AP Environmental Review Caroline, Kristina, Lauren, Gwen, Colby

 All members of a species inhabiting a specific geographic area (at a time)  Size dictated by  Emigration  Immigration  Birth  Death

 “Geometric” growth  J-shaped Curve  Starts slowly but then accelerates with population increase

 S-shaped Curve  Begins exponential  Environmental resistance comes into play  Growth slows to accommodate carrying capacity (K)

 Maximum number of species which may survive together at a given time  Determined by resources and biotic potential  Exceeding leads to a dieback or crash

 How a population might grow without presence of environmental resistance (limiting factors)  Density - independent  Exponential

 Early reproduction  Large bounties of offspring  accounts for high instance of death  Little care provided  Generally lower tropic levels

 Reproduce later in life  Few offspring  Large energy input for care  More prone to extinction  More specialized

 Show the number/proportion of group individuals surviving at specific ages  Reflection of reproductive strategies  I. Late loss: K-strategist that produce few young and care for them until they reach reproductive age, reducing juvenile mortality.  II. Constant loss: Intermediate reproductive strategist with fairly constant mortality.  III. Early loss: r- strategists with high infant mortality

 Total Fertility Rate (TFR)  Average offspring a woman will have in her lifetime  Replacement Fertility Rate  Number of children which must be born to replace those creating them

 The ultimate goal of a population  Occurs at two phases  When both rates (birth/death) are equally high  When both are equally low (birth+ immigration)= (death+ emigration)

 Rapid Growth  Appears “bottom-heavy”  Large portion of population which will soon move to the reproductive stage  Slow Growth  General evenness with growth  Negative Growth  Large portion of population post-reproductive  Small portion to move into reproductive

 Societal change in birth and death rates  Both change as industrialization develops

 Slow population growth  Due to high birth rate and high death rate  Living conditions are poor

 Improvements bring a decline in death rate  Medical, sanitation, food  Birth rate remains high  Rapid population growth

 Birth rate slows  Due to further innovation  Meets death rate  General growth slows

 Birth rate falls below death  Zero population growth