St. Norbert College professor reports groundbreaking ecological research

From St. Norbert College, April 28, 2011
by Mike Counter, mike.counter@snc.edu, (920) 403-3089

James Hodgson, professor of biology and environmental science at St. Norbert College, along with research colleagues report they are able to predict changes in an ecosystem before it occurs. The theoretical background for these shifts is rich, but real-world tests are rare, especially for whole ecosystems.

Hodgson and his colleagues were researching regime shifts -- the sudden, unexpected and often catastrophic reorganization of ecosystems from one stable state to another. Such shifts could include the desertification of rangeland, collapse of commercial fisheries, or an ecosystem response to climate change.

This report is the first of its kind and just published in the scientific journal Science.

"The findings are a benchmark in science, says Hodgson. "They have extreme relevance to ecosystem management and general public interest relative to ecosystem services."

The researchers hypothesized that they could predict such system changes in advance by noting statistical "early warning signals." In the case of lake environments, those signals included variance in chlorophyll concentration, algal growth, zooplankton biomass or forage fish schooling behavior.

They tested their hypothesis in two lakes on Michigan's Upper Peninsula, introducing a top predator, largemouth bass, to one in order to induce a regime shift in the food web, while leaving another lake's ecosystem unchanged. Through careful monitoring, they were able to determine "tipping points," and identify warning signals of regime shift more than a year prior to the actual event.

Besides Hodgson, scientists from the University of Wisconsin-Madison, the University of Virginia and Cary Institute of Ecosystems Study in New York unearthed this potentially ground-breaking research.

Hodgson, who will retire in August after 41 years of teaching and research at St. Norbert College, is available for interviews. He can be reached at jim.hodgson@snc.edu or 920-403-3186. For more information on the article go to http://www.sciencemag.org/.