# [Part 3]- B16- Organising an ecosystem ๐ฅฌ๐๐ฆ Flashcards

1
Q

What are the two methods of sampling ?

A
• random sampling
• and sampling along a transect
2
Q

Describe how to do random sampling ๐ฒ

A
• 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, itโ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
3
Q

How can it be ensured that a quadrat, is placed randomly ? ๐ฉ

A
• 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
4
Q

Why is it important that a large number of random locations should be sampled, when using a quadrat ? ๐ฒ

A
• itโ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 doesnโt accurately represent the whole area
5
Q

Whatโs the equation for the total population size ?

A

total area โ area sampled โ๏ธthe number of organisms of that species counted in sample

6
Q

Describe how to do sampling, along a transect ๐ชข

A
• 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- itโs placed, so it runs across the habitat weโ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
7
Q

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

A
• itโ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.
8
Q

Whatโs the difference between a quadrat ๐ a transect ?

A
• a quadrat, is a wooden or plastic square.
• and a transect, is a line such as a tape measure, or a piece of rope
9
Q

Whatโs the difference between random sampling ๐ sampling along a transect ?

A
• 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.