Sown Summer-Blooming Wildflowers as a Tool to Support Pollinator Biodiversity During Dry Periods in Mediterranean Agroecosystems

Summer abiotic stresses typical of Mediterranean agro-environments, now exacerbated by climate change, reduce floral resource availability and further compromise the survival of pollinators already threatened in the so-called Anthropocene. The aim of this study was to evaluate several summer-blooming wildflower species, collected from ecologically disturbed and diversified habitats, in order to assess their ecological role in attracting pollinators within agroecosystems. The primary dormancy typical of wild species seeds was partially overcome through appropriate pre-sowing seed treatments, while secondary dormancy was reduced by soil rolling after sowing. Soil rolling proved particularly beneficial for species with very small seeds, highlighting the importance of adequate seed-soil contact for successful establishment. All tested species exhibited summer flowering between May and July, with some flowering later in the season, and showed high attractiveness to pollinators both in terms of abundance and taxonomic diversity. However, this ecosystem service declined significantly in the second year, although certain species demonstrated a strong capacity to persist and to maintain satisfactory pollinator attractiveness over time. In conclusion, while the experiment revealed several critical aspects, it also provides encouraging prospects for further research aimed at enhancing pollinator survival in agroecosystems that are severely threatened by pollinator decline.