Integrating the Impacts of Non-native Species on Ecosystem Services into Environmental Policy

Abstract

As momentum increases to apply ecosystem service perspectives to a wide range of environmental and conservation-related policy issues, it is increasingly important that this approach be applied to the prevention and management of harmful non-native species. A tiered approach can be applied that first recognises the value of the ecosystem service at risk from non-native species, subsequently demonstrates the impacts quantitatively, and finally captures these impacts through the introduction of mechanisms that incorporate the values of ecosystems into decision making. A few risk assessment approaches follow this tiered approach but as yet do not capture the complexity of ecosystem service impacts generated by non-native species. The absence of quantitative ecological and economic data on the impacts of certain ecosystem services limits the development of regulatory initiatives. Most non-native species introduced by humans have value to one or more sectors of society. As a result, conflicts arise in the estimates of the net value of non-native species to ecosystem services. A series of scenarios are used to illustrate how the strength of such conflicts might vary under different circumstances and what options might exist to achieve resolution. Addressing the impacts on ecosystem services will require understanding of environmental conflicts and policy tools that can better capture impacts of commercially important non-native species. Conflict resolution may involve management rather than eradication of a particular non-native species if this species proves to be appreciated by certain stakeholders. Alternatively, a polluter-pays principle could require those introducing non-native species internalise the costs of any subsequent environmental impacts.