A new approach for investigating evidence for the capacity of plant colonization between islands and the success of plant morphological traits associated with seed dispersal is presented. The Galápagos archipelago comprises 107 12 islands > 10 km2 that harbour 403 native angiosperms, of which 313 native species occupy lowland habitats that are present on all islands. We inferred the minimum number of colonization events within the archipelago for the species (289 lowland species) present on more than one island (floristic analysis). The distribution (number of islands) of species across the islands was slightly left-skewed, with 58% of all lowland species being present on one to six islands. The success of dispersal syndromes favourable to inter-island dispersal (medium-distance dispersal, MDD) was also analysed (syndrome analysis). In particular, the 289 lowland species were classified into four dispersal groups (syndromes): sea (thalassochory), wind (anemochory), and animal interior (endozoochory) or animal exterior (epizoochory). Most species (N = 174, 55.6%), however, displayed no traits related to MDD (unspecialized diaspores). Our analyses suggest that: (1) species with one or more of the four MDD syndromes did not have broader distributions than those with unspecialized diaspores; (2) species with sea dispersal traits were the most broadly distributed; and (3) a net loss of dispersability for diaspore traits (from nonendemic natives to endemic species) was not supported for the whole flora by our analyses. In summary, our analyses showed that species with sea-drifting diaspore traits were significantly associated with the success of plant colonization across the Galápagos Islands.

Trabajo presentado en el el congreso Island Biology 2014 celebrado en Hawai del 7 al 11 de julio de 2014.

Peer Reviewed