Succession Check for Understanding

Which of the following best describes succession?

• The evolution of species through natural selection to become different species over time.

• The changes in species composition in a community over time as species colonize an area.

• The reduction in biodiversity of an ecosystem over time.

• The creation of new life from nothing in an ecosystem.

Which of the following are true?

• Secondary succession occurs in an area that already had life and soil.

• Primary succession begins in an area that does not have soil.

• Primary succession begins in an area that did not have life before.

• All of the above.

Which organism(s) would appear first during primary succession?

• bushes and shrubs

• grasses and annual flowers

• lichens and moss

• trees

Answer explanation

Remember lichens and moss must appear first to break down the rocks into soil.

Lichens are often the first species to colonize an environment during primary succession. In general, the first species to colonize an environment is called

• a pioneer species

• primary succession

• a primary consumer

• secondary succession

Why do lichens and mosses get mostly replaced by larger plant species during succession?

• Larger plants are not edible so they are more likely to avoid predation.

• Larger plants do not use as many resources as lichens and mosses.

• Larger plants are autotrophs but lichens and mosses are heterotrophs.

• Larger plants compete for resources like space, sunlight, and soil nutrients more successfully.

Do animals or plants come first in succession? Why?

• Plants come first because animals rely on them for food production.

• Plants come first because plants are more mobile than animals.

• Animals come first because animals are needed to regulate plant populations.

• Animals come first because all plants require pollinators.

How do lichens alter the abiotic environment to favor the establishment of other species of plants?

• They are a good food source for pollinators.

• They provide energy for other plants.

• They reflect sunlight to help them to grow.

• They break down rock and form soil.

What is the proper order of events for secondary succession given the list below?

i. An intact ecosystem is disrupted by a natural disaster.

ii. Bushes begin to dominate.

iii. Pioneer species like grasses and flowers grow.

iv. The climax community for the area is established once again.

v. Trees become common and outcompete other plants for sunlight.

• i, ii, iii, iv, v

• iv, v, ii, iii, i

• i, iii, v, ii, iv

• i, iii, ii, v, iv

Which of the following would be the last organisms to successfully colonize an area?

• tertiary consumers

• producers

• secondary consumers

• primary consumers

How do living things alter the biotic and abiotic environment to cause the process of succession?

I. Lichens and small plants produce soil that allow larger plants to grow.

II. Large trees produce shade and compete for resources with smaller plants, causing a reduction in their populations.

III. Animals replace plants due to their superior intelligence.

• II and III only

• I, II, and III

• I only

• I and II only