Dr Talia Stelling-Wood1,2, Dr Paul Gribben2, Dr Alistair Poore2
1The Sydney Institute of Marine Science, Sydney, Australia, 2UNSW Sydney, Sydney, Australia
Habitat-forming organisms provide three-dimensional structure that supports abundant and diverse communities. Variation in the structure of habitat-formers will therefore likely influence how they facilitate associated communities, either directly via food and habitat provisioning, or indirectly by altering predator-prey interactions. The characteristics that mediate their value to associated organisms are, however, not always clear. Trait-based approaches (TBAs) measure traits at the level of the individual and therefore have the potential to capture both inter- and intraspecific variation. Thus, they potentially offer a novel way to link the characteristics of habitat-formers to ecosystem functioning. We used TBAs to explore the relationship between macroalgae and their associated communities in south-eastern Australia, a region of rapidly changing ocean conditions. We documented extensive morphological variability but found despite this, morphological traits were good predictors of associated communities. Traits were, however, found to affect associated communities only in the presence of predators, suggesting that the importance of habitat-formers lies in their ability to mediate predation risk, and is not related to habitat-provisioning. Along a latitudinal gradient, algal morphological traits were found to correlate with ocean climate, highlighting the potential for future environmental change to alter the physical structure of subtidal reefs via shifts in the morphological traits of macroalgae. Our results suggest TBAs offer a useful method to develop our understanding of the relationships between habitat-formers and their associated communities. Furthermore, by studying traits and how they change across large scales we can potentially predict and anticipate the impacts of environmental change on these communities.
Presentation Slides – Talia Stelling-Wood
