lecture 15: Modeling populations Flashcards
What are the four main factors that influence population structure?
- Mortality/Survival rates
- Age distribution
- Sex ratio
- Dispersal
What are the two main Life tables used when modeling populations?
Cohort tables
Static Life Tables.
What is the purpose of Models?
Describe ecological processes
What way are models often presented?
Usually, but not always presented quantitative
What can cause population growth?
Births & Immigration
What can cause Population loss?
Emigration & deaths
What is Birth?
Any process that produces new individuals in a given population.
What are 5 examples of birth?
- Laying eggs
- Birthing live young
- Seed production
- Shoot production (asexual)
- Cell division. (asexual)
What is death?
The loss of life within a population that is caused by:
- old age
- disease
- lack of resources
- predation
Why is it often better to look at per capita data for population growth assumptions?
It gives you a more realistic representation of how the population dynamic changes, as it looks at the population on a individual level.
What is a Density Dependent factor?
A factor that is influenced by population density.
What is an example of a Density Dependent Factor?
Competitors
Predators
Disease
What is an example of a Density Dependent Factor?
Competitors
Predators
Disease
What is a Density-independent factor?
A factor that will not vary with population density
What is a Density independent factor?
Floods
Extreme temperatures
Will a Density-independent or Density Dependent graph with two parallel lines.
With the top being Birth and the bottom being death.
Density independent.
Will a Density-independent or Density Dependent graph with two intercepting lines?
Density dependent.
Using a ____ and a _____ is it possible to estimate the rates of change in a population.
Life table
Fecundity schedule
What is a fecundity schedule?
A tabulation of birthrates for females of different ages in population.
Using a life table and fecundity schedule, what can you predict?
Net reproductive rate
Geometric rates of increase
Generation time
Per Capita rate of increase
What is Net Reproductive rate?
Average number of offspring produced by an individual in a population
What is Geometric rate of increase?
The Ratio of the popular size at two points at the same time,
What is generation time?
The average age within a population at which a female gives birth to her offspring.
Can be greater than age of first reproduction in female reproduces more than once
What is per capita rate of increase?
Equal to per capita birthrate minus per capita death rate.
Births - deaths.
