Speed and directedness predict colonization sequence post-disturbance

Area of Science:

• Ecology
• Community Ecology
• Behavioral Ecology

Background:

• Ecological models often simplify dispersal into speed and directional bias.
• Predicting species colonization order in heterogeneous landscapes remains a challenge.

Purpose of the Study:

• To test if two behavioral traits (speed and directional bias) predict fish colonization order after disturbance.
• To evaluate the efficacy of a two-parameter model for forecasting community assembly.

Main Methods:

• Estimated maximum aerobic swimming speed (UCRIT) for six fish species using endurance tests.
• Utilized Agent-Based Models (ABMs) incorporating species-specific speed, direction, and density to simulate dispersal.
• Compared simulated colonization orders with a 20-year empirical dataset of marsh fish colonization.

Main Results:

• Simulated colonization orders closely matched observed patterns from the long-term dataset.
• Faster swimming species (higher UCRIT) were predicted as early colonizers, slower species as late colonizers.
• Directional bias was a more robust predictor of colonization order than swimming speed, independent of species density.

Conclusions:

• Two simple behavioral traits (speed and directional bias) are sufficient to predict species colonization order in complex landscapes.
• Trait-based models offer a powerful tool for generating realistic community assembly dynamics.
• Findings support the use of simplified ecological models for understanding complex ecological processes.