Conceptual model on habitats as surrogates for taxonomic, functional and trophic structure.

<p>A conceptual model illustrating the match between pre-defined habitat types and traditional taxonomic, functional and trophic community structure on a coarse and a fine level of habitat division. Habitats as surrogates could be used to safeguard taxonomic and functional structure on a fine level (four separate units). However, high functional similarity is evident on a coarser scale and is important for management to recognize. On this scale, only bare sand as a habitat type is clearly functionally different, and a separation into only two habitat units is possible. Habitat divisions may not meet the variability of the trophic structure at all (based on simple stable isotope values) or only show a distinction between epi- and infaunal habitat types (accounting for density in the trophic structure). Type of community measure (taxonomic, functional or trophic structure) and number of pre-defined habitat types identified using that measure are shown on the left and specific input variables (species density, biological traits or stable isotopes) used in the analyses on the right.