Question

Growth of a forest in an abandoned corn field is an example of _____. a. primary succession c. secondary succession b. resource partitioning d. competitive exclusion

Short answer

Secondary succession.

Step-by-step solution

Define Primary Succession

Primary succession occurs in lifeless areas where there is no soil or where the soil is incapable of sustaining life. It begins with the colonization of a new or barren habitat, such as volcanic islands or glaciated areas.

Define Secondary Succession

Secondary succession takes place in areas where an ecosystem has previously existed but has been removed by disturbances like fires, hurricanes, or human activities. The soil is already present, which allows for quicker colonization of plants and return of the ecosystem.

Define Resource Partitioning and Competitive Exclusion

Resource partitioning involves species dividing resources to avoid competition, whereas competitive exclusion refers to the principle that two species competing for the same resources cannot coexist at constant population values.

Analyze the Scenario

The scenario involves a cornfield that previously existed, indicating that there is already soil present. The field is transitioning into a forest, suggesting the return or change of an ecosystem.

Conclusion and Final Answer

Given that the area was previously a cornfield, the soil is already prepared, making the process secondary succession, as it doesn't involve creating soil from bare rock or a completely new barren habitat.

Key concepts

Primary Succession

In the natural world, primary succession is a remarkable process representing the start of life in a barren area. It occurs in places where no ecosystem existed previously and where the soil is either absent or incapable of supporting life initially. Such environments may include a newly formed volcanic island or land exposed by a retreating glacier. In these places, the succession begins with pioneering species, often lichens or mosses. These organisms can survive harsh conditions and start the gradual process of soil formation.

Once the soil begins to form, it allows for other plants and animals to establish themselves. Over time, the environment gradually transitions from these simple beginnings to complex ecosystems capable of supporting various life forms. Primary succession is incredibly slow, sometimes taking hundreds or thousands of years, but it highlights nature's resilience and ability to build life from almost nothing. Primary succession is a critical initial step in developing any ecosystem from a lifeless starting point.

Resource Partitioning

Resource partitioning is a fascinating ecological strategy allowing multiple species to coexist in the same environment. In ecosystems, resources such as food, water, and space might be limited, leading to competition among organisms. However, through resource partitioning, species evolve to exploit different aspects or times of the available resource, thereby minimizing competition.

For instance, one bird species might feed on insects in the upper canopy of a tree, while another might focus on insects found at the tree's base. This division not only alleviates direct competition but also can lead to greater biodiversity, as more species can thrive in the same habitat. By adapting to different niches within the same environment, species manage to reduce overlap in their usage of resources, leading to a more harmonious coexistence.

Competitive Exclusion

The competitive exclusion principle is a fundamental ecological concept describing how two species competing for identical resources cannot sustain stable populations together. Essentially, if two species vie for the same limited resource within an ecosystem, one will invariably have a slight advantage over the other. This advantage could be due to differences in reproduction, growth rate, or ability to obtain resources effectively.

Over time, this leads to the exclusion of the less adapted species from that specific niche. For example, if two species of bacteria are competing for the same nutrient, the one that can consume the nutrient more efficiently will outcompete the other.

Competitive exclusion underscores the importance of niche differentiation in nature, which involves species evolving unique adaptations to utilize resources differently. This principle underscores why biodiversity is crucial for stability in ecosystems, allowing various species to adapt and find niches that reduce direct head-to-head competition.