Final answer:
To calculate the population growth rate, use the equation r = (b + i) - (d + e), where 'b' stands for birth rate, 'd' for death rate, 'i' for immigration, and 'e' for emigration. This equation helps us understand whether a population is increasing or decreasing in size and the overall health of that population.
Step-by-step explanation:
Population Growth Rate and Population Change
The population growth rate (r) determines how a population's size changes over time and can be influenced by both natural factors (births and deaths) and migratory patterns (immigration and emigration). To calculate this rate, you use the demographic equation:
r = (b + i) - (d + e)
Where:
- b is the birth rate
- d is the death rate
- i is the rate of immigration
- e is the rate of emigration
When birth rates are higher than death rates and the rate of immigration exceeds emigration, the population is likely to grow. Conversely, if death rates and emigration surpass births and immigration, the population decreases. It's important to note that populations showing exponential growth have abundant resources such as food and moisture, while those with limited resources may reflect a different growth pattern.
Understanding these dynamics provides insight into the health and future trends of a population. For example, a population with a high birth rate and low death rate is generally healthy and growing, while an equal birth and death rate indicates a stable population size.