Population Growth Curves

Population Growth Curve

1. Exponential Stage

2. Transition Phase

3. Plateau Phase

What occurs during the Exponential Stage of population growth?

Limiting factors are not restricting population growth

With low or reduced limiting factors what can the population do?

Expand exponentially into the habitat

What characterizes the Transition Phase of population growth?

The increase in population number begins to slow due to limiting factors affecting growth.

What are some examples of these limiting factors that restrict a populations growth?

Increased competition, predators, rate of disease and moratlity

What does the Plateau Phase represent in population growth?

It indicates that limiting factors restrict the population to its carrying capacity.

What do changes in limiting factors cause populations to do?

Fluctuate (increase and decrease) around the carrying capacity

What are the four main factors that affect population growth?

Natality, Immigration, Mortality, and Emigration.

Natality

Increases the population size through reproduction

Immigration

Increases the population size from external populations

Mortality

Decreases the population size as a result of deaths

Emigration

Decreases the population size as a result of loss to external populations

How is Population Size calculated?

Population Size = (Natality + Immigration) - (Mortality + Emigration).

What does it mean when I + N > E + M?

It indicates population growth.

What indicates Population Stability in terms of population factors?

I + N = E + M.

What does I + N < E + M indicate about a population?

It signifies a population decline.