1. 180 170 160 150 140130120 110100 90 80 7060504030 20 1098765432 1 0 This screen will disappear in 3 minutes. Seconds Remaining. What is ecological succession?

2. The gradual change of the type of species that line in an area.

3. 180 170 160 150 140130120 110100 90 80 7060504030 20 1098765432 1 0 This screen will disappear in 3 minutes. Seconds Remaining. Explain the difference between primary and secondary succession.

4. Primary succession begins on rock. Secondary succession begin on soil.

5. 180 170 160 150 140130120 110100 90 80 7060504030 20 1098765432 1 0 This screen will disappear in 3 minutes. Seconds Remaining. What is the difference between pioneer species and climax communities ?

6. Pioneer species are the first species that settle or colonize an area. Climax communities are made of species that are stable and don’t change very much.

7. 180 170 160 150 140130120 110100 90 80 7060504030 20 1098765432 1 0 This screen will disappear in 3 minutes. Seconds Remaining. Rosie heard about an ecosystem that was a climax forest community before a devastating fire occurred 50 years ago. She wants to know if the forest is again a climax community, so she makes some observations about the ecosystem. – Explain what is meant by a climax community. – Describe three observations that would indicate that the forest Rosie is observing has been restored to equilibrium.

8. A climax community is the last stage in succession, a stage where an ecosystem reaches a stable state. It is a mature ecosystem. One clue is that a wide variety of plants have had time to move into the area. There could be grasses, shrubs, mosses, and other plants. Another clue to look for is mature trees. These are the last type of plants to move into an area. The rate of change in species is also a clue. Climax communities are stable. So, there should be little if any change in the mix of species.

9. 180 170 160 150 140130120 110100 90 80 7060504030 20 1098765432 1 0 This screen will disappear in 3 minutes. Seconds Remaining. A large area of bare rock becomes exposed by a glacier that has retreated. – Describe the changes that occur in the organisms living in the area as the bare rock area is transformed into a forest over time in four distinct steps. Each step you describe should include the organisms that live in the area and how those organisms change over time.

10. The process begins when a pioneer species, such as lichens, colonize the rock. Lichens can grow in areas that lack nutrients and are exposed to harsh conditions. The growth of lichens attracts microscopic plants and animals. The lichens produce materials that dissolve the surface of the rock, thereby beginning the process in which soil forms. Eventually, the lichens die. As they decompose, they add nutrients to the soil. As the soil builds up, organisms such as bacteria, mosses, worms, and insects can inhabit the region. Eventually the soil is able to support small plants, such as weeds and plants that die after one growing season (annuals). These small plants crowd out and replace the moss and pioneer communities. In time, the small plants die. As they decay, the soil layer becomes thicker and richer in nutrients. This makes it able to support grasses, woody shrubs, and plants that live many years (perennials). In time, the shrubs crowd out the grasses. Eventually, trees take root and crowd out the shrubs. Over the course of many years, the bare rock has been transformed into a forest. Many different types of animals live in the forest. The organisms of the forest make up a stable climax community, which can exist for many years.

11. Diagram the stages of primary succession. 180 170 160 150 140130120 110100 90 7060504030 20 1098765432 1 0 This screen will disappear in 3 minutes. Seconds Remaining.