Personal Summary

My primary interest lies in integrating community and invasion ecology to advance these fields of research and improve invasive species 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 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 cannot reveal the sequences of ecological and evolutionary mechanisms that serve to structure communities over time. Biological invasions represent unique natural experiments whereby a completely novel organism enters into a new system and either fails to establish, establishes with little effect or establishes and alters the recipient community in ways that forces it to reassemble. Hence, biological invasion events provide acid tests for ecological theory by illustrating processes of community assembly and reassembly in real time. Such experiments provide unique research opportunities to simultaneously advance ecological theory and improve invasive species management.

 

Education

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

Teaching Experience

With the University of Montana, I serve primarily as a graduate student advisor or member of graduate student committees.

Research Interests

My primary interest lies in integrating community and invasion ecology to advance these fields of research and improve invasive species 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 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 cannot reveal the sequences of ecological and evolutionary mechanisms that serve to structure communities over time. Biological invasions represent unique natural experiments whereby a completely novel organism enters into a new system and either fails to establish, establishes with little effect or establishes and alters the recipient community in ways that forces it to reassemble. Hence, biological invasion events provide acid tests for ecological theory by illustrating processes of community assembly and reassembly in real time. Such experiments provide unique research opportunities to simultaneously advance ecological theory and improve invasive species management.

Projects

Predicting effects of perturbations on ecological systems

Biogeography of plant invasions

Predator and consumer effects in grassland ecosystems

How strong invaders break the rules

Field of Study

Community ecology, invasion ecology, predator-prey interactions, indirect interactions

Selected Publications

1. Pearson, D.E., Y. Lekberg, Ö. Eren, Y.K. Ortega, N. K. Boote, B. Karakuş, L. Bullington and J.L. Hierro. 2022. Biogeographic approaches to invasion ecology: a comparative assessment.  Journal of Ecology 110:2033-2045.

2. Clark-Wolf, T.J., P.G. Hahn, E. Brelsford, N. Hayes, J. Francois, B. Larkin, P. Ramsey, and D. E. Pearson.  2022.  Preventing a series of unfortunate events: using qualitative models to improve conservation.  Journal of Applied Ecology 59:2322–2332.

3. Pearson, D.E., T.J. Clark, P. Hahn.  2021.  Evaluating unintended consequences of intentional species introductions and eradications for improved conservation management.  Conservation Biology 2021: 1-10.

4. Dylewski, L., Ortega, Y.K., Bogdziewicz, M., Pearson, D.E.  2021.  Seed predator effects on plants: moving beyond time-corrected proxies.  Ecology Letters 24:1526-1529.

5. Pearson, D.E., Valliant, M., Carlson, C., Thelen, G.C., Ortega, Y.K., J.L. Orrock, and Madsen, M.D.  2019.   Spicing up restoration: can chili peppers improve reseeding success by reducing seed predation?  Restoration Ecology 27:254-260.

6. Pearson, D.E., Y.K. Ortega, Ö. Eren, and J.L. Hierro. 2018. Community assembly theory as a conceptual framework for invasions.  Trends in Ecology and Evolution 33:313-325.

7. Pearson, D.E., Y.K. Ortega, D. Villarreal, Y. Lekberg, M. C. Cock, Ö. Eren, and J.L. Hierro. 2018.  The fluctuating resource hypothesis explains invasibility but not exotic advantage? Ecology 99:1296-1305.

8. Pearson, D.E., Eren, Ö., Ortega, Y.K., Villareal, D., Åžentürk, M., Miguel, M. F., Weinzettel, C. M., Prina, A. and Hierro, J.L.  2017.  Are exotic plants more abundant in the introduced versus native range?  Journal of Ecology 106:727-736.

9. Pearson, D.E., Y.K. Ortega, J. Runyon, and J. Butler.  2016. Secondary invasion: the bane of weed management.  Biological Conservation 197:8-17.

10. 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.

