Definition
Resilience of a system
Resilience is a system’s ability to resist disturbances, recover, and maintain stability instead of reaching a tipping point that leads to a new equilibrium.
- Resilience applies to both ecological and social systems, allowing them to adapt, survive, and function despite external shocks.
- It involves two key aspects:
- Resistance: The ability to withstand disturbances without significant change.
- Recovery: The ability to bounce back to its original state after a disturbance.
Factors Affecting System Resilience
- Resistance: The ability to withstand stress or change without breaking down.
- Recovery: The speed and efficiency with which a system returns to its original state after a disturbance.
- Adaptability: The capacity to reorganize or adjust processes to cope with new conditions.
- Redundancy: The presence of multiple species or components performing similar roles, ensuring function if one fails.
- Feedback control: The system’s ability to use negative feedback loops to restore balance.
Coral reefs exposed to repeated bleaching events struggle to recover, leading to ecosystem collapse.
Common Mistake- A common mistake is assuming that all human interventions reduce resilience.
- In reality, actions like reforestation or sustainable agriculture can enhance it.
Ecological vs Social Resilience
| Ecological Resilience | Social Resilience |
|---|---|
| Maintains ecosystem functions like nutrient cycling, energy flow, and biodiversity. | Maintains ecosystem functions like nutrient cycling, energy flow, and biodiversity. |
| Driven by biodiversity, storage capacity, and feedback mechanisms. | Driven by institutions, culture, education, and technology. |
| Example: Coral reefs recovering after bleaching. | Example: A community rebuilding after a natural disaster. |
Why is Resilience Important?
- Stability: Resilient systems maintain equilibrium and avoid tipping points.
- Adaptation: They can adjust to new conditions, such as climate change or economic shifts.
- Sustainability: Resilience supports long-term survival and functionality.
Don't confuse resilience with resistance.
- Resistance = ability to withstand change.
- Resilience = ability to recover after change.
Diversity and resilience
- Biodiversity enhances resilience through redundancy.
- Multiple species perform similar ecological functions.
- When one species declines, another can fulfill its role (e.g., pollination, nutrient cycling).
- Diverse ecosystems distribute risk.
- Not all species respond identically to stress.
In tropical rainforests, if one pollinator species declines, others can continue pollination, maintaining ecosystem productivity.
Common Mistake- Don't confuse diversity with abundance.
- A system with many individuals of a single species is less resilient than one with fewer individuals spread across multiple species.
Storage Size and System Stability
- Storage refers to the quantity of energy, matter, or biomass contained in a system component (e.g. trees, soil, water).
- Large storages act as buffers, slowing the rate of change and providing stability against disturbances.
- Smaller storages respond more quickly to inputs or losses, leading to less stable systems.
Puddle vs. Lake
- A puddle has a small water storage and it heats, cools, or evaporates quickly, showing low stability.
- A lake has a much larger storage, so temperature and water level changes occur slowly, giving greater resilience.
