1.
During secondary succession, which of these best describes why decomposing pioneer plants give way to larger, more complex plant species, such as hardwood trees?
Correct Answer
D. Increased amounts of soil from decomposing pioneer species allow plants with more extensive root systems to become established.
Explanation
During secondary succession, decomposing pioneer plants contribute to an increased amount of soil. This increased soil provides a favorable environment for plants with more extensive root systems to become established. These larger, more complex plant species, such as hardwood trees, require a substantial root system to support their growth and development. Therefore, the availability of more soil from decomposing pioneer species plays a crucial role in facilitating the growth of these larger plants.
2.
Biologists often recommend purposefully starting fires called prescribed burns, which are monitored and controlled Biologists observe greater diversity in plant and animal life in the years following a prescribed burn. What natural processes are biologists attempting to imitate from the burns?
Correct Answer
C. Succession
Explanation
Biologists are attempting to imitate the natural process of succession through prescribed burns. Succession refers to the gradual and predictable changes in plant and animal communities over time. By starting fires, biologists mimic the disturbance that occurs in natural ecosystems, which promotes the growth of pioneer species and allows for the establishment of a more diverse plant and animal community. This process helps to maintain a healthy and balanced ecosystem.
3.
What do biologists hope to gain from prescribed burns?
Correct Answer(s)
A. Reduce forest fires
C. Restore nutrients
D. Create more desirable plant growth
Explanation
Biologists hope to gain multiple benefits from prescribed burns. Firstly, by reducing forest fires through controlled burns, they can prevent uncontrolled wildfires that can cause significant damage to ecosystems. Secondly, prescribed burns help restore nutrients to the soil by breaking down organic matter and releasing nutrients back into the ecosystem. Lastly, these burns create more desirable plant growth by promoting the growth of fire-adapted species and reducing competition from invasive plants.
4.
Which statement best describes the differences in species diversity between an ecosystem beginning the process of primary succession and one beginning the process of secondary succession?
Correct Answer
D. Species diversity is greater in the ecosystem undergoing secondary succession because the soil already contains seeds and spores of various species.
Explanation
In the process of primary succession, the ecosystem starts from bare rock or barren land, where there is no soil or living organisms. This lack of soil limits the availability of nutrients and resources, resulting in a lower species diversity. On the other hand, in secondary succession, the ecosystem begins with existing soil that already contains seeds and spores of various species. This soil provides a suitable environment for the growth of a wider range of organisms, leading to a greater species diversity compared to primary succession.
5.
What geological event is most likely the cause of the changes in species diversity in the ecosystem shown on the graph?
Correct Answer
A. Volcano
Explanation
The most likely cause of the changes in species diversity in the ecosystem shown on the graph is a volcano. Volcanic eruptions can have a significant impact on the surrounding environment, including altering the physical landscape, destroying habitats, and releasing gases and ash that can affect the survival of different species. This can lead to changes in the composition and diversity of the ecosystem as some species may thrive in the new conditions while others may struggle to survive.
6.
What are the two types of ecological succession?
Correct Answer(s)
A. Primary
B. Secondary
Explanation
Ecological succession refers to the process of change in the structure and composition of a community over time. Primary succession occurs in areas where no soil or organisms exist, such as after a volcanic eruption, and involves the colonization of pioneer species and the gradual development of a stable community. Secondary succession, on the other hand, occurs in areas where soil and organisms still remain, such as after a forest fire, and involves the reestablishment of a community that was previously present. Therefore, the correct answer is primary and secondary.
7.
When an area is burned in a forest fire, and then plants and animals begin to return to the burned area, this is called
Correct Answer
B. Secondary succession
Explanation
Secondary succession refers to the process of ecological succession that occurs in an area that has been previously disturbed or destroyed by a disturbance such as a forest fire. After the fire, the area is left barren and devoid of life. However, over time, plants and animals gradually colonize the area, starting with pioneer species that are able to tolerate harsh conditions. As these pioneer species establish themselves, they create a more favorable environment for other species to colonize the area. This gradual recolonization and establishment of a new community is known as secondary succession.
8.
What makes primary succession different than secondary succession is the presence of soil.
Correct Answer
B. False
Explanation
Primary succession is different from secondary succession because primary succession occurs in an area where there is no soil present, such as after a volcanic eruption or on newly formed land. In primary succession, pioneer species, such as lichens and mosses, begin the process of soil formation by breaking down rocks and organic matter. Over time, as the pioneer species die and decompose, they contribute to the development of soil, which allows other plant species to colonize the area. In contrast, secondary succession occurs in an area where soil is already present, such as after a forest fire or a clear-cutting of land.
9.
What does secondary succession have that primary succession does not have?
Correct Answer
soil
Explanation
Secondary succession has soil, while primary succession does not have soil. In primary succession, the process starts on barren land where there is no pre-existing soil. Over time, through the weathering of rocks and the accumulation of organic matter from pioneer plants, soil gradually develops. In secondary succession, on the other hand, the process occurs on land that has been previously inhabited by plants, meaning that soil is already present. This allows for a quicker establishment of vegetation and a faster recovery of the ecosystem compared to primary succession.
10.
What kind of succession occurs following the disruption of an existing ecosystem?
Correct Answer
secondary
Explanation
Secondary succession occurs following the disruption of an existing ecosystem. This type of succession takes place when an ecosystem is disturbed or destroyed, but the soil is still intact. It involves the reestablishment of plant and animal communities in an area that was previously inhabited. In secondary succession, the process starts with pioneer species, which are the first organisms to colonize the disturbed area. Over time, these pioneer species are replaced by more complex and diverse plant and animal species.
11.
During ecological succession, when are pioneer species found?
Correct Answer
A. During the early stages of succession
Explanation
Pioneer species are the first organisms to colonize a newly formed or disturbed habitat. They are able to thrive in harsh conditions and are often characterized by their ability to tolerate extreme temperatures, low nutrient levels, and lack of soil. As ecological succession progresses, the habitat becomes more stable and conditions become more favorable for other, more specialized species to establish themselves. Therefore, pioneer species are typically found during the early stages of succession when the habitat is still undergoing significant changes and is not yet suitable for other organisms.