Publications

Hierro, J.L., W.A. Muiño, A. Farji-Brener, M.C. Cock, D.E. Pearson.  2023. Species introduction shifts trait function from mutualism to antagonism: elaiosomes in a myrmecochory cold spot.  Oikos 10.1111/oik.09770

Slate, M.L. Durham, R.A., Casper, C., Mummey, D., Ramsey, P., Pearson, D.E. 2022. No evidence for herbicide or surfactant effects on biological soil crusts.  Restoration Ecology, doi: 10.1111/rec.13802

Clark-Wolf, T.J., P.G. Hahn, E. Brelsford, N. Hayes, J. Francois, B. Larkin, P. Ramsey, and D. E. Pearson.  2022.  Preventing a series of unfortunate events: using qualitative models to improve conservation.  Journal of Applied Ecology 59:2322–2332.

Pearson, D.E., Y. Lekberg, Ö. Eren, Y.K. Ortega, N. K. Boote, B. Karakuş, L. Bullington and J.L. Hierro. 2022. Biogeographic approaches to invasion ecology: a comparative assessment.  Journal of Ecology 110:2033-2045.

Pearson, D.E. 2022.  Biological invasions: an overview.  Pgs. 1-11, Encyclopedia of Biodiversity, 3rd Edition, Elsevier. doi:10.1016/B978-0-12-822562-2.00037-2

Litt, A. and D.E. Pearson.  2022.  A functional ecology framework for understanding and predicting animal responses to plant invasion.  Biological Invasions 1-13.  doi.org/10.1007/s10530-022-02813-7

Pearson, D.E., Y.K. Ortega, H. Cimino, D. Mummey, P. Ramsey.  2022. Does grassland restoration restore small mammal community structure and function?  Restoration Ecology 30(1):1-9.

Pearson, D.E., T.J. Clark, P. Hahn.  2021.  Evaluating unintended consequences of intentional species introductions and eradications for improved conservation management.  Conservation Biology 2021: 1-10.

Dylewski, L., Ortega, Y.K., Bogdziewicz, M., Pearson, D.E.  2021.  Seed predator effects on plants: moving beyond time-corrected proxies.  Ecology Letters 24:1526-1529.

Zhong, Z., X. Li, D. Sanders, Y. Liu, L. Wang, Y.K. Ortega, D.E. Pearson, D. Wang. 2021.  Soil engineering by ants facilitates plant compensation for large herbivore removal of aboveground biomass.  Ecology 102:1-11 doi/10.1002/ecy.3312

Sanderlin, J.S., J.D. Golding, T. Wilcox, D.H. Mason, K.S. McKelvey, D.E. Pearson, and M.K. Schwartz.  2021.  Occupancy modeling and resampling overcomes low test sensitivity to produce accurate SARS-CoV-2 prevalence estimates.  BMC Public Health 21 577 (2021). https://doi.org/10.1186/s12889-021-10609-y

Jang, W., Crotteau, J.S., Ortega, Y.K., Hood, S.M., Keyes, Pearson, D.E., C. R., Lutes, D.C., Sala, A. 2021.  Native and non-native understory vegetation responses to restoration treatments in a dry conifer forest over 23 years.  Forest Ecology and Management 481: 118684

Mayfield, Albert E., III; Seybold, Steven J.; Haag, Wendell R.; Johnson, M. Tracy; Kerns, Becky K.; Kilgo, John C.; Larkin, Daniel J.; Lucardi, Rima D.; Moltzan, Bruce D.; Pearson, Dean E.; Rothlisberger, John D.; Schardt, Jeffrey D.; Schwartz, Michael K.; Young, Michael K. 2021. Impacts of Invasive Species in Terrestrial and Aquatic Systems in the United States. 2021. In: Poland, Therese M.; Patel-Weynand, Toral; Finch, Deborah M.; Ford Miniat, Chelcy; Hayes, Deborah C.; Lopez, Vanessa M., eds. Invasive Species in Forests and Rangelands of the United States: A Comprehensive Science Synthesis for the United States Forest Sector. Heidelberg, Germany: Springer International Publishing: 5 - 40. Chapter 2. https://doi.org/10.1007/978-3-030-45367-1_2.

Poland, Therese M.; Juzwik, Jennifer; Rowley, Allen; Huebner, Cynthia D.; Kilgo, John C.; Lopez, Vanessa M.; Olson, Deanna H.; Pearson, Dean E.; Progar, Robert; Rabaglia, Robert; Rothlisberger, John D.; Runyon, Justin B; Sing, Sharlene E. 2021. Management of Landscapes for Established Invasive Species. 2021. In: Poland, Therese M.; Patel-Weynand, Toral; Finch, Deborah M.; Ford Miniat, Chelcy; Hayes, Deborah C.; Lopez, Vanessa M., eds. Invasive Species in Forests and Rangelands of the United States: A Comprehensive Science Synthesis for the United States Forest Sector. Heidelberg, Germany: Springer International Publishing: 133 - 184. Chapter 7. https://doi.org/10.1007/978-3-030-45367-1_7.

