Bivalves as ecosystem engineers in Patagonian rocky shores.

BAGUR, M.; JORGE LUIS CEFERINO GUTIERREZ; ARRIBAS, L.P.; PALOMO, M.G.

Monterey

Congreso; 100th Anniversary Western Society of Naturalists Meeting; 2016

Structural modification of the environment by physical ecosystem engineers often allows for the occurrence ofspecies that are not able to establish in unengineered habitats, thus leading to increased species richness at thelandscape-level. This study investigates the contribution of mussels (Perumytilus purpuratus) and boring bivalves(Lithophaga patagonica and Petricola dactylus) to rocky intertidal species richness in Patagonia, Argentina. Ourresults show that bivalve-engineered patches harbor a substantial number of invertebrate species in addition tothose occurring in the unenegineered rock substrate. Furthermore, when different bivalve species co-occurr in thesame site, they complementarily contribute to increases overall species richness, since the distinctive habitatpatches they create add exclusive subsets of species to the study area. Complementary engineering effects onlandscape-level species richness occur when the engineered patches structurally differ from each other and vary intheir relative ability to modulate two or more abiotic conditions and/or resources that prevent species establishmentin the unengineered state. This study highlights the importance of structurally different engineered habitats for themaintenance of species richness in cases when two or more abiotic conditions and/or resources prevent speciesestablishment in the unengineered state.