Warm-up What is one fact about your biome you remember from the research on your biome?

What if humans suddenly went extinct?  w9fKhD0

Succession intro activity  What would happen if the SAHS football field was abandoned?  Draw pictures (using color) to show what the field might look like in the future…10 years…25…50…100 years down the road.

Ch. 3 Communities & Biomes

Succession  Series of predictable changes that occurs in a community over time

Primary Succession  The 1 st stage  On land where there are no living organisms.  Pioneer Species: 1 st species to populate the area

Secondary Succession  When a disturbance changes the existing community, things must grow again  Ex. Land is cleared for farming, then abandoned, trees begin to grow again

Biomes  Complex of terrestrial community that covers a large area  Has a certain soil & climate  Has particular plant & animals

Warm-Up An uncut lawn becomes a meadow and eventually a forest. This process is an example of ___________. A.Primary Succession B.Secondary Succession C.Limiting Factor D.Tundra

Biome Presentations Respect every group. I will deduct points from your entire group if you talk or interrupt other presentations. Write one fact from each presentation to turn in. Relax (not all of you) and have fun while you are PRESENTING but take notes while you watch.

Ch. 4: Populations

Characteristics of Populations  Geographic Distribution  Density  Growth rate

Factors that Affect Population Growth  # of Births  # of Deaths  # of individuals that enter or leave the population.

Exponential Growth  Individuals reproduce at a constant rate  Unlimited growth  J shaped curve

Logistic Growth  As resources become less available, the growth of a population slows or stops  Carrying capacity: The largest number of individuals that an environment can support.  S shaped curve Number of Yeast Cells Time (hours) Carrying capacity

represented bycharacterized by represented by which cause a Population Growth can be Exponential growth Logistic growth Falling growth rate S-shaped curve Limits on growth No limits on growth J-shaped curve Constant growth rate Unlimited resources Section 5-1 Concept Map

Limiting Factors  A factor that causes population growth to decrease.  Nutrients, competition, predation, parasitism, water, humans

Density Dependent Factors  Depend on population size  Competition, predation, parasitism, disease

How do increases and decreases in the moose population affect the wolf population? MooseWolves

Density Independent Factors  Affect all populations in similar ways (do not depend on size)  Weather, Seasons, Natural Disasters, Human Activities

Human Population Growth  Until about 500 years ago, the world’s human population remained fairly stable. Then, as advances in medicine, agriculture, and technology occurred, the human population began growing very rapidly. Today, the world’s human population is greater than 6 billion people, and it continues to grow, but at a slower rate.

Human Population Growth Agriculture begins Plowing and irrigation Bubonic plague Industrial Revolution begins

Age Distribution U.S. PopulationRwandan Population Males Females

 The human population is increasing by about 1.4% each year. If the population is 6 billion (6,000,000,000) this year. How large will the population be next year?  6,000,000,000 X = 84,000,000 people, so the population would be 6,084,000,000 people.  If the human population continues to grow at a rate of 1.4 percent per year, the population would double in size (to 12 billion people) in only 51 years!

What effect might this increase in population have on the environment and on other people?

 What will happen when humans reach their carrying capacity on Earth?  What do you think the carrying capacity of humans on the Earth is?