Ecological Thresholds, Abiotic Stress, and Climate Change: A Conceptual Framework

by the US Geological Survey
June 16, 2025

As climate change accelerates, the risk of sudden, large-scale shifts in ecosystems is growing. A new USGS study examines the mechanisms behind these abrupt ecological transformations—known as threshold responses—and offers a roadmap for predicting where and when they might occur.

Published in the journal Ecosphere, the research introduces a conceptual framework that links climate-driven changes, abiotic stress (such as extreme temperatures, drought, or salinity), and the vulnerability of ecosystems to transformation. The authors argue that ecosystems already teetering near their physiological limits are especially prone to sudden change, providing examples of this climate-driven threshold behavior from four high-stress environments: coastal wetlands, coral reefs, drylands, and alpine ecosystems.

Ecosystems don’t always respond gradually to environmental change. In some cases, a relatively minor shift—like a slight rise in temperature or a modest drop in soil moisture—can push a system past its breaking point.

The framework zeroes in on ecosystems where foundation species—organisms that create and define habitat, like corals, seagrasses, or kelp—play a central role. These species often live close to the edge of their environmental tolerance. When conditions tip even slightly beyond that edge, it can result in rapid, widespread shifts in structure, function, and biodiversity. In addition, the study emphasized the growing threat of compound and cascading effects to global ecosystems, leading to species loss and disturbance.

Keep reading: https://www.usgs.gov/programs/cmhrp/news/ecological-thresholds-abiotic-stress-and-climate-change-a-conceptual-framework

Read the Ecosphere paper: https://www.usgs.gov/programs/cmhrp/news/ecological-thresholds-abiotic-stress-and-climate-change-a-conceptual-framework