Bell Ringer!Do the quick write on the bottom of page 14 (Biomes page). Intestines!Also, add that your independent variables also included the heterotrophs & autotrophs for the Eco-Zones!

Nitrogen and Carbon Cycles Page 9

Cycling of Nutrients:Carbon Cycle

Cycling of Nutrients:Nitrogen Cycle

Population GrowthPage 17

How fast do populations grow?Starts slow…increases fastExponential growth = “J curve”

Population GrowthWill populations keep increasing?

No! something always runs out

Called “limiting factors”Limiting Factors- resources that limit the growth, abundance, or distribution of an organism or population of organisms in an ecosystem

Can you think of any examples?

Population GrowthTwo types of limiting factors:

Density dependent

More affected when population is largerExamples: food, water, shelter

Density independent

Does NOT matter how many are in the populationExamples: flood, tornado, etc

Population GrowthSo, how many can live in a habitat?

Carrying capacity

# of organisms environment can supportIf population goes above the CC, death rate will increase

Population Growth

Variations in Population Growth

Populations of organisms have highly variable patterns of growth

What does this data indicate

about the growth

pattern of each

population?

Growth StrategiesPopulation growth is controlled by two things:

~ Carrying capacity of environment (K)

~ Rate of reproduction (r)

r Selection:reproduction rate is more important

These organisms…Have a high growth rateTend to be in disturbed habitatsHave “Type III” curve…early lossesRapid development…short lives

K Selection:hovers near carrying capacity

These organisms…Have fewer offspringTend to be in stable habitatsHave “Type I or II” curve…constant or late lossSlower development… longer lives

r and K Strategies

Age Structures & MortalityPopulation growth is influenced by age structure within a population

Higher #s in the “reproductive ages” means more growth

Which population is growing the

fastest?

The slowest?

How do you know?

Page 12- ReflectionsWrite 5-7 sentences reflecting on what SYMBIOSIS meant to you

Write 5-7 sentences reflecting on what POPULATION GROWTH meant to you