paper 2 specification 5

Question 1

Explain how communities can be affected by abiotic
factors, including:
a temperature, light, water, pollutants

Answer 1

temperature-the distribution of bird species is changing due to a rise in temp
amount of water- daisies grow best in soils that are slightly damp. If it is waterlogged or too dry the pop will decrease
light intensity-trees provide shade, grasses may be replaced by fungi which are better able to cope with lower intensity
levels of pollutants-lichen are unable to survive if the concentration of sulfur dioxide is too high

Question 2

competition, predation

Answer 2

competition-compete with other species for the same resources
predation-number of predators decreasing will lead o an influx in preys

Question 3

how to use a quadrat

Answer 3

place 1m squared quadrat on the ground at a random point -use random coordinate generator to make it fair
-count organisms within quadrant
-repeats steps 1 and 2 lots of times
-work out the mean number of organisms per quadrant
-repeat steps 1 and 4 in the second sample area and compare the two means

Question 4

how to use a belt transect

Answer 4

Mark out a line using a tape measure
collect data along the line using quadrats placed next to each other. if the transect is long place quadrats at regular intervals
collect data by counting organisms of the species that want
-u can record other data such as the mean height
-repeat steps 1 and 2 several times then find the mean number of organisms for each quadrat

Question 5

why should you use the quadrat more than once

Answer 5

because using it once doesn’t give an accurate representation of the whole area and wold be unreliable

Question 6

how to find the total pop size

Answer 6

total area divided by the area sampled multiplied by no. of organisms of that species counted in the sample