Rocky Mountain Research Station

Dean E. Pearson, Ph.D.

Research Ecologist - Team leader Ecology and Management of Invasive Species

Phone: 406-542-4159
Fax: 406-543-2663
e-mail: dpearson@fs.fed.us

Address:
Rocky Mountain Research Station
800 E. Beckwith Ave.
Missoula, MT 59801, USA

CURRICULUM VITAE in pdf format

EDUCATION:
University of Montana Organismal Biology and Ecology Ph.D. May 2005
University of Montana Zoology M.A.S. May 1995
University of Montana Wildlife Biology B.S. March 1992

RESEARCH INTERESTS:
improve invasives management. Ecological theory is founded on traditional manipulation experiments, where we attempt to understand processes of community assembly by removing individual system components and examining the outcome. However, even relatively recent species assemblages in the northern United States represent collections of organisms that have had roughly 11,000 years to interact and assemble themselves. Thus, simple manipulation experiments can be misleading. Biological invasions represent massive natural experiments whereby a completely novel organism enters into a new system and either fails to establish, establishes with little effect or establishes and completely disrupts the recipient community and forces it to reassemble. Thus, biological invasions provide acid tests for ecological theory by illustrating processes of community assembly and disassembly before our eyes. Such experiments provide unique research opportunities to simultaneously advance ecological theory and improve invasive species management.

EMPLOYMENT/PROFESSIONAL HISTORY:

• Research Ecologist, USDA Forest Service, Rocky Mountain Research Station, June 2005 to present.
• Faculty Affiliate, University of Montana, Missoula, MT, September 2005 to present.
• Wildlife Biologist, USDA Forest Service, Rocky Mountain Research Station, September 1995 to June 2005.
• Research Assistant, University of Montana, September 1994 to September 1995.
• Private Contractor, USDA Forest Service, Rocky Mountain Research Station, 1995.
• Biological Technician, Glacier National Park, 1991 to 1994.
• Teaching Assistant, University of Montana, 1991 to 1993.
• Biological Technician, Conservation Biology Project, UCLA, stationed in Baja Mexico, Sept. to Dec. 1990.
• GIS Technician, Glacier National Park, June to September 1990.
• Biological Technician, Wolf Ecology Project, University of Montana, 1988 to 1989.

PUBLICATIONS

Bricker, M., D.E. Pearson, and J.M. Maron. In press. Small mammal seed predation limits the recruitment and abundance of two perennial grassland forbs. Ecology.

Zwolak, R., D.E. Pearson, Y.K. Ortega, and E.E. Crone. In press. Fire and mice: Seed predation trumps fire’s influence on conifer recruitment. Ecology

Pearson, D.E. 2009. Biological invasions on oceanic islands: implications for island ecosystems and avifauna. . Pages 3-14 in Proceedings of the 3rd International Symposium on Migratory Birds. Seabirds in danger: invasive species and conservation of island ecosystems. Keynote address. Mokpo, Korea, 25 September.
full text PDF

Crone, E. E., M. Marler, D. E. Pearson. 2009. Non-target effects of broadleaf herbicide on a native perennial forb: a demographic framework for assessing and minimizing impacts. Journal of Applied Ecology 46:673-682.
full text PDF

Pearson, D.E. 2009. Invasive plant architecture alters trophic interactions by changing predator abundance and behavior. Oecologia (2009) 159:549–558.
full text PDF

Pearson, D.E. and Y.K. Ortega. 2009. Managing invasive plants in natural areas: moving beyond control. Pgs. 1-21 in (ed.) Rudolf V. Kingley, Weeds: Management, Economic Impacts and Biology. Nova Publishers, NY.
full text PDF

Pearson, D. E. and R. J. Fletcher, Jr. 2008. Mitigating exotic impacts: restoring native deer mouse populations elevated by an exotic food subsidy. Ecological Applications18 (2):321-334.
full text PDF

Pearson, D. E. and R. M. Callaway. 2008. Weed biocontrol insects reduce native plant recruitment through second-order apparent competition. Ecological Applications, 18(6), pp. 1489–1500.
full text PDF

Sturdevant, N., S. Kegley, Y. K. Ortega, and D. E. Pearson. 2006. Evaluation of establishment of Cyphocleonus achates and its potential impact on spotted knapweed. USDA FS FHP General Technical Report 06-08:1-9.
full text PDF

Shick, K. R., D. E. Pearson, and L. F. Ruggiero. 2006. Forest habitat associations of the golden-mantled ground squirrel: implications for fuels management. Norwest Science 80:133-139.
full text PDF

