Defne Sahin, Nestor E. Bosch, Chenae Cooper, Karen Filbee-Dexter, Ben Radford, Verena Schoepf, Damian P. Thomson, Thomas Wernberg
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引用次数: 0
Abstract
Climate-driven species range expansions are underway with more tropically affiliated species, including Scleractinian corals, becoming increasingly abundant at higher latitudes. However, uncertainty remains on how these range shifts will affect reef-scale ecosystem processes, which will ultimately depend on the traits of the taxa that dominate these assemblages. Here, we quantified spatiotemporal patterns in the taxonomic and trait structure of coral assemblages along the subtropical-temperate coast of Western Australia (27°–34°S). Coral abundance was generally low and coral cover < 5% across our study sites. Coral assemblages shared similarities in morphological trait structures across the latitudinal gradient, mostly characterised by taxa with simple morphologies; yet subtle differences were also observed across latitudes, with high-latitude corals characterised by slower growth rates and reduced maximum colony sizes. We found a 3.4-fold increase (from 1 to 3.4 individuals m−2) in coral abundance at one heavily disturbed location, where canopy-forming seaweeds were replaced by turfing algae, a pattern that was partly driven by an increase in the relative contribution of warm affinity taxa, such as Acropora spp. We predicted these changes would be reflected in different components of functional diversity; yet, despite a localised signal of tropicalisation, we only observed subtle changes in the functional identity, richness, evenness, and divergence. The spatially invariant trait structure of coral assemblages suggests that the nature of ecosystem functions will likely remain unchanged during early stages of tropicalisation, and hence their contribution to temperate reef-scale ecological processes will depend on dominance over other benthic foundational species.
期刊介绍:
Coral Reefs, the Journal of the International Coral Reef Society, presents multidisciplinary literature across the broad fields of reef studies, publishing analytical and theoretical papers on both modern and ancient reefs. These encourage the search for theories about reef structure and dynamics, and the use of experimentation, modeling, quantification and the applied sciences.
Coverage includes such subject areas as population dynamics; community ecology of reef organisms; energy and nutrient flows; biogeochemical cycles; physiology of calcification; reef responses to natural and anthropogenic influences; stress markers in reef organisms; behavioural ecology; sedimentology; diagenesis; reef structure and morphology; evolutionary ecology of the reef biota; palaeoceanography of coral reefs and coral islands; reef management and its underlying disciplines; molecular biology and genetics of coral; aetiology of disease in reef-related organisms; reef responses to global change, and more.