broadleaf weeds with targeted grazing.  In:  Targeted grazing: A natural approach to vegetation management and landscape enhancement.  pp 32-39.  American Sheep Industry Association
  • Henderson, J., and B. E. Olson.  2006.  Understanding plant response to grazing.  In:  Targeted grazing: A natural approach to vegetation management and landscape enhancement.  pp 58-67.  American Sheep Industry Association
  • Hook, P. B., Olson, B. E., and Wraith, J. M.  2004.  Effects of the invasive forb Centaurea maculosa on grassland carbon and nitrogen pools in Montana, USA.  Ecosystems  7:686-694.
  • Blicker, P. S., Olson, B. E., and Wraith, J. M.  2003.  Water use and water use efficiency of spotted knapweed and three native grasses.  Plant Soil  254:371-381.
  • O’Neill, K. M., Olson, B. E., Rolston, M. G., Wallander, R. T., Larson, D. P., and Seibert, C. E.  2003.  Effects of livestock grazing on rangeland grasshopper (Orthoptera: Acrididae) abundance.  Agriculture, Ecosystems and Environment  97:51-64.
  • Olson, B. E., and Blicker, P. S.  2003.  Response of the invasive Centaurea maculosa and two native grasses to N-pulses.  Plant Soil  254:457-467.
  • Olson, B. E., and Wallander, R. T.  2003.  Comparing indicators of sheep grazing leafy spurge and perennial grasses.  Sheep and Goat Res. J.  18:101-108.
  • Sperber, T. D., Wraith, J. M., and Olson, B. E.  2003.  Soil physical properties associated with the invasive spotted knapweed and native grasses are similar.  Plant Soil  252:241-249.
  • Blicker, P. S., and Olson, B. E., and Engel, R.  2002.  Traits of the invasive Centaurea maculosa and two native grasses: effect of N supply.  Plant and Soil  247:261-269.
  • Olson, B. E., and Wallander, R. T.  2002.  Does ruminal retention time affect leafy spurge seed of varying maturity?  J. Range Manage.  55:65-69.
  • Olson, B. E., and Wallander, R. T.  2002.  Effects of invasive forb litter on seed germination, and seedling growth and survival.  Basic and Applied Ecology  3:309-317.
  • Olson, B. E., and Wallander, R. T.  2002.  Influence of winter weather and shelter on activity patterns of beef cows.  Can. J. Anim. Sci.  82:491-501.
  • Olson, B. E., and Wallander, R. T.  2001.  Sheep grazing of spotted knapweed and Idaho fescue.  J. Range Manage.  54:25-30
  • Olson, B. E., Wallander, R. T., and Beaver, J. M.  2000.  Comparing nondestructive measures of forage structure and phytomass.  Can. J. Plant Sci.  80:565-573.
  • Olson, B. E., Wallander, R. T., and Paterson, J. A.  2000.  Do windbreaks minimize stress on cattle grazing foothill winter range?  Can. J. Anim. Sci.  80:265-272.