Investigating Ecosystems

Question 1

what is a quadrat

Answer 1

a square frame enclosing a known area such as 1m^2

Question 2

what is the process in comparing how common an organs is in two sample areas carried out

Answer 2

• place a 1m quadrat on the ground at a random point within the first sample area
• count all the organisms youre interested in within the quadrat
• repeat the steps multiple times
• work out the mean number of organisms per quadrat within the first sample area (average)
• repeat all the steps in the second sample area
• compare the two means

Question 3

what do you do to work out the population size of an organism in one sample area

Answer 3

• you work out the mean number of organisms per m^2

- then multiply the mean by the total area of the habitat

Question 4

what is a change across a habitat known as

Answer 4

a gradient

Question 5

what cane you use multiple quadrats to do

Answer 5

find out how many organisms are distributed along a gradient

Question 6

what is an example of how the distribution of an organisms can change across an environment

Answer 6

• a species may become more or less common as you move from an area of shade to an area full of sun
• like near a hedge to the edge of a field
• to the middle of a field

Question 7

what do quadrats laid out in a long line form

Answer 7

a belt transect

Question 8

how is the process of using a belt transect carried out

Answer 8

• mark out a line in the area you want to study
• collect data along the line using quadrats placed next to each other
• count all the organisms of the species youre interested in or estimate their percentage cover
• repeat the process several times to find the man number of organisms or mean percentage for each quadrat
• plot graphs to see if the changing abiotic factor is correlated with a change in the distribution of the species youre studying

Question 9

what should you do is your belt transect is very long

Answer 9

• place the quadrats at regular intervals

- like every 2 meters

Question 10

what does it mean to estimate the percentage cover of an organism in a quadrat

Answer 10

estimating the percentage area of a quadrat covered by a particular organism

Question 11

what other data could you record other than the number of the organism

Answer 11

• the mean height of the plants youre counting
• or the abiotic factors in each quadrat
• like using a light meter to measure light intensity