Invasion Biology

Biological invasions offer unique opportunities to understand fundamental issues in ecology and evolution (Callaway and Maron 2006).  Biological invasions are essentially large-scale “natural experiments” that provide insight into key issues such as population regulation, community assembly, niche partitioning, and the interplay between plasticity and rapid evolutionary change in allowing species to colonize new areas.  Our interests in invasion biology center on three major issues. First, we are interested in how attributes of recipient communities influence community invasibility and invader impact.  We have explored how native plant diversity influences invasibility and invader impact, how invasibility and impact differ among invaders, and how impact scales with invader abundance (relevant publications: Maron and Marler 2007, 2008a, 2008b).   As part of this work, we have also shown the important role of soil pathogens in driving the common positive relationship between plant diversity and productivity (Maron et al. 2011).

research grids with plants
bed of palnts and flowers

More recently we have also examined the role of generalist rodent consumers in providing biotic resistance to invasion (Pearson et al. 2011, 2012).

field with fenced research area
research area bounday

Second, using biogeographical approaches, we are interested in determining the factors that enable a small subset of exotics to go from being relatively uncommon where they are native to occurring in virtual monocultures in recipient communities.  In  collaboration with Dr. Ray Callaway (University of Montana), we have explored whether altered interactions with plant competitors contributes to invasive success of spotted knapweed (Centaurea stoebe; relevent publications:  Callaway et al. 2011, 2012, Maron et al. 2013).   Other work, in collaboration with Drs. Callaway and J. Klironomos explores whether biogegraphical differences in the suppressive effects of soil biota  contribute to invasion success.

Finally, we are interested in the role of rapid evolutionary change in allowing exotics to adapt to new ecological circumstances.   In previous research (a collaboration with Dr. Montse Vila, Estación Biológica de Doñana (EBD-CSIC), Spain), we combined genetic data on invasion history with common garden experiments in the native and introduced range to quantify the evolutionary response of introduced genotypes of the invasive forb, St. John’s Wort (Hypericum perforatum), to new climatic conditions within the introduced range (relevenat publications: .  Publications from this work can be found here (Vila et al. 2003, Maron et al. 2004a, 2004b, Vila et al. 2005, Maron 2006, Maron et al. 2007, Seifert et al. 2009, Molins et al. 2014).