ES 5.2 Lesson Ecosystem Response to Change

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Environmental Science, 1e
SUSTAINING YOUR WORLD
G. TYLER MILLER | SCOTT E. SPOOLMAN

5

Species Interactions, Ecological

Succession, and Population

Control

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• Ecological succession

– The normal, gradual change in species composition in a given

geographic area

– Species composition of an ecosystem or community can change in

response to changing environmental conditions

• Examples: fires, volcanic eruptions, climate change, clear-cutting

– Primary and secondary succession are examples of natural

ecological restoration.

5.2 How Do Ecosystems Respond to Changing
Conditions?

Multiple Choice

Species composition in an area changes in response to _________ environmental conditions.

• harsh

• changing

• mild

• constant

Multiple Choice

Ecological Succession is the normal ________ change in species composition in an area.

• sudden

• gradual

• rapid

• nonexistent

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• The gradual establishment of biotic communities in lifeless

areas where there is no soil in a terrestrial ecosystem or no
bottom sediment in an aquatic system

– Takes hundreds to thousands of years

Primary Ecological Succession

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Primary Ecological Succession, Illustrated

Drag and Drop

​

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succession establishes life in lifeless areas with no soil or sediment. It takes ​

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.

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Primary

hundreds to thousands of years

Secondary

millions of years

several months

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• Occurs where communities or ecosystems have been

disturbed, removed, or destroyed, but retain some soil or
bottom sediments

• An important ecosystem service

– Enriches biodiversity of communities and ecosystems by increasing

species diversity and interaction among species

• Doesn’t always follow a predictable path

Secondary Ecological Succession

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​

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succession establishes life in lifeless areas with soil or sediment. It ​

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follow a predictable path.

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Secondary

doesn't always

will always

Primary

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• Promotes population control

– Increases the complexity of food webs

– Enhances energy flow

– Increases nutrient cycling

Secondary Succession Also Enhances Sustainability

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Secondary Ecological Succession, Illustrated

Drag and Drop

Secondary succession enriches ​

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which enhances ​

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.

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biodiversity

sustainability

extinction

climate change

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• Arise out of complex processes that result in some degree of

stability or sustainability

– Withstand external stress in response to changing environmental

conditions

• Two aspects of stability/sustainability:

– Inertia (persistence) is ability of ecosystem to survive moderate

disturbance

– Resilience is ability of ecosystem to be restored through secondary

succession after severe disturbance

Living Systems Are Sustained Through Constant Change

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​

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is the ability of an ecosystem to be restored through secondary succession.

​

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, or persistence, is the ability of an ecosystem to survive moderate disturbances.

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Resilience

Inertia

Succession

Labelling

Label the type of succession.

Drag labels to their correct position on the image

Tertiary

Primary

Secondary