Question

1. explain what it means when we describe an ecosystem as being in equilibrium. k/u
2. distinguish between primary and secondary succession. k/u
3. explain which type of succession occurs most often and why. k/u
4. describe how biotic and abiotic conditions change during secondary succession. k/u
5. from your own experience, list two examples of secondary succession. a

Explanation:

1. An ecosystem in equilibrium means the populations of organisms and the physical - chemical conditions remain relatively stable over time. There is a balance between birth and death rates, and inputs and outputs of energy and matter.
2. Primary succession occurs in an area with no previous soil or life, like a newly formed volcanic island. Secondary succession happens in an area where soil and some life already exist, such as after a forest fire.
3. Secondary succession occurs most often because disturbances like wild - fires, floods, and human activities (logging, agriculture) are common and often leave behind soil and some residual life, which allows for a faster recovery of the ecosystem.
4. During secondary succession, biotic conditions change as pioneer species (like grasses) are replaced by more complex plants and animals over time. Abiotic conditions also change; for example, soil quality improves as organic matter accumulates, and microclimates may develop as vegetation cover changes.
5. Examples of secondary succession: A field that is abandoned and over time is colonized by weeds, then shrubs, and eventually small trees. Another example is a forest area after a small - scale logging operation, where new plants start to grow and animals return.

Answer:

1. An ecosystem in equilibrium has stable populations and physical - chemical conditions.
2. Primary succession starts in a lifeless area with no soil; secondary succession in an area with soil and some life.
3. Secondary succession occurs most often due to common disturbances leaving soil and residual life.
4. Biotic: pioneer species are replaced; Abiotic: soil quality and microclimates change.
5. Abandoned field succession; Succession after small - scale logging.