(Millbrook, N.Y.) By closely monitoring environmental conditions at a remote Wisconsin lake, researchers have found that models used to assess catastrophic changes in economic and medical systems can also predict environmental collapse. Stock market crashes, epileptic seizures, and ecological breakdowns are all preceded by a measurable increase in variancebe it fluctuations in brain waves, the Dow Jones index, or, in the case of the Wisconsin lake, chlorophyll.
In a paper published this week in the journal Science, a team of ecologists is the first to show that by paying attention to variability in key ecosystem processes, scientists can detect the early warning signs that herald environmental collapse. Insight into regime shiftsthe reorganization of an ecosystem from one state to anotheris critical to identifying ecosystems that will fail without intervention.
"Early warning signs help you prepare for, and hopefully prevent, the worst case scenario," notes contributing author Jonathan J. Cole, a biogeochemist at the Cary Institute of Ecosystem Studies. "We are surrounded by problems caused by ecological regime shiftswater supply shortages, fishery declines, unproductive rangelandour study shows that there is promise in identifying these changes before they reach their tipping point."
The team, led by Stephen Carpenter, a limnologist at the University of Wisconsin-Madison, triggered a regime shift in a Wisconsin lake by introducing a top predator. The study lake was originally dominated by small fish, such as golden shiners, that feed on tiny free-swimming invertebrates. Researchers destabilized the lake by adding largemouth bass. The goal: to observe the cascade of environmental changes that eventually led to a food web dominated by piscivorous, or fish-eating, fish.
Throughout the lake's three-year manipulation, its chemical, biological, and physical vital signs were continuously monitored to track even the smalle
|Contact: Lori M. Quillen|
Cary Institute of Ecosystem Studies