Figure 1. Summary of the four scenarios tested in this study,
which differ on how the colonization of the swash zone affects taxonomic
and functional diversity. A. In scenario 1, the conditions of
the swash level select for a subset of the species that live in the
shoaling and subtidal levels, with differences in species composition
across beach levels explained by differences in species richness.B. In scenario 2, this subset of species found in the swash
level is not random, but depends on the presence of specific traits.C. In scenario 3, if species respond differently to the
conditions in the swash level according to their traits, differences in
diversity across beach levels will be mostly explained by species
functional traits, for example with a higher proportion of adhesive and
burrowing species found in the swash level. D. Scenario 4, is
neutral and not functional nor taxonomic diversity is affected by the
conditions in the swash zone. The silhouettes in the central part
represent the potential species pool; the silhouettes in each level
represent their actual occurrence, with repeated silhouettes in one
level representing different species within the same genus.