What the study found
The study found that marine biogeochemical cycles can enter alternative dynamic regimes, meaning different stable patterns of behavior, when the environment is pushed to extreme values. It also found that these cycles commonly respond reversibly, so the original regime returns when the perturbation is removed.
Why the authors say this matters
The authors say this matters because alternative regimes in marine biogeochemical cycles are relevant for understanding climate change impacts and for developing mitigation and adaptation strategies. They also conclude that identifying these regimes may help reveal potentially dangerous paths for the ocean state under future climate conditions.
What the researchers tested
The researchers used a state-of-the-art marine biogeochemical model, including a one-dimensional water-column physical-biogeochemical model. They tested extreme changes in environmental conditions such as air temperature, wind velocity, and nutrient input, using sequential simulations, initial condition perturbation, and demographic stochasticity.
What worked and what didn't
The model showed that alternative dynamic regimes exist across a wide range of environments and methodologies. A single forcing, nutrient depletion, produced hysteresis, meaning the system's response depended on its prior state, in the planktonic trophic web that supports the biogeochemical cycles. The cycles were usually reversible after perturbations were removed.
What to keep in mind
The abstract does not describe specific numerical outcomes or effect sizes. It also does not state detailed limitations beyond noting that the findings come from simulations with a one-dimensional water-column model, though the authors say the large number of simulations and sensitivity analysis support the generality and accuracy of the model even under extreme environments.
Key points
- Marine biogeochemical cycles can shift into alternative dynamic regimes under extreme environmental perturbations.
- The cycles commonly return to the original regime after the perturbation is removed.
- Nutrient depletion was the single forcing that induced hysteresis in the planktonic trophic web.
- The study used a one-dimensional water-column physical-biogeochemical model with many simulations.
- The authors say the results may help identify dangerous future ocean-state paths under climate change.
Disclosure
- Research title:
- Marine biogeochemical cycles can shift into alternative regimes
- Authors:
- Guido Occhipinti, Davide Valenti, Paolo Lazzari
- Institutions:
- Centre National pour la Recherche Scientifique et Technique (CNRST), Ifremer, Marine Biodiversity Exploitation and Conservation, National Institute of Oceanography and Applied Geophysics, National Institute of Oceanography and Applied Geophysics, Université de Montpellier, University of Palermo, University of Palermo
- Publication date:
- 2026-03-17
- OpenAlex record:
- View
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