1



Ecological Succession Webquest

Directions: Read the overview below and answer questions below on a separate piece of paper.

Ecological Succession - Overview

The term SUCCESSION comes from the Latin word, “succedere” which means to follow after.

Succession can be described as "Change in the species composition of a community over time."

• Primary Succession follows the formation of new land surfaces consisting of rock, lava, volcanic ash, sand, clay, or some other exclusively mineral substrate.

• This means that there is NO SOIL present. (Soil is a mixture of mineral material, decaying organic material, and living organisms. The area is barren.)

• Secondary Succession follows the destruction or partial destruction of the vegetation area by some sort of disturbance, like a fire, windstorm, or flood that leaves the soil intact.

• Pioneer species initiate recovery following disturbance in both primary AND secondary successions.

Pioneers "pave the way" for later colonists (plant species) by altering the biotic and abiotic environment:

• Species composition tends towards a Climax Community through succession.

The climax community describes an end product of succession that persists until disturbed by environmental change.

Part 1:

Visit the link above, read the introduction, watch the animation, take the quiz, and answer the following questions:

1. What are some of the “pioneer” species in glacial moraines?

2. How do alder trees affect nitrogen content in soil?

3. How do the alder trees influence spruce tree growth?

4. Write the answers to the two quiz questions.

Part 2: Go to the following website to complete this activity.

Primary Succession: Now choose the tab labeled “Primary Succession”. Using the “Temperature and Rainfall” slider control, select “LOW” temperature and then watch the animation.

5. What creates the island at the very beginning (re-run the animation if necessary)?

6. What happens with TOP SOIL and NUTRIENTS as time passes? (look at the gauges)

7. IN ORDER OF SUCCESSION, describe the sequence of ecological changes that take place on island:

8. How much TIME does this PRIMARY SUCCESSION take when temperature and rainfall are LOW?

Now set the “Temperature and Rainfall” slider to MEDIUM and then watch the animation.

9. How much TIME does this PRIMARY SUCCESSION take when temperature and rainfall are MEDIUM?

Now set the “Temperature and Rainfall” slider to HIGH and then watch the animation.

10 How much TIME does this PRIMARY SUCCESSION take when temperature and rainfall are HIGH?

Secondary Succession: Choose the tab labeled “Secondary Succession”. Click the arrow to start the fire in the forest. This will trigger SECONDARY succession.

11. How are the TOP SOIL and NUTRIENTS changing during this secondary succession?

12. What explanation can you give for why there is a difference from primary succession?

13. IN ORDER OF SUCCESSION, describe the sequence of ecological changes that take place after the fire:

14. Contrast PRIMARY and SECONDARY succession in terms of the amount of TIME it takes and the development of TOP SOIL and NUTRIENTS in the ecosystem? Give reasons why they are different.

................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download