Spatial Management of Invasive Species: Pathways and Policy Options

Abstract

In addressing the problem of invasive species, decision makers have a variety of options, each targeting different aspects as it evolves over time and space. We develop a 2-region bioeconomic model that includes several transmission pathways that spread the invader. Within each region, inspections, removal efforts, and sustainable land management practices, including habitat restoration and less damaging production activities, are available to the regulator. We investigate the implications of different transmission pathways and second-best policies on the control patterns and invasive populations. Second-best settings where certain controls are not available to the regulator result in large distortions on the optimal use of the land. Overall, we find that non-linear interactions between regions, pathways, and controls are significant determinants of the optimal management of invasive species.

Economics of invasive species policy and management

“…They find that total effort mattered more than the specific strategy, but that at the landscape scale, targeting peripheral stands was most effective. Sanchirico et al (2010) study the effects of an invasive species on trade between regions and note substantial welfare gains from spatially optimized rather than uniform policies across locales, accounting for differences in productivity and risk. In the context of forests affected by a native pest, mountain pine beetle, Aadland et al (2015) show that optimal harvesting of each patch depends on both the pest and tree stocks across the landscape, as the beetles disperse to areas with high tree stocks.…”

Optimal Control of Spatial-Dynamic Processes: The Case of Biological Invasions

“…These assumptions simplify the problem but also mandate maximal control in all time periods. Other studies simplify by solving only for the equilibrium optimality conditions, rather than the path by which that equilibrium is optimally achieved (Albers et al 2010;Potapov and Lewis 2008;Sanchirico et al 2010b). Some approaches incorporate realistic features of control options and the characterization of space but make the problem tractable by reducing the dimension.…”

“…Some approaches incorporate realistic features of control options and the characterization of space but make the problem tractable by reducing the dimension. For example, Albers et al (2010) and Sanchirico et al (2010b) identify equilibrium control solutions for a complex model of invasion spread and reproduction dynamics in a two-patch model allowing for multiple types of control. Blackwood et al (2010) take the closest to our approach by accounting for large-scale explicit space, but solve for optimal spatial-dynamic control policies over a finite horizon with no transversality condition.…”

Invasive species control in a one-dimensional metapopulation network

“…These include Huffaker et al (1992), Albers et al (2010), Sanchirico et al (2010), Zhang et al (2010), Carrasco et al (2012), McDermott et al (2013), Fenichel et al (2014) and Kovacs et al (2014). The literature considering single jurisdictions consisting of multiple spatial areas has the shortcoming that it either does not allow for varying stock sizes within areas (i.e., areas are modelled in binary terms: either invaded or not invaded) or restricts removal of invasions in a given area to complete eradiction only (Carrasco et al, 2010a;Finnoff et al, 2010;Epanchin-Niell and Wilen, 2012;.…”