1. population ecology
- 1. study of changes in population size and factors that regulate populations over time
- 2. group of individuals of a single species living in the same place; interbreeding
- 3. number of individuals per unit area or volume
- 4. pattern among spacing among individuals
- 1. add new individuals from other populations
- 2. movement of individuals out of a population
1. life tables
3. survivorship curve
a. Type I Curve
b. Type II Curve
c. Type III Curve
- 1. age specific summaries of survival pattern in population
- 2. group of individuals of the same age; follow fate from birth to death
- 3. plot of proportion in cohort still alive at each age
- a. low death rates in early and middle life; increase in older age groups
- b. death rate constant for all age groups... why?
- c. high death rates highest for young age groups... why?
1. exponential growth
2. limiting factors
3. carrying capacity
4. logistic populationg growth
- 1.geometric increase in unlimited conditionswhole population multiplies by constant factor (each time interval ) 2, 4, 8,16, 32, 64, etc.does exponential growth happen in nature?
- 2. environmental factors that restrict pop. growth
- 3. max. pop. size that environment can support- defined for given organism, habitat; varies with resources- consider food, water, sunlight, refuges, nesting sites, etc.
- 4. population growth slowed by limiting factors as sizeincreases; approaching carrying capacity
1. density dependent (birth or death rate)
2. population cycle
3. trade offs
- 1. reproductive changes with population density (i.e., inverse relationship)
- 2. (rare event) – regular fluctuations;“boom & bust”unusually long-term sets ( like traps for fur pelts)
- 3. when time, energy, nutrients are used for one thingthey cannot be used for another
Why are there high death rates and low birth rates?
higher death rate- intense competition for resourcesexploitative vs. interference- health (malnutrition, epidemics, etc.)- increased predation (& cannibalism)- toxic waste build-uplower birth rate- intrinsic factors (social, hormonal, etc.)
1. sustainable resource management
2. maximum sustained yield
3. intergrated pest management
4. age structure
- 1. harvesting withoutdamaging the resourcemaximum sustained yield
- 2. harvesting at a level that producesa constant yield without forcing a population into decline
- 3. use of ecological knowledge & principles to control unwanted species
- 4. relative number of individuals of each age group
1. Zero Population growth
2. demographic transition
3. ecological footprint
4. ecological capacity
- 1.There are two ways to reach r = 0 Zero Population Growth (ZPG)
- A.) ZPG = high birth rate - high death rate
- B.) ZPG = low birth rate - low death rate
- 2. movement from first scenario (above)to second scenario; during this time growth rate (r) is positive
- 3. aggregate land & water used for a nation,state, city, individual, etc.
- - crop lands, pasture, forest, ocean, urbanization, fossil energy
- 4. actual resource base of each nation consider sustainability
What factors will limit population growth?
- nonrenewable resources?
- voluntary reduction:
- * offspring production
- * resource use