Anticipating Abrupt Ecological Change in the 21st Century

Scientists have documented sudden changes in populations and ecosystems in the past, but it remains difficult to anticipate such changes in coming decades. Rates of environmental change are accelerating, yet there is no general framework for predicting when, where, why, and how abrupt and fundamental changes in ecosystems occur. Abrupt changes often are visible only in retrospect because system dynamics are complex and time lags can separate cause from effect. “Anticipating Abrupt Ecological Change in the 21st Century” will develop new theoretical and mathematical approaches to establish a broadly applicable framework for understanding ecological change.

The grant funds the new “UW-Madison Center for Study of Abrupt Change in Ecological Systems” (ACES) to focus on four real-world examples, each related to key natural resources and vulnerable to sudden change: harmful algal blooms that occur in over-fertilized lakes, tree population collapses related to variation in climate in deciduous forests of eastern North America, loss of conifer forests as climate and fire regimes change in western North America, and risk to crop yields with climate warming and declining water availability.

As rates of environmental change increase, the program will address fundamental questions: How much disturbance can living resources absorb before they change qualitatively? Where are the tipping points in ecosystems? When and where should we expect significant changes in our landscapes and waters? The project will attempt to derive simple mathematical models that describe system dynamics without forcing a priori assumptions about ecosystem processes. Results are expected to be relevant for a broad range of ecological systems.