Population Dynamics and Distribution

Study Notes

Population size refers to the total number of individuals in a specific area or group.
Population density is a measure of the number of individuals per unit area.
Population growth is the change in the size of a population over a period of time.
Factors influencing population growth include birth rate, death rate, immigration, and emigration.
Birth rate is the number of births per 1,000 people per year.
Death rate is the number of deaths per 1,000 people per year.
Immigration is the movement of individuals into a population.
Emigration is the movement of individuals out of a population.

Population distribution refers to the spatial arrangement of individuals within a given area.
Patterns of distribution can be random, uniform, or clumped.
Random distribution occurs when individuals are spaced out in an unpredictable pattern.
Uniform distribution occurs when individuals are spaced evenly throughout the area.
Clumped distribution occurs when individuals cluster together in specific areas.
Factors influencing population distribution include resources, biotic interactions, and environmental conditions.

Exponential growth occurs when a population increases at a constant rate.
Logistic growth occurs when a population's growth rate slows as it approaches its carrying capacity.
Carrying capacity is the maximum number of individuals that an environment can sustainably support.
The carrying capacity of an environment is influenced by factors such as the availability of resources, predation, and disease.
Factors limiting population growth are classified as either density-dependent or density-independent.
Density-dependent factors affect population size in relation to population density.
Examples include competition for resources, predation, and disease.
Density-independent factors affect population size regardless of population density.
Examples include natural disasters, climate change, and habitat destruction.

Various methods are used to estimate and monitor population size, including direct counts, sampling techniques, mark-recapture methods, and remote sensing.
Direct counts are used when the population is relatively small and accessible.
Sampling techniques are used when the population is large or difficult to access.
Mark-recapture methods involve marking individuals, releasing them, and then recapturing them to estimate population size.
Remote sensing techniques, like aerial photography or satellite imagery, can be used to monitor large populations in vast areas.

Human population growth has been significant and rapid throughout history.
Factors contributing to the increase in human population include improved sanitation, healthcare, and agriculture.
Concerns exist regarding the environmental impact of the rapidly increasing human population, such as resource depletion and pollution.
Understanding human population dynamics is important to effectively manage resources and the environment.