Population Ecology 1 & 2 Flashcards
Describe a population
- Group of individuals of a single species living in same general area
- Populations are described by their boundaries and size
What are the 5 Ds of population ecology?
- Density
- Distribution
- Dispersion (pattern of spacing)
- Dispersal (av distance an individual moves from where it was born to where it reproduces)
- Demographics
what factors influence spacing of individuals ?
- Environmental and social factors
Describe demographics
- Demographics: the statistical study of the structure of a population &
the changes that occur over time. - Incorporates:
- birth rates & death rates
- age structure
- sex ratios
What is Semelparity?
Single event (ollowed by death)
What is Iteroparity? what two types?
Repeated reproductive events =>
Seasonal iteroparity: e.g. birds, perennial plants
Continuous iteroparity: e.g. primates, tropical species
Population diagrams - how do they look when population is growing?
pyramid
Describe a mark-recapture survey
a method of population estimation in which
researchers capture and mark a subset of a
population from an area, return it to the area,
and capture a second sample of the population
after time has passed.
How is population size estimated:
What two life tables can we have?
Age specific summary of survival pattern of a population =>
1. Cohort Life Tables - follows an age group from birth to death
2. Time specific (static) - quantifies survival`::fecundity of ALL individuals at one time interval
What important stats for life history?
- age
- No alive each year
- survival
-Deaths - Mortality rate
- Mean expectation of further lfie at age x
What are the patterns of survivorship: intermediate types?
Type II/III intermediate
- High young mortality
* - then constant adult mortality rate
(e.g. many birds, mud turtles)
Type I/II intermediate
- Low mortality in young,
* - then steady adult mortality rate
Use of population models?
help understand complex real ecological
systems in simple terms.
- Test theories, enables predictions to be made & help in decision making for managing & conserving populations of species
why is it helpful to study population growth ?
in an idealized situation to help us
understand the capacity of species to increase and the conditions that
may facilitate this growth.
Population dynamics modelling?
Express mathematically population growth ?