Community structure and zonation of the macroinfauna along a dissipative‐reflective range of beach category in southern Chile

Abstract

Three oceanic sandy beaches, covering a full range of dissipative‐reflective categories were sampled at southern Chile (ca. 39'S) during the summer of 1990. The purpose of this study was to analyse the abundance, species richness and zonation schemes of the macroinfauna in relation to physical characteristics (e.g. texture, slope) of that sites. In addition, we also sampled an estuarine protected beach located nearby. Furthermore, we analysed the body sizes of the crustacean species to assess between‐ and within‐size variability. Principal component analysis showed that gravel percentage, mean grain size and slope were the most important variables accounting for by the spatial variability in the physical characteristics of the studied beaches. Maximum species richness (6) and abundances occurred at a dissipative and at an intermediate type of beach, respectively. Almost no macroinfaunal organisms were collected at the reflective beach of Matías. Kite diagrams and cluster analysis showed that the macroinfauna can be classified in four faunistical zones, each of one characterized by a particular species or duple of species. That zonation schemes are compared with other studies. Finally, body size comparisons detected that sizes of some species differed between and within beaches.