Stochastic microbial dispersal drives local extinction and global diversity

Area of Science:

• Ecology
• Microbiology
• Theoretical Biology
• Spatial Dynamics

Background:

• Microbial dispersal via airborne routes is a fundamental ecological process connecting distinct habitats.
• Understanding the ecological consequences of microbial migration is crucial for microbial ecology.
• Classical Lotka-Volterra models describe population dynamics but often lack spatial and discrete population considerations.

Purpose of the Study:

• To investigate the ecological implications of airborne microbial dispersal on bacteria-phage interactions.
• To model the effects of spatial biomass exchange on local and global microbial diversity.
• To explore how stochastic dispersal influences species persistence and coexistence.

Main Methods:

• Development of a simple spatial model for bacteria-phage interactions.
• Utilized Lotka-Volterra equations with integer populations, incorporating a discrete extinction threshold.
• Simulated stochastic airborne dispersal of species between habitats.

Main Results:

• Spatial biomass exchange leads to continuous population density oscillations within habitats.
• These oscillations frequently drive local species extinctions.
• Dispersal-induced migration balances local extinctions, enabling global species persistence and increasing overall diversity.

Conclusions:

• Airborne dispersal acts as a disruptive force that enhances microbial diversity at the system scale.
• It allows for the coexistence of species that would otherwise be eliminated by local competitive exclusion.
• Stochastic migration is key to maintaining biodiversity in spatially structured microbial communities.