Castellane’s 2025 Biodiversity Atlas: Over 2,200 Species Documented Through Citizen Science

Volunteers who participated in the Castellane Communal Biodiversity Atlas (ABC) project within the Alpes-de-Haute-Provence department have recently concluded their observations for the year 2025. This initiative is part of a broader national movement in France dedicated to citizen science, which aims to democratize ecological knowledge and accelerate the gathering of scientific data. The results underscore the profound impact that non-professional researchers can have on our collective understanding of local ecosystems and environmental health.

The project successfully compiled more than 12,000 individual naturalist data points, leading to a detailed inventory of 2,296 distinct species across the categories of flora, fauna, fungi, and lichens. Significantly, 1,533 of these recorded observations represent new entries into the regional database, highlighting previous gaps in professional scientific surveys. To maximize the project's impact, organizers specifically targeted under-researched taxonomic groups, including aquatic insects, arachnids, wild bees, hoverflies, lichens, and various types of fungi.

The formal presentation of the 2025 ABC findings took place on Saturday, January 10, 2026, marking a major milestone in the project’s three-year operational cycle. The success of the initiative was largely driven by civic participation; local residents contributed more than 700 observations covering 191 species, 48 of which had never been previously documented by staff naturalists. This level of community involvement follows successful precedents set by other French programs, such as the BioLit initiative used for monitoring coastal biodiversity.

A particular area of interest during the study was the role of private gardens, especially those maintained with a 'wilder' approach, as vital biodiversity hotspots. In one notable instance, a single small garden was found to be home to 59 different species of wild bees, proving that private land can serve as a critical sanctuary for faunal diversity and essential pollinators. These localized successes in Castellane reflect France's long-term environmental goals, which since 2004 have sought to integrate biodiversity conservation into every facet of public policy.

While the broader Provence-Alpes-Côte d'Azur region has seen a general increase in vertebrate populations—with 45% of species showing growth compared to 41% in decline—the highly detailed data collected by volunteers is essential for identifying specific local threats. By providing a granular view of the ecosystem, these efforts allow for the creation of more effective, localized conservation measures. The 2025 Castellane Atlas ultimately demonstrates how the power of collective citizen action can significantly enrich scientific research and support the long-term protection of natural heritage.