ecosystem engineering Polychaeta 10 Argentina 6 Ecosystem engineer 6 polychaete 6 Animals 4 Atlantic Ocean 4 Atlantic Ocean (Southwest) 4 Bivalvia 4 Brachidontes rodriguezii 4 Crustacea 4 Ecosystem engineers 4 Habitat complexity 4 Macroinvertebrate assemblage 4 Orchestia gammarella 4 Patagonia 4 Spartina 4 Thoracica 4 abundance 4 article 4 coastal zone 4 community response 4 community structure 4 dominance 4 ecosystem 4 ecosystem management 4 experimental study 4 habitat management 4 intertidal community 4 intertidal environment 4