Which of the following growth curves shows a population that is at its carrying capacity?
A.
B
B.
C
C.
A
D.
D
The Correct Answer and Explanation is:
The correct answer is D. D.
Explanation:
In ecology, the concept of carrying capacity refers to the maximum population size that an environment can sustain indefinitely without being degraded. This concept is crucial in understanding population dynamics and how various factors influence the growth of a population.
Growth Curves Overview:
- Exponential Growth Curve (Curve A): This curve represents unchecked or unlimited population growth. It shows a J-shaped trajectory where the population size increases rapidly over time. This type of growth occurs when resources are abundant and environmental resistance is minimal. However, exponential growth cannot continue indefinitely in natural systems due to limitations like food, space, and other resources.
- Logistic Growth Curve (Curve B): This curve illustrates population growth that is limited by the carrying capacity of the environment. It starts with exponential growth but slows as the population size approaches the environment’s carrying capacity. Eventually, the growth rate stabilizes, and the population size fluctuates around the carrying capacity, represented by an S-shaped curve. This is a more realistic model for many natural populations, where growth slows as resources become scarcer.
- Overshoot and Collapse Curve (Curve C): This curve depicts a population that exceeds its carrying capacity (overshoot) and then experiences a sharp decline in size (collapse) due to overuse of resources. It represents a scenario where the population temporarily exceeds the environment’s capacity to support it, leading to a crash or significant reduction in population size.
- Stable at Carrying Capacity (Curve D): This curve shows a population that has stabilized at its carrying capacity. The population size remains relatively constant over time, oscillating around the carrying capacity of the environment. This indicates a balance between the birth rate and death rate and that the population is being supported at the maximum sustainable level by the available resources.
In summary, Curve D best represents a population that is at its carrying capacity, as it illustrates a stable population size that fluctuates around the carrying capacity without significant long-term growth or decline.