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Section 1.2 NOTES. Studying Populations. II A. DETERMINING POPULATION SIZE : How do you determine the population size of a species? 1. Direct Observation 2. Indirect Observation 3. Sampling 4. Mark and Recapture. II A. Match The Methods.
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Section 1.2 NOTES Studying Populations
II A. DETERMINING POPULATION SIZE: How do you determine the population size of a species? 1. Direct Observation 2. Indirect Observation 3. Sampling 4. Mark and Recapture
II A. Match The Methods Counting Individual organisms Indirect Observation Counting organisms in a small sample then projectting to a larger, similar area Mark and Recapture Locating nests and estimating organisms per nest Sampling Capturing, Marking, then recapturing And using the frequency of recapturing Direct Observation To determine Population Size
II B. Changes in Population Sizes • When New Members Join or Leave a Population • Birth and Death Rates • The Population Statement • Immigration and Emigration • Graphing Changes in Population • Population Density
Births and Deaths • Births = additions, Deaths = subtractions • The Population Statement • Birth Rate > Death Rate = Population increases • Birth Rate < Death Rate = Population decreases • Immigration and Emigration • Individuals moving INTO a population • Individuals moving OUT of a population • Graphing Changes in Population • Population Density • Number of individuals / Unit area
Thomas Austin of England introduced introduced 24 breeding rabbits in October 1859 as game for shooting parties… BIG MISTAKE!
Population Density • The number of individuals in an area of a specific size • Population growth and resulting higher population density is often argued to lead to increased stress on water and natural resources, decreased food security.
II C. Limiting Factors (abiotic resources) • Environmental factor that causes a population to decrease • Food and Water • Space • Carrying Capacity • The largest population that an area can support. • Weather
Carrying Capacity is the largest population an area can support.
Section 1.3 NOTES Interactions Among Living Things