Ecosystem Function after the K/Pg Extinction:Decoupling of Marine Carbon Pump and Diversity

The ocean biological pump is the mechanism by which carbon and nutrients are transported to depth. As such, the biological pump is critical in the partitioning of carbon dioxide between the ocean and atmosphere, and the rate at which that carbon can be sequestered through burial in marine sediments....

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Bibliographic Details
Published in:Proceedings of the Royal Society B: Biological Sciences
Main Authors: Birch, Heather, Schmidt, Daniela N, Ridgwell, Andy J, Coxall, Helen Katherine, Croon, Dick
Format: Article in Journal/Newspaper
Language:English
Published: 2021
Subjects:
Online Access:https://hdl.handle.net/1983/24194d77-0cb9-4cff-b0ff-9ff67224bcfa
https://research-information.bris.ac.uk/en/publications/24194d77-0cb9-4cff-b0ff-9ff67224bcfa
https://doi.org/10.1098/rspb.2021.0863
https://research-information.bris.ac.uk/ws/files/278648438/RSPB_2021_0863.R1_Proof_hi.pdf
Description
Summary:The ocean biological pump is the mechanism by which carbon and nutrients are transported to depth. As such, the biological pump is critical in the partitioning of carbon dioxide between the ocean and atmosphere, and the rate at which that carbon can be sequestered through burial in marine sediments. How the structure and function of planktic ecosystems in the ocean governs the strength and efficiency of the biological pump and its resilience to disruption are poorly understood. The aftermath of the impact at the Cretaceous/Palaeogene (K/Pg) boundary provides an ideal opportunity to address these questions as both the biological pump and marine plankton size and diversity were fundamentally disrupted. The excellent fossil record of planktic foraminifera as indicators of pelagic-biotic recovery combined with carbon isotope records tracing biological pump behaviour, show that the recovery of ecological traits (diversity, size, photosymbiosis) occurred much later (~4.3m.y) than biological pump recovery (~1.8m.y.). We interpret this decoupling of diversity and the biological pump as an indication that ecosystem function had sufficiently recovered to drive an effective biological pump, at least regionally in the South Atlantic.