Population Ecology Chapter 53

A) Properties of Populations 1) Size: total number of ind. And is represented by N

2) Density a) number of individuals in a particular area. a1) use sampling techniques like mark and recapture

3) Dispersion a) Spacing between the individuals a1) most common is clumped

4) Survivorship curves a) Type1 : low death for young and middle aged b) Type 2: death rate is constant at any age c) Type 3: very high death rate at young age but rate declines for older ind.

5) Age Structure a) show relative numbers of individuals at each age

Fig. 53-8 RESULTS 100 Male Female 80 60 Parents surviving the following winter (%) 40 20 Reduced brood size Normal brood size Enlarged brood size

6) Trade offs between survival and reproductive success a) Time, energy, and nutrients limit reproductive capabilities. how different organisms balance these has been selected for

B) Population Growth 1) Exponential growth a) no predation, parasitism, or competition

2) S-shaped(logistical growth) a) outside factors act upon the population until it reaches carrying capacity

C) Limiting Factors 1) Density Dependent a) limiting factors that increase affect as density of population increases

a1) food, waste, predation, and disease

2) Density independent a) unrelated to density of population a1) earthquakes, flooding, fires, etc.

D) Growth Patterns 1) r-strategists - many young - little or no parenting - Rapid maturation - small young - reproduce once - example: insects 2) K- strategists - few young - intensive parenting - slow maturation - reproduce many times - Ex: mammals

E) Human Population Growth 1) started growing exponentially around 1650 a) started here at 500 million

b) factors that have allowed our continued growth b1) waste management b2) medicine b3) farming