While nature often changes slowly, sometimes large changes occur fast. Fisheries collapse, rangelands decline, and invasive species expand rapidly often with high costs to human society. Big changes in ecological systems are difficult to forecast but recent theoretical studies and experiments indicate that they are preceded by early warnings. These early warnings are like economic indicators and can be detected in environmental variables that can be measured frequently. In principle when early warning indicators are detected actions can either avert unwanted changes, like responding to a check engine light in a car, or help minimize risk, like responding to a tornado siren. This project will test the potential to avoid unwanted changes in lakes by detecting early warning signals. Several lakes will be experimentally fertilized with nutrients to create the potential for massive growths of algae. Early warning signals will be detected by continuously monitoring the lakes with modern electronic sensors. In a further experiment, the researchers will respond to signals that indicate impending changes and stop the nutrient additions to one lake in an attempt to avoid algae proliferating to nuisance levels. Treatments to the other lakes will continue so that all possible responses are included.
This project will determine if methods for detecting early warnings signals can be developed. The findings from this study will be extended to a network of researchers who have established continuous measurement systems on lakes throughout the world. If successful, the results should be widely applicable for the management of a range of natural systems, not only lakes. The project will train graduate and undergraduate students and contribute to teaching materials for courses at universities in Virginia and Wisconsin, as well as advanced special topics courses at the Cary Institute of Ecosystem Studies in New York.
