Finish Your Levels of OrganizationPyramid:Remember eachLayer is based on size

Quiz

1. What basic needs are provided by an organisms habitat?

2. List these terms in order from smallest unit to largest:

Population, organism, ecosystem, community3. Why do ecologist study biotic and abiotic factors in an ecosystem.4. Would all the insects of a forest be consisdered a population? Why / why not?5. List two abiotic factors?

Populations

Fold your paper“hotdog” Right to left

Direct Observation

Indirect Observation

Sampling

Mark and Recapture Studies

Direct ObservationMost obvious means of determining size is to count one by one.

Indirect Observation

~ Sometimes organisms are too small or too hard to find.~ Observing their tracks or other signs rather than counting.

Sampling

Most cases there are too many organisms in an are to count.Take a set area, estimate the number in the area and multiply by the number of areas.

Count 8 red maples in a 10 meter by-10-meter area of the forest. If the entire forest were 100x that size, you would mulitply your count by 100 to estimate total population, 800 red maples.

Mark and recapture

Catch a group of animals – tag themCatch a second group of animals –tag them

Changes In Population Size

Births and Deaths

Population Equation

Immigration and Emigration

Graphing Changes in Population

Populations can change in size when new members enter the population or when members leave the population

Births and Deaths

Birth rate of a population is the number of births in a population in a certain amount of time.

Death rate is the number of deaths in a certain amount of time.

The population Equation

If birth rate > death rate, population size increases

If death rate is > birth rate, population size decreases

Immigration and emigration

• Immigration means moving into a population

• Emigration means leaving a population

Graphing changes in population

Limiting Factors

Food

space

Weather

Limiting factor is an environmental factor that prevents a population from increasing.

Food

Limiting factor when food become scarce.

No matter how much shelter, water and other resources are found, population will not grow without right amount of food.

Space

Space is often a limiting factor of population because there is not enough room to repopulate

Weather

Weather conditions such as temperature and amount of rainfall can also limit population growth.

Watch this videohttp

://www.learner.org/courses/envsci/unit/text.php?unit=4&secNum=1

Watch this video: summarize in one paragraph what its teaching:

http://studyjams.scholastic.com/studyjams/jams/science/ecosystems/ecosystems.htm

Watch this video: summarize in one paragraph what it is teaching (make sure to describe the difference between

secondary and primary succession)http://studyjams.scholastic.com/studyjams/jams/science/ecosystems/changes-ecosystems.htm Click on Ecosystem Terms / Ecosystem Quiz write the vocabulary word and definition• http://www.neok12.com/Ecosystems.htm