Investigation 4.3: Ecological Succession

The first species to colonize an environment is called:

Pioneer species

Do animals or plants come first in succession? Why?

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

What is the difference between primary succession and secondary succession?

Primary succession occurs in an area with no life and no soil but secondary succession happens in an area where an existing community was disrupted.

What type of succession do you think is displayed in the case of Mount Saint Helens? Why?

Secondary succession because there had already been a thriving ecosystem before the eruption

What would be a correct sequence for the events of secondary succession? First is 1 and last is 5.

1. An intact ecosystem is disrupted by a natural disaster. 2. Pioneer species like grasses and flowers grow. 3. Bushes begin to dominate. 4. Trees become common and outcompete other plants for sunlight. 5. The climax community for the area is established once again.

Place the following types of organisms in the order in which they would appear during primary succession, with 1 being the first organism and 5 being the last.

1. Lichens 2. Mosses 3. Grasses and annual flowers 4. Bushes and shrubs 5. Trees

Which of the following statements are true?

All of the above are true

Biodiversity is the variety of life in an area. Think about the process of succession. How does biodiversity change during succession?

Biodiversity increases through the process of succession.

The graph above illustrates the mass of different types of plants during succession. What best explains the decrease in the mass of mosses?

Competition for light and resources with grasses.

What type of limiting factor is this volcanic eruption?

Density-independent

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 tree produce shade and compete for resources with smaller plants, causing a reduction in their populations. III. Animals replace plants due to their superior intelligence.

I and II only

The graph above illustrates the mass of different types of plants during succession. Which of the following best describes what occurs to the amount of grasses in the graph?

It increases for a while and then decreases.

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

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

Which species did you pick to be your pioneer species?

Lichens

Which of the following best describes succession?

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

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

They break down rock and form soil