Question

When the carrying capacity of the environment is exceeded, the population will typically a. increase, but at a slower rate. b. stabilize at the highest level reached. c. decrease. d. die off entirely.

Short answer

When the carrying capacity of an environment is exceeded, the population will typically decrease (c). This is because the scarcity of resources will lead to competition and struggle, causing the population size to reduce until it is again sustainable within the environment's carrying capacity.

Step-by-step solution

Understand the concept of carrying capacity

Carrying capacity refers to the maximum number of individuals of a species that an environment can support over a period of time. It is the tipping point at which there are not enough resources to sustain the population, leading to potential changes in the population.

Review the possible outcomes

The exercise provides four possible outcomes when the carrying capacity of an environment is exceeded: a. The population will increase, but at a slower rate. b. The population will stabilize at the highest level reached. c. The population will decrease. d. The population will die off entirely.

Apply knowledge of carrying capacity

When an environment's carrying capacity is exceeded, there will no longer be enough resources available for individuals to survive and reproduce effectively. This lack of resources will lead to competition and struggle in the population.

Identify the best outcome

Given the circumstances, the most likely outcome is: c. The population will decrease. As resources become scarce, the population will dwindle because some individuals will fail to secure the resources needed for survival and reproduction. The population size will reduce until it is again sustainable within the environment's carrying capacity. The other options can be ruled out because: a. When carrying capacity is exceeded, resources are scarce, and it is unlikely for the population to continue to increase, even at a slower rate. b. If the population stabilizes at the highest level reached, it would still be exceeding the carrying capacity, which is unsustainable long-term. d. Die-offs could happen in extreme cases, but it is more likely that the population will decrease to a sustainable size rather than disappearing entirely.

Key concepts

Population Dynamics

The study of changes in population sizes and the factors that cause these changes is known as population dynamics. It is a fundamental concept in the field of ecology, providing insights into how species interact with their environment and each other. Major factors influencing population dynamics include birth rates, death rates, immigration, and emigration.

In a stable ecosystem, these elements are in balance, allowing the population to remain relatively constant. However, if there is a disturbance, such as an ecological event or a significant change in the environment, the population may experience growth or decline.

• A population increase might occur when resources are ample and predation pressures are low.
• Conversely, a decrease is often the result of factors like food scarcity, increase in predators, or disease.

Understanding the carrying capacity is crucial as it determines the limit to which an environment can sustain a particular population size without undergoing degradation.

Environmental Resources

Environmental resources play a key role in the carrying capacity of an ecosystem. These resources include food, water, shelter, and the space required for a species to live and reproduce. When the availability of these resources is high, populations tend to grow until they reach the environment’s carrying capacity.

The concept of carrying capacity hinges on the balance of resource availability and consumption. When consumption exceeds production, the natural resources become scarce, causing a strain on the population that depends on them.

Resource Scarcity and Population Impact

As resources become scarce, individuals compete more fiercely, often leading to increased mortality. Survival and reproduction rates drop, ultimately leading to a population decline. To prevent overexploitation of environmental resources, natural checks and balances such as predator-prey relationships, diseases, and natural disasters come into play.

Population Decrease

A population decrease is often the result when an environment's carrying capacity is exceeded. This decrease can occur through a variety of mechanisms including reduced birth rates, increased death rates, or a combination of both.

Factors such as food scarcity can lead to malnutrition and starvation, reducing individuals’ health and reproductive success. With fewer offspring surviving to adulthood, the population begins to decline.

Potential Consequences

A declining population affects not just individual species but the entire ecosystem. It can lead to reduced genetic diversity and disrupting the balance of ecosystems, potentially causing cascading effects on other species. As populations diminish, the environment may eventually recover, allowing the resources to replenish, and the remaining population may stabilize at a new, lower carrying capacity.