Liebhold, Andrew M.; Campbell, Faith T.; Gordon, Doria R.; Guo, Qinfeng; Havill, Nathan; Kinder, Bradley; MacKenzie, Richard; Lance, David R.; Pearson, Dean E.; Sing, Sharlene E.; Warziniack, Travis; Venette, Robert C.; Yemshanov, Denys. 2021. The Role of International Cooperation in Invasive Species Research. 2021. In: Poland, Therese M.; Patel-Weynand, Toral; Finch, Deborah M.; Ford Miniat, Chelcy; Hayes, Deborah C.; Lopez, Vanessa M., eds. Invasive Species in Forests and Rangelands of the United States: A Comprehensive Science Synthesis for the United States Forest Sector. Heidelberg, Germany: Springer International Publishing: 293 - 304. Chapter 13. https://doi.org/10.1007/978-3-030-45367-1_13.

Koch, Jennifer; Pearson, Dean E.; Huebner, Cynthia D.; Young, Michael K.; Sniezko, Richard A. 2021. Restoration of Landscapes and Habitats Affected by Established Invasive Species. 2021. In: Poland, Therese M.; Patel-Weynand, Toral; Finch, Deborah M.; Ford Miniat, Chelcy; Hayes, Deborah C.; Lopez, Vanessa M., eds. Invasive Species in Forests and Rangelands of the United States: A Comprehensive Science Synthesis for the United States Forest Sector. Heidelberg, Germany: Springer International Publishing: 185 - 202. Chapter 8. https://doi.org/10.1007/978-3-030-45367-1_8.

Maron, J.L., Hahn, P.G., Hajek, K.L., and D.E. Pearson.  2021.  Trade-offs between seed size and biotic interactions contribute to coexistence of co-occurring species that vary in fecundity. Journal of Ecology 109:626-638.

Gaskin, John F., Erin Espeland, Casey D. Johnson, Diane L. Larson, Jane M. Mangold, Rachel A. McGee, Chuck Milner et al. 2020.  "Managing invasive plants on Great Plains grasslands: A discussion of current challenges." Rangeland Ecology & Management 78: 235-249.

Pearson, D.E.  2020. Is there a breach in the barrier protecting humans from cervid Chronic Wasting Disease?  mBio 11:e01971-20.

Dylewski, L., Ortega, Y.K., Bogdziewics, M., and D. E. Pearson.  2020.  Seed size predicts global effects of small mammal seed predation on plant recruitment. Ecology Letters 23:1024-1033. 

Slate, M.L., R.M. Durham, D.E. Pearson. 2020. Strategies for restoring the form and function of lichen-moss biocrust communities. Restoration Ecology 28:S160-S167.

Taylor, J.B., K.L. Cass, D.N. Armond, M.D. Madsen, D.E. Pearson, S.B. St. Clair.  2020.  Deterring rodent seed-predation using seed-coating technologies.  Restoration Ecology 28:927-936.

Dylewski, Ł., Ł. Myczko, D. E. Pearson.  2019.  Native generalist consumers may both inhibit and facilitate the invasive wild cucumber (Echinocystis lobata). NeoBiota 53: 25-39.

Ortega, Y. K., Vallient, M. T., and D. E. Pearson.  2019. To list or not to list: using time since invasion to refine impact assessment for an exotic plant proposed as noxious.  Ecosphere 10(11):e02961. 

Maron, J.L., Hajek, K.L., Hahn, P.G., and D.E. Pearson.  2019.  Recruitment is seed-limited among co-occurring grassland forbs regardless of seed size.  Ecology 91:85-92.

Slate, M. L., R. M. Callaway, and D. E. Pearson.  2019.  Life in interstitial space: biocrusts resist exotic but not native plant establishment.  Journal of Ecology 107:1317-1327.

