Population Ecology: Logistic Growth Populations expand when resources such as fo
ID: 177615 • Letter: P
Question
Population Ecology: Logistic Growth
Populations expand when resources such as food, water, and shelter are abundant. Under ideal conditions, including unlimited access to food and reproduction at physical capacity, a population will increase exponentially, producing a J-shaped growth curve. However, resources are rarely unlimited, and exponential growth cannot continue indefinitely. The logistic model describes how population growth slows as the population size approaches a habitat’s carrying capacity (K).
Part A - Factors that affect K
For a hypothetical mouse population, determine whether the actions described will increase K, decrease K, or not affect K.
Drag each statement to the appropriate bin.
K increases:
K decreases:
No effect on K:
1) a main competitor for food is eliminated, increasing food availability
2) a parking lot is built, shrinking the habitat
3) offsprings live longer
4)wetlands are drained, decreasing the amount of avail water
5) an abandoned buidling creates more nesting areas
6) a species with the same food requirements is introduced
Explanation / Answer
1. a main competitor for food is eliminated, increasing food availability - K increases (Removing a limiting factor results in increase in K. Here, competitor is the limiting factor and hence, its elimination leads to an increase in K)
2) a parking lot is built, shrinking the habitat - k decreases (habitat loss causes loss of resources, increased competition for food and resources, resulting in decrease in k)
3) offsprings live longer - K not affected
4) wetlands are drained, decreasing the amount of avail water - K decreases
5) an abandoned buidling creates more nesting areas - K increases. If population colonize new habitats, K inceases.
6) a species with the same food requirements is introduced - k decreases