In this unit you will learn about how to:

Analyze how ecosystems differ from each other due to abiotic and biotic

factors.

LIVING THINGS LIVING THINGS AND THE AND THE

ENVIRONMENTENVIRONMENT

A prairie dog is one type of organism.

Each organism must live in a specific type of

environment.An organism obtains

food, water, shelter, and things it needs to live, grow, and reproduce from its environment.

An environment that provides the things the organism needs to live, grow and reproduce is

called its habitat.

An organism interacts with both the living and nonliving

parts of its habitat.

The living parts of a habitat are called ____________.biotic factors

The nonliving parts of an organism’s habitat are called

____________.abiotic factors

Abiotic factors include:

-water -sunlight -oxygen-temperature-soil

ECOLOGICAL ORGANIZATION

Organism(prairie

dog)

Population(prairie

dog town)

Community (all the living things that interact on the

prairie)

Ecosystem (all the living and nonliving

things that interact on the prairie)

CHANGES IN POPULATION

SIZEPopulation can change in size when new members join the population or when members leave the population.BIRTH RATE:

The number of births in a population in a certain amount of time.

DEATH RATE:The number of deaths in a population in a certain amount of time.

CHANGES IN POPULATION

SIZEIf birth rate > death rate =

If death rate > birth rate =

Population

increases

Population

decreasesIf death rate = birth rate

=

PopulationStays the

same

POPULATION DENSITY

- The number of individuals in a specific area.

What is the formula to calculate population density?

Population Density = Number of individuals_____________ Unit Area

Calculate the population density of flamingos.

Population

Density

10 flamingos___________8 square meters

= 1.25 Flamingos/square meter

=

Calculate the population density of flamingos.

PopulationDensity

=20 flamingos___________8 square meters

= 2.5 Flamingos/Square meter

The largest population an area can support is called its

____________.carrying capacity

The carrying capacity of a population is determined by limiting factors. Limiting factor:

An environmental factor that causes a population to decrease.

food

water

space

weather conditions