Lecture 8Population Dynamics II

Question 1

• Carrying capacity

Answer 1

The maximum population size of the species that the environment can sustain indefinitely

Question 2

• Ecological density

Answer 2

number of individuals per unit of suitable habitat

Question 3

• Harvestable surplus

Answer 3

Number of individuals that can be harvested from the population without affecting its long-term stability

Question 4

1. Describe what is expected to change as a population reaches its carrying capacity.

Answer 4

As a population reaches its carrying capacity, several changes are expected, including increased environmental resistance due to lower resource availability, a decrease in birth rates alongside an increase in mortality rates, individuals being in worse health condition, and a decline in habitat quality. These factors together may reduce the carrying capacity itself, indicating a self-regulating mechanism of population size to align with the available resources and environmental conditions.

Question 5

2. Explain why using population size relative to the measured carrying capacity may not allow a projection of how a population changes from one year to the next.

Answer 5

ChatGPT
The document explains that using population size relative to the measured carrying capacity may not allow for accurate year-to-year population change projections due to the inherent complexity of ecosystems and the dynamic nature of carrying capacity. Factors such as environmental changes, resource availability, and interactions within the population can cause fluctuations in the carrying capacity itself. These variables introduce uncertainty and make it difficult to predict population dynamics solely based on current size and carrying capacity estimates.

Question 6

3. Describe how a population manager could reduce the ecological density of a population.

Answer 6

A population manager can reduce the ecological density of a population by implementing strategies that increase the availability of resources or reduce the population size. This could involve habitat management to enhance resource availability, such as food and shelter, thus supporting a larger population at a lower ecological density. Alternatively, direct population control measures like culling, relocation, or fertility control can decrease the number of individuals competing for the same resources, effectively reducing ecological density.

Question 7

4. Compare species with high biotic potential to species with low biotic potential in their population characteristics, and in the importance of management of these species.

Answer 7

ChatGPT
Species with high biotic potential tend to reproduce quickly, have large numbers of offspring, and can rapidly adapt to changing environments, which can lead to swift population growth under favorable conditions. These species often require active management to prevent overpopulation and the resultant ecological imbalances. In contrast, species with low biotic potential reproduce more slowly, have fewer offspring, and may struggle to adapt to rapid environmental changes. Management efforts for these species typically focus on conservation and protection measures to ensure their survival and maintain ecosystem diversity. The management importance lies in preventing the overexploitation or decline of species with low biotic potential and controlling or managing populations of species with high biotic potential to avoid ecological damage.