Chapter 1 Populations Flashcards
What is a population?
A group of individuals of the same species in the same habitat
What is an ecosystem?
Area made up of all abiotic and biotic factors
What is a community?
Groups of different species in one area
What is a habitat
A place where communities or populations live
What is a ecological niche?
All things needed for a organism to survive and reproduce, how it fits into an environment
What are abiotic factors?
Non living
For example: volume of rainfall, concentration of co2 or sunlight
Describe biotic factors and give examples?
Living things
For example: predation and competition
What does abundance mean?
To count the number of individuals of one species in a specific area
What are the two ways or investigating population?
Random sampling through quadrats
Or
Systematic sampling along transects
What are three things to think about when using a quadrat?
Size: larger species=larger quadrat
Amount of results recorded:larger amount of species=more results recorded
Position:random
Why use random sampling?
Reduces sampling bias=more valid results!
What are the two different ways you can measure abundance?
1) frequency
2) percentage coverage
Describe mark release recapture?
Measuring abundance approximately
1) capture a sample
2) wait some time
3) return ad recapture a sample
4) use the mark release recapture equation to work out an estimation of population size
What is that mark release recapture equation and what does it show us?
Number of individuals in sample 1 x number of individuals in sample 2 \ number of mark individuals captured in sample 2.
It shows us an estimated population size.
What is needed so that mark release recapture is valid?
1) if possible no migration or immigration
2) few deaths and births
3) no harm to the animal and for the mark to not make them more noticeable to predators
4) for the mark to be strong so it will not get lost or rubbed off