Cooperative Fish and Wildlife Research Units Program: South Carolina
Education, Research and Technical Assistance for Managing Our Natural Resources

Bower, L. M., Stoczynski, L., Peoples, B. K., Patrick, C. J., & Brown, B. L. (2023). Multiple dimensions of functional diversity affect stream fish taxonomic β‐diversity. Freshwater Biology, 68(3), 437-451.


Aims: When investigating community assembly, functional differences among species are assumed to be as important as environmental differences between sites in determining β-diversity. However, few studies have examined the influence of functional diversity on β-diversity. Our study examines the relative importance of regional functional diversity partitioned by niche dimensions and environmental variation in structuring β-diversity of stream fishes using a large dataset.
Location: One hundred and sixty-eight watersheds in the eastern United States.
Time period: 1990 to 2013
Major taxa studied: Freshwater fishes (Teleostei)
Methods: We predicted that both functional diversity and environmental variation play a role in determining β-diversity. We tested this prediction by modeling the patterns of stream fish β-diversity as a function of environmental variation, functional diversity, and γ-richness across 10,220 sites for 329 fish species using a series of conceptual path models.
Results: Environmental variation consistently affected β-diversity across all models, while functional diversity and γ-richness influenced β-diversity only in some models. We show that including relevant trait differences among species in path models can improve their ability to explain β-diversity, suggesting that functional traits played a role in determining β-diversity.
Main conclusions: The ability of path models to predict β-diversity varied depending on the trait grouping included in the model, demonstrating how specific path models representing different niche dimensions can improve the model’s ability to explain β-diversity. Additionally, parsing traits into different niche dimensions revealed alternate patterns of functional diversity-β-diversity relationships that have been otherwise missed.