IB Environmental systems and societies Topic 3.2H Loss of Biosphere Integrity Revision Notes (HL)

IB Environmental systems and societies Topic 3.2H Loss of Biosphere Integrity Revision Notes (HL) | RevisionDojo

Written by official IB examiners

Biosphere Integrity: The Planetary Boundary We Have Already Crossed

Biosphere integrity is the biodiversity planetary boundary, one of the nine boundaries that mark a safe operating space for humanity.
It measures the stability and resilience of the living part of the Earth system.
The boundary has two components used to track it:
1. Genetic diversity, the variation within species that lets them adapt.
2. Functional diversity, the variety of ecological roles that species perform.

Definition

Biosphere integrity

Biosphere integrity refers to the capacity of ecosystems to maintain biodiversity (genes, species, functions) and continue providing essential ecological services.

How Far the Boundary Has Been Crossed

Biosphere integrity is one of only two planetary boundaries humanity has already transgressed.
The main signal is that the species extinction rate is now roughly 100 to 1,000 times the natural background rate.
This rate is measured in extinctions per million species-years (E/MSY).
1. The background rate is about 1 extinction per million species-years.
2. The proposed safe boundary is around 10 E/MSY, and we are well above it.
The drivers are the familiar pressures of habitat loss, overexploitation, pollution, invasive species, and climate change.

Note

The current loss is often called the Sixth Mass Extinction.
It is the first driven by a single species: humans.

Why Losing Biosphere Integrity Destabilises Ecosystems

Reduced ecosystem stability
1. Diverse ecosystems have functional redundancy, where several species can do a similar job.
2. As species are lost, that redundancy falls and the ecosystem becomes more fragile.
3. Removing a key species can destabilise whole food webs and nutrient cycles.

Nice try, unfortunately this paywall isn't as easy to bypass as you think. Want to help devleop the site? Join the team at https://revisiondojo.com/join-us. exercitation voluptate cillum ullamco excepteur sint officia do tempor Lorem irure minim Lorem elit id voluptate reprehenderit voluptate laboris in nostrud qui non Lorem nostrud laborum culpa sit occaecat reprehenderit

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

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.

Unlock the rest of this chapter with a free account

Biosphere Integrity: The Planetary Boundary We Have Already Crossed

Biosphere integrity is the biodiversity planetary boundary, one of the nine boundaries that mark a safe operating space for humanity.
It measures the stability and resilience of the living part of the Earth system.
The boundary has two components used to track it:
1. Genetic diversity, the variation within species that lets them adapt.
2. Functional diversity, the variety of ecological roles that species perform.

Definition

Biosphere integrity

Biosphere integrity refers to the capacity of ecosystems to maintain biodiversity (genes, species, functions) and continue providing essential ecological services.

How Far the Boundary Has Been Crossed

Biosphere integrity is one of only two planetary boundaries humanity has already transgressed.
The main signal is that the species extinction rate is now roughly 100 to 1,000 times the natural background rate.
This rate is measured in extinctions per million species-years (E/MSY).
1. The background rate is about 1 extinction per million species-years.
2. The proposed safe boundary is around 10 E/MSY, and we are well above it.
The drivers are the familiar pressures of habitat loss, overexploitation, pollution, invasive species, and climate change.

Note

The current loss is often called the Sixth Mass Extinction.
It is the first driven by a single species: humans.

Why Losing Biosphere Integrity Destabilises Ecosystems

Reduced ecosystem stability
1. Diverse ecosystems have functional redundancy, where several species can do a similar job.
2. As species are lost, that redundancy falls and the ecosystem becomes more fragile.
3. Removing a key species can destabilise whole food webs and nutrient cycles.

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.

Topic 1: Foundation 3 subtopics

Topic 2: Ecology5 subtopics

Topic 3: Conservation and biodiversity3 subtopics

Topic 4: Water4 subtopics

Topic 5: Land2 subtopics

Topic 6: Atmosphere and climate change4 subtopics

Topic 7: Natural resources3 subtopics

Topic 8: Human populations and urban systems3 subtopics

HL lenses 3 subtopics

IB Environmental systems and societies 3.2H Loss of Biosphere Integrity Notes

Topic 1: Foundation 3 subtopics

Topic 2: Ecology5 subtopics

Topic 3: Conservation and biodiversity3 subtopics

Topic 4: Water4 subtopics

Topic 5: Land2 subtopics

Topic 6: Atmosphere and climate change4 subtopics

Topic 7: Natural resources3 subtopics

Topic 8: Human populations and urban systems3 subtopics

HL lenses 3 subtopics

Biosphere Integrity: The Planetary Boundary We Have Already Crossed

How Far the Boundary Has Been Crossed

Why Losing Biosphere Integrity Destabilises Ecosystems

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

Biosphere Integrity: The Planetary Boundary We Have Already Crossed

How Far the Boundary Has Been Crossed

Why Losing Biosphere Integrity Destabilises Ecosystems

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