Bivalves as ecosystem engineers in Patagonian rocky shores.

BAGUR, MARIA; GUTIÉRREZ, JORGE LUIS CEFERINO; ARRIBAS, LORENA PILAR; PALOMO, MARIA GABRIELA

Monterey

Congreso; 100th Anniversary Western Society of Naturalists; 2016

Western Society of Naturalists

Structural modification of the environment by physical ecosystem engineers often allows for the occurrence of species that are not able to establish in unengineered habitats, thus leading to increased species richness at the landscape-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. Our results show that bivalve-engineered patches harbor a substantial number of invertebrate species in addition to those occurring in the unenegineered rock substrate. Furthermore, when different bivalve species co-occurr in the same site, they complementarily contribute to increases overall species richness, since the distinctive habitat patches they create add exclusive subsets of species to the study area. Complementary engineering effects on landscape-level species richness occur when the engineered patches structurally differ from each other and vary in their relative ability to modulate two or more abiotic conditions and/or resources that prevent species establishment in the unengineered state. This study highlights the importance of structurally different engineered habitats for the maintenance of species richness in cases when two or more abiotic conditions and/or resources prevent species establishment in the unengineered state.