(1) B Flashcards
Systematic Sampling
Measured systematically
Transition - seashore
Random sampling
All members of pop have equal chance of being selected
Avoid bias
Abundance
No of ind w/I given space
Frequency
Likelihood of species w/I quadrat (grass)
Pro’s/Cons of number (3)
Count
:) - precise
:( - slow & damage
Pro’s // cons %Cover (3)
Estimation
:)- rapid, ind NOT counted
:( - overlaps = ineffective
To consider;
Samples; representative of pop/habitat as whole
Yes = conclusion = valid
Quadrat - No (3)
+Sample/+Qs = +reliable but time consuming
+Diff species = +Q = +Reliable results
Random sampling process
2 tape measures @ RA, along 2 sides of study area
Random no. Generator for co-ords
Place quadrat @ co-ord
Record species within it
Transect // systematic sampling (4)
Transition; seashore
Stages of zonation; shown w/ Transect
Line transect; string/tape stretched across ground- any org which crosses is recorded
Belt Transect; 2 x lines - org b/w lines recorded
MRR calc
Estimated pop =
Tot no of ind in 1st x tot no ind in 2nd / no marked recaptured
MRR Technique
Estimate abundance of motile (animals) Known no marked ind caught Marked Released back into population Individuals collected No of marked counted Calculation
MRR assumptions (8)
Proportion to marked: unmarked in sample 2 = eq to marked:unmarked in pop as whole
Marked ind released from 1st sample distribute evenly amongst remainder of pop & time
No EMI/IMI No toxic marking Individual not more predated Mark/Label not rubbed or lost No deaths / births
Anaylysing data
Use a statistical test to determine a correlation
Ethics of MRR
Measure in situ ; if removing - few as possible
Return to original habitat ASAP (even dead)
Leave some time
Avoid disturbing and damaging habitats