Pearson, D.E., Valliant, M., Carlson, C., Thelen, G.C., Ortega, Y.K., J.L. Orrock, and Madsen, M.D.  2019.   Spicing up restoration: can chili peppers improve reseeding success by reducing seed predation?  Restoration Ecology 27:254-260.

Pearson, D.E., Y.K. Ortega, Ö. Eren, and J.L. Hierro. 2018. Community assembly theory as a conceptual framework for invasions.  Trends in Ecology and Evolution 33:313-325.

Pearson, D.E., Y.K. Ortega, D. Villarreal, Y. Lekberg, M. C. Cock, Ö. Eren, and J.L. Hierro. 2018.  The fluctuating resource hypothesis explains invasibility but not exotic advantage? Ecology 99:1296-1305.

Pearson, D.E., Y.K. Ortega, J. Runyon, J. L. Butler.  2018. Secondary invasion re-redefined: the distinction between invader-facilitated and invader-contingent invasions as subclasses of secondary invasion. Ecology and Evolution doi: 10.1002/ece3.3966.

Maron, J.L. K. Hajek, P. Hahn, and D.E. Pearson.  2018.  Rodent seed predators and a dominant grass competitor affect coexistence of co-occurring forb species that vary in seed size.  Journal of Ecology 106:1795-1805.

Pearson, D.E., Eren, Ö., Ortega, Y.K., Villareal, D., Şentürk, M., Miguel, M. F., Weinzettel, C. M., Prina, A. and Hierro, J.L.  2017.  Are exotic plants more abundant in the introduced versus native range?  Journal of Ecology 106:727-736.

Zhong, Z., Xiaofei, L., D. E. Pearson, W. Deli, D. Sanders, Y. Zhu, and L. Wang.  2017.  Ecosystem engineering strengthens bottom-up and weakens top-down effects via trait-mediated indirect interactions.  Proceedings of the Royal Society B, 284:1-9, doi.org/10.1098/rspb.2017.0894

Larios, L., D.E. Pearson, and J.L. Maron.  2017.  Incorporating the effects of generalist seed predators into plant community theory.  Functional Ecology, doi: 10.1111/1365-2435.12905

Pearson, D.E., Y.K. Ortega, and J.L. Maron. 2017.  The tortoise and the hare: reducing resource availability shifts competitive balance between plant species.  Journal of Ecology 105, 999-1009.

Loehman, R.A., B.B. Bentz, G.A. DeNitto, R.E. Keane, M.E. Manning, J.P. Duncan, J.M. Egan, M.B. Jackson, S. Kegley, I.B. Lockman, D.E. Pearson, J.. Powell, S. Shelly, B.E. Steed, and P.J. Zambino.  2017.  Effects of Climate Change on Ecological Disturbance in the Northern Rockies.  In J.E. Halofsky, D.L. Peterson (eds.), Climate Change and Rocky Mountain Ecosystems, Advances in Global Change Research 63, DOI 10.1007/978-3-319-56928-4_7

Pearson, D.E., Y.K. Ortega, J. Runyon, and J. Butler.  2016. Secondary invasion: the bane of weed management.  Biological Conservation 197:8-17.

Rudgers, J.A., B. Fletcher, E. Olivas, C.A. Young, N.D. Charlton, D.E. Pearson, and J.L. Maron.  2016. Exclusion of ungulates reduces fungal symbiont frequency within host plants in native grasslands. Oecologia 181:1151-1161.

Pearson, D.E., Y.K. Ortega, O. Eren, J.L. Hierro.  2016.  Quantifying “apparent” impact and distinguishing impact from invasiveness in multispecies plant invasions.  Ecological Applications 26:162-173.

Maron, J.L., Smith, A., Pearson, D.E., Ortega, Y.K., and R.M. Callaway.  2016.  Negative plant-soil feedbacks increase with plant abundance, and are unchanged by competition.  Ecology 97:2055-2063.

Smith, J.N., Emlem, D.J., and Pearson, D.E. 2016. Community reassembly: web spider community restructuring following simulated plant invasion.  PLoS One 11(4): e0153661. doi:10.1371/journal.pone.0153661

Pinto, S.M., D. E. Pearson, J.L. Maron.  2014.  Seed dispersal is more limiting to grassland diversity than competition or seed predation. Journal of Ecology 102:1258-1265.

