Ayres Abstracts

Lovett, Gary M., M. Weiss, A. M. Liebhold, T. P. Holmes, B. Leung, K. Fallon Lambert, D. A. Orwig, F. T. Campbell, J. Rosenthal, D. G. McCullough, R. Wildova, M. P. Ayres, C. D. Canham, D. R. Foster, S. L. LaDeau, and T. Weldy. 2016. Non-native forest insects and pathogens in the U.S.: Impacts and policy options. Ecological Applications: 26: 1437-1455. Link. Request reprint. News. Tree-SMART Trade. Noted in Science. Segment on Vermont Public Radio (starts at 32 min into recording). Text from VPR interview.

Abstract. We review and synthesize information on invasions of non-native forest insects and diseases in the US, including their ecological and economic impacts, pathways of arrival, distribution within the US, and policy options for reducing future invasions. Non-native insects have accumulated in US forests at a rate of about 2.5 y-1 over the last 150 y. Currently the two major pathways of introduction are importation of live plants and wood packing material such as pallets and crates. Introduced insects and diseases occur in forests and cities throughout the US, and the problem is particularly severe in the Northeast and Upper Midwest. Non-native forest pests are the only disturbance agent that has effectively eliminated entire tree species or genera from US forests in the span of decades. The resulting shift in forest structure and species composition alters ecosystem functions such as productivity, nutrient cycling and wildlife habitat. In urban and suburban areas, loss of trees from streets, yards and parks affects aesthetics, property values, shading, stormwater runoff, and human health. The economic damage from non-native pests has yet to be fully reckoned, but is likely in the billions of dollars per year, and the majority of this economic burden is borne by municipalities and residential property owners.
Current policies for preventing introductions are having positive effects but are insufficient to reduce the influx of pests in the face of burgeoning global trade. Options are available to strengthen the defenses against pest arrival and establishment, including measures taken in the exporting country prior to shipment, measures to ensure clean shipments of plants and wood products, inspections at ports of entry, and post-entry measures such as quarantines, surveillance and eradication programs. Improved data collection procedures for inspections, greater data accessibility and better reporting would support better evaluation of policy effectiveness. Lack of additional action places the nation, local municipalities, and property owners at high risk of further damaging and costly invasions. Adopting stronger policies to reduce establishments of new forest insects and diseases would shift the major costs of control to the source and alleviate the economic burden now borne by homeowners and municipalities.

Keywords: forest, invasive, insect, pathogen, disease, policy