Pearson, D. E. and R. M. Callaway. 2006. Biological control agents elevate hantavirus by subsidizing mice. Ecology Letters 9:442-449.
full text PDF

Pearson, D. E., and R. M. Callaway. 2005. Indirect nontarget effects of host-specific biological control agents: implications for biological control. Biological Control 35:288-298.
full text PDF

Ortega, Y. K., and D. E. Pearson. 2005. Weak vs. Strong Invaders of Natural Plant Communities: Assessing Invasibility and Impact. Ecological Applications 15:651-661.
full text PDF

Pearson, D. E. 2005. Biological control is more than just natural enemies. Review of Natural Enemies: an Introduction to Biological Control. Trends in Ecology and Evolution 20: 10-11.
full text PDF

Pearson, D. E. and R. M. Callaway. 2004. Response to Thomas et al.: biocontrol and indirect effects. Trends in Ecology and Evolution 19:62-63.
full text HTML

Ortega Y. K., D. E. Pearson, and K. S. McKelvey. 2004. Effects of biological control agents and exotic plant invasion on deer mouse populations. Ecological Applications 14: 241-253.
full text PDF

Pearson, D. E., and L. F. Ruggiero. 2003. Transect versus grid trapping arrangements for sampling small mammal communities. Wildlife Society Bulletin 31(2): 454-459.

Pearson, D. E., Y., K. Ortega, and L. F. Ruggiero. 2003. Trap-induced mass declines in small mammals: mass as a population index. Journal of Wildlife Management 67(4):684-691.
full text PDF

Pearson, D. E. and R. M. Callaway. 2003. Indirect effects of host-specific biological control agents. Trends in Ecology and Evolution 18(9):456-461.
full text PDF

Pearson, D. E., and Y. K. Ortega. 2001. An indirect dispersal pathway for spotted knapweed seeds via deer mice and great-horned owls. Canadian Field-Naturalist 115(2):354.
full text PDF

Pearson D. E., Y. K. Ortega, K. S. McKelvey and L. F. Ruggiero. 2001. Small mammal communities and habitat selection in Northern Rocky Mountain bunchgrass: Implications for exotic plant invasions. Northwest Science 75: 107-117.
full text PDF

McKelvey KS, Pearson DE. 2001. Population estimation with sparse data: the role of estimators versus indices revisited. Canadian Journal of Zoology 79: 1754-1765.
full text PDF

Ortega, Y. K., and D. E. Pearson. 2001. Occurrences of the western skink (Eumeces skiltonianus) in grasslands of western Montana. Northwestern Naturalist 82:125-125.
html

Pearson, D. E., and L. F. Ruggiero. 2001. Test of the prey-base hypothesis to explain use of red squirrel midden sites by American martens. Canadian Journal of Zoology 79(8):1372-1379.
full text PDF

Pearson D. E., K. S. McKelvey , L. F. Ruggiero. 2000. Non-target effects of an introduced biological control agent on deer mouse ecology. Oecologia 122 : 121-128
full text PDF

Pearson, D. E. 2000. Evidence of red-squirrel fall breeding in western Montana. Canadian Field-Naturalist 114(4):703-704.

Buskirk, S. W., L. F. Ruggiero, K. B. Aubry, D. E. Pearson, J Squires, and K. S. McKelvey. 1999. Comparative ecology of lynx in North America. Pp. 397-417. In L.F. Ruggiero, K.B. Aubry, S.W. Buskirk, G.M. Koehler, C.J. Krebs, K.S. McKelvey, and J.R. Squires (eds.) Ecology and conservation of lynx in the United States. RMRS-GTR-30WWW. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station.
Full Text PDF

Pearson, D. E. 1999. Deer mouse predation on the biological control agent, Urophora spp., introduced to control spotted knapweed. Northwestern Naturalist 80(1): 26-29.
full text PDF

Pearson, D. E. 1999. Small mammals of the Bitterroot National Forest: a literature review and annotated bibliography. USDA Forest Service, General Technical Report RMRS-GTR-25.
pdf

Foresman, K. R., and D. E. Pearson. 1999. Activity patterns of American martens, fishers, snowshoe hares, and red squirrels in westcentral Montana. Canadian Field-Naturalist 113(3):1-4.

Foresman, K. R., and D. E. Pearson. 1998. Comparison of proposed survey procedures for detection of forest carnivores. Journal of Wildlife Management 62(3):1217-1226.

