Lesson 7:
Primary and Secondary Succession
Big Idea: Ecosystems change all the time.
Learning Goal: To understand how human and natural interactions can change ecosystems, and how ecosystems respond to these changes.
Learning Goal: To understand how human and natural interactions can change ecosystems, and how ecosystems respond to these changes.
Succession is a natural change of the environment. It is the process by which a biological community changes over time. These changes may be slow and hard to see over short time periods. Examples are the growth of hardwood forests, and the development of the Great Barrier Reef.
There are two types of succession:
1) Primary succession:This is the process of an ecosystem development, and takes place in areas lacking soil (bare rocks, sand dunes, and cooled lava for example). It can be started by pioneer species like lichens.
2) Secondary succession: The process by which an ecosystem changes after it has been disturbed, for example by a forest fire. This succession represents the re-growth of a community.
There are two types of succession:
1) Primary succession:This is the process of an ecosystem development, and takes place in areas lacking soil (bare rocks, sand dunes, and cooled lava for example). It can be started by pioneer species like lichens.
2) Secondary succession: The process by which an ecosystem changes after it has been disturbed, for example by a forest fire. This succession represents the re-growth of a community.
Forest fires can be very damaging, but they also have benefits. These include:
1) Cleaning the forest floor: Fire removes low-growing underbrush, cleans the forest floor of debris, opens it up to sunlight, and nourishes the soil. Reducing this competition for nutrients allows established trees to grow stronger and healthier.
2) Providing habitat: Fire cleans wild lands of heavy brush, leaving room for new plant species that provide a habitat for wildlife.
3) Killing Disease: Fire kills diseases and insects that prey on trees and provides valuable nutrients that enrich the soil. More trees die each year from insect infestation and disease than from fire.
4) New Generations: Change is important to a healthy forest. Some species of trees and plants are actually fire dependent. They must have fire every 3-25 years in order for life to continue.
1) Cleaning the forest floor: Fire removes low-growing underbrush, cleans the forest floor of debris, opens it up to sunlight, and nourishes the soil. Reducing this competition for nutrients allows established trees to grow stronger and healthier.
2) Providing habitat: Fire cleans wild lands of heavy brush, leaving room for new plant species that provide a habitat for wildlife.
3) Killing Disease: Fire kills diseases and insects that prey on trees and provides valuable nutrients that enrich the soil. More trees die each year from insect infestation and disease than from fire.
4) New Generations: Change is important to a healthy forest. Some species of trees and plants are actually fire dependent. They must have fire every 3-25 years in order for life to continue.
ACTION ITEM # 1:
Click on the picture to go to a link to an interactive game on succession. Explore the game and try the check your understanding quiz at the end.
ACTION ITEM #2:
Succession can impact: soil composition, plant types, animal types, and amount of light in an ecosystem. With a partner, draw and label and illustrate a diagram demonstrating and explaining these changes. Make your thinking visible!
Click on the link below to complete your science journal:
https://docs.google.com/forms/d/1MXOd4yEV7H3bauEa0Ii_MJTlBwzkcthercxSrNHf8SM/viewform
Click on the picture to go to a link to an interactive game on succession. Explore the game and try the check your understanding quiz at the end.
ACTION ITEM #2:
Succession can impact: soil composition, plant types, animal types, and amount of light in an ecosystem. With a partner, draw and label and illustrate a diagram demonstrating and explaining these changes. Make your thinking visible!
Click on the link below to complete your science journal:
https://docs.google.com/forms/d/1MXOd4yEV7H3bauEa0Ii_MJTlBwzkcthercxSrNHf8SM/viewform