The role of E. maritimum (L.) in the dune pollination network of the Balearic Islands

Eryngium maritimum L. (Apiaceae) is a geophyte that inhabits in the dunes of the Mediterranean and Atlantic. In Northern Europe, it is considered a highly endangered species due to reproductive problems, while in the Mediterranean, populations are in a good state of conservation. Although it is a highly entomophilous species, there is little literature on its pollinators. The aim of this study is to analyse the role played by E. maritimum in the dune pollination network of the Balearic Islands. For this purpose, two populations located in the North and South of Mallorca were chosen, in which diurnal transects were carried out to observe and capture pollinators on 15 plant species during the anthesis period of E. maritimum. In parallel, an analysis of the flowering period of 10 of these plant species was carried out to identify periods of competition. A total of 82 pollinator species were found, belonging to 30 different families. Eryngium maritimum is a strongly generalist species, with a total of 46 pollinator species. Functionally, Teucrium dunense and Helichrysum stoechas are functionally the most similar species to E. maritimum. However, analysis of phenology suggests that these three species have been able to decouple their blooms to avoid competition. The present study shows that E. maritimum plays a key role in the dune pollination network, being its anthesis located at the end of the dune flowering season, when there are no functionally similar species in flower.