A good idea or just an idea: Which adaptation strategies for conservation are tested?

Several highly cited review articles identify recommended adaptation strategies for conservation. However, those reviews do not include evaluation of whether the recommended adaptation measures were tested and found to be effective in reducing climate change vulnerability. The basic question of this paper is to determine if there has been assessment of the potential effectiveness of adaptation recommendations for conservation reported in the published literature, and if so, what kind of assessment was used. To answer this question, literature was surveyed from the references in previous review papers focused on climate change adaptation recommendations, and augmented by a targeted literature search to identify studies that assess the effectiveness of recommended adaptation actions listed in those reviews. Identified studies were categorized by study type according to a hierarchy of adaptation efficacy testing. The result was a very modest number of studies that experimentally tested adaptation efficacy (n = 13), including only one indicating the chosen strategy did not achieve its intended goal, and only one study that tested efficacy through monitoring. For some of the recommendations, only one efficacy-assessing paper was identified. There appears to be a significant shortage of studies presenting evidence that would be most useful in determining if a recommended action is likely to confer the desired conservation improvement, as well as a stagnation in the growth of the field. This points to a need for more efforts to monitor and evaluate the effectiveness of adaptation recommendations for biodiversity management. Without it, we cannot learn which are the good ideas. •Adaptation strategies to improve biodiversity outcomes are largely untested.•Only 14 studies were identified in which adaptation efficacy was tested.•Efforts to test adaptation efficacy do not appear to be increasing.