A new functional approach investigating the role of coral assemblages based on colonies’ morphology
Coral morphological groups and their richness have traditionally been used to compare functional compositions of coral assemblages because these groups play an important role in ecosystem processes and coral reef resilience. However, thus far, studies on this topic have remained descriptive and qualitative which are inadequate to describe changes affecting this ecosystem. To fill this knowledge gap, Prof. Denis from the Institute of Oceanography, National Taiwan University, led a research team and proposed a quantitative approach which allows to extract information directly from field survey data. This approach offers an easy way to assess the functional diversity (the range of things that organisms do in communities and ecosystems) of coral assemblage based on simple traits; i.e. colony morphologies. Using their new approach on a previously published dataset documenting changes in coral diversity and associated species covers following the 1983 bleaching event which affected the coral reef off Tikus Island (Indonesia), the team identified a return of the coral assemblage’s functions five years after the disturbance. However, this was accompanied by a decrease in species number of each morphological entities (functional redundancy) and an increase in the number of single-species entities (functional vulnerability). Together with species loss, the results indicate an overall functional erosion of the coral assemblage and suggest that the role of the coral reef habitat could be strongly imperiled under repeated or synergistic disturbances. Their work entitled ‘A functional approach to the structural complexity of coral assemblages based on colony morphological features’ is published in Scientific Reports. A generalization of their approach would facilitate the identification of various facies of coral reef degradation and functional recovery. The extension to different benthic organisms other than corals would further contribute to the understanding of the coral reef roles and expected changes under increasing disturbances.
Denis V*, Ribas-Deulofeu L, Sturaro N, Kuo CY, Chen CA (2017) A functional approach to the structural complexity of coral assemblages based on colony morphological features. Scientific Reports 7:9849
Figure title: Changes in functional diversity between 1981 and 1988 at Tikus Island, Indonesia