Beyond the continuum: a multi-dimensional phase space for neutral-niche community assembly

Area of Science:

• Ecology
• Community Ecology
• Theoretical Ecology

Background:

• The neutral-niche continuum model posits that ecological communities are structured by a spectrum of neutral and niche processes.
• This model assumes limited interaction feedback between community processes and the environment.
• It does not fully capture the complexity of how environmental factors influence community assembly.

Purpose of the Study:

• To introduce the Community Assembly Phase Space (CAPS) as a novel framework for studying community assembly.
• To test the limitations of the neutral-niche continuum hypothesis.
• To explore the feedback interactions between neutral and niche processes and the environment.

Main Methods:

• Developed and utilized the Community Assembly Phase Space (CAPS) model.
• Modeled communities in a heterogeneous landscape under pure neutral, pure niche, and composite process scenarios.
• Analyzed community patterns generated by different combinations of assembly processes.

Main Results:

• The neutral-niche continuum hypothesis is only valid under strong dispersal limitation and niche separation.
• Weaker dispersal limitation and niche separation lead to amplified neutral and niche processes through environmental feedback.
• These feedback mechanisms generate community patterns not predicted by the continuum model, revealing hidden complexity.

Conclusions:

• The continuum perspective can lead to misguided inferences about community assembly processes.
• CAPS provides a more comprehensive tool for understanding community structuring by capturing feedback and complexity.
• This framework can be applied to diverse questions in community and metacommunity ecology.