5.1.5 - Stages Of Succession

Question 1

What Is Succession?
(2 Points)

Answer 1

~ Process of ecosystem change over time.

~ As ecosystems are dynamic and constantly changing.

Question 2

What Changes During Succession?

Answer 2

The biotic and abiotic conditions.

Question 3

What Is Primary Succession?
(2 Points)

Answer 3

~ Process that occurs when newly formed or exposed land is inhabited by an increasing number of species.

~ The arrival of new organisms in new land is known as colonisation, the bare land is then said to be colonised.

Question 4

How Can Newly Formed Land By Created?

Answer 4

Magma from erupting volcanos cooling and forming new rock surfaces or new rocky islands in the sea.

Question 5

How Can Newly Exposed Land By Created?
(2 Points)

Answer 5

~ Land slide that exposes bare rock.

~ Glacier that retreats to reveal bare rock.

Question 6

Describe The Stages Of Primary Succession
(7 Points)

Answer 6

~ Seeds and spores that are carried by the wind, land on exposed rock and begin to grow.

~ Pioneer species colonise the new land, they can germinate easily and withstand harsh conditions.

~ As pioneer species die and decompose, the dead organic matter forms soil, making conditions less harsh.

~ Larger plants, shrubs and small trees can now begin to grow, but they require more water, which can be stored in deeper soils.

~ Over time the soil becomes sufficiently deep, contains enough nutrients and can retain more water to support the growth of other species.

~ The final species to colonise the new land, become the dominant species of the now complex ecosystem.

~ The final community formed, containing all the different plant and animal species is known as the climax community.

Question 7

Describe How Succession Changes The Biotic & Abiotic Conditions
(4 Points)

Answer 7

~ At each stage in succession the newly arriving species change the local environment, so that it becomes more suitable for other species.

~ Often the new colonising species then change the environment in such a way, that it becomes less suitable for the previous species.

~ Pioneer species will be outcompeted for light and other resources, as they are often poor competitors.

~ As soil deepens and trees are able to grow, they block light outcompeting them and causing them to die.

Question 8

Describe Secondary Succession
(2 Points)

Answer 8

~ Takes place on previously occupied land.

~ Is similar to primary succession, except the soil is already present.

Question 9

Describe How Humans Can Prevent Succession
(3 Points)

Answer 9

~ Stops climax community from developing.

~ E.g. Regular mowing.

~ Species developed as a result of human activities are known as plagioclimax species.