Plankton Communities Behave Chaotically Under Seasonal or Stochastic Temperature Forcings

Area of Science:

• Marine ecology
• Biogeochemical modeling
• Ecosystem dynamics

Background:

• Chaos is prevalent in natural systems, particularly in rapidly reproducing populations like plankton.
• Understanding the drivers of chaos in marine ecosystems is crucial for predicting population dynamics.

Purpose of the Study:

• To investigate the role of external forcings in inducing chaos within a marine biogeochemical model.
• To analyze the impact of seasonal temperature cycles and temperature noise on ecosystem dynamics.

Main Methods:

• Utilized a state-of-the-art marine biogeochemical model.
• Simulated external forcings including deterministic seasonal temperature cycles and stochastic temperature fluctuations.
• Examined the interaction between these forcings and biological interactions like competition.

Main Results:

• Deterministic periodic forcing induced chaos only when biological interactions had already established periodic oscillations.
• Random temperature fluctuations were identified as a significant driver of chaos in plankton populations.
• The stochastic mechanism for chaos occurrence has broad applicability, requiring no preconditions.

Conclusions:

• External forcings, especially random temperature fluctuations, can be a primary cause of chaos in plankton populations.
• The stochastic nature of the marine environment facilitates the occurrence of chaos.
• The findings suggest a widely applicable mechanism for chaos in natural systems.