Networks of interaction between flowers and hymenopters in two coastal communities. Effects of habitat loss.

Pollination is a key process for the functioning of the ecosystem. The environmental crisis is affecting pollinators around the world. The study of the structure and dynamics of pollination networks can give us information on species conservation and on the importance of pollination as an ecosystem service. In this work we analyzed the pollination networks of hymenoptera in two coastal localities of the island of Mallorca, one of them affected by habitat loss. A set of parameters was obtained describing the structure of interaction networks at both community and species level. In addition, we evaluated the species richness, diversity, and conservation status of hymenopterans presumably with greater functional relevance in each community (the most general and least selective). Both communities showed low connectance, a relatively high specialization and a low niche overlap, which suggests a high fragility to disturbances. In fact, the loss of habitat caused a decrease in the richness of plant species that resulted in a lower diversity of hymenopterans and plant-pollinator interactions. The community affected by the perturbation showed to be less robust to future disturbances than the unaltered community. The analyzed parameters allowed assessing the ecological role of the most important bees and wasps in the community and their behaviour at the temporal scale. With such results, we suggest specific management measures for each locality.