Population dynamics

Population Dynamics

Understanding Population

  • A population refers to all the individuals of a species living in a specific area at a given time.
  • It is important to understand the concept of a species - a group of similar living organisms that can interbreed and produce fertile offspring.

Growth of Populations

  • Populations grow as a result of birth (natality) and immigration (movement into an area).
  • The population decreases due to death (mortality) and emigration (movement out of an area).
  • When birth and immigration is greater than death and emigration, the population increases, and vice versa.

Density Dependent Factors

  • Density dependent factors are environmental influences that have a greater effect when a population is large or dense.
  • These factors can regulate population growth and include competition, predation, disease, and resource availability.

Density Independent Factors

  • Density independent factors are usually physical or abiotic factors like temperature, storms, floods, and pollution that influence population growth regardless of population density.

Carrying Capacity

  • Carrying capacity refers to the maximum number of individuals of a species that a particular environment can sustain indefinitely.
  • Overshooting the carrying capacity leads to population crash due to exhaustion of resources and increase in competition, predation, and disease.

Population Structures

  • Populations are structured according to age, sex, and reproductive status in what is known as a population pyramid.
  • The pyramid is used to predict the future growth of a population.

Intraspecific and Interspecific Competition

  • Intraspecific competition occurs between members of the same species competing for the same resources in an ecosystem.
  • Interspecific competition occurs between different species competing for the same resources.

Predator Prey Relationships

  • Predator prey relationships are a crucial aspect of population dynamics, often leading to cyclic fluctuations in both predator and prey populations due to impacts on reproductive success and mortality rates.