Ecological Succession

What is ecological succession?

• A) A sudden change in an ecosystem caused by humans

• B) The gradual process by which ecosystems change over time

• C) The extinction of species in an ecosystem

• D) The yearly cycle of plant growth

What is a climax community?

• The very first stage of succession

• A temporary community of pioneer species

• A stable, mature ecosystem at the “end” of succession

• An ecosystem that can never change again

Which of the following best describes pioneer species?

• Animals that move into a mature forest

• Hardy organisms that first colonize bare rock or soil

• Plants that arrive after shrubs are established

• Species that only live in climax communities

Which organisms are common pioneer species in primary succession?

• Lichens and mosses

• Oaks and maples

• Deer and wolves

• Earthworms and insects

Tags

NGSS.MS-LS2-4

Primary succession begins in areas where:

• Soil is already present

• Only water exists

• No soil exists, just bare rock or sediment

• Large animals already live

Secondary succession occurs after:

• A) A volcanic eruption creates new lava rock

• B) A glacier retreats and exposes bare ground

• C) A forest fire, hurricane, or abandoned farmland

• D) A sand dune forms for the first time

Why is secondary succession faster than primary succession?

• The soil is already present with seeds and nutrients

• Pioneer species grow more quickly

• Larger animals move in first

• Climax communities form instantly

Which stage of succession includes grasses, shrubs, and fast-growing trees?

• Pioneer stage

• Intermediate stage

• Climax community

• Disturbance stage

What is the correct order of stages in succession?

• Climax → Pioneer → Intermediate → Disturbance

• Pioneer → Intermediate → Climax → Disturbance

• Disturbance → Intermediate → Pioneer → Climax

• Pioneer → Climax → Intermediate → Disturbance

Which of the following is a human activity that disrupts succession?

• Reforestation projects

• Logging and repeated farming

• Restoring wetlands

• Planting cover crops