Pearson, D.E., Icasatti, N., J.L. Hierro, and B. Bird.  2014.  Are local filters blind to provenance? Ant seed predation suppresses exotic plants more than natives.  PLoS ONE 9(8): e103824. doi:10.1371/journal.pone.0103824

Connolly, B., Pearson, D. E., and Mack, R. N. 2014.  Granivory of invasive, naturalized, and native plants in communities differentially susceptible to invasion.  Ecology 95: 1759-1769.

Ortega, YK, Greenwood, L., Callaway, R.M. and Pearson, D.E.  2014. Differential response of congeneric consumers to an exotic food resource: who gets the novel resource prize?  Biological Invasions 16:1757-1767.

Maron, J.L., Auge, H., Korell, L., D. E. Pearson, Hensen, I., Suding, K.N., and C. Stein.  2014.  Staged invasions across disparate grasslands: effects of seed provenance, consumers, and disturbance on productivity and species richness.  Ecology Letters 17:499-507.

Pearson, DE, JL. Hierro, M. Chiuffo and D. Villarreal. 2014. Rodent seed predation as a biotic filter influencing exotic plant abundance and distribution. Biological Invasions 16: 1185-1196.

Litt, A., and D. E. Pearson.  2013.  Nonnative plants and wildlife in the Intermountain West.  Wildlife Society Bulletin 37:517-526.

Pearson, D.E., T. Potter, and J.M Maron.  2012. Biotic resistance: exclusion of native rodent consumers releases populations of a weak invader.  Journal of Ecology 100:1383-1390.

Maron, J.L., D. E. Pearson, T. Potter, and Y. K. Ortega. 2012. Seed size and provenance mediate the joint effects of disturbance and seed predation on community assembly. Journal of Ecology 100:1492-1500.

Ortega, YK, Pearson, DE, Waller, LP, Sturdevant, NJ., Maron, JM.  2012.  Population-level compensation impedes biological control of an invasive forb and indirect release of a native grass. Ecology 93:783-792.

Pearson, D. E., Y. K. Ortega, and S. Sears.  2012. Darwin’s naturalization hypothesis up-close: intermountain grassland invaders differ morphologically and phenologically from native community dominants.  Biological Invasions 14:901-913.

Zwolak, R., D. E. Pearson, Y. K . Ortega, E. E. Crone. 2012. Mechanisms driving post-fire increase of a generalist mammal.  Canadian Journal of Zoology 90:51-60.

Pearson, D.E., R.M. Callaway, J.L. Maron.  2011. Biotic resistance via granivory: establishment by invasive, naturalized and native asters reflects generalist preference.  Ecology 92:1748-1757.

Maron, J. L., and D. E. Pearson.  2011. Vertebrate predators have minimal cascading effects on plant production or seed predation in an intact grassland ecosystem. Ecology Letters 14:661-669.

Pearson, D. E., M. Kim, and J. Butler.  2011.  Rocky Mountain Research Station invasive species visionary white paper.  Gen. Tech. Rep. RMRS-GTR-265. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station. 38 p.

Ortega Y.K., and D.E. Pearson.  2011.  Long-term effects of weed control with picloram along a gradient of spotted knapweed invasion.  Rangeland Ecology and Management 64: 67-77.

Pearson, D. E.  2010.  Trait- and density- mediated indirect interactions initiated by an exotic plant autogenic ecosystem engineer.  The American Naturalist 176:394-403.

Maron, J. L., D. E. Pearson, and R. Fletcher, Jr.  2010.  Counter-intuitive effects of large-scale predator removal on a mid-latitude rodent community.  Ecology 91: 3719-3728.

Ortega Y.K., and D.E. Pearson. 2010. Effects of picloram application on community dominants vary with initial levels of spotted knapweed (Centaurea stoebe) invasion   Invasive Plant Science and Management 3:70-80.

Zwolak, R., D.E. Pearson, Y.K .Ortega, E.E. Crone.  2010.  Fire and mice: seed predation moderates fire's influence on conifer recruitment.  Ecology 91:1124-1131.

Maron, J.L., D. E. Pearson, S. M. Hovick, W. P. Carson.  2010.  Funding needed for assessments of weed biological control.  Frontiers in Ecology and the Environment 8:122-123.

