Review of the approaches for assessing protected areas' effectiveness

Sustainable development requires improvement of both the quantity and quality of protected areas (PAs). This paper reviews the assessments of PAs' effectiveness and provides further guidance of using the assessment approaches, including: (1) evaluation based on a theory of change that describes how and why an intervention is supposed to work; (2) counterfactual evaluation using a random or constructed control group, or baseline of the treatment group as the counterfactual; (3) economic evaluation that assesses benefits and costs of interventions; (4) consultation; (5) case studies; (6) rapid assessments based on readily available evaluation sheets (e.g., scorecards); and (7) approaches focusing on a specific aspect of PAs (e.g., ecological integrity, representativeness, and threats). These approaches have different characteristics and suitability to different assessment purposes and should be selected accordingly. For future research, we anticipate (1) an expanded PA effectiveness assessment guidebook integrating detailed instructions of the approaches and potential indicators, (2) more practical control-group-constructing techniques (3) more sophisticated and reliable techniques for valuing ecosystem services and biodiversity, and (4) further work to clarify the features of different evaluation sheets for rapid assessments. In terms of linkage with global initiatives, this review may help in the preparation of the National Reports (that indicate information on PAs' effectiveness) submitted to the Convention on Biological Diversity and evaluation of actions taken to fulfill PA-related goals of the United Nations Sustainable Development Goals, Convention to Combat Desertification 2018–2030 Strategic Framework, Paris Agreement, and especially Post-2020 Global Biodiversity Framework.