Ecosystem Experiments: How Does Manipulation Rate Affect Indicators of Resilience?

Abstract Experiments on entire ecosystems have contributed knowledge on effects of atmospheric CO 2 and climate change, environmental pollutants, trophic cascades, response of fisheries to management, consumer interactions, ecosystem resilience and stability, and early warning indicators of critical transitions in ecosystem state. Rate of change in external drivers of an ecosystem such as climate warming, inflow of water or nutrients, or harvest of apex predators may affect signals of critical transitions but rates of change of drivers are rarely considered in whole-ecosystem studies. We studied effects of drivers’ rates of change on indicators of critical transitions using models for whole lake manipulations of nutrient enrichment, light-absorbing substances, and apex predators. Results show that times of signals from indicators relative to times of critical transitions can vary depending on the rate of external drivers, including the rate of manipulation in whole-ecosystem experiments.