Ruggiero, L. F., D. E. Pearson, S. E. Henry. 1998. Characteristics of American marten den sites in Wyoming. Journal of Wildlife Management 62(2):663-673.
html

GRANTS

• NSF, DEB-0915409, $585,000. Indirect effects of apex predators in a grassland ecosystem. John M. Maron and D. E. Pearson. Awarded September 2009.
• USDA FS, Rocky Mountain Research Station's FY08 Rangeland Research Competitive Proposals. $27,900.00. Pearson, D. E., Y. K. Ortega, R. M. Callaway. 2008. Long-term efficacy of broadleaf herbicide treatments for restoration of weed-invaded rangelands. Awarded June 2008.
• USDA FS, Rocky Mountain Research Station Cross-Program Award, $60,000, Native seed mixes for improving invasives management and reducing new invasions following fuels treatments, D. Pearson, R. Callaway, S. Sutherland, M. Harrington, and J. Butler. Awarded 7/17/07.
• USDA FS, Rocky Mountain Research Station Cross-Program Award, $63,000, Prediction, detection, and monitoring of invasive species in forests, rangeland, and aquatic ecosystems: A synthesis of RMRS research for marketing, education, and outreach. J. Butler, M. Kim, D. Pearson, S. Sutherland, D. Finch, M. Young, G. Markin, N. Klopfenstein, A. Hudak, B. Richardson, P. Zambino. Awarded 7/17/07.
• USDA FS, Native Plant Materials Project, $50,893, Using weed-resistant native seed mixes to restore burned areas: a collaboration between Forest Service Research, University of Montana, and Native Yards, S. Sutherland, R. Callaway, and D. Pearson. Awarded 3/07/07. 4/07- 11/09.
• USDA, NRI - National Research Initiative and Integrated Programs in Ecological Systems, $300,000.00. Assessing indirect effects of top predators on diversity, productivity, and health of grassland ecosystems. J. Maron and D. E. Pearson. USDI-USDA Joint Fire Sciences Program, $162,000, June 2003, Y. K. Ortega, D. E. Pearson, and D. L. Six.
• NSF, DEB-0236061, $294,267, December 2002. Nontarget effects of host-specific biocontrols: direct and indirect effects of biocontrols that subsidize native consumers. R. M. Callaway and D. E. Pearson.
• USDI National Park Service, Inventory and Monitoring Award, $27,000, April 2002. Small mammal surveys of Little Bighorn National Monument and Grant-Kohrs Ranch National Historic Site. D. E. Pearson and L. F. Ruggiero.
• NSF SGER-010889, $22,000, May 2001. Do Gall Fly-induced Increases in Deer Mouse Populations increase the Prevalence of Hantavirus? R. M. Callaway and D. E. Pearson.

AWARDS

• Presidential Early Career Award for Science and Engineering (PECASE). July 2009. "Selection for this award is based on the combination of innovative research at the frontiers of science and technology and community service demonstrated through scientific leadership and community outreach."
• Deputy Chief’s Early Career Scientist Award. 19 December 2008. This honor was awarded in recognition of significant contributions to the fields of biological control, invasive species ecology, and wildlife biology.
• Best Scientific Publication Award, USDA Forest Service, Rocky Mountain Research Station, Feb 2009, for the publication: Ortega, Y.K and D. E. Pearson. 2005. Strong versus weak invaders of natural plant communities: distinguishing invasibility from impact. Ecological Applications 15:651-661.
• Best Scientific Publication Award, USDA Forest Service, Rocky Mountain Research Station, October 2007, for the publication: Pearson, D. E. and R. M. Callaway. 2006. Biological control agents elevate hantavirus by subsidizing mice. Ecology Letters 9:442-449.
• Merit Award, USDA Forest Service, Rocky Mountain Research Station, October 2007, for leaderships of the Invasive Species /Disease Research Team in the Wildlife and Terrestrial Ecosystems Program.
• Merit Award, USDA Forest Service, Rocky Mountain Research Station, August 2007, for role as team leader on the Invasive Species Ecology and Community Dynamics Team and for contributions toward changing paradigms in the field of biological control.
• Merit Award, USDA Forest Service, Rocky Mountain Research Station, March 2006, “for your role on the RMRS Invasives Meeting Team in planning and conducting a workshop to share information, identify needs, and complete a white paper.”
• Early Career Scientist Publication Award, USDA Forest Service, Rocky Mountain Research Station, March 2005, for the publication: Ortega, Y. K., D. E. Pearson, and K. S. McKelvey. 2004. Effects of introduced biological control agents and exotic plant invasion on native deer mouse populations. Ecological Applications 14:241-253.
• Project TRAIN (NFS). September 2003. Certificate of Recognition for support and service as a Project TRAIN Student Mentor.
• Early Career Scientist Publication Award, USDA Forest Service, Rocky Mountain Research Station, March 2001, for the publication: Pearson, D. E., K. S. McKelvey, and L. F. Ruggiero. 2000. Non-target effects of an introduced biological control agent on deer mouse ecology. Oecologia 122(1):121-128.

