Meeting Abstract

S10.3  Wednesday, Jan. 6  Habitat cascades – a conceptual overview and estuarine examples THOMSEN, M/S; National Environmental Research Institution, Denmark

Habitat formers, like trees, saltmarshes, coral reefs and seagrasses, have direct positive effects on many closely associated organisms. Recent studies have also highlighted the importance of indirect positive effects of certain habitat formers, for example, trees and saltmarshes can provide habitat for nest epiphytes and mussels, respectively, which again provide habitat for small mobile invertebrates. I will provide a conceptual overview over these ‘indirect habitat/facilitation cascades’, and show new data on understudied estuarine analogues from Europe, North America, Australia and New Zealand. The estuarine cascades are unique by being characterized by small primary habitat formers (polychaetes, bivalves, gastropods) that provide attachment space for larger secondary habitat formers (various seaweed species) that again provide space, food and shelter for small mobile invertebrates. Data will be shown for cascades that are represented by both native and introduced primary and secondary habitat providers. Finally, based on estuarine examples, I will discuss cascading effects on biodiversity and ecosystem processes and outline current research gaps.