Functional redundancy and stability in a subtidal macroalgal community in the Southwestern Atlantic coast

Abstract

Functional redundancy can stabilize ecological functions as asynchronous fluctuations among functionally similar species may buffer environmental changes. We investigated the temporal dynamics of a subtidal macroalgal community in the warm temperate Southwestern Atlantic coast (SWA) to evaluate whether functional redundancy stabilize ecosystems functions through compensatory dynamics under realistic environmental scenarios. Despite temporal variations in the community structure occurred, a high stability in macroalgal coverage was found at the community-level driven by taxa asynchronous fluctuations. No relationship between functional redundancy and stability occurred, suggesting that functional compensation cannot surpass the influence of environmental fluctuations on the performance of ecological functions. Declines in Sargassum species abundance, along with its low functional redundancy, indicate that this canopy-forming algae must be prioritized in conservation efforts in the SWA. Our study adds to the comprehension and generalization of biodiversity-stability findings in natural systems across distinct geographical areas, also contributing to their operationalization in marine ecosystems.

Keywords: Canopy-forming algae; Compensatory dynamics; Functional-form groups; Rocky reefs; Warm temperate area.