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Faculty Image Dean Pearson
Office: Forestry Sciences Lab, 800 E. Beckwith Ave.
Phone: 406-542-4159


Current Position:

Research Ecologist (community ecology emphasis), Rocky Mountain Research Station, USDA Forest Service.  Faculty affiliate with Division of Biological Sciences, UM.


Research interests:

My primary interest lies in integrating community and invasion ecology to advance these fields of research and 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.  

Selected Publications:

Pearson, D. E. and R. J. Fletcher, Jr. 2008.  Exotic organisms as food subsidies: removal of biological control agents reduces consumer populations. Ecological Applications, In Press 

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

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.

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.

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.

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.

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.

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.

Pearson, D. E., Y., K. Ortega, and L. F. Ruggiero. 2003. Trap-induced mass declines in small mammals and the implications for body mass as a negatively biased index. Journal of Wildlife Management 67(4):684-691.

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.