Rainfall and river networks prove accurate predictors of fish biodiversity

Ignacio Rodríguez-Iturbe is the senior author of a new paper in the journal Nature showing that water dynamics play a pivotal role in the biodiversity of river networks. Researchers have... Click here for more information.

Princeton researchers have invented a method for turning simple data about rainfall and river networks into accurate assessments of fish biodiversity, allowing better prediction of the effects of climate change and the ecological impact of man-made structures like dams.

The mathematics behind the new method also can be used to model and predict a wide range of other questions, from the transmission of waterborne illnesses to vegetation patterns on land adjacent to rivers.

The researchers, who published a report in the May 8 issue of Nature, have created a computer simulation that allows them to predict -- based on rainfall measurements and the structure of river networks -- how many species of fish will occupy any given region.

“It is an extremely simple model but it predicts absolutely fantastically well all of the characteristics of biodiversity that we were interested in,” said Ignacio Rodríguez-Iturbe, the James S. McDonnell Distinguished University Professor of Civil and Environmental Engineering and the leader of the research group that published the report in Nature.

The figure at the top right represents average runoff (the amount of rainfall that ends up in rivers or streams) with the driest regions appearing in red and the wettest... Click here for more information.

“Our model implies that water dynamics have a commanding effect on biodiversity in river basins.”

Paolo D'Odorico, associate professor of environmental sciences at the University of Virginia, called the research “exquisitely original and thought-provoking.”