Download G.1.3 Describe one method of random sampling, based on quadrat

G.1.3 DESCRIBE ONE METHOD OF RANDOM SAMPLING, BASED ON QUADRAT METHODS,
THAT IS USED TO COMPARE THE POPULATION SIZE OF TWO PLANT OR TWO ANIMAL
SPECIES.
• Statistics- Topic 1!!!
• Easier than counting every individual
• Random = each organism has equal chance of being selected for the
count
• Quadrat: square (certain size, dep. on organism)
• Map the whole area
• Determine quadrat size
• Use a #d grid over the map
• Random # table to decide which squares (quadrats) to sample
• Count # of xxxx and # of yyyy within sample quadrats
• Calculate avg # xxxx and avg # yyyy in each
• Multiply avg (for xxxx, for yyyy) x total # quadrats in whole area to
estimate population of xxxx and yyyy
G.1.4 OUTLINE THE USE OF A TRANSECT TO CORRELATE THE
DISTRIBUTION OF PLANT OR ANIMAL SPECIES WITH AN ABIOTIC
VARIABLE.
• Common for studying distribution of plants/animals in ecosystem, abiotic
factors affecting it
• Use a tape/line through the area
• Every 10-20 m along tape, mark a quadrat (use consistent size for all)
• Identify, count plant/animal species of interest in quadrats
• Measure abiotic feature in each quadrat (temp, light, soil pH, water,
mineral nutrients)
• Determine pattern of distrib of species  correlation w/abiotic factor??
HMMM...QUADRAT OR TRANSECT??
Depends on if habitat’s fairly uniform –orif you see a progression along an environmental
gradient