Wild bee-plant network of Madeira Island with a comparison to Porto Santo (Madeira Archipelago, Portugal)

Abstract

The aim of this study was to analyse wild bee-plant interactions in Madeira Island and construct a network structure covering the largest parts of the island and most altitudes and habitat types. The interaction data were sampled at 179 localities from 1989 to 2012 mainly by the authors; additionally, data from the collections of the Laboratório Agrícola da Madeira, Camacha (ICLAM) and the Museu de História Natural do Funchal, Madeira, Portugal, were used. Twelve wild-bee species (the complete species pool of permanently established Madeiran wild-bee species) were collected or observed on 82 plant taxa (belonging to 30 plant families). The total dataset from Madeira Island includes 637 data points of bee-plant interactions. We assigned the data set to the main thermotypes infra- / thermo- Mediterranean zone as well as meso- Mediterranean / temperate zone and constructed two networks. In contrast to most of the mainland networks of temperate and Mediterranean ecosystems with more wild-bee than plant species, the bee-plant networks demonstrate high asymmetry, with many more plant than bee species. This phenomenon has also been documented, e.g., in Porto Santo (Madeira Archipelago).