Bricker, M., D. E. Pearson and J. L. Maron.  2010. Small mammal seed predation reduces forb recruitment and abundance in semi-arid grasslands.  Ecology 91:85-92.

Finch, D. M., Pearson, D. E, Wunderle, J. and Arendt, W.  2010.  Terrestrial animals in the invasive species strategy plan.  Pages 43-54 In (Eds) Dix, M.E.; Britton, K., comps. 2010. A dynamic invasive species research vision: Opportunities and priorities, 2009-2029. Gen. Tech. Rep. WO-79. Washington, DC: U.S. Department of Agriculture, Forest Service.

Pearson, D. E.  2009.  Invasive plant architecture alters trophic interactions by changing predator abundance and behavior.  Oecologia 159:549-558. 

Pearson, D. E. 2009.  Biological invasions on oceanic islands: implications for island ecosystems and avifauna.  Pages 3-14 in Proceedings of the 3^rd International Symposium on Migratory Birds.  Seabirds in Danger: Invasive Species and Conservation of Island Ecosystems.  Keynote Address, 25 September 2009, Mokpo, Korea.

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.

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

Pearson, D. E. and R. M. Callaway. 2008.  Weed biocontrol insects reduce native plant recruitment through second-order apparent competition.  Ecological Applications 18:1489-1500.

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.

Sturdevant, N., Kegley, S., Ortega, Y., and D. 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.

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

Pearson, D. E. and R. M. Callaway.  2006.  Biological control agents elevate hantavirus by subsidizing mice. Ecology Letters 9:443-450.

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: assessing invasibility and 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 biological control agents and exotic plant invasion on 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.

McKelvey, K. S., and D. E. Pearson.  2001.  Population estimation with sparse data: the role of indices versus estimators revisited.  Canadian Journal of Zoology 79(10):1754-1765.

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.

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.

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(2):107-117. 

Pearson, D. E., and L. F. Ruggiero.  2001.  Test of a prey-base hypothesis for American marten use of red squirrel middens. Canadian Journal of Zoology 79(8):1372-1379.

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

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.

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.  University Press of Colorado, Colorado, USA.

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.

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

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.

Affiliations

Adjunct faculty with Ecology and Evolution in Division of Biological Sciences, UM.

Professional Experience

Research Ecologist, USDA Forest Service, Rocky Mountain Research Station, June 2016 to present.

Deputy Program Manager, Wildlife and Terrestrial Ecosystems, RMRS, USDA FS, Oct 2010 to present.

Research Ecologist, USDA Forest Service, Rocky Mountain Research Station, June 2005 to Oct 2010.
Adjunct Faculty, University of Montana, Missoula, MT, April 2012 to present.
Faculty Affiliate, University of Montana, Missoula, MT, September 2005 to April 2012.
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.

International Experience

I lead international scientific collabotions examining the biogeographic aspects of invasion by studying multiple plant species in their native and invaded ranges. 

Honors / Awards

Best Scientific Publication Award, USDA Forest Service, Rocky Mountain Research Station, Sept 29, 2021, for the publication: Pearson, D.E., Y.K. Ortega, Ö. Eren, and J.L. Hierro. 2018. Community assembly theory as a conceptual framework for invasions.  Trends in Ecology and Evolution 33:313-325.

Best Scientific Publication Award, USDA Forest Service, Rocky Mountain Research Station, Oct 2019, for the publication: Pearson, D.E., Y.K. Ortega, J. Runyon, and J. Butler.  2016. Secondary invasion: the bane of weed management.  Biological Conservation 197:8-17.

National Forest System Invasive Species Program Award for Landscape Restoration and Rehabilitation Against Invasive Species, March 2012, Dr. Dean Pearson, Rocky Mountain Research Station, in recognition of his high level of leadership and expertise on invasion biology and invasive species management, linking management concepts to long-term landscape restoration and rehabilitation. 

Visionary Science Publication Award, USDA Forest Service, Rocky Mountain Research Station, January 2013, for the publication: 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.

National Academy of Sciences, Kavli Fellow Recipient, 5 November 2010.

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.  Received 25 March 2009 in Washington D.C.  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.

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.

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.
 

Hobbies

Birding, fossil hunting, bow hunting elk, naturalizing, exploring the desert, landscaping, gardening