[Part 3]- B16- Organising an ecosystem 🥬🐌🦉

Question 1

What are the two methods of sampling ?

Answer 1

• random sampling
• and sampling along a transect

Question 2

Describe how to do random sampling 🔲

Answer 2

• random sampling, is used to compare the numbers of organisms in different areas- a quadrat is used to do this
• a quadrat, is a wooden or plastic square.
• To use it, it’s placed at random locations across the area [on the ground], and the number of organisms inside the quadrat is counted- this technique can be used to sample plants, or slow-moving animals

Question 3

How can it be ensured that a quadrat, is placed randomly ? 🎩

Answer 3

• random numbers can be used to select the different locations and the numbers of each organism in the quadrat, are counted [this could be done by pulling cards out of a hat]
• or the random number generator button on a calculator, can also be used

Question 4

Why is it important that a large number of random locations should be sampled, when using a quadrat ? 🔲

Answer 4

• it’s important that a large number of random locations should be sampled, when using a quadrat because, it makes it more likely to get valid results.
• ; if the quadrat is placed only one, it might give a sample that doesn’t accurately represent the whole area

Question 5

What’s the equation for the total population size ?

Answer 5

total area ➗ area sampled ✖️the number of organisms of that species counted in sample

Question 6

Describe how to do sampling, along a transect 🪢

Answer 6

• sampling along a transect, is used to investigate if the number of species change as we move across a habitat.
• a transect, is a line such as a tape measure, or a piece of rope- it’s placed, so it runs across the habitat we’re looking at
• after the transect has been placed, a quadrat is then used to count the number of organisms at intervals on the transect

Question 7

Why is it important, that the transect should be carried out a number of times?

Answer 7

• it’s important, that the transect should be carried out a number of times.
• This is because, it means valid results can be produced.
• therefore when sampling along a transect, move the tape measure/rope along to get more valid data, on how the numbers of the different species, change across a habitat.

Question 8

What’s the difference between a quadrat 🆚 a transect ?

Answer 8

• a quadrat, is a wooden or plastic square.
• and a transect, is a line such as a tape measure, or a piece of rope

Question 9

What’s the difference between random sampling 🆚 sampling along a transect ?

Answer 9

• random sampling, is used to compare the numbers of organisms in different areas- a quadrat is used to do this
• ; sampling along a transect is used, to investigate: if the number of species change as we move across a habitat.