Biotic resistance predictably shifts microbial invasion regimes

Area of Science:

• Microbial ecology
• Community dynamics
• Invasion biology

Background:

• Microbial invasions are common but often hindered by resident microbes, an effect termed biotic resistance.
• Understanding the interplay between microbial dispersal and biotic resistance is crucial but challenging in natural systems.

Purpose of the Study:

• To investigate microbial invasion dynamics under varying levels of biotic resistance.
• To develop a predictive framework for microbial invasions and identify invasion-resistant communities.

Main Methods:

• Tracking microbial invasions in laboratory model systems, including pairwise and multi-strain communities.
• Utilizing a simple, parameter-free framework to model invasion dynamics and compare predictions with simulations.

Main Results:

• Observed three distinct invasion regimes: consistent, pulsed, and pinned, where strong biotic resistance can halt invasion.
• Demonstrated that a simple framework, ignoring species interactions, can predict invasion dynamics across different community complexities.
• Showcased the framework's ability to accurately predict simulated invasions from various mechanistic models.

Conclusions:

• Biotic resistance significantly shapes microbial invasion outcomes, leading to diverse invasion regimes.
• A broadly applicable, simple predictive framework can forecast microbial invasion dynamics and aid in identifying invasion-resistant microbial communities.