Chapters 2-3: Zones of Tolerance and Ecological Succession

What kind of ecosystem does secondary succession occur in?

Started by an event (e.g. forest fire, harvesting, hurricane) that reduces an already established ecosystem (e.g. a forest or a wheat field) to a smaller population of species, and as such secondary succession occurs on preexisting soil ...

What causes one community to replace another during succession?

The previous community is out competed by the new community for resources and stats

How long does primary succession take?

100-1000 Years

How long does secondary succession take?

About 100 Years

What is an example of a pioneer species?

After the lava cooled and hardened, it would be very difficult for plants to survive, because of the lack of soil. Pictures: - They are the first to colonize in a area. - The first species are the first stages of ecological succession. -Common pioneer species include bacteria , fungi, and lichens.

How does the process of primary succession occur from start to finish?

Begins in barren areas, such as on bare rock exposed by a retreating glacier. The first inhabitants are lichens or plants—those that can survive in such an environment. Over hundreds of years these "pioneer species" convert the rock into soil that can support simple plants such as grasses. These grasses further modify the soil, which is then colonized by other types of plants. Each successive stage modifies the habitat by altering the amount of shade and the composition of the soil. The final stage of succession is a climax community, which is a very stable stage that can endure for hundreds of years.

What is a pioneer species?

First species to colonize an ecosystem: lichens, moss

Where are the zones of physiological stress and how much life do you find there?

Low population of life (closes to middle)

Where are the zones of intolerance and how much life do you find there?

No population (Beginning and Ending of Diagram)

Where is the optimum zone found in the diagram and how much life do you find there?

Optimum Zone (Middle)

What type of succession is this?

Primary Succession

What kind of ecosystem does primary succession occur in?

Primary succession occurs in essentially lifeless areas—regions in which the soil is incapable of sustaining life as a result of such factors as lava flows, newly formed sand dunes, or rocks left from a retreating...

What type of succession is this?

Secondary Succession

What is the difference between the upper and lower limits on the diagram?

The upper limits have high tolerance and lower has low tolerance

How does the process of secondary succession occur from start to finish?

secondary succession is a process started by an event (e.g. forest fire, harvesting, hurricane) that reduces an already established ecosystem (e.g. a forest or a wheat field) to a smaller population of species, and as such secondary succession occurs on preexisting soil whereas primary succession usually occurs in a place lacking soil.