Ecological Techniques Flashcards
Define ecosystem
The environment and all the organisms that live in the area
What are 2 methods that can be used to study ecosystems?
1) Randomly Placed Quadrats
2) Quadrats along a Belt Transect
3) Mark-release-recapture
Why must samples that are taken be large?
To avoid anomalies having too big of an effect on results.
Why is random sampling used?
To avoid bias
To be representative
Produce statistically significant results
What are the 3 measures of abundance when using quadrats?
1) Measure of frequency
2) Measure of percentage cover
3) Measure of species density
Describe how you can collect data using random sampling
Tape measures to mark out a grid
Random number generator
Place quadrat and count population
Repeat until you have 20 samples
Work out the mean number per quadrat and multiply by the number of quadrats in the area
Describe the belt transect method
Place a belt transect
Measure percentage cover
What method is used to measure abundance in mobile animals?
Mark-release-recapture
Describe the mark release recapture method
Collect a large sample
Mark the sample in a way that will not harm them or affect their chances of survival
Release them and allow the to mix with the rest of the population (24 hours)
Recapture the sample
Count sample that have been marked
Formula of Lincoln Index
What are the assumptions made when using the mark-release-recapture method?
No deaths/births
No emigration/ immigration
Marked individuals have had time to mix with the population
Mark methods don’t endanger sample
