Increasing the credibility of conservation plans through citizen science

Plans for protected area systems (hereafter, prioritizations) need to identify cost-effective priority areas. They must also be supported by information that stakeholders value as credible. Although field observations are often considered highly credible, species distribution models are generally required to overcome sampling gaps and biases. Here we investigate how field observations collected through citizen science could help improve the credibility of prioritizations. Examining a case study in southern Ontario (Canada), we obtained expert survey and citizen science data for 14 plant species and fitted species distribution models. We generated conventional prioritizations following standard conservation planning approaches. We then generated prioritizations that allocated increasing budgets for representing species through priority areas with confirmed occurrences from expert surveys. We also generated prioritizations with confirmed occurrences from both expert surveys and citizen science. Assuming that greater coverage of confirmed occurrences conveys greater credibility, we assessed the putative credibility of prioritizations according to their ability to meet species representation targets with confirmed occurrences. We found trade-offs between minimizing the cost of prioritizations and maximizing their putative credibility. Although such trade-offs were most acute under limited budgets, prioritizations generated with confirmed occurrences from expert surveys and citizen science achieved a moderate increase in putative credibility for only a minor increase in cost. Additionally, our results showed that prioritizations generated with expert surveys and citizen science had greater putative credibility than those generated with expert surveys alone. By considering the perceived credibility of supporting data, conservation planning exercises may achieve greater approval by stakeholders. • Citizen science may help boost credibility of conservation plans. • There were trade-offs between the credibility and cost of conservation plans. • It is possible to increase credibility for a small increase in cost. • Conservation plans with higher targets may have difficulty maintaining credibility.