Dr. Pearson's current research focus is applying community ecology to address conservation and management challenges in general and the problem of biological invasions (introduced pest species) in particular. He leads a small team that is tackling the three key components of the invasion problem: 1) understanding the causes of invasion by conducting international research on many plant species in their native and introduced ranges to determine how the introduction of organisms to new ranges creates pest species; 2) studying invader impacts in the introduced range to identifying mitigation targets and strategies; and 3) quantifying the efficacy of management tools (e.g., biological control, herbicides, restoration strategies) and refining their applications for mitigating invader impacts.
Ecology and management of invasive species: http://www.fs.fed.us/rm/wildlife-terrestrial/invasive-species/
Invasive plant impact rankings for intermountain bluebunch wheatgrass: http://ow.ly/PQKz9
Adjunct Faculty, Organismal Biology Ecology Evolution, University of Montana: http://hs.umt.edu/dbs/grad-programs/obe/faculty.php?id=1063
Dr. Pearson's primary research interest is to advance community ecology through studies of biological invasions and to use this information to improve invasive species management. Biological invasions serve as grand natural experiments that provide unique opportunities to view the processes that structure ecological communities. Even in the most recently assembled natural communities organisms have had hundreds or thousands of years to interact and sort themselves into the modern assemblages we see. This makes it very challenging to identify the relative roles of competition, predation, parasitism, resource availability, etc. in structuring extant communities. However, with biological invasions, it is possible to observe these processes in real time as a novel organism invades, establishes, and dominates (in the case of strong invaders) a new assemblage. It is also possible to see how the assemblage finally settles into a new equilibrium state as the invader's dominance wanes through the ecological and evolutionary adaptation of the community to its presence. Newly hypothesized understandings of these processes can then be tested in the context of directed community assembly through the applied largescale natural experiments that are attempts to manage the invasion problem, for example, classical biological control - the intentional introduction of exotic organisms to manage invasions. Thus, biological invasions offer an opportunity to advance understandings of community ecology that can in turn be tested by applying these understandings to the management of the invasives problem.
Dr. Pearson's prior research focused on wildlife biology, studying wildlife-habitat relationships and techniques for wildlife studies.
Biological invasions present the second greatest threat to natural ecosystems and the services they provide next only to actual land transformation. Exotic species invasions cost the United States 120-140 billion dollars per year in revenue losses and mitigation costs. Management of this problem has been particuarly challenging due to a lack of understanding of the fundamental processes underlying invasion. My research attempts to better understand the causes and consequences of invasion and the efficacy of current managmen tools in order to better guide management approaches toward more effective mitigation. Success in these efforts offers tremendous benefits in terms of US revenues and stability of ecosystem services.