Multiple mutualist effects: conflict and synergy in multispecies mutualisms

Area of Science:

• Ecology
• Evolutionary Biology
• Theoretical Biology

Background:

• Organisms frequently engage with multiple mutualistic species, each providing distinct benefits.
• Existing frameworks struggle to integrate the complexity of multiple mutualisms and their fitness consequences.
• Network and consumer-resource approaches offer partial insights but are not fully integrated.

Purpose of the Study:

• To merge network and consumer-resource approaches to define multiple mutualist effects (MMEs).
• To explore interaction pathways and fitness consequences within MMEs.
• To develop new hypotheses for species interaction outcomes in complex mutualistic networks.

Main Methods:

• Utilized graphical models to define MMEs for species with multiple mutualistic partners.
• Reviewed existing literature for examples of MMEs across a spectrum of fitness effects.
• Examined factors like reward overlap and network topology to predict interaction outcomes.

Main Results:

• Defined MMEs as a framework for understanding interactions with multiple mutualists.
• Identified diverse pathways and fitness effects (positive to negative) in MMEs.
• Proposed that reward overlap and network structure influence nonadditive interaction outcomes.

Conclusions:

• The MME framework enhances predictions of ecosystem responses to changes in mutualisms.
• Understanding MMEs is crucial for predicting the stability and function of ecological networks.
• This integrated approach advances the study of complex mutualistic interactions.