Population Dynamics

Any ecosystem can only sustain a certain number of organisms for a given population The number of individuals that are living in a defined area is known as the population density

Clumped dispersion Uniform Random Geographic dispersion of a population shows how individuals in a population are spaced.

Geographic Dispersion There are 3 types of geographic Dispersion 1) Clumped 2) Uniform 3) Random

In any given ecosystem, there are only enough resources for a certain number of organisms to survive. The carrying capacity is maximum stable population size that an environment can support The change in the population size is known as the growth rate Can be positive, negative, or zero

If a population is provided with ideal conditions (no restrictions), healthy organisms will reproduce at a rate greater than their death rate. As long as the conditions are maintained, the rate of growth will increase as the population grows larger. This is called exponential growth Produces a J shaped curve

However, as a population’s size increases, resources become limited, and the growth of the population slows and begins to stabilize. This is called logistic growth Produces a S shaped curve

Carrying Capacity Graph

Once a population has reached its carrying capacity, two types of limiting factors help to stabilize the size Density-Dependent Limiting Factors Competition, Predation, Parasitism, Crowding/Stress Density-Independent Limiting Factors Weather, Fires, Droughts/Floods, Human Activities

Two of the most basic factors that affect the rate of population growth rate are: Birth rate Death rate