2.5C Ecosystem resilience Notes

1. The ability of an ecosystem to tolerate disturbances and maintain equilibrium depends on its diversity and resilience.
2. Ecosystems naturally experience disturbances, such as fires, floods, storms, volcanic eruptions, or human activities, but their response determines their long-term stability and sustainability.
3. Some systems can absorb shocks and return to their original state, while others shift into alternative stable states with new sets of species and ecological conditions.

Key Components Influencing Ecosystem Resilience

1. Biodiversity (Species and Genetic Diversity)

1. High biodiversity means more species are available to perform similar ecological functions (known as functional redundancy).
2. If one species declines or goes extinct, others can fill its role, maintaining stability in energy flow and nutrient cycling.
3. Genetic diversity within species enhances adaptability to changing conditions, improving survival under stress such as drought, disease, or temperature shifts.

2. Habitat Diversity

1. Ecosystems with diverse habitats (e.g., wetlands, forests, rivers) offer multiple niches, supporting a wide range of organisms.
2. This diversity cushions the ecosystem from large-scale collapse, as different habitats recover at different rates.

3. Trophic Complexity

1. Complex food webs (many interlinked feeding relationships) distribute energy more efficiently and prevent chain reactions of species loss.
2. Simple systems (e.g., monocultures) collapse more easily when a single species fails.

4. Functional Diversity

1. Refers to the variety of ecological roles or “functions” organisms perform, such as nitrogen fixation, decomposition, and pollination.
2. Greater functional diversity ensures the ecosystem continues functioning even when individual species are affected.

Human Impacts on Ecosystem Resilience and Succession

1. Deforestation