Ecological Sampling

Question 1

What is random sampling

Answer 1

Random sampling is sampling which is used to compare 1 or more factors at different sites e.g people walking.
Within each area, every part of area must have equal chance of being chosen

Question 2

What is stratified sampling

Answer 2

Stratified sampling is when a proportionate number of observations is taken from each part of population. Divide habitat into zones which appear different and take samples of each zone e.g if vegetation is 60% heather and 40%gorse, a stratified sample takes 60% of samples within heather and 40% from gorse

Question 3

What is systematic sampling

Answer 3

Systematic sampling is used where study area includes an environmental gradient. Transect is used to sample systematically along environmental gradient. E.g every 10m along a line running from seashore inland across sand dune to measure distribution of plant species.

Question 4

What are the 2 ways of systematic sampling

Answer 4

2ways of systematic sampling are continuous belt transect where you sample at every point along area or systematic interrupted belt transect where sample at particular intervals depending on how species and area changes e.g every 5m

Question 5

How do you measure angle of slope

Answer 5

Measure angle of slope with clinometer

Question 6

How to measure aspect

Answer 6

Measure aspect with compass to determine in which direction slope faces

Question 7

How can light and pH be measured

Answer 7

Light can be measured with light meter and pH can be measured by universal indicator once soil sample has been mixed with water

Question 8

What is a kick sample

Answer 8

Kick sample is a method of collecting small invertebrates in water

Question 9

How can you measure % cover

Answer 9

An measure % cover by doing random/systematic sampling using a quadrat. Count number of squares which have stuff in, divide by total area and x by 100

Question 10

How can data collected be used to show a relationship

Answer 10

Data collected can be used to show relationship by plotting a scatter graph of independent variable against dependent variable. Draw a line of best fit and use Spearman’s rank test.

Question 11

5 point plan for hill reaction

Answer 11

5 point plan for hill reaction is:
IV: depends on question e.g light intensity, chloroplasts
DV: how quickly DCPIP decolourises use a stopwatch and observe
Controlled: temperature (water bath), volume of DCPIP[pipette), concentration of DCPIP, time left in light stopwatch
Control:depends complete darkness, no chloroplasts
Repeat 5 times to identify anomalous results