IB Biology Topic D4.2.1 Stability as a Property of…

Stability Comes From an Ecosystem's Resistance and Resilience

Definition

Ecosystem Stability

Ecosystem stability is the ability of an ecosystem to maintain structure and function over time, even when faced with disturbances like climate change, natural disasters, or human activity. High biodiversity plays a critical role in promoting this stability.

Resistance is the ability of an ecosystem to withstand a disturbance without significant change.
Resilience is the ability of an ecosystem to recover and return to its original state after a disturbance.
A stable ecosystem keeps its structure and functions roughly constant over time, even when conditions change.

Analogy

Resistance is like a sturdy tree that barely bends in a storm.
Resilience is like grass that gets flattened but springs back up once the storm passes.

High Biodiversity Makes Ecosystems More Stable

Redundancy means several species perform similar roles, so if one is lost, others take over and the system keeps working.
Complex interactions such as predator-prey relationships, mutualism, and competition regulate populations and prevent any one species from taking over.
Genetic diversity within a species makes its populations more resilient to disease, climate change, and other environmental stress.

Example

A genetically diverse population of trees is less likely to be wiped out by pests or drought, so the ecosystem stays functional.
Coral reefs with genetically diverse corals are more likely to survive bleaching events.

Exam technique

Name redundancy, genetic diversity, and complex interactions when explaining how biodiversity supports stability.
Use real world examples like coral reefs or tropical rainforests to strengthen your argument.

Active recall

What is the difference between resistance and resilience in an ecosystem?
What does it mean to say an ecosystem is stable?
How does redundancy help an ecosystem keep functioning when a species is lost?
How do complex interactions like predator-prey and competition keep populations in check?
Why does high genetic diversity make a population more resilient?

Stability Comes From an Ecosystem's Resistance and Resilience

Definition

Ecosystem Stability

Resistance is the ability of an ecosystem to withstand a disturbance without significant change.
Resilience is the ability of an ecosystem to recover and return to its original state after a disturbance.
A stable ecosystem keeps its structure and functions roughly constant over time, even when conditions change.

Analogy

Resistance is like a sturdy tree that barely bends in a storm.
Resilience is like grass that gets flattened but springs back up once the storm passes.

High Biodiversity Makes Ecosystems More Stable

Redundancy means several species perform similar roles, so if one is lost, others take over and the system keeps working.
Complex interactions such as predator-prey relationships, mutualism, and competition regulate populations and prevent any one species from taking over.
Genetic diversity within a species makes its populations more resilient to disease, climate change, and other environmental stress.

Example

A genetically diverse population of trees is less likely to be wiped out by pests or drought, so the ecosystem stays functional.
Coral reefs with genetically diverse corals are more likely to survive bleaching events.

Exam technique

Name redundancy, genetic diversity, and complex interactions when explaining how biodiversity supports stability.
Use real world examples like coral reefs or tropical rainforests to strengthen your argument.

Active recall

What is the difference between resistance and resilience in an ecosystem?
What does it mean to say an ecosystem is stable?
How does redundancy help an ecosystem keep functioning when a species is lost?
How do complex interactions like predator-prey and competition keep populations in check?
Why does high genetic diversity make a population more resilient?

IB Biology Topic D4.2.1: Stability as a Property of Natural Ecosystems Notes

IB Biology Topic D4.2.1: Stability as a Property of Natural Ecosystems Notes

Stability Comes From an Ecosystem's Resistance and Resilience

High Biodiversity Makes Ecosystems More Stable

Stability Comes From an Ecosystem's Resistance and Resilience

High Biodiversity Makes Ecosystems More Stable

A - Unity and Diversity

B - Form and Function

C - Interaction and Interdependence

D - Continuity and Change

A - Unity and Diversity

B - Form and Function

C - Interaction and Interdependence

D - Continuity and Change

IB Biology Topic D4.2.1: Stability as a Property of Natural Ecosystems Notes

IB Biology Topic D4.2.1: Stability as a Property of Natural Ecosystems Notes

Stability Comes From an Ecosystem's Resistance and Resilience

High Biodiversity Makes Ecosystems More Stable

Stability Comes From an Ecosystem's Resistance and Resilience

High Biodiversity Makes Ecosystems More Stable