iNaturalist projects represent a valuable resource for aggregating plant observations and engaging society: A case study of the Flora of Mongolia project

Societal Impact Statement Citizen science – collaboration between scientists and the public – has the potential to advance biodiversity monitoring. Using a case study from Mongolia, called the Flora of Mongolia project in iNaturalist, we illustrate how crowd‐sourced biodiversity data fills gaps of plant diversity in Mongolia. Over 52,200 observations covering 2,241 species of vascular plants (ca. 3,050 species) were observed by 665 participants between 2019 and 2023, showcasing the vast potential for rapid biodiversity inventories. This case study, from an under‐resourced region, illustrates the potential role of citizen science, and iNaturalist, in future biodiversity monitoring efforts. Summary At a time of alarming biodiversity loss, biodiversity monitoring is crucial. Yet, funding for such monitoring is difficult to attain, leading to data gaps of baseline biodiversity information in regions of the world that are often the most threatened. In Mongolia, there are limited resources for finding wild photos and distribution points of vascular plant species. Therefore, we established the Flora of Mongolia project in iNaturalist in January 2019 to fill the gap of quantifying the country's plant diversity. Over the course of five years, 665 participants have contributed 52,286 observations belonging to 2,241 species. To date, participants have already observed 69% of the estimated total vascular plant species (ca. 3,050 species) in Mongolia including numerous threatened and endemic species. The total number of observations in iNaturalist is now higher than both herbarium records from GBIF and FloraGREIF for Mongolia, showcasing the potential of crowd‐sourcing data. The majority of species and observation numbers were observed in the western and central parts of Mongolia. This iNaturalist project is significantly expanding the capacity for data collection and analysis of vascular plants, highlighting the important role that customized iNaturalist projects can have in biodiversity data generation. As citizen science data collections continue to grow, we can expect them to play a significant role in further improving our knowledge of plant diversity, monitoring invasive species, and quantifying the impacts of climate change on rare and threatened plants.