Genotypic variation in foundation species generates network structure that may drive community dynamics and evolution

Area of Science:

• Ecology
• Evolutionary Biology
• Genetics

Background:

• Genetic variation within a species can influence community structure, but its impact on complex ecosystem interaction networks is poorly understood.
• Foundation species, like narrowleaf cottonwood (Populus angustifolia), play a critical role in structuring ecological communities.

Purpose of the Study:

• To investigate how genetic variation in a foundation tree species affects the structure of associated arthropod interaction networks.
• To explore the relationship between tree genotype diversity and the modularity and co-occurrence patterns within ecological networks.

Main Methods:

• Utilized a long-term, common garden experiment with replicated genotypes of Populus angustifolia.
• Employed a bipartite "genotype-species" network analysis to map arthropod interactions.
• Conducted simulation experiments to model the impact of genotypic variation on network structure.

Main Results:

• The empirical "genotype-species network" demonstrated significant structure, with higher modularity than null models.
• Significant positive arthropod co-occurrence patterns were observed, consistent with the modular network structure.
• Simulations revealed that increased genotypic variation led to increased network modularity.

Conclusions:

• Genetic variation in a single foundation species demonstrably contributes to the structure of ecological interaction networks.
• This genetic influence on network structure can have cascading effects on ecological dynamics, including community assembly and stability.
• Understanding genotype-species interactions is crucial for predicting ecosystem responses to environmental change and evolutionary processes.