Unit 4B Pt5

Ecological Succession

​Unit 4 Pt5 - (Lessons 4.8-4.14)
Standards: HS-LS-1, 2, 6 & 7

Multiple Choice

The picture shows what type of succession?

• primary

• secondary

• tertiary

• quaternary

Multiple Choice

What is the order of succession shown in this figure?

• A, B, C, D

• B, A, D, C

• C, D, A, B

• D, A, B, C

Multiple Choice

After a volcanic eruption, lava covers the land. What is the order that plants grow to repopulate the area?

• Lichens → Shrubs → Grasses → Trees

• Lichens → tree → shrubs→Grasses

• Grasses → Lichens → Shrubs → Trees

• Lichens → Grasses → Shrubs → Trees

Causes of Primary Succession

Caused by disturbances such as:

• Volcanos & lava flows

• Re-treating glacier

• Oil spills

• Landslides

Results in no soil or soil that cannot sustain life!

Steps of Primary Succession

• Barren rock is covered by moss

• Pioneer species such as lichens and mosses form on rocks

• Lichen can break rock down and mosses decompose, helping create soil

• Grasses begin to grow

• Small shrubs and small organisms start to come in

• Larger trees and different types of organisms come in, when there is more diversity and the ecosystem is back in equilibrium it is a climax community

Causes of Secondary Succession

Caused by disturbances such as:

• Forest Fire

• Floods

• Hurricanes & Tornadoes

• Deforestation

• Abandoned farmer's field

  Remember: Soil is present before & after disturbance!

Multiple Choice

4.8 - Which change would create a new ecosystem?

• a dam flooding a valley

• a yearly migration

• an introduced species

• a lake freezing over

Steps of Secondary Succession

1. Annual plants come about

2. Followed by grasses and small plants

3. Shrubs, small trees, and small animals

4. Large trees, diverse animals

5. Climax community

Multiple Choice

4.9 - Consider the following scenario: Every year, the tropical rain forest has a rainy season. The forest floor floods, covering once dry areas with water. Some organisms are unable to tolerate the increased water, so they have to move to other locations to survive. Which word can best be used to describe this scenario?

• damming

• biodiversity

• disturbance

• predation

Predicts that the highest biodiversity, or species richness will occur at levels of moderate disturbance

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​Intermediate Disturbance Hypothesis

• Scheduled hunting seasons

• Seasonal flooding or drought

These disturbances may have a great impact initially, but over time, might not impact the ecosystem very much.

Some scientists believe that these types of disturbances may actually serve to maximize ecosystem diversity.

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​Moderate Disturbances

Low level disturbances -- species tend to overspecialize

• Ex: If a river is always stable, then most competitive species are those best adapted to the river's level.

Competition between species, NOT adaptation to change, will determine makeup of ecosystem.

Dominant species will outcompete all others for food & resources.

Less competitive populations decrease, less biodiversity.

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​Light Disturbances

Species are at risk of total extinction.

• Ex: No species can adapt to survive a direct meteor hit

Only highly mobile individuals can escape.

High-stress environments can be lethal to entire ecosystems.

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​High Disturbances

Multiple Choice

4.8 - A light disturbance in an ecosystem could include

• cutting down a forest for wood manufacturing.

• a tree falling over from a thunderstorm.

• filling in a paving over a lake for a parking lot.

• a volcanic eruption.

Ecological Succession Takes Time

• Primary usually takes longer than secondary

  It can take a year for pioneer species or annual plants to come in

• 3-4 years for shrubs and bushes to come in

• 5-150 years for small trees

• and 150 or more years for large trees and for the community to be in equilibrium which is a climax community

Purpose of Succession

• Growth and development of an ecosystem

• Allows ecosystems to thrive once again and balance to return

• Generates biodiversity over time

Multiple Choice

What term BEST describes the diagram?

• Primary Succession

• Pioneer Species

• Climax Community

• Secondary Succession

Multiple Choice

What disturbance can cause secondary succession?

• volcanic eruption

• landslide

• glacier

• forest fire

Multiple Choice

What term BEST describes the diagram?

• Primary Succession

• Pioneer Species

• Secondary Succession

• Climax Community

Role of Pioneer Species in Succession

• Soil stabilization

• Nutrient enrichment - humus formation

• Promote nitrogen fixation and carbon cycle

• Reduction of light availability

• Reduction of wind exposure

• Temperature moderation

• Lichens are commonly recognized as a symbiotic association of a fungus and a chlorophyll containing partner, either green algae or cyanobacteria, or both.

• The fungus provides a suitable habitat for the partner.

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​Lichen - Mutualism

Multiple Choice

What term BEST describes the first species that inhabitants an ecosystem after a disturbance?

• Producers

• Invasive Species

• Native Species

• Pioneer Species

Multiple Select

What type of natural disturbance will lead to Secondary Succession? (Choose all that apply.)

• Flood

• Volcano Eruption

• Forest Fire

• Hurricane

• Tornado

Multiple Select

Which are a part of primary succession? (Choose all that apply.)

• Soil is not available

• soil is available

• moss is first to appear

• annual plants are first to appear

Multiple Choice

A volcanic eruption occurred in Hawaii, what would be the correct beginning stages of primary succession?

• Soil is there, moss forms, and grasses grow

• bare rock covered in moss, moss decomposes, soil forms

• Bare rock, grasses start to form, followed by moss

• soil is there, moss creates more soil, shrubs grow

Multiple Choice

What disturbance can cause secondary succession?

• Landslide

• Forest Fire

• Volcanic Eruption

• Glacier

Multiple Select

What role do micro-organisms play in an ecosystem? (Choose all that apply.)

• help create soil

• bring nutrients back

• help bring nitrogen into soil

• are producers

• are a main food source

Match

Match the following

Primary succession

pioneer species

abiotic factor

secondary sucession

climax community

• Primary succession

• pioneer species

• abiotic factor

• secondary sucession

• climax community

​Let's see who our winners are and head back to the

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