Rethinking coral reef functional futures

摘要

Tropical coral reefs currently face an unprecedented restructuring since their extant form and function emerged similar to 24 million years ago in the early Neogene. They have entered the Anthropocene-an epoch where humans have become the dominant force of planetary change. Human impacts on and interactions with coral reefs are escalating across multiple trophic levels and scales, but we have a rudimentary understanding of what this means for their functional ecology. The overall goal of this special feature is to unpack what the Anthropocene means for the functional ecology of coral reefs, laying the foundations for new approaches and research directions in coral reef science. The collection describes the functional changes and novel dynamics that characterise Anthropocene reefs, from variations in their taxonomy and geology through to the resulting shifts in ecosystem services they provide to humanity. Common changes to coral reefs are occurring that are challenging their historical functional role. These include reductions in benthic calcifiers and declining carbonate production, and benthic assemblage shifts leading to a loss of structural complexity and flattening of reef seascapes. As reefs as we know them are lost from some locations, range extensions and the "tropicalisation" of temperate locations present novel ecosystem configurations that are challenging ecological paradigms and our historical approach to ecosystem management. Hindering our progress, however, is a "functionality crisis." Coral reef functional ecology to date has lacked a clear and universal definition of the term "function," and many assumed links between taxa and reef processes lack empirical evidence. Moving forward, we must establish causal links between functional traits, the species that possess them, and specific ecosystem processes if we are to successfully manage Anthropocene reefs. The functional space coral reefs occupy has arguably widened, presenting ethical challenges surrounding the increasingly interventionist management practices required to achieve particular functional endpoints. For us to steer coral reefs towards a desirable functional future will require a more mechanistic understanding between ecosystem attributes and the provision of services, acknowledging that such services are coproduced by the ecosystem and society. Ultimately, this era in coral reef ecology requires a new approach to coral reef science, one that addresses the complex socio-ecological nature of coral reefs. These works outline a path ahead for defining and studying the functional ecology of coral reefs, drive debate as to what we want their functional future to look like and call for ecosystem function to be at the heart of managing coral reef futures during this period of rapid transition.