Examining the Role of Humans in the Spread of Invasive Species
Scientists and collaborators with the Eastern Threat Center have previously estimated annual rates of establishment of non-native forest insect species for more than 3,000 U.S. urban areas based on historical data on U.S. merchandise imports and insect incursions, pest interceptions at U.S. ports of entry, and international and domestic freight shipment networks. Researchers are revisiting this work and using new and updated data sources to project non-native insect establishment rates until 2045, which will support broader, economically-focused models of potential non-native insect impacts on U.S. forests, particularly in the Southeast. These analyses anticipate where and how often invasive alien forest insects are likely to be established in the United States to assist decision makers and offer guidance for border control efforts, post-border surveillance, and rapid-response measures.
Researchers have also developed similar non-native forest insect establishment rate estimates for Canada based on trade, and have analyzed travel patterns of campers in the United States and associated firewood transport—a practice that can introduce forest pests into new and often remote areas. More recently, researchers developed a network model of camper travel and firewood movement that facilitates two-way analysis of forest pest invasion pathways. They identified the likeliest destinations if a pest were to spread from a currently infested location, or alternatively, the likeliest origins for a recently discovered infestation in a location of interest. In addition, a recent collaboration resulted in the creation of a similar network model of camper travel and firewood movement for North Carolina State Parks, which should provide insights into the risks of human-assisted pest spread on a smaller scale.
Right: A map shows the links between visitor origin ZIP codes and destination campgrounds, as documented in the U.S. National Recreation Reservation Service database between January 2004 and September 2009. Link color indicates the number of individual reservations recorded in the database; links with 10 or fewer reservations have been omitted for clarity. Click to enlarge.
References:
Koch, F.H.; Yemshanov, D.; Haack, R.A.; Magarey, R.D. 2014. Using a network model to assess risk of forest pest spread via recreational travel. PLoS ONE 9(7):e102105.
Yemshanov, D.; Koch, F.H.; Ducey, M.; Koehler, K. 2012. Trade-associated pathways of alien forest insect entries in Canada. Biological Invasions 14:797–812.
Koch, F.H.; Yemshanov, D.; Magarey, R.D.; Smith, W.D. 2012. Dispersal of Invasive Forest Insects via Recreational Firewood: A Quantitative Analysis. Journal of Economic Entomology. 105(2):438-450.
Yemshanov, Denys.; Koch, Frank H.; Lyons, D. Barry.; Ducey, Mark.; Koehler, Klaus 2011. A dominance-based approach to map risks of ecological invasions in the presence of severe uncertainty. Diversity and Distributions 18:33–46.
Magarey, R. D.; Borchert, D. M.; Engle, J. S.; Colunga-Garcia, M; Koch, F. H.; Yemshanov, D 2011. Risk maps for targeting exotic plant pest detection programs in the United States. EPPO Bulletin 41:46-56.
Koch, Frank H.; Yemshanov, Denys; Colunga-Garcia, Manuel; Magarey Roger D.; Smith, William D 2011. Potential establishment of alien-invasive forest insect species in the United States: where and how many? Biological Invasions 13:969-985.
External Partners/Collaborators: Canadian Forest Service; USDA Animal and Plant Health Inspection Service; Michigan State University; University of Florida; The Nature Conservancy; North Carolina State Parks
Contact: Frank Koch
