The annual export of the Mediterranean seagrass (Posidonia oceanica) litter to adjacent beaches and coastal dunes was quantified by examining the fortnight evolution of seagrass beach-cast volume on two beaches in the NW Mediterranean (Son Real and Es Trenc, Mallorca Island, Spain) for two years and analyzing the wind speed and direction obtained from the closest Meteorological Spanish Agency surface weather stations. The decomposition stage of the deposits was examined by analyzing the total hydrolysable amino acids, its percentage distribution and derived degradation indexes. Prevalent winds exceeding 6 m s-1 , the coastline morphology and type of terrestrial vegetation determine the annual dynamics of the seagrass beach-cast. In the most protected beach (Son Real) the seagrass beach-cast remained nearly stationary during the two studied years while it exhibited wide annual fluctuations in the less protected one (Es Trenc). The amounts of P. oceanica wrack washed on Son Real and Es Trenc beaches, respectively, were estimated at 309 kg DW m coastline-1 yr-1 and 1359 kg DW m coastline-1 yr-1. They supplied between 20 kg CaCO 3 m coastline-1 yr-1 and 47 kg CaCO 3 m coastline-1 yr-1. Between 54% (Son Real) and 70 % (Es Trenc) of seagrass beach-cast, respectively accounting for 1.5 kg N m coastline-1 yr-1 and 8.6 kg N m coastline-1 yr-1 , were annually exported from the beaches to adjacent dune systems. Our results reveal that Mediterranean seagrass meadows might be an important source of materials, including sand and nutrients, for adjacent terrestrial systems, able to support their functioning. KEY WORDS: wrack, detritus, beach-cast, wind rose, weather conditions, Mediterranean Sea, Balearic Islands, coastal systems, dune dynamics, land-sea interface HIGHLIGHTS (3 to 5 bullet points with 85 characters) * The annual evolution of the seagrass beach-cast depends on the beach exposure. * Changes of the seagrass beach-cast are linked to strong wind events. * Winds are the responsible of the mass transport of nutrients to the dunes. * Beach-cast deposits might be an important source of carbonates and nutrients to the coastal dune system.

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Although the Mediterranean basin is a hotspot of pollinator diversity, little is still known about how such diversity is distributed in the region and about its conservation status. This study contributes to filling this information gap by studying pollinator diversity parameters in one of the main Mediterranean islands, Mallorca, and further evaluating their conservation category according to the IUCN criteria. We focus on three communities, two coastal and one mountain shrubland, which we have studied for several years. For each community, we obtained the following variables: (1) Shannon diversity (H'), (2) Pielou's index (J'), (3) Number of pollinators per plant (Lp), (4) Flower visitation rate (FVR), (5) Specialisation index (d') and (6) Normalised degree of pollinators, i.e. the number of plants visited per pollinator species relative to the total number of plant species in the community (ND). All pollinators were categorised into functional groups to test for differences in such variables among them. Differences across communities, years and functional groups were tested through GLMMs. The three communities showed differences in pollinator species composition, species richness and diversity. Pollinator diversity also varied with time, especially in the coastal community, which suffered a major disturbance during one of the study years. Regardless of the functional group, the pollinator specialisation degree seems context-dependent. Native and endemic species might disappear in the short term if appropriate management measures are not taken to narrow down the threats to pollinator populations. Further research is urgently needed to assess most insect pollinators' conservation status in the Mediterranean before such rich diversity is lost forever.