Invasion Biology
Biological invasions are a major challenge to communities across natural and managed systems, leading to the loss of biodiversity and community function and billions of dollars in economic costs. Our goal is to gain a mechanistic understanding of how invasive species interact with their environment to help us understand how to prevent or reduce the spread of invasive species and the damage they cause. To accomplish this we use a combination of empirical studies of the biology of invasive species and modeling approaches that allow us to integrate our knowledge, test our understanding, and ask questions that would be impractical to do in the real world.
Community responses to removal of an invasive
Invasive species can significantly alter community composition and the recruitment of native species is limited by the local species pool, dispersal capabilities, and species interactions. Therefore, understanding how communities will respond to being released from the effects of an introduced dominant competitor is not as easy to predict as we would like and can lead to many interesting dynamics of importance for conservation and restoration efforts.
Selected Publications (Please contact me for reprints):
Emry,D.J., R.J. Mercader, P.E. Bergeron, J.V. Eilert, and B.A. Riddle. 2024. Small-scale amur honeysuckle removal and passive restoration may not create long-term success. Natural Areas Journal. 44(2):98-103.
Mercader, R.J., L.R. Apenfeller, P.O. McCoy, T. Sadikot, and J.L. Smith. 2022. Parasitoid increase during and outbreak of a native herbivorous insect following small-scale amur honeysuckle (Lonicera maackii) removal. The American Midland Naturalist. 188(1):127-134.
Mercader, R.J., T.J. Paulson, P.J. Engelken, and L.R. Appenfeller. 2020. Defoliation by a native herbivore, Omphalocera munroei, leads to patch size reduction of a native plant species, Asimina triloba, following small-scale removal of the invasive shrub, Amur honeysuckle, Lonicera maackii. Plant Ecology 221:125–139.
Bergeron, P.E, S.J. Clary, and R.J. Mercader. 2019. Influence of host use on the dispersal propensity of Callosobruchus maculatus. Journal of applied entomology 143: 693-698.
Mercader, R.J., D.G. McCullough, A.J. Storer, J.M. Bedford, R. Heyd, N.W. Siegert, T.M. Poland, and S. Katovich. 2016. Estimating local spread of recently established emerald ash borer, Agrilus planipennis, infestations and the potential to influence it with a systemic insecticide and girdled ash trees. Forest Ecology and Management 366:87-97.
Mercader, R.J., D.G. McCullough, A.J. Storer, J.M. Bedford, R. Heyd, T.M. Poland, and S. Katovich. 2015.Evaluation of the potential use of a systemic insecticide and girdled trees in area wide management of the emerald ash borer. Forest Ecology and Management 350:70-80
Siegert, N.W., R.J. Mercader, and D.G. McCullough. 2015. Spread and dispersal of emerald ash borer (Coleoptera: Buprestidae): estimating the spatial dynamics of a difficult-to-detect invasive forest pest. The Canadian Entomologist 147: 338-348.
McCullough, D.G., R.J. Mercader, and N.W. Siegert. 2015. Developing and integrating tactics to slow ash (Oleaceae) mortality caused by emerald ash borer (Coleoptera: Buprestidae). The Canadian Entomologist 147: 349-358.
Kovacs, K.F., R.G. Haight, R.J. Mercader, and D.G. McCullough. 2014. A bioeconomic analysis of an emerald ash borer invasion of an urban forest with multiple jurisdictions. Resource and Energy Economics. 36(1): 270-289
Mercader, R.J., D.G. McCullough, J Bedford. 2013. A comparison of girdled ash detection trees and baited artificial traps for emerald ash borer (Agrilus planipennis Fairmaire) detection. Environmental Entomology.42:1027-1039.
Mercader, R.J., N.W. Siegert, and D.G. McCullough. 2012. Estimating the influence of population density and dispersal behavior on the ability to detect and monitor Agrilus planipennis (Coleoptera: Buprestidae) populations. Journal of economic entomology. 105: 272-281
McCullough, D.G. and R.J. Mercader. 2012. Evaluation of potential strategies to SLow Ash Mortality (SLAM) caused by emerald ash borer (Agrilus planipennis): SLAM in an urban forest. International journal of pest management 58(1):9-23.
Kovacs, K., R.J. Mercader, R.G. Haight, N.W. Siegert, D.G. McCullough, and A.M. Liebhold. 2011. The influence of satellite populations of emerald ash borer on projected economic costs in U.S. communities, 2010-2020 . Journal of environmental management 92: 2170-2181.
Mercader, R.J., N.W. Siegert, A.M. Liebhold, and D.G. McCullough. 2011. Influence of foraging behavior and host spatial distribution on the localized spread of the emerald ash borer, Agrilus planipennis. Population Ecology 53(2): 271-285.
Mercader, R.J., N.W. Siegert, A.M. Liebhold, and D.G. McCullough. 2011. Simulating the effectiveness of three potential management options to slow the spread of emerald ash borer. populations in localized outlier sites. Canadian Journal of Forestry 41(2): 254-264
Kovacs, K., R.G. Haight, D.G. McCullough, R.J. Mercader, N.W. Siegert, and A.M. Liebhold. 2010. Cost of Potential Emerald Ash Borer Damage in U.S. Communities, 2009-2019. Ecological Economics 69(3): 569-578.
Mercader, R.J., N.W. Siegert, A.M. Liebhold, and D.G. McCullough. 2009. Dispersal of the Emerald Ash Borer, Agrilus plannipennis, in newly colonized sites. Agricultural and Forest Entomology 11(4): 421-424.