Dispersal of Invasive Forest Insects via Recreational Firewood: A Quantitative Analysis

  • Author(s): Koch, Frank H.; Yemshanov, Denys; Magarey, Roger D.; Smith, William D.
  • Date: 2012
  • Source: J. Econ. Entomol. 105(2):438-450
  • Station ID: JRNL-SRS-105

Abstract

Recreational travel is a recognized vector for the spread of invasive species in North America. However, there has been little quantitative analysis of the risks posed by such travel and the associated transport of firewood. In this study, we analyzed the risk of forest insect spread with firewood and estimated related dispersal parameters for application in geographically explicit invasion models. Our primary data source was the U.S. National Recreation Reservation Service database, which records camper reservations at >2,500 locations nationwide. For >7 million individual reservations made between 2004 and 2009 (including visits from Canada), we calculated the distance between visitor home address and campground location.We constructed an empirical dispersal kernel (i.e., the probability distribution of the travel distances) from these “origin-destination” data, and then fitted the data with various theoretical distributions. We found the data to be strongly leptokurtic (fat-tailed) and fairly well fit by the unbounded Johnson and lognormal distributions. Most campers (~53%) traveled <100 km, but ~10% traveled >500 km (and as far as 5,500 km). Additionally, we examined the impact of geographic region, specific destinations (major national parks), and specific origin locations (major cities) on the shape of the dispersal kernel, and found that mixture distributions (i.e., theoretical distribution functions composed of multiple univariate distributions) may fit better in some circumstances. Although only a limited amount of all transported firewood is likely to be infested by forest insects, this still represents a considerable increase in dispersal potential beyond the insects' natural spread capabilities.

  • Citation: . . Dispersal of Invasive Forest Insects via Recreational Firewood: A Quantitative Analysis. J. Econ. Entomol. 105(2):438-450.

Requesting Publications

You can order print copies of our publications through our publication ordering system. Make a note of the publication you wish to request, and visit our Publication Order Site.

Publication Notes

  • This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.
  • Our on-line publications are scanned and captured using Adobe Acrobat. During the capture process some typographical errors may occur. Please contact the SRS webmaster if you notice any errors which make this publication unuseable.
  • To view this article, download the latest version of Adobe Acrobat Reader.