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• Test on Ecology = Friday
• Purple Water Survey due TOMORROW
• Biomes worksheets from poster project due TODAY!!!
• Biomes “color” worksheet due TOMORROW!
• Graded papers need to be passed back.
• Still being graded:– Food Web mini lab
Population Size• Number of individuals in
a specific habitat of the same species
Ex. In Alaska, the population of dall sheep is estimated to be about 70,000.
Bell Ringer #6• Define the following terms from
section 4.1
Dispersion
Population Growth
Whether a population grow, shrinks or stays the same depends on:
1. Birth rates2. Death Rates3. Immigration – moving into a population
or community.4. Emmigration – moving out of a
population or community.Ex. Migrating caribou, migrating birds
Exponential Model
• If birth rate surpasses death rate a population will continue to increase exponentially.
• Occurs if a population goes unchecked
Logistic Model• Any factor, such as space,
that restrains the growth of a population is a limiting factor.
• All populations are ultimately limited by their environment.
• The logistic model builds an exponential model but takes into account limiting factors.
• The resources in any given habitat can support only a certain quantity of wildlife.
• As seasons change, food, water, or cover may be in short supply.
• Carrying capacity is the number of animals the habitat can support all year long.
Population Regulation
• Density-Independent factors are events that affect the growth of a population, irrelevant of the population size.
• Ex. Drought, freezes, hurricane, floods, forest fires
New Orleans after Hurricane Katrina
Turnagain Arm at Portage
• A density–dependent factor is a limiting factor triggered by increasing population density, for example a food shortage, predation, competition for light, disease, parasitism
• Can be within a species (intraspecific) or between species (interspecific)
Compare and Contrast …
Please accomplish this task with the person next to you… your partner Mrs. Thiede usually sets you up
with
Extra Time…
• You may work on your BIOME
coloring worksheet that is
due tomorrow
