The study, which focused specifically on aquatic plants that live completely submerged, also showed that when plants have easier access to carbon dioxide, they will use that as their carbon source, even if bicarbonate is available.

“One of the main points of this study is that aquatic plants are different. We cannot use our extensive knowledge about terrestrial plants in the same way as aquatic plants,” said Iversen, a researcher in Assistant Professor Ben Blonder’s ecology lab. “This is really important because, on a global scale, at least one-third of the human population is very closely linked to freshwater systems. So things like deltas, drinking water and fishing grounds are critical to human survival. If we are to understand how these systems will persist and change within the next 100 years, then we really need to know how some of the main components and structures in freshwater systems are working.” 

Environmental changes caused by human activity, such as deforestation, land cultivation, and the use of fertilizers, are causing large increases in bicarbonate concentrations in many freshwater bodies around the world. Iversen said the insight from this study will help researchers evaluate how ecosystem functions change if concentrations of bicarbonate increase.

Iversen’s research is funded by the Carlsberg Foundation (CF-17-0155 and CF-18-0062). Colleagues from 14 additional institutions located in Finland, Denmark, Germany, Canada, Sweden, Estonia, Poland, Norway, the U.S., Kenya, the U.K. and Australia participated in this study.

Sandra Leander

Assistant Director of Media Relations, ASU Knowledge Enterprise