Population Ecology Flashcards
Define the term population size
The number of individual organisms of a specific species living in a particular area
Population size is calculated by
(Immigration + Births) - (Emigration + Deaths)
Define the term population Density
The number of individual organisms of a specific species per unit area (or volume)
(individual organism/area)
Population Distribution is ________.
The arrangement of individuals within a habitat at a particular point in time
What are the three dispersion patterns?
Clumped, Random and Uniform
Population Frequency can be defined as
The total number of species per sample represented as a percentage
Population Sampling involves
Identifying the number of individuals in a small area and then estimating the population total using information known
What is the purpose of Random sampling, and why is it used?
Used when the population is uniform, large, and when limited time is available. This method prevents observer bias in the selection and taking of samples and allows for more samples to be taken at once.
What is systematic sampling and what is its use?
Done at specific intervals using a belt or line transect where an environmental gradient is present. This method zones in on the species present along the gradient.
What sampling methods are used for mobile or non-mobile species?
non moble: quadrant throws, belt/line transect
mobile species: capture-mark-release-recapture method
What is the difference between percentage frequency and percentage cover?
While percentage cover is an estimate, percentage frequency is the number of samples and quadrants in which the species were recorded or did not occur
What is the Lincoln Index used for?
To estimate population size based on the capture-mark-release-recapture method
Using the lincoln index, how is population size calculated?
(n1 x n2)/n3
What assumptions are made according to the Lincoln index?
-All organisms have an equal chance of being captured
-After release, organisms will be randomly distributed
-Marking does not affect the birth or death rate of a species
-There will be no significant migration between captures
