A spatial-dynamic value transfer model of economic losses from a biological invasion

a r t i c l e i n f o Rigorous assessments of the economic impacts of introduced species at broad spatial scales are required to provide credible information to policy makers. We propose that economic models of aggregate damages induced by biological invasions need to link microeconomic analyses of site-specific economic damages with spatial-dynamic models of value change associated with invasion spread across the macro-scale landscape. Recognizing that economic impacts of biological invasions occur where biological processes intersect the economic landscape, we define the area of economic damage (AED) as the sum of all areas on the physical landscape that sustain economic damage from a biological invasion. By subsuming fine-scale spatial dynamics in the AED measure, temporal dynamics of the AED can be estimated from an empirical distribution of the AED effective range radius over time. This methodology is illustrated using the case of a non-native forest pest, the hemlock woolly adelgid (HWA; Adelges tsugae). Geographic Information Systems and spatially referenced data provide the basis for statistical estimation of a spatial-dynamic value transfer model which indicates that HWA is annually causing millions of dollars of economic losses for residential property owners in the eastern United States. Biological invasions by non-native forest insects and diseases currently pose a substantial, complex, and long-term threat to forest ecosystems and the services they provide to societies around the globe. For millennia, the world's biota has been separated into independently evolving ecological communities. The growth in international trade represents but a brief moment in the evolution of ecological species and yet has provided new linkages between geographically dispersed markets, and the movement of products has created new pathways for arrivals of non-native species which threaten ecological communities (Stanaway et al. Although many invasions have been inconsequential, history has shown that a few species have the potential to become major pests (Williamson and Fitter, 1996). Forests provide suitable habitat for an assortment of invading organisms (Liebhold et al., 1995). Since the time Europeans discovered North America, more than 368 exotic phytophagous insects have become established in forests, woodlots, parks, and orchards (Mattson et al., 1994). Despite the fact that most non-native forest insects have proven to be innocuous and cause little harm, a few — such as the European gypsy moth (Lymantria dispar), emerald ash borer (Agrilus planipennis), and hemlock woolly adelgid (Adelges tsugae) — have become major pests. The number of non-native tree …