The Anthropocene Epoch is characterized by novel and increasingly complex dependencies between the environment and human civilization, with many challenges of biodiversity management emerging as wicked problems. Problems arising from the management of biological invasions can be either tame (with simple or obvious solutions) or wicked, where difficulty in appropriately defining the problem can make complete solutions impossible to find. We review four case studies that reflect the main goals in the management of biological invasions – prevention, eradication, and impact reduction – assessing the drivers and extent of wicked ness in each. We find that a disconnect between the perception and reality of how wicked a problem is can profoundly influence the likelihood of successful management. For example, managing species introductions can be wicked, but shifting from species-focused to vector-focused risk management can greatly reduce the complexity, making it a tame problem. The scope and scale of the overall management goal will also dictate the wickedness of the problem and the achievability of management solutions (cf. eradication and ecosystem restoration). Finally, managing species that have both positive and negative impacts requires engagement with all stakeholders and scenario-based planning. Effective management of invasions requires either recognizing unavoidable wickedness, or circumventing it by seeking alternative management perspectives.
The Anthropocene Epoch represents an era of unprecedented environmental change driven by human activities, a key component of which is the widespread trans portation, spread, and resulting homogenization of fauna and flora (Williams et al. 2015). In a world fundamentally altered by anthropogenic processes, problems encountered in ecosystem management, and in particular in conservation biology and resource management, are becoming increasingly complex, where problems may not have a single, technical solution (Haubold 2012). More specifically, deci sions regarding conservation in the Anthropocene need to consider the social and economic context (Ban et al. 2013), including the differing values stakeholders use when assessing risk (Liu et al. 2011, Kumschick et al. 2012). Conservation goals are set more often by the social-political perspectives of different stakeholders than by the empirical evidence (Geist and Galatowitsch 1999, Sagoff 2009). The consequent multitude of conflicting perspectives, objectives, and management goals can make the problem almost impossible to characterize, let alone solve, to the satisfaction of all stakeholders.
Such problems were first recognized in the policy and planning field by Rittel and Webber (1973), who coined the term “wicked problem”. They defined a wicked problem according to 10 interrelated criteria, later condensed to six criteria by Conklin (2005; see Box 1). Wicked problems can also be viewed in the context of complex
ity theory as management problems where the cause-and-effect relationships between components, whether they be logistical components or stakeholders involved in man agement, are unordered and thus have solutions that are not obvious and require col laboration among stakeholders to determine appropriate actions (Kurtz and Snowdon 2003, Van Beurden et al. 2011). Such problems are contrasted against “tame” prob lems where the cause-and-effect relationships between components are ordered and the
solutions obvious or discernible after careful investigation (Box 1). Problems in the management of biological invasions have previously been referred to as wicked problems. The term was used by Evans et al. (2008), citing difficulties encountered when managing aquatic pests in the Crystal River, Florida; by McNeely (2013) when describing the management of plant introductions in conservation areas; and by Seastedt (2014) when describing the socio-political and ethical issues surround ing biocontrol. The management of biological invasions is particularly susceptible to wickedness in the form of conflicting social pressures. Differing values and risks as cribed to individual taxa by affected parties can lead to social conflicts around their management (Liu et al. 2011, Estévez et al. 2015). The wickedness of a problem will vary from case to case. Not all criteria might apply, some criteria may out-weigh others in making a particular problem more or less wicked, and the wickedness of a problem can vary by region or country according to the perspectives of the different stakeholders involved. In each of these cases, however, it is important to understand how the nature of the problem affects how it can be managed.
In this review, we assess how altering perceptions of managers and stakeholders to the nature and scope of problems presented by biological invasions can complicate or simplify the management solution. The options available to conservationists and envi ronmental managers change with subsequent stages of invasion from initial incursion to spread to widespread establishment (Blackburn et al. 2011, McGeoch et al. 2016) and the complexity associated with solving the problem will intensify as invasions progress through these phases. We interrogate four examples of invasive species man agement problems across aquatic and terrestrial ecosystems, which focus on achieving prevention, eradication, or impact reduction. Our aim was to illustrate how wicked ness in conservation management can arise and might be counteracted, realising that this is not always possible. We also identify situations where biological invasions can best be managed by shifting one’s perspective and subsequent management approach to the problem.