Unit 9- Lesson 5 (Succession)

Unit 10:
Ecology

2

Lesson 4- Ecological

Succession

(recovery of ecosystems)

What is ecological succession?

● Succession is the process by which the

structure of a biological community evolves
over time.

• Two different types:

– primary succession
– secondary succession

Multiple Choice

To Evolve means to...

• Turn into a different form once you reach a certain amount of experience

• Use a specific item to change forms and level up

• Instantaneously change phenotype or genotype

• Gradually change over time

Primary Succession

● Primary succession is ecological succession

that occurs in barren areas or that are
devoid of vegetation and topsoil

● Where does primary succession occur? Bare

rock after glacial retreat, lava flows, newly
formed sand dunes

From Mt. St. Helens volcanic ashes, Mother Nature rebuilds
https://www.youtube.com/watch?v=YmrgoCUjHAw

Primary Succession

● Primary succession begins with mosses and

lichens

Primary Succession

Reorder

Reorder the following (1 is earliest stage)

• Bare Rock

• Lichen

• Herbs

• Shrubs

• Oaks

1

2

3

4

5

• 1
• 2
• 3
• 4
• 5

Secondary Succession

● Secondary succession is the sequence of

events that take place after an existing
community is severely disrupted in some way.

• Secondary succession occurs in

areas that still have land
containing nutrients in the soil.
Not completely starting from
scratch like primary succession.

Why certain naturally occurring wildfires are necessary -
https://www.youtube.com/watch?v=cNVZEVq3KzY

Secondary Succession

● Secondary succession begins with pioneer

species, hardy species that are first to
colonize previously damaged areas

Secondary Succession

Reorder

Reorder the following: (1 is first)

• Fire

• soil, roots, seeds

• Pioneer species

• Intermediate species

• Climax community

1

2

3

4

5

• 1
• 2
• 3
• 4
• 5

Succession

Climax Community

● A climax community is

the end result of
ecological succession
where populations of
plants or animals
remain stable and exist
in balance with each
other and their
environment.

Which succession process takes longer?

● The amount of time to reach a climax community

varies- from days to hundreds of years
○ It depends on the disturbance or size of the

ecosystem

● Primary succession will take longer overall to

reach a climax community
○ The reason is the lack of soil. It takes time to develop

a significant layer of soil to support plant life.

Common Misconception

● Misconception: Secondary succession follows

primary succession

● NO!!!
● Primary and secondary succession are two

separate concepts that are not dependent
on one another

Hotspot

Which of the Following is the Climax Community?

Hotspot

Which of the Following is likely soil, roots, and seeds?