Ecological Succession and Its Impact on Ecosystems

Mr. Anderson explains ecological succession, a process by which ecosystems recover after disturbances. He distinguishes between primary succession, which occurs on bare rock, and secondary succession, which happens when soil remains. Examples include Mount St. Helens and Yellowstone Park. Pioneer species play a crucial role in ecosystem recovery, eventually leading to a climax community. Disturbances like fires or human activities can restart the succession process.

What is ecological succession?

• A way to prevent forest fires

• A process where life disappears from an area

• A series of events by which life returns to an area

• A method of planting trees in a barren land

What characterizes primary succession?

• Presence of soil

• Absence of soil

• Abundance of water

• Lack of sunlight

Which event is an example of primary succession?

• A field being plowed for agriculture

• A forest regrowing after a fire

• A new island forming from a volcanic eruption

• A city being built on a plain

How do pioneer species contribute to secondary succession?

• They consume all available resources

• They block sunlight from reaching the ground

• They prevent other species from growing

• They prepare the soil for other species

What is a characteristic of Lodgepole Pines in secondary succession?

• They are the last species to appear

• They require human intervention to grow

• Their cones open only after a fire

• They grow only in wet conditions

What are climax species?

• Species that are always present in an ecosystem

• Species that appear first after a disturbance

• Species that dominate the final stage of succession

• Species that cannot survive in disturbed areas

Which of the following is a disturbance that can lead to succession?

• A light rain

• A gentle breeze

• A forest fire

• A sunny day

How do disturbances affect climax species?

• They make them more resilient

• They can destroy them, restarting succession

• They have no effect

• They help them grow faster

What happens to the amount of bare rock as succession progresses?

• It decreases

• It increases

• It fluctuates randomly

• It remains the same

Why don't grasses remain dominant in an area undergoing succession?

• They require more sunlight

• They are replaced by taller species

• They deplete the soil nutrients

• They are eaten by animals