Non-linear changes in modelled terrestrial ecosystems subjected to perturbations

Area of Science:

• Ecology
• Ecosystem Dynamics
• Environmental Science

Background:

• Ecosystems face rapid, non-linear changes known as regime shifts due to human impact.
• Understanding the scale, nature, and reversibility of these shifts is critical.
• General ecosystem models offer a mechanistic approach to project ecosystem changes.

Purpose of the Study:

• To model ecosystem changes in terrestrial biomes under vegetation removal.
• To identify thresholds for irreversible ecological state changes.
• To forecast the impact of land-use change on ecosystem structure and function.

Main Methods:

• Simulation of ecosystem dynamics using general ecosystem models.
• Analysis of four terrestrial biomes subjected to varying levels of vegetation biomass removal.
• Assessment of impacts across different trophic levels and ecosystem productivities.

Main Results:

• Irreversible, non-linear ecosystem responses observed when vegetation removal exceeds 80%.
• Higher trophic levels and less productive ecosystems are particularly vulnerable.
• Vegetation removal levels comparable to intensive land use predict substantial ecosystem structure changes.

Conclusions:

• Projected increases in agricultural land conversion may trigger widespread trophic cascades.
• Significant and potentially irreversible changes to ecosystem structure are likely.
• Ecosystem modeling is crucial for forecasting thresholds and impacts of human-induced environmental change.