Equilibrium, stability and resilience

A chain where a change causes effects that feed back to influence the original change.

Movement of matter or energy without changing its form.

A positive feedback loop where tourism growth generates more income and investment, attracting even more tourism.

Wealth enables investment and influence, producing more wealth, widening the gap unless interrupted.

A diagram showing cause-and-effect links between variables, forming feedback loops over time.

A condition where inputs and outputs are balanced so the system stays roughly the same over time.

A mature forest: growth and death balance so overall biomass stays similar.

A positive relationship: the variables change in the same direction.

A change in form, state, or chemical nature of matter or energy.

Creates jobs and income, and can fund infrastructure or conservation.

Negative feedback reduces change and helps stabilise a system.

Start change → chain of effects → show the loop closes → state if reinforcing or balancing.

Higher water/energy demand, more waste/pollution, and habitat loss from development.

Body temperature control: too hot → sweating → cooling → back to normal.

A time gap between a change and when its effects are seen in the system.

A negative relationship: the variables change in opposite directions.

Positive feedback amplifies change; negative feedback counteracts change and stabilises the system.

It stabilises systems by reducing change and helping maintain equilibrium.

Positive feedback amplifies the original change and pushes the system further from balance.

Because the output (tourism income/infrastructure) feeds back to increase the input (tourist attraction).

Eutrophication: more nutrients → more algae → plant death/decomposition → more available nutrients.

It amplifies change and can push systems towards tipping points.

Reinforcing loops amplify change; balancing loops resist change and stabilise the system.

People or processes overcorrect because the system responds slowly, leading to repeated over- and under-shooting.

Predator–prey: prey increases → predators increase → prey decreases → predators decrease.

Ice-albedo: ice melts → darker surface → more heat absorbed → more melting.

Crossing a tipping point can shift a system into a new equilibrium that may be difficult to reverse.

A threshold where a small change triggers a large, often hard-to-reverse shift to a new equilibrium.

Name variables, follow arrows, explain +/− links, and state whether the loop is reinforcing or balancing.

Use limits such as visitor caps, zoning, pricing/taxes, and protected areas to reduce growth pressure.

Resilience is a system’s ability to absorb disturbance and keep functioning (or recover) without collapsing.

Loss of biodiversity, repeated disturbances, removal of storages, or strong human pressures (pollution/deforestation).

Ability to recover from disturbance and keep functioning over time.

Strong negative feedback loops usually support resilience because they counteract change.

Excess nitrates and phosphates from agriculture runoff or sewage discharge.

It reduces biodiversity and biomass storage, weakening buffers and increasing tipping point risk.

It reduces biodiversity and functional redundancy, making ecosystems less able to recover from disturbance.

High biodiversity and large/multiple storages (buffers).

Strong positive feedback amplifies change and can reduce resilience by pushing systems toward tipping points.

Rapid growth of algae due to high nutrient levels, often turning water green and reducing light.

More species/roles create redundancy; if one fails, others can replace its function.

A sudden event that disrupts a system (e.g., fire, flood, disease, pollution).

Protect habitats, restore mixed native species, improve soil management, or restore wetlands.

They can change in the short term after disturbance but remain stable in the long term.

Decomposition of dead algae/plants uses dissolved oxygen, causing hypoxia and fish kills.

Large/multiple storages buffer change and slow system response, reducing collapse risk.

Clear lake + nutrient input → algal bloom → murky, low-oxygen lake state.

Loss of diversity, shrinking storages, and strong human pressures (pollution/deforestation/overuse).

Soil nutrients, forest biomass, water in lakes/reservoirs, or carbon in vegetation.

The system settles into a new equilibrium, often difficult to reverse.

A diverse forest that can regrow after fire and continue functioning.

Crossing tipping points and shifting to a new equilibrium.

Feedback delays mean impacts appear later, so humans may respond only when collapse is near.

Nutrients stored in sediments can keep feeding algal growth even after inputs are reduced.

Human actions can raise or lower resilience by changing biodiversity and storages, affecting tipping point risk.

Actions that increase diversity and storages usually increase resilience.

The system is more likely to cross a tipping point and shift to a new equilibrium.

With weaker buffers and fewer stabilising processes, disturbances push the system past thresholds more easily.

Yes: more nutrients → more algae → more death/decomposition → conditions that can release/retain nutrients, driving more algae.

Reduce pressures, protect diversity, and strengthen storages/buffers to support stabilising feedback.