Pre-invasion economic assessment of invasive species prevention: A putative ambrosia beetle in Southeastern loblolly pine forests

Abstract

Invasive wood borers vectoring pathogenic fungi have nearly exterminated several North American tree species, and it is unclear whether landscape dominant trees, such as pines, will face similar threats in the future. This paper explores the economic impacts of a hypothetical arrival of a destructive ambrosia beetle "X" (Coleoptera: Curculionidae) that infests loblolly pine (Pinus taeda L.) forests in the Southeastern United States. We develop an economic framework for pre-invasion assessment that incorporates fluctuating economic and environmental conditions for a representative loblolly pine stand and biological assumptions from the ongoing laurel wilt epidemic. Assuming an initial annual probability of arrival of a pine infesting ambrosia beetle to be between 0.04 and 0.07, we determine that, on average, the timber economic benefits for a forest landowner are $5325.3 ha^-1, with a harvest time of 17.8 years. Our results indicate that an increase in enforcement consistent with an international phytosanitary standard that partially prevents the arrival of ambrosia beetles (30% arrival reduction) would have a strong, positive impact for forest landowners. On average, economic revenues increase to $6116.4 ha^-1 and the harvest age is extended to 19 years. On average, the economic losses for forest landowners with no control of ambrosia beetle X would be $791 ha^-1, with a harvest time reduction of 1.2 years. The upper-bound regional cost savings from pine-dominated forestry would be roughly $4.6 billion dollars if invasion preventative measures are in place. These benefits vastly outweigh the cost of programs that reduce the expected arrival of exotic ambrosia beetles.

Keywords: Ambrosia beetle; International phytosanitary standard; Invasive species; Net present value; Pre-invasion.