Practucal: Investigation Populations Flashcards
1
Q
What 2 strategies investigate non motile organisms
A
Quadrats and transects
2
Q
Explain mark capture release
A
- Capture a sample of species and count them
- Mark them in a harmless way eg. Dot with paint
- Release them back into the habitat
- Wait a week
- Capture a second sample
- Count how many orgs are marked
3
Q
What is the equation for population size from mark capture release
A
No in 1st sample x no in 2nd sample/ no MARKED in 2nd sample
4
Q
What are the 3 assumptions with mark capture release
A
- The marked samples had enough time and opportunity to mix back in with the population
- The ,raking technique didn’t affect the orgs chance of survival and the mark still has to be visible
- There are no change in poluation sizes (birth death or migration) during the study period
5
Q
How to measure an environmental factor and species distribution in a coastal system
A
- Place tape measure in straight line from shore to inland (transect)
- Place à 1mx1m quadrat at 10m intervals along the transect
- Count the number of squares containing marram grass
- Calculate % cover
- Measure ph at each quadrat using a ph probe
6
Q
How to measure ph w/out a ph probe
A
Sieve to remove debris Add barium sulfate Add distilled water Add universal indicator Compare to ph chart
7
Q
Why does ph decrease inland
A
Shores = lost of broken shells made of CaCO3 = alkali Inland = decomposing vegetation = acid