Model successfully predicts large river system fish diversity

“With a neutral model, we can suggest that a coarse assumption of equality is an excellent starting point for large scale investigations when little species-specific information is available.”

M-M River System

The Mississippi-Missouri River System was a good study area, Fagan says, because it is the largest confluent drainage system covered by the NatureServe dataset.

“The fact that we can replicate key aspects of the spatial patterns of fish biodiversity from the Appalachians to the Rockies testifies to the robustness of this approach,” said Fagan.

“One upshot from this work, still to be vetted in other systems, is the idea that some knowledge of the branching geometry of a river network, coupled with average runoff production, can provide crucial insights into the amount and spatial distribution of freshwater biodiversity and how that biodiversity may change as discharge patterns change.”

Research Team

Co-principal investigator with Fagan was Ignacio Rodriguez-Iturbe of Princeton University. This study is one of several ongoing projects between the University of Maryland and Princeton, building on the theme that the geometry of river networks influences key aspects of biodiversity.

The Fagan lab helped develop the analytical approach of the study, which blends the U.S. Geological Survey geomorphic and hydrologic databases with a comprehensive dataset on fish biodiversity, and facilitated access to the fish biodiversity dataset.

Heather Lynch, a postdoctoral fellow in the Fagan lab, also worked on the study, along with lead author Rachata Muneepeerakul of Princeton and Enrico Bertuzzo and Andrea Rinaldo of the Universita di Padova, Italy. The research was funded by a grant from the James S. McDonnell Foundation.