Population Graphs What is a population A population

What is a population? A population is a group of members of the same

Carrying Capacity Most ecosystems have a limited amount of resources available to the organisms

Limiting Factors Limiting factors are the factors that will prevent a population from growing

Limiting Factors Some examples of limiting factors are: Oxygen availability Food supply Diseases Weather

Limiting Factors There are 2 types of limiting factors: a) Abiotic – factors such

Limiting Factors b) Biotic factors – factors such as the availability of food, predators,

Population Graphs P o p ul a ti o n n u m b

Population Graphs Populations grow in common ways. When a population begins in an area,

Population Graphs Once a population reaches a certain size, it begins to grow more

Population Graphs At a certain point, the population may begin to be affected by

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Population Graphs

What is a population? A population is a group of members of the same species that live in the same area. If enough resources are available (like space, food, oxygen, water, shelter), a population could grow very large.

Human Population Growth

Carrying Capacity Most ecosystems have a limited amount of resources available to the organisms that live there, so it can only sustain a population of a certain size. The largest population that can be sustained by an ecosystem is called the carrying capacity.

Limiting Factors Limiting factors are the factors that will prevent a population from growing uncontrollably. These factors control the carrying capacity of a population. Most ecosystems are affected by the same limiting factors.

Limiting Factors Some examples of limiting factors are: Oxygen availability Food supply Diseases Weather Space availability Competition Parasites Sunlight availability Predators

Limiting Factors There are 2 types of limiting factors: a) Abiotic – factors such as availability of light, temperature, chemicals in the environment (hazardous and beneficial)

Limiting Factors b) Biotic factors – factors such as the availability of food, predators, diseases, parasites, competition for resources.

Population Graphs P o p ul a ti o n n u m b e r A B C Time

Population Graphs Populations grow in common ways. When a population begins in an area, it starts out small. It takes a period of time for a population to increase. The period of slow growth is represented by letter A in the graph.

Population Graphs Once a population reaches a certain size, it begins to grow more quickly. If the resources needed by the population are readily available, the population will show a period of rapid growth, as is seen in part B on the graph.

Population Graphs At a certain point, the population may begin to be affected by limiting factors. The population will begin to level off and slightly fluctuate around a set number. This is what section C on the population graph shows. At this point, we say the population reaches equilibrium at the carrying capacity.