Fluctuation-Dependent Coexistence of Stage-Structured Species

Area of Science:

• Ecology
• Evolutionary Biology
• Population Dynamics

Background:

• Modern coexistence theory explains how environmental fluctuations promote species coexistence.
• Assessing fluctuation-dependent coexistence mechanisms in empirical systems with diverse life histories is challenging.

Purpose of the Study:

• To explore how perennial and seedbanking annual life histories differ in competition with nonseedbanking annuals.
• To link vital rates and interaction strengths to coexistence patterns and mechanisms across different environmental scenarios.
• To build intuition for the role of fluctuation-dependent mechanisms in diverse ecological systems.

Main Methods:

• Comparative analysis of two stage-structured life histories (perennial and seedbanking annuals) against a nonseedbanking annual.
• Modeling of three environmental scenarios defining resource partitioning and competition intensity during favorable/unfavorable periods.
• Linking demographic vital rates and interspecific interaction strengths to coexistence outcomes.

Main Results:

• Fluctuation-dependent coexistence mechanisms are significant for both perennial (with adult storage) and seedbanking annual species.
• Coexistence outcomes diverge between perennial and seedbanking annuals based on competition intensity in favorable environments.
• Differences in vital rates and interaction strengths directly influence coexistence patterns.

Conclusions:

• Coexistence theory and fluctuation-dependent partitioning frameworks can be applied to perennial and mixed stage-structured communities.
• Environmental variation's role in driving species dynamics is better understood across a broader range of systems.
• This research facilitates empirical assessment of coexistence mechanisms in complex ecological communities.