SELECTED PRESENTATIONS

• Pearson, D. E. 2009. Biological invasions on oceanic islands: implications for island ecosystems and avifauna. Invited Keynote Address, Proceedings of the 3rd International Symposium on Migratory Birds. Seabirds in Danger: Invasive Species and Conservation of Island Ecosystems. 25 September 2009, Mokpo, Korea.
• Pearson, D. E. and Y. K. Ortega. 2009. Climate change and exotic weeds: what should we expect? Invited presentation for the United States Fish and Wildlife Service Integrated Pest Management and Invasives Species Coordinating Meeting, 16 July 2009, Great Falls MT.
• Pearson, D. E. 2009. Biological invasions and avian species: impacts, implications for native communities and management. Invited opening presentation for the Special Symposium - Biological invasions: consequences for native birds in a changing world. 79th Annual Meeting of the Cooper Ornithological Society. April 17 2009, Tucson AZ.
• Pearson, D. E. and Y. K. Ortega. 2008. A heuristic model for guiding research on the ecology and management of invasive species. Invasive Species in Natural Areas Conference, February 13-14th, Hilton Garden Inn, Missoula, MT.
• Pearson, D. E. and Y. K. Ortega. 2008. Ecology and management of invasive species. Invited presentation, Montana Weed Control Association, Annual Meeting, January 16th Greatfalls, MT.
• Pearson, D. E. 2007. Indirect nontarget effects of spotted knapweed biological control agents due to food-web interactions. Invited Presentation for the Symposium on Biocontrol of Centaurea at the 55th Annual Meeting of the Entomological Society of America, 9-11 Dec. 2007, San Diego, CA.
• Pearson, D. E., R. M. Callaway, Y. K. Ortega. 2006. Ecological challenges of weed management in natural systems. Invited presentation for Weeds and their Management: A Problem for Wildlife? Special Symposium at the Montana Chapter of the Wildlife Society 2006 Annual Meeting, Helena, Montana 21-22 February 2006.
• Pearson, D. E., and R. M. Callaway. 2005. Nontarget effects of host-specific biological control agents. Invited Presentation, Montana Weed Control Association Annual Conference, 25 January 2005, Helena, MT, USA.
• Pearson, D. E., Y. K. Ortega, R. M. Callaway, and K. S. McKelvey. 2004. Indirect effects of host-specific biological control agents. 89th Annual meeting of the Ecological Society of America, Portland, OR, USA.
• Pearson, D. E. and R. M. Callaway. 2004. Nontarget effects of host-specific biological control agents. Invited Presentation 4th International Symposium on Science and Decision Making in the Biological Control of Weeds. Denver, CO, USA.
• Pearson, D.E., Y. K. Ortega, K. S. McKelvey, R. M. Callaway, L. F. Ruggiero. 2003. From spotted knapweed to hantavirus: and ecological tail. Invited Presentation for Centers for Disease Control and Prevention Hantavirus Conference, August, 2003. Cascade, MT, USA.
• Pearson, D.E., K.S. McKelvey, L.F. Ruggiero, and Y.K. Ortega. 2001. Nontarget effects of an introduced biological control agent on deer mouse ecology. 81st Annual Meeting, American Society of Mammalogists, 19 June 2001, University of Montana, Missoula, Montana.
• Pearson, D. E., Y. K. Ortega, K. S. McKelvey, and L. F. Ruggiero. 2001. Direct and indirect effects of well behaved biological control agents on nontarget species – a case study: spotted knapweed, gall flies, and deer mice. International Knapweed Symposium, March 15-16, Coeur d’Alene, Idaho.
• Pearson, D. E., McKelvey, and L. F. Ruggiero. 2000. Nontarget effects of a “well-behaved” biological control agents: implication for conservation of native communities susceptible to exotic plant invasion. Society for Conservation Biology, 14th Annual Meeting. University of Montana, Missoula, Montana. 10-12 June 2000.
• Pearson, D.E., and L.F. Ruggiero. 1999. Understanding the relationship between species detection and species abundance: probability of detection as an index for monitoring vertebrate populations. Professional paper presented at the International Monitoring Symposium, Snowbird, Utah. 18-22 October 1999.