Impact network analysis: Evaluating the success of interventions

The success of intervention projects in ecological systems depends not only on the quality of a management strategy, but also how that strategy plays out among decision makers. Impact network analysis (INA) is a framework for evaluating the likely regional success of interventions before, during, and after projects, for project implementers, policy makers, and funders. INA integrates across three key system components: (a) the quality of a management strategy and the quality of information about it, (b) the socioeconomic networks through which managers learn about the management strategy and decide whether to use it, and (c) the biophysical network that results from those decisions. A common example where INA can be useful is management of an invasive (or endangered) species or genotype. A management strategy to reduce (or increase) the probability of establishment of a species may or may not be adopted by each land manager in a region, depending on the quality of the management strategy and the information they have available about it. The resulting management landscape will determine whether the intervention project is successful, in terms of how much of the region the species can spread through and the resulting effects on the desired ecosystem services. INA can be applied in general to evaluate the success of immediate intervention strategies, and to contribute to fundamental understanding about what makes interventions successful.