In which situation will primary succession most likely occur?
• Sheets of ice that once covered an area melt away, exposing a layer of rock.
• Trees in a forest ecosystem are cut down for logging.
• A small pond dries up, leaving behind moist soil.
• A disease kills off most of the plant species in an ecosystem.
Sheets of ice that once covered an area melt away, exposing a layer of rock.
Primary succession is most likely to occur in the situation where sheets of ice that once covered an area melt away, exposing a layer of rock.
To determine which situation will most likely result in primary succession, let's explain what primary succession is and then analyze each situation:
Primary succession is a process that occurs in places where no life existed previously, such as on bare rock or newly formed volcanic islands. It is characterized by the gradual establishment of plant and animal communities in an area lacking soil or organic matter. Primary succession begins with the colonization of pioneer species, such as lichens and mosses, which can grow on bare rocks and break them down to create soil. Over time, these pioneer species pave the way for the growth of larger plants, such as grasses and shrubs, and eventually trees. This process can take hundreds or even thousands of years.
Now let's consider each situation to determine where primary succession would most likely occur:
1. Sheets of ice that once covered an area melt away, exposing a layer of rock:
In this situation, primary succession is likely to occur because the exposed layer of rock lacks soil and organic matter necessary to support plant growth. Pioneer species, such as lichens and mosses, would first colonize the bare rock and gradually create soil over time.
2. Trees in a forest ecosystem are cut down for logging:
While this situation is destructive to the existing forest ecosystem, it would not necessarily result in primary succession. The forest already has existing soil and organic matter, so the regrowth of vegetation, including trees, would likely occur through secondary succession.
3. A small pond dries up, leaving behind moist soil:
In this case, secondary succession is more likely to occur rather than primary succession. Since the pond already had water and soil, the drying up would not create a bare area lacking soil or vegetation, which is a prerequisite for primary succession.
4. A disease kills off most of the plant species in an ecosystem:
This situation also refers to secondary succession rather than primary succession. The ecosystem already has soil and vegetation, and the disease would not eliminate all the plants, allowing for the regrowth of existing species or the invasion of new ones.
Therefore, the situation where primary succession is most likely to occur is when sheets of ice melt away, exposing a layer of rock.