IB Biology Topic A4.2.4 Causes of Ecosystem Loss Revision Notes (SL/HL)

IB Biology Topic A4.2.4 Causes of Ecosystem Loss Revision Notes (SL/HL) | RevisionDojo

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Ecosystem Loss: Human Activities Degrade and Destroy Natural Habitats

Definition

Ecosystem loss

Ecosystem loss refers to the degradation or destruction of natural systems

It is primarily driven by human activities, including deforestation, pollution, and climate change.
It can manifest as:
1. Degradation: Reduced ecosystem health (e.g., polluted rivers).
2. Destruction: Total conversion to another land use (e.g., a forest replaced by agriculture).

Why It Matters: Ecosystems Provide Essential Resources, Climate Regulation, and Cultural Value

Healthy ecosystems:
1. Provide essential resources like food, water, and medicines.
2. Regulate climate through carbon storage and temperature moderation.
3. Support cultural, recreational, and spiritual values.
The loss of ecosystems disrupts these functions, creating cascading environmental, economic, and social consequences.

Analogy

Think of an ecosystem as a woven fabric.
Each thread represents a species, a process, or a resource.
When one thread is pulled out, the fabric weakens.
If enough threads are removed, the entire fabric unravels.

Anthropogenic Causes: Six Major Human Activities Drive Ecosystem Destruction

Human activities are the primary drivers of ecosystem loss.
These activities can be categorized into several major causes:
Land-use change
Agricultural Expansion: Forests, grasslands, and wetlands are cleared to grow crops or raise livestock.
Urbanization: The rapid growth of cities and infrastructure development has led to widespread destruction of natural habitats.

Example

Tropical rainforests are often replaced by monoculture plantations like oil palm or soy.

Overexploitation of resources
Overharvesting of timber, fuelwood, and animal populations destabilizes ecosystems.

Example

Removing keystone species such as large predators or primary producers can trigger cascading effects throughout the ecosystem.

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Definition

Paywall

(on a website) an arrangement whereby access is restricted to users who have paid to subscribe to the site.

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Lorem ipsum dolor sit amet, consectetur adipiscing elit. Sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.

Duis aute irure dolor in reprehenderit

Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.

Note

Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam quis nostrud exercitation.

Excepteur sint occaecat cupidatat non proident

Nemo enim ipsam voluptatem quia voluptas sit aspernatur aut odit aut fugit, sed quia consequuntur magni dolores eos qui ratione voluptatem sequi nesciunt. Neque porro quisquam est, qui dolorem ipsum quia dolor sit amet, consectetur, adipisci velit.

Tip

Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.

Lorem ipsum dolor sit amet, consectetur adipiscing elit.
Sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.
Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris.
Duis aute irure dolor in reprehenderit in voluptate velit esse cillum.

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Ecosystem Loss: Human Activities Degrade and Destroy Natural Habitats

Definition

Ecosystem loss

Ecosystem loss refers to the degradation or destruction of natural systems

It is primarily driven by human activities, including deforestation, pollution, and climate change.
It can manifest as:
1. Degradation: Reduced ecosystem health (e.g., polluted rivers).
2. Destruction: Total conversion to another land use (e.g., a forest replaced by agriculture).

Why It Matters: Ecosystems Provide Essential Resources, Climate Regulation, and Cultural Value

Healthy ecosystems:
1. Provide essential resources like food, water, and medicines.
2. Regulate climate through carbon storage and temperature moderation.
3. Support cultural, recreational, and spiritual values.
The loss of ecosystems disrupts these functions, creating cascading environmental, economic, and social consequences.

Analogy

Think of an ecosystem as a woven fabric.
Each thread represents a species, a process, or a resource.
When one thread is pulled out, the fabric weakens.
If enough threads are removed, the entire fabric unravels.

Anthropogenic Causes: Six Major Human Activities Drive Ecosystem Destruction

Human activities are the primary drivers of ecosystem loss.
These activities can be categorized into several major causes:
Land-use change
Agricultural Expansion: Forests, grasslands, and wetlands are cleared to grow crops or raise livestock.
Urbanization: The rapid growth of cities and infrastructure development has led to widespread destruction of natural habitats.

Example

Tropical rainforests are often replaced by monoculture plantations like oil palm or soy.

Overexploitation of resources
Overharvesting of timber, fuelwood, and animal populations destabilizes ecosystems.

Example

Removing keystone species such as large predators or primary producers can trigger cascading effects throughout the ecosystem.

Definition

Paywall

(on a website) an arrangement whereby access is restricted to users who have paid to subscribe to the site.

anim nostrud sit dolore minim proident quis fugiat velit et eiusmod nulla quis nulla mollit dolor sunt culpa aliqua

Duis aute irure dolor in reprehenderit

Note

Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam quis nostrud exercitation.

Excepteur sint occaecat cupidatat non proident

Tip

Lorem ipsum dolor sit amet, consectetur adipiscing elit.
Sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.
Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris.
Duis aute irure dolor in reprehenderit in voluptate velit esse cillum.

A - Unity and Diversity9 subtopics

B - Form and Function10 subtopics

C - Interaction and Interdependence9 subtopics

D - Continuity and Change12 subtopics

IB Biology Topic A4.2.4: Causes of Ecosystem Loss Notes

A - Unity and Diversity9 subtopics

B - Form and Function10 subtopics

C - Interaction and Interdependence9 subtopics

D - Continuity and Change12 subtopics

Ecosystem Loss: Human Activities Degrade and Destroy Natural Habitats

Why It Matters: Ecosystems Provide Essential Resources, Climate Regulation, and Cultural Value

Anthropogenic Causes: Six Major Human Activities Drive Ecosystem Destruction

anim nostrud sit dolore minim proident quis fugiat velit et eiusmod nulla quis nulla mollit dolor sunt culpa aliqua

Duis aute irure dolor in reprehenderit

Excepteur sint occaecat cupidatat non proident

Unlock the rest of this chapter with a free account

Ecosystem Loss: Human Activities Degrade and Destroy Natural Habitats

Why It Matters: Ecosystems Provide Essential Resources, Climate Regulation, and Cultural Value

Anthropogenic Causes: Six Major Human Activities Drive Ecosystem Destruction

anim nostrud sit dolore minim proident quis fugiat velit et eiusmod nulla quis nulla mollit dolor sunt culpa aliqua

Duis aute irure dolor in reprehenderit

Excepteur sint occaecat cupidatat non proident

Unlock the rest of this chapter with a free account