LIFE 4 Pollinators' platform: How citizen science can help monitoring plants and pollinators

Plant diversity is critical to ensure the future of humanity, as it provides essential ecosystem services and functioning. As recent estimates showed that animal-mediated pollination is crucial for the reproduction of approximately 90% of flowering plants, playing an essential role in maintaining biodiversity and agricultural productivity, effort to preserve plants cannot be disjoined from pollinator conservation initiatives. Despite their importance, pollinators have experienced alarming declines. The LIFE 4 Pollinators project was launched to involve people protecting wild bees and other pollinators in the Mediterranean. This study presents data collected through the project's web-platform, where users uploaded over 2,000 photographs of plant-pollinator interactions between 2021 and 2024. The dataset focuses on the identification of flower-visiting insects and plants, and the current study gives emphasis to citizen scientists' ability to identify plants and pollinators. 1,407 photo-records were analysed, revealing that bees and beetles were the most frequent pollinators, with plants of the Asteraceae and Cistaceae families being the most recorded. Users correctly identified 93.7% of insect taxonomic aggregations and 74.2% of plant species. The study also highlights the recording of threatened, alien, and invasive species, including the vulnerable Callicera spinolae and the invasive Vespa velutina. The plant-pollinator network analysis supports the floral syndrome concept, with floral morphologies like 'Head' and 'Disk' attracting a wide range of pollinators. The results indicate that citizen science contributes to the identification and monitoring of pollinators, generating knowledge that may be key to the conservation of these organisms and to better understand plant-pollinator interactions. Data collection through citizen-generated photographs allows to significantly expand the geographic area and the magnitude of studies, facilitating large-scale analyses that would be difficult to achieve with traditional monitoring methods. These findings provide a useful basis for future conservation initiatives and the development of policies aimed at mitigating